Archived Policies - Surgery
Transcatheter Aortic-Valve Implantation for Aortic Stenosis
Transcatheter aortic valve replacement, performed via the transfemoral approach, may be considered medically necessary for patients with aortic stenosis when all of the following conditions are present:
Transcatheter aortic valve replacement, performed via the transapical approach, may be considered medically necessary for patients with aortic stenosis when all of the following conditions are present:
*Note: Severe aortic stenosis is defined by one or more of the following criteria:
**Note: FDA definition of high risk for open surgery:
Transcatheter aortic valve replacement is considered experimental, investigational and/or unproven for all other indications, including but not limited to:
Transcatheter aortic valve implantation (TAVI; also known as transcatheter aortic valve replacement or TAVR) is a potential alternative treatment for patients with severe aortic stenosis. Many patients with aortic stenosis are very elderly and/or have multiple medical comorbidities, thus indicating a high, often prohibitive, risk for surgery. This procedure is being evaluated as an alternative to open surgery for high-risk patients with aortic stenosis and as an alternative to nonsurgical therapy for patients with a prohibitive risk for surgery.
Aortic stenosis. Aortic stenosis is defined as narrowing of the aortic valve opening, resulting in obstruction of blood flow from the left ventricle into the ascending aorta. Progressive calcification of the aortic valve is the most common etiology in North America and Europe, while rheumatic fever is the most common etiology in developing countries. (1) Congenital abnormalities of the aortic valve, most commonly a bicuspid valve, increase the risk for aortic stenosis, but aortic stenosis can also occur in a normal aortic valve. Risk factors for calcification of a congenitally normal valve mirror those for atherosclerotic vascular disease, including advanced age, male gender, smoking, hypertension, and hyperlipidemia. (1) Thus, the pathogenesis of calcific aortic stenosis is thought to be similar to that of atherosclerosis, i.e., deposition of atherogenic lipids and infiltration of inflammatory cells, followed by progressive calcification.
The natural history of aortic stenosis involves a long asymptomatic period, with slowly progressive narrowing of the valve until the stenosis reaches the severe stage. At this time, symptoms of dyspnea, chest pain, and/or dizziness/syncope often occur and the disorder progresses rapidly. Treatment of aortic stenosis is primarily surgical, involving replacement of the diseased valve with a bio-prosthetic or mechanical valve by open heart surgery.
Burden of illness. Aortic stenosis is a relatively common disorder of elderly patients and is the most common acquired valve disorder in the U.S. Approximately 2-4% of individuals older than 65 years of age have evidence of significant aortic stenosis, (1) increasing up to 8% of individuals by age 85 years. (2) In the Helsinki Aging Study, a population-based study of 501 patients aged 75-86 years, the prevalence of severe aortic stenosis by echocardiography was estimated to be 2.9%. (3) In the U.S., more than 50,000 aortic valve replacements are performed annually due to severe aortic stenosis.
Aortic stenosis does not cause substantial morbidity or mortality when the disease is mild or moderate in severity. By the time it reaches the severe stage, there is an untreated mortality rate of approximately 50% within 2 years. (4) Open surgical repair is an effective treatment for reversing aortic stenosis, and artificial valves have demonstrated good durability for periods of up to 20 years. (4) However, these benefits are accompanied by a perioperative mortality of approximately 3-4% and substantial morbidity, (4) both of which increase with advancing age.
Unmet needs. Many patients with severe, symptomatic aortic stenosis are poor operative candidates. Approximately 30% of patients presenting with severe aortic stenosis do not undergo open surgery due to factors such as advanced age, advanced left ventricular dysfunction, or multiple medical comorbidities. (5) For patients who are not surgical candidates, medical therapy can partially alleviate the symptoms of aortic stenosis but does not affect the underlying disease progression. Percutaneous balloon valvuloplasty can be performed, but this procedure has less than optimal outcomes. (6) Balloon valvuloplasty can improve symptoms and increase flow across the stenotic valve but is associated with high rates of complications such as stroke, myocardial infarction (MI), and aortic regurgitation. In addition, restenosis can occur rapidly, and there is no improvement in mortality. As a result, there is a large unmet need for less invasive treatments for aortic stenosis in patients who are at increased risk for open surgery.
Transcatheter aortic valve implantation (TAVI). TAVI has been developed in response to this unmet need and is intended as an alternative treatment for patients in whom surgery is not an option due to prohibitive surgical risk or for patients who are at high risk for open surgery. The procedure is performed percutaneously, most often through the transfemoral artery approach. It can also be done through the subclavian artery approach and transapically using mediastinoscopy. Balloon valvuloplasty is first performed in order to open up the stenotic area. This is followed by passage of a bioprosthetic artificial valve across the native aortic valve. The valve is initially compressed to allow passage across the native valve and is then expanded and secured to the underlying aortic-valve annulus. The procedure is performed on the beating heart without the need for cardiopulmonary bypass.
There are at least two transcatheter aortic valve devices being tested. The Edwards SAPIEN heart-valve system™ (Edwards Lifesciences, Irvine, CA) is a tri-leaflet bioprosthetic porcine valve that is contained within a stainless steel frame. This device has been commercially available in Europe since 2007 but has not yet received U.S. Food and Drug Administration (FDA) approval in the U.S. There is currently a next generation version of this valve in testing, called the SAPIEN XT™ (Edwards Lifesciences, Irvine, CA), which has been redesigned with the intention of reducing procedural complications.
The Medtronic CoreValve ReValving System™ is a second transcatheter valve system under testing. This device is a porcine bioprosthetic valve that is sewn within a self-expanding nitinol frame. It is inserted via the transfemoral artery approach and has also been inserted via the subclavian artery approach. This device has also been approved for use in Europe since 2007 but has not yet received FDA approval in the U.S.
The Sapien Transcatheter Heart Valve System™ (Edwards LifeSciences, Irvine, CA) received original FDA approval in November 2011 for patients with severe aortic stenosis who are not eligible for open-heart procedures and have a calcified aortic annulus. In 2012, an additional FDA premarket approval (PMA) was granted for the Edwards SAPIEN™ transcatheter heart valve Model 9000TFX (Edwards LifeSciences, Irvine, CA) with expanded indications for use. (7) Approval was granted for both the transfemoral and transapical approach. For the transfemoral approach, patient indications were broadened to include patients who are at high risk for open surgery. For the transapical approach, approval was granted for patients who are at high risk for open surgery.
The evidence on transcatheter aortic-valve implantation (TAVI) consists of many uncontrolled case series and one pivotal randomized controlled trial (RCT) - the PARTNER trial. These studies report on two potential populations for TAVI: 1) patients who are not surgical candidates, and 2) patients who are high risk for surgery but still considered to be surgical candidates. The evidence on these two groups of patients will be discussed separately.
Does transcatheter aortic-valve implantation improve outcomes for patients with aortic stenosis who are not suitable candidates for open surgery?
Many case series of TAVI have been published in the last 10 years, the majority of which have included patients who are not candidates for open surgery. However, the selection process for TAVI has largely been subjective, with the expert opinion of the surgeons and/or cardiologists as the main factor determining suitability for open surgery. As a result, there may be some overlap in these series with patients who are surgical candidates, but the distinction cannot be easily made from the reported studies.
An Agency for Healthcare Research and Quality (AHRQ)-sponsored review in 2010 reviewed 84 publications enrolling 2,375 patients. (2) Implantation was successful in 94% of patients overall, with higher success rates reported in more recent publications. The aggregate 30-day survival was 89% across all studies. Adverse event rates were reported in the larger case series, with an estimated 30-day rate of major cardiovascular adverse events and stroke of 8%.
The two largest series included in the AHRQ review reported on 646 patients treated with the Medtronic CoreValve™ (8) and 339 patients treated with the Edwards SAPIEN™ valve. (9) The CoreValve™ study by Piazza et al. was notable in that it used more objective patient selection criteria than is common in this literature. Their criteria for eligibility included the following: 1) Logistic EuroScore ≥15%, 2) age ≥75 or, 3) age ≥65 with liver cirrhosis, pulmonary insufficiency, pulmonary hypertension, previous cardiac surgery, porcelain aorta, recurrent pulmonary emboli, right ventricular insufficiency, previous chest burns or radiation precluding open surgery, or body mass index (BMI) ≤18kg/m2. Procedural success was 97% and 30-day survival was 92%. The 30-day combined rate of death, myocardial infarction (MI) or stroke was 9.3%. The study by Rodes-Cabou et al. was performed in Canada and used Edwards SAPIEN™ valve. This study had subjective inclusion criteria, relying on the judgment of the participating surgeons to determine eligibility for TAVI. The procedural success rate was 93.3%, and the 30-day mortality was 10.4%. The authors also reported a mortality rate of 22.1% at a median follow-up of 8 months.
A second systematic review was published in 2011 by Figulla et al. (10) This review included studies that enrolled symptomatic patients with severe aortic stenosis, had a mean age of 75 years or older, reported on 10 or more patients, and had a follow-up duration of 12 months or more. A total of 12 studies met these criteria and were compared to a group of 11 studies that treated severe aortic stenosis with nonsurgical therapy. The procedural success in these studies ranged from 86-100%, and the 30-day mortality ranged from 5.3-23%. The combined mean survival rate at 1 year was 75.9% (95% confidence interval [CI]:73.3-78.4). This 1-year survival rate compared favorably to medical therapy, which was estimated to be 62.4% (95% CI: 59.3-65.5).
Since these systematic reviews, there continue to be numerous case series of TAVI published in the literature. The largest of these was a case series from Germany reporting on 697 patients treated with the CoreValve™ system. (11) Procedural success was 98.4%, and 30-day mortality was 12.4%. Another large case series from Italy (12) included 663 patients treated with the CoreValve™ device. Procedural success was 98% and mortality at 1 year was 15%. A notable study was published by Gurvitch et al. in 2011 (13) that reported on durability and longer clinical outcomes up to 3 years. Seventy patients who underwent TAVI and survived for greater than 30 days were included. Survival at 1, 2, and 3 years was 81%, 74%, and 61%, respectively. One patient (1.5%) required reoperation during this time period. The valve area decreased from 1.7 ± 0.4 cm2 following the procedure to 1.4±0.3 cm2 at 3 years. Aortic incompetence was trivial or mild in 84% of patients and did not worsen over time.
The PARTNER trial is a pivotal multicenter RCT of TAVI performed in the U.S., Canada, and Germany, using the SAPIEN™ heart-valve system. Leon et al. 2010 (14) reported results of the cohort of patients from the PARTNER trial with severe aortic stenosis who were not candidates for open surgery. In order to be classified as unsuitable for open surgery, patients had to have a predicted probability of ≥50% for death or a serious irreversible condition at 30 days post-surgery. This probability was determined by two surgeon investigators using clinical judgment and the Society of Thoracic Surgery (STS) risk score. The executive committee of the PARTNER trial reviewed all patient selection decisions and approved the classification of patients as unsuitable for surgery. A total of 3,105 patients were screened for aortic-valve surgery, and 12% of these were eventually included in the cohort of patients deemed unsuitable for surgery.
A total of 358 patients were randomized to TAVI or usual care. TAVI was performed by the transfemoral approach under general anesthesia. Standard therapy was determined by the treating clinicians. In most cases (83.8%), standard treatment included balloon valvuloplasty of the aortic valve. A small number of patients (6.7%) underwent open surgical valve replacement despite the high risk, and another 2.2% of patients underwent TAVI at a center outside the U.S. that was not participating in the trial. The primary outcome was death from any cause over the course of the trial (median follow-up 1.6 years). A “coprimary” endpoint was the composite of time to death from any cause or time to repeat hospitalization related to aortic stenosis or TAVI. Secondary endpoints were cardiovascular mortality, New York Heart Association (NYHA) functional class, the rate of hospitalizations due to aortic stenosis or TAVI, the 6-minute walk test, valve performance as measured by echocardiography, and procedural complications (myocardial infarction [MI], stroke, acute kidney injury, vascular complications, and bleeding).
The mean age of enrolled patients was 83.2 years. There were some baseline imbalances in the patient population indicating that the standard therapy group may have had a higher severity of illness. Standardized scores of surgical risk were higher in the standard therapy group. The Logistic EuroSCORE was significantly higher in the standard therapy group compared to the TAVI group (30.4±19.1 vs. 26.4±17.2, p=0.04) and the Society of Thoracic Surgery (STS) score was numerically higher but did not reach statistical significance (12.1±6.1 vs. 11.2±5.8, p=0.14). Significantly more patients in the standard therapy group had chronic obstructive pulmonary disease (COPD) (52.5% vs. 41.3, p=0.04) and atrial fibrillation (48.8% vs. 32.9%, p=0.04), and there was a nonsignificant trend for more patients in the standard therapy group having a lower ejection fraction (51.1 vs. 53.9%) and frailty, as determined by prespecified criteria (28.0 vs. 18.1%).
Death from any cause at 1 year following enrollment was lower for the TAVI group (30.7% vs. 49.7%, p<0.001). This represents a 19% absolute risk reduction, a 38.2% relative risk reduction, and a number needed to treat of 5.3 to prevent one death over a 1-year follow-up. Most secondary outcomes also favored the TAVI group. Cardiovascular death was lower in the TAVI group (19.6% vs. 44.1%, p<0.001). The composite of all-cause mortality and repeat hospitalizations was reached by 42.5% of the patients in the TAVI group compared with 70.4% in the standard therapy group. Symptoms and functional status were also superior in the TAVI group. The percent of patients in NYHA Class I or II at 1 year was higher for the TAVI group (74.8% vs. 42.0%, p<0.001), and there was a significant improvement in the 6-minute walk test for the TAVI group but not for the standard therapy group (between group comparisons not reported). Subgroup analysis did not report any significant differences in outcomes according to clinical and demographic factors.
Complication rates were higher for the TAVI group. Stroke or transient ischemic attack (TIA) at 1 year was more than twice as frequent for the TAVI group (10.6% vs. 4.5%, p=0.04). Major bleeding and vascular complications occurred in a substantial percent of patients undergoing TAVI and were significantly higher than in the standard therapy group (22.3% vs. 11.2%, p=0.007; and 32.4% vs. 7.3%, p<0.001 respectively).
Quality of life (QOL) outcomes from this trial were reported by Reynolds et al. in 2012. (15) QOL outcomes were evaluated using the Kansas City Cardiomyopathy Questionnaire (KCCQ) summary score, the Medical Outcomes Study Short-Form 12 (SF-12), and the EuroQol (EQ-5D). The number of participants who completed the QOL measures was not clearly reported, estimates from graphical representation show that between 149-170 patients in the TAVI group and 138-157 patients in the medical therapy group completed baseline QOL measures. At the follow-up time points of 30 days, 6 months, and 12 months, the change in the QOL scores was greater for the TAVI group. At 30 days, the mean difference in the KCCQ was 13.3 points (95% CI: 7.6-19.0, p<0.001). This mean difference increased at later time points to 20.8 points (95% CI: 14.7-27.0, p<0.001) at 6 months and 26.0 points (95% CI: 18.7-33.3, p<0.001) at 12 months. Changes in the SF-12 and EQ-5D measures showed similar patterns.
Two-year outcomes were reported from the PARTNER trial in 2012. (16) Mortality at 2 years was 43.3% in the TAVI group compared to 68.0% in the medical therapy group (Hazard ratio 0.58, 95% CI: 0.36-0.92, p=0.02). Cardiovascular mortality was also lower in the TAVI group compared to medical therapy (31.0% vs. 62.4%, p<0.001). The rate of hospitalization over the 2-year period was lower in the TAVI group compared to medical therapy (35.0% vs. 72.5%, p<0.001).
Conclusion. Numerous case series have demonstrated feasibility and short-term efficacy for TAVI in patients who are not surgical candidates. In the PARTNER B trial, there was a large decrease in all-cause mortality and cardiovascular mortality at 1 year for TAVI compared to standard therapy. Subsequent publications from this same trial reported that the mortality benefit was maintained at 2 years and that QOL was improved for the TAVI group. Baseline group differences were present, indicating that the TAVI group may have been healthier. While these differences are unlikely to account for the degree of mortality benefit reported, they may have resulted in an overestimation of the mortality benefit.
The benefit in mortality was accompanied by an increased stroke risk, as well as substantial increases in vascular complications and major bleeding. There is also uncertainty concerning the generalizability of these results, since patient selection was primarily determined by the judgment of the cardiovascular surgeons and/or cardiologists. It is not known whether this type of decision making by surgeons and cardiologists is reliable across the range of practicing clinicians.
Does transcatheter aortic-valve implantation improve outcomes for high-risk patients with aortic stenosis as an alternative to open surgery?
Results from the cohort of patients in the PARTNER trial who were high risk for open surgery, but still suitable candidates, were published in June 2011. (17) The inclusion and exclusion criteria were generally the same as for the prior cohort, except that these patients were classified as high risk for surgery rather than unsuitable for surgery. For high risk, patients had to have a predicted perioperative mortality of ≥15%, as determined by a cardiac surgeon and cardiologist using clinical judgment. An STS score of ≥10 was included as a guide for high-risk, but an STS score threshold was not a required criterion for enrollment. The executive committee of the PARTNER trial reviewed all patient selection decisions and approved the classification of patients as high risk for surgery. A total of 3,105 patients were screened for aortic valve surgery, and 22.5% of these were eventually included in the cohort of patients deemed high-risk for surgery.
A total of 699 patients were randomized to TAVI or usual care. The primary hypothesis was that TAVI was non-inferior to open aortic valve replacement (AVR), using a one-sided non-inferiority boundary of 7.5% absolute difference in mortality at 1 year. TAVI was performed under general anesthesia using the transfemoral approach if possible (n=492). If the transfemoral approach was not possible, transapical approach was used (n=207). The comparison group underwent open AVR. Details of the open procedure were not provided in presentation slides.
The primary outcome was death from any cause at 1-year follow-up. A second powered endpoint was non-inferiority at 1 year for the patients undergoing TAVI by the transfemoral approach. Secondary endpoints were cardiovascular mortality, NYHA functional class, rehospitalizations, the 6-minute walk test, valve performance as measured by echocardiography, and procedural complications (MI, stroke, acute kidney injury, vascular complications, and bleeding). The mean age of enrolled patients was 83.6 years in the TAVI group and 84.5 years in the open AVR group. Other baseline demographics and clinical characteristics were generally well-balanced, except for a trend toward an increased percent of patients in the TAVI group with a creatinine level >2.0 (11.1% vs. 7.0%, p=0.06).
Death from any cause at 1 year following enrollment was 24.2% for the TAVI group compared to 26.8% for the open AVR group (p=0.44 for difference between groups). The upper limit of the 95% confidence interval (CI) for the difference between groups was a 3.0% excess mortality in the TAVI group, which was well within the non-inferiority boundary of 7.5%. Thus the criterion of non-inferiority was met, with a p value of 0.001. For the subgroup of patients who underwent TAVI by the transfemoral approach, results were similar with 22.2% mortality in the TAVI group compared with 26.4% mortality in the open AVR group (p=0.002 for non-inferiority). The secondary outcomes of cardiovascular mortality (14.3% vs. 13.0%, p=0.63) and rehospitalizations (18.2% vs. 15.5%, p=0.38) were not significantly different for the TAVI versus open AVR groups. The percent of patients in NYHA Class I or II at 1 year was similar between groups at 1 year, as was the improvement in the 6-minute walk test. On subgroup analysis, there was a significant effect for gender, with women deriving greater benefit than men (p=0.045), and a significant effect for prior coronary artery bypass graft (CABG), with patients who had not had prior CABG deriving greater benefit in the TAVI group.
Certain complication rates showed significant differences between groups. Stroke or TIA at 1 year was higher for the TAVI group (8.3% vs. 4.3%, respectively, p=0.04). Vascular complications occurred in 18.0% percent of patients undergoing TAVI, compared with 4.8% in the open AVR group (p=0.01), and major vascular complications were also higher in the TAVI group (11.3% vs. 3.5%, p=0.01). On the other hand, major bleeding was more common in the open group compared to TAVI (25.7% vs. 14.7%, p=0.01).
Reynolds et al. (18) published quality of life (QOL) results from the PARTNER trial in 2012. QOL outcomes were evaluated using the Kansas City Cardiomyopathy Questionnaire (KCCQ) summary score, the Medical Outcomes Study Short-Form 12 (SF-12), and the EuroQol (EQ-5D). Of 699 patients in the trial, 628 completed baseline QOL measures. Patients in both the TAVI group and the surgical AVR group demonstrated significant improvements in all QOL measures over the 12 months following treatment. The TAVI group had superior improvement at one month on the KCCQ (mean difference 9.9, 95% CI: 4.9-14.9, p<0.001), but this difference was no longer present at 6 months or 12 months. A similar pattern of results was reported for the SF-12 and EQ-5D measures.
Conclusion. This trial in high-risk patients who were eligible for surgical AVR reports no differences between TAVI and open AVR in terms of mortality at 1 year and most major secondary outcomes. The non-inferiority boundaries for this trial included an upper limit of 7.5% absolute increase in mortality, but in actuality, the reported mortality for the TAVI group was lower than for the open group, although not significantly different. QOL was also similar at one year between the TAVI and AVR groups. Stroke or TIA was significantly more common for the TAVI group, occurring at a rate of almost 2 times that reported for open surgery. Other secondary outcomes were similar between groups, except for higher rates of vascular complications in the TAVI group and higher rates of major bleeding in the open surgery group. As in the first PARTNER cohort, there is concern for generalizability of results given that the patient selection process relied largely on the judgment of surgeons and cardiologists participating in the trial. In 2012, the U.S. Food and Drug Administration (FDA) broadened patient indications for TAVI to include patients who are at high risk for surgery, as defined by a STS risk score of >8%, or judged by a heart team to have an operative mortality of >15% for open surgery.
Does transcatheter aortic-valve implantation by alternative approaches (e.g. transapical or transaxillary) achieve similar outcomes to those reported from the transfemoral approach?
The majority of all patients treated with TAVI, and all the patients enrolled in the PARTNER B trial, have been by the transfemoral approach. Other approaches, such as the transapical approach, have been used in patients with inadequate femoral access. There is a limited amount of evidence comparing outcomes from different approaches. In the PARTNER A trial, slightly less than one-third of procedures were performed by the transapical approach, (14) and there were no substantial differences in outcomes between the 2 approaches.
Some non-randomized, comparative studies have compared outcomes for the transfemoral approach compared to the transapical approach. Ewe et al. (19) included 107 consecutive patients undergoing TAVI, 47 by the transfemoral approach and 50 by the transapical approach. Mortality was not significantly different for the transfemoral approach versus the transapical approach at 30 days (11.1% vs. 8.5%, respectively, p=0.74) or at one year (19.8% vs. 14.3%, respectively). Vascular complications were more common in the transfemoral group (18% vs. 5%, respectively, p=0.05). Fluoroscopy time and total radiation exposure was more reduced for the transapical approach.
A non-randomized, comparative study reported higher complication rates with the transapical approach. Thomas et al. (20) used data from a European registry to compare patients undergoing TAVI by the transfemoral approach (n=463) with patients undergoing TAVI by the transapical approach (n=575). Complications were more frequent in the transapical group, but the transapical group also may have been more severely ill as judged by a higher Euro-qual risk score. A publication from the UK TAVI registry (21) evaluated risk factors for adverse outcomes in 877 TAVI procedures. On univariate analysis, TAVI by the transapical approach was associated with lower survival, although this relationship did not persist after controlling for demographic and clinical factors.
Conclusion. There is some evidence comparing different approaches for TAVI. The highest quality evidence is for the transapical approach. This evidence includes a subgroup analysis from the PARTNER RCT and several case series of patients treated via the transapical approach. While this evidence is insufficient to form definite conclusions on the comparative efficacy of different approaches, it suggests that there are not large differences in outcomes between the transfemoral and transapical approach. There is very little evidence on other approaches such as the transaxillary and transiliac. In 2012, the FDA approved TAVI by the transapical approach for patients who are at high risk for open surgery.
What is the complication rate following transcatheter aortic valve implantation?
Aside from the complications reported in clinical trials, some studies have specifically reported on one or more complications in large numbers of patients. Representative studies of this type will be reviewed here.
The most common complications following TAVI are vascular complications related to the access site. Van Miegham et al. (22) pooled results from prospective databases on 986 patients undergoing transfemoral TAVI from 5 clinical centers in Europe. The rate of major vascular complications was 14.2%. Major bleeding occurred at a rate of 17.8% and life-threatening/disabling bleeding occurred at a rate of 11%.
Acute kidney injury (AKI) is also relatively common following TAVI. In 218 patients treated at one academic medical center in the U.S., (23) stage 2 or higher AKI occurred in 8.3% (18/218). Half of the patients with AKI (9/18) required dialysis. Mortality at 30 days (44.4% vs. 3.0%, p<0.0001) and one year (55.6% vs. 16.0%, p<0.0001) was much higher in patients with AKI compared to those without AKI. In a similar study of 248 patients from an academic center in Europe, stage 2 or higher AKI was more common, occurring in 35.9% of patients (89/248). Mortality was also increased at 30 days (13.5% vs. 3.8%, p<0.001) and at one year (31.5% vs. 15.0%, p<0.001) for patients with AKI.
For patients with degenerated bio-prosthetic valves or failed TAVI, does transcatheter aortic valve implantation using the “Valve-in-Valve” approach improve outcomes?
The evidence on this question consists of case series, most of which are small. The largest case series published to date is from the Global Valve-in-Valve registry. (24) This study included 202 patients from 38 cardiac centers with a prior surgical bioprosthetic valve replacement that had failed. The procedure was successful in 93.1% of attempts, and 95% of patients had one degree or less of aortic regurgitation post-procedure. Early adverse events occurred in 15.3%, with the most common events being malposition of the device and ostial coronary obstruction. Overall mortality was 8.3% at 30 days and 16.3% at one year. At 30 days’ follow-up, 83.7% of patients were in New York Heart Association functional Class I or II.
Other case series are smaller and generally from a single-center. A case series from Europe using the Medtronic CoreValve enrolled 27 patients from one cardiology center. (25) There were 2 deaths within 30 days. Improvements in the aortic valve gradient and the degree of regurgitation were noted. Adverse events included stroke (7.4%), kidney failure (7.4%), life-threatening bleeding (7.4%), and access site complications (11.1%). Another case series from Europe treated 18 patients with a degenerated bio-prosthetic valve and symptoms due to valve dysfunction. (26) Implantation was successful in 17/18 patients. Complications included acute kidney injury in 3/18 patients, major bleeding in 4/18 patients, and major access site complications in 1/18 patients. At a median follow-up of 11 months, mortality was 5.6% and symptoms were improved with all patients in NYHA Class II or lower.
Smaller case series have reported on valve-in-valve implantation for patients with failed TAVI. For example, a publication from Canada reported on 21 patients with transcatheter valve failure due to aortic regurgitation. (27) The procedure was successful in 19/21 patients; the remaining 2 patients required conversion to open surgery. Mortality at 30 days was 14.3% and at one year was 24%. Aortic regurgitation was absent in 4 patients, mild in 13 patients, and moderate in 2 patients.
Transcatheter aortic-valve implantation (TAVI) is a treatment for patients with severe aortic stenosis who require intervention, but who are a high or prohibitive risk for open surgery. There is currently one transcatheter aortic valve that is FDA-approved, the Edwards SAPIEN™ valve (Edwards LifeSciences, Irvine, CA).
For patients who are not surgical candidates due to excessive surgical risk, the PARTNER B trial reported results for patients treated with TAVI by the transfemoral approach compared to continued medical care with or without balloon valvuloplasty. There was a large decrease in mortality for the TAVI patients at 1 year compared to medical care. This trial also reported improvements on other relevant clinical outcomes for the TAVI group. There was an increased risk of stroke and vascular complications in the TAVI group. Despite these concerns, the overall balance of benefits and risks from this trial indicate that health outcomes are improved. Therefore, TAVI may be considered medically necessary for patients with severe aortic stenosis (AS) who are not surgical candidates when performed by the transfemoral approach.
For patients who are high risk for open surgery, but are operable candidates, the PARTNER A trial reported non-inferiority for survival at 1 year compared to open surgery. In this trial, TAVI patients also had higher risks for stroke and vascular complications. In 2012, the FDA expanded indications for TAVI to include patients who are at high risk for surgery, as defined by a Society of Thoracic Surgery (STS) risk score of >8%, or judged by a heart team to have a risk for operative mortality that is >15%. Based on the results of the PARTNER A trial and the FDA approval, TAVI for patients who are operable candidates but at high risk for open surgery may be considered medically necessary. The PARTNER A trial also included a subgroup analysis comparing the transfemoral and transapical approaches and reported no outcome differences between the 2 approaches. The 2012 FDA approval also expanded indications to include the transapical route in patients who were high risk for open surgery. Based on the available evidence and the 2012 FDA approval, TAVI performed by the transapical approach may be considered medically necessary in patients who are operable candidates but at high risk for open surgery.
TAVI has also been used as a “valve-in-valve” treatment for degenerated bio-prosthetic valves and for failed transcatheter valves. The evidence on this indication consists only of case series and is insufficient to determine whether outcomes are improved compared to alternatives. As a result, TAVI used for a “valve-in-valve” approach is considered experimental, investigational, and/or unproven.
Ongoing Clinical Trials
A search of online site ClinicalTrials.gov returned 17 ongoing trials of TAVI in various stages of evolution. The majority of these are single-arm trials evaluating the safety and efficacy of TAVI, using various types of valves, delivery systems, ancillary treatments, and outcomes. The following RCTs were identified that compared TAVI to alternative treatments, or compared outcomes of different types of valves:
Clinical Practice Guidelines and Position Statements
A “Professional Society Overview” on transcatheter valve therapy was published July 2011 by the American College of Cardiology Foundation and the Society of Thoracic Surgeons. (28) The purpose of this document was to enumerate the core issues that will be anticipated in integrating TAVI into general clinical care. As part of this document, a list of necessary components for the successful introduction of Transcatheter Heart Valve Therapies was developed:
2008 National Institute for Health and Clinical Excellence (NICE). Interventional procedure guidance ranscatheter aortic valve implantation for aortic stenosis. No. 266
The NICE guidance noted that the evidence on transcatheter aortic valve implantation for aortic stenosis is limited to small numbers of patients who were considered to be at high risk for conventional cardiac surgery. It shows good short-term efficacy, but there is little evidence on long-term outcomes. There is a potential for serious complications; however, the patients on whom this procedure has been used have a poor prognosis without treatment and are at high risk if treated by open heart surgery. Clinicians wishing to use this procedure should do so only with special arrangements for clinical governance, consent and for audit or research.
Each benefit plan, summary plan description or contract defines which services are covered, which services are excluded, and which services are subject to dollar caps or other limitations, conditions or exclusions. Members and their providers have the responsibility for consulting the member's benefit plan, summary plan description or contract to determine if there are any exclusions or other benefit limitations applicable to this service or supply. If there is a discrepancy between a Medical Policy and a member's benefit plan, summary plan description or contract, the benefit plan, summary plan description or contract will govern.
Disclaimer for coding information on Medical Policies
Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive.
The presence or absence of procedure, service, supply, device or diagnosis codes in a Medical Policy document has no relevance for determination of benefit coverage for members or reimbursement for providers. Only the written coverage position in a medical policy should be used for such determinations.
Benefit coverage determinations based on written Medical Policy coverage positions must include review of the member’s benefit contract or Summary Plan Description (SPD) for defined coverage vs. non-coverage, benefit exclusions, and benefit limitations such as dollar or duration caps.
The following codes may be applicable to this Medical policy and may not be all inclusive.
|33361, 33362, 33363, 33364, 33365, 33366, 33367, 33368, 33369, [Deleted 1/2014: 0318T], [Deleted 1/2013: 0256T, 0257T, 0258T, 0259T]|
ICD-9 Diagnosis Codes
395.0-395.9, 396.0-396.9, 424.1
ICD-9 Procedure Codes
ICD-10 Diagnosis Codes
I06.0-I06.9, I08.0, I08.2-I08.9, I35.0-I35.9
ICD-10 Procedure Codes
02RF0JZ, 02RF3JZ, 02RF3JH
The information contained in this section is for informational purposes only. HCSC makes no representation as to the accuracy of this information. It is not to be used for claims adjudication for HCSC Plans.
The Centers for Medicare and Medicaid Services (CMS) does have a national Medicare coverage position.
A national coverage position for Medicare may have been changed since this medical policy document was written. See Medicare's National Coverage at <http://www.cms.hhs.gov.
3/1/2014 Document updated with literature review. The following was added to the coverage section: 1) “Left ventricular ejection fraction >20%;” and “patients who are operable candidates but are at high risk for open surgery” were added to existing criteria for Transcatheter aortic valve replacement, performed via the transfemoral approach, for patients with aortic stenosis. 2) Transcatheter aortic valve replacement, performed via the transapical approach, may be considered medically necessary for patients with aortic stenosis when additional criteria are met. 3) Transcatheter aortic valve replacement is considered experimental, investigational, and/or unproven for all other indications, including but not limited to: Patients with a degenerated bio-prosthetic valve (“Valve-in-Valve” implantation) or Procedures performed via the transaxillary, transiliac, transaortic, or other approaches. 4) FDA definition of high risk for open surgery was added to the coverage section. CPT/HCPCS code(s) updated.
1/1/2013 Document updated. The following was added under coverage: Transcatheter aortic valve replacement performed via approaches other than transfemoral, including but not limited to the transapical approach for any indication is considered experimental, investigational and unproven. CPT/HCPCS code(s) updated.
10/15/2012 Document updated with literature review. Title changed from “Transcatheter Heart Valve Replacement”. The following was added: Transcatheter aortic valve replacement, performed via the transfemoral approach, may be considered medically necessary for patients with aortic stenosis when stated criteria are present. Transcatheter aortic valve replacement is considered experimental, investigational, and unproven for all other indications, including but not limited to, patients at high risk for open surgery but who are operable candidates. Transcatheter aortic valve replacement performed via the transapical approach for any indication is considered experimental, investigational, and unproven. Transcatheter Pulmonary Valve Implantation was moved from this document to SUR707.029.
6/15/2011 Document updated with literature review. Coverage unchanged. The following was added: Medtronic Melody® Transcatheter Pulmonary Valve (TPV) and Ensemble® Transcatheter Valve Delivery System was added. The number of the policy was changed from SUR717.015 to SUR707.028.
3/1/2011 New Medical Document converted from position statement. Percutaneous heart valve replacement is considered experimental, investigational, and unproven by any method.
1/1/2011 Position Statement. Percutaneous heart valve replacement is considered experimental, investigational, and unproven by any method.
|Title:||Effective Date:||End Date:|
|Transcatheter Aortic-Valve Implantation for Aortic Stenosis||07-15-2017||10-31-2018|
|Transcatheter Aortic-Valve Implantation for Aortic Stenosis||07-01-2016||07-14-2017|
|Transcatheter Aortic-Valve Implantation for Aortic Stenosis||11-01-2015||06-30-2016|
|Transcatheter Aortic-Valve Implantation for Aortic Stenosis||03-01-2014||10-31-2015|
|Transcatheter Aortic-Valve Implantation for Aortic Stenosis||01-01-2013||02-28-2014|
|Transcatheter Aortic-Valve Implantation for Aortic Stenosis||10-15-2012||12-31-2012|
|Transcatheter Heart Valve Replacement||06-15-2011||10-14-2012|
|Percutaneous Heart Valve Replacement||03-01-2011||06-14-2011|
|Percutaneous Heart Valve Replacement||01-01-2011||02-28-2011|