2019 Canadian Cardiovascular Society Position Statement for Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation (TAVI) or replacement has rapidly changed the treatment of patients with severe symptomatic aortic stenosis. It is now the standard of care for patients believed to be inoperable or at high surgical risk, and a reasonable alternative to surgical aortic valve replacement for those at intermediate surgical risk. Recent clinical trial data have shown the benefits of this technology in patients at low surgical risk as well. This update of the 2012 Canadian Cardiovascular Society TAVI position statement incorporates clinical evidence to provide a practical framework for patient selection that does not rely on surgical risk scores but rather on individual patient evaluation of risk and benefit from either TAVI or surgical aortic valve replacement. In addition, this statement features new wait time categories and treatment time goals for patients accepted for TAVI. Institutional requirements and recommendations for operator training and maintenance of competency have also been revised to reflect current standards. Procedural considerations such as decision-making for concomitant coronary intervention, antiplatelet therapy after intervention, and follow-up guidelines are also discussed. Finally, we suggest that all patients with aortic stenosis might benefit from evaluation by the heart team to determine the optimal individualized treatment decision.     

Outcomes of Surgical Aortic Valve Replacement: The Benchmark for Percutaneous Therapies

Historically, many patients with severe senile calcific aortic valve stenosis (AS) were not offered surgery, largely due to the perception that the risks of operation were prohibitive. Such patients have subsequently been formally designated as ‘high risk’ or ‘inoperable’ with respect to their suitability for surgical aortic valve replacement (SAVR) in the evolving lexicon of heart valve disease. The recent availability of transcatheter aortic valve replacement (TAVR) represents an alternative treatment option, and permits the opportunity to re-examine algorithms for assessing operative risk. As the experience with TAVR grows, expanded use in new patient populations can be anticipated. While TAVR in high risk AS patients has demonstrated benefits, the emerging indication in intermediate AS is less clear and conclusions will necessarily await the availability of results from ongoing clinical trials. This article will discuss current outcomes for SAVR among high- and intermediate-risk patients with AS as a barometer in assessing the results of nascent percutaneous therapies.     

Role of Multimodality Imaging in Transcatheter Aortic Valve Replacement

The treatment of aortic stenosis (AS) has reached an exciting stage with the introduction of transcatheter aortic valve replacement (TAVR). It is the treatment of choice in patients with severe AS who are considered very high risk for surgical valve replacement. Multimodality imaging (MMI) plays a crucial role in TAVR patient selection, intra‐procedure guidance, and follow‐up. With the ever‐increasing scope for TAVR, a better understanding of MMI is essential to improve outcomes and prevent complications.     

Transcatheter Versus Surgical Aortic Valve Replacement in Patients With Rheumatic Aortic Stenosis

BackgroundPatients with rheumatic aortic stenosis (AS) were excluded from transcatheter aortic valve replacement (TAVR) trials.ObjectivesThe authors sought to examine outcomes with TAVR versus surgical aortic valve replacement (SAVR) in patients with rheumatic AS, and versus TAVR in nonrheumatic AS.MethodsThe authors identified Medicare beneficiaries who underwent TAVR or SAVR from October 2015 to December 2017, and then identified patients with rheumatic AS using prior validated International Classification of Diseases, Version 10 codes. Overlap propensity score weighting analysis was used to adjust for measured confounders. The primary study outcome was all-cause mortality. Multiple secondary outcomes were also examined.ResultsThe final study cohort included 1,159 patients with rheumatic AS who underwent aortic valve replacement (SAVR, n = 554; TAVR, n = 605), and 88,554 patients with nonrheumatic AS who underwent TAVR. Patients in the SAVR group were younger and with lower prevalence of most comorbidities and frailty scores. After median follow-up of 19 months (interquartile range: 13 to 26 months), there was no difference in all-cause mortality with TAVR versus SAVR (11.2 vs. 7.0 per 100 person-year; adjusted hazard ratio: 1.53; 95% confidence interval: 0.84 to 2.79; p = 0.2). Compared with TAVR in nonrheumatic AS, TAVR for rheumatic AS was associated with similar mortality (15.2 vs. 17.7 deaths per 100 person-years (adjusted hazard ratio: 0.87; 95% confidence interval: 0.68 to 1.09; p = 0.2) after median follow-up of 17 months (interquartile range: 11 to 24 months). None of the rheumatic TAVR patients, <11 SAVR patients, and 242 nonrheumatic TAVR patients underwent repeat aortic valve replacement (124 redo-TAVR and 118 SAVR) at follow-up.ConclusionsCompared with SAVR, TAVR could represent a viable and possibly durable option for patients with rheumatic AS.     

Transcatheter Aortic Valve Replacement: 2015 in Review

Transcatheter aortic valve replacement (TAVR) has emerged as an attractive option for patients with severe symptomatic aortic stenosis (AS) who are either at high risk or extreme risk for surgical aortic valve replacement (SAVR). This article summarizes the major advances in TAVR that were published or reported in 2015. (J Interven Cardiol 2016;29:27–46)

     

Long-term outlook for transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) revolutionized the treatment of severe symptomatic aortic stenosis (AS). TAVR is increasingly offered for lower-risk patients. The role and place of TAVR in the future treatment of AS is not clear yet. In this review, we discuss the long-term outlook for TAVR, its challenges and its relationship to conventional surgical aortic valve replacement.     

Health-Related Quality of Life After Transcatheter or Surgical Aortic Valve Replacement in High-Risk Patients with Severe Aortic Stenosis: an Updated Review of Literature

Recent trials have highlighted the comparable mortality benefits and durability of the results for patients with severe aortic stenosis (AS) and high surgical risk managed with either transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (AVR). Various national guidelines and international regulatory bodies have approved TAVR, thereby leading to potential wide usage and dissemination of this technique worldwide. Quality-of-life outcomes, in spite of being an important measure of success and acceptability of the procedure, have not been publicized as extensively. For high risk patients with severe AS, implementation of TAVR has resulted in comparable survival, but different and novel adverse events compared with AVR. We present an updated review focusing on the quality-of-life outcomes and issues with this new and important procedural approach.     

Sex-Specific Considerations in Women with Aortic Stenosis and Outcomes After Transcatheter Aortic Valve Replacement

Aortic stenosis (AS) is the most common valvular disease in the elderly and is associated with poor outcomes. Transcatheter aortic valve replacement (TAVR) is an alternative to surgical aortic valve replacement (SAVR) in high-risk patients. Herein, we describe the gender-related differences in baseline characteristics and pathophysiologic response to severe AS, imaging considerations unique to females, and short- and long-term outcomes after TAVR. Women undergoing TAVR are older and frailer, have less cardiovascular comorbidities, smaller femoral artery size, better left ventricular systolic function, hypertrophied and small left ventricles leading to a higher incidence of paradoxical low-flow low-gradient AS, and a greater prevalence of porcelain aorta, smaller aortic annulus size, and lower coronary ostia heights. Imaging and histopathological data also suggests a sex-related myocardial response to pressure overload from AS. Women experience more vascular complications and blood transfusion requirements, serious procedural complications, and a greater incidence of stroke, but have better long-term outcomes than men. Patient-prosthesis mismatch, which is a concern in patients with a small aortic annulus size undergoing SAVR, has not been problematic with TAVR. The aforementioned findings suggest that TAVR may be preferable for women with severe AS. Further studies are warranted to directly compare TAVR with SAVR in women.     

Temporal Trends and Outcomes of Transcatheter Versus Surgical Aortic Valve Replacement for Bicuspid Aortic Valve Stenosis

ObjectivesThe purpose of this study was to assess the temporal trends of transcatheter aortic valve replacement (TAVR) in patients with bicuspid aortic stenosis (AS), and to compare the outcomes between TAVR and surgical aortic valve replacement (SAVR) in this population.BackgroundRandomized trials comparing TAVR to SAVR in AS with bicuspid valve are lacking.MethodsThe study queried the National Inpatient Sample database (years 2012 to 2016) to identify hospitalizations for bicuspid AS who underwent isolated aortic valve replacement. A propensity-matched analysis was used to compare outcomes of hospitalizations for TAVR versus SAVR for bicuspid AS and TAVR for bicuspid AS versus tricuspid AS.ResultsThe analysis included 31,895 hospitalizations with bicuspid AS, of whom 1,055 (3.3%) underwent TAVR. TAVR was increasingly utilized during the study period for bicuspid AS (p_trend = 0.002). After matching, TAVR and SAVR had similar in-hospital mortality (3.1% vs. 3.1%; odds ratio: 1.00; 95% confidence interval: 0.60 to 1.67). There was no difference between TAVR and SAVR in the rates of cardiac arrest, cardiogenic shock, acute kidney injury, hemopericardium, cardiac tamponade, or acute stroke. TAVR was associated with lower rates of acute myocardial infarction, post-operative bleeding, vascular complications, and discharge to nursing facility as well as a shorter length of hospital stay. On the contrary, TAVR was associated with a higher incidence of complete heart block and permanent pacemaker insertion. TAVR for bicuspid AS was associated with similar in-hospital mortality compared with tricuspid AS.ConclusionsThis nationwide analysis showed similar in-hospital mortality for TAVR and SAVR in patients with bicuspid AS. TAVR for bicuspid AS was also associated with similar in-hospital mortality compared with tricuspid AS. Further studies are needed to evaluate long-term outcomes of TAVR for bicuspid AS.     

Transcatheter Aortic Valve Replacement in Rheumatic Aortic Stenosis: A Comprehensive Review

Rheumatic heart disease (RHD) mainly affects people in developing, low-income countries. However, due to globalization and migration, developed countries are now seeing more cases of RHD. In RHD patients who develop severe symptomatic aortic stenosis, surgical aortic valve replacement remains the treatment of choice. In the past decade, there has been an extension of transcatheter aortic valve replacement (TAVR) to intermediate-risk and lower-risk patients with aortic stenosis. This review suggests the possible utility of TAVR for the treatment of rheumatic aortic stenosis. Rheumatic aortic stenosis has been excluded from major TAVR studies due to the predominantly noncalcific pathology of the rheumatic aortic valve. However, there have been case reports and case series showing successful implantation of the valve even in patients with and without significant leaflet calcification. In this review article, we summarize the latest evidence of severe rheumatic aortic stenosis treated with TAVR and discuss the procedure's impact on patient care, safety, and efficacy.     

Minimally Invasive Surgical Aortic Valve Replacement: An Overview of Recent Advances

Aortic valve replacement (AVR) is the only definitive treatment for severe aortic stenosis. Options for valve replacement include surgical AVR (SAVR) and percutaneous transcatheter AVR. Although transcatheter AVR has recently been shown to be the optimal approach for high-risk patients, SAVR is the gold standard for patients with low and intermediate surgical risk. Advances in technique and innovations in rapid-deployment and sutureless valves have facilitated the development of a third alternative. Accumulating evidence suggests that minimally invasive SAVR can be performed as safely as conventional SAVR, and perhaps with less morbidity, allowing patients a quicker return to their productive lives. The following discussion outlines the surgical technique, patient selection and advances in valve design.     

Transcatheter Aortic Valve Replacement in Low-Risk Patients With Symptomatic Severe Bicuspid Aortic Valve Stenosis

ObjectivesThe aim of this study was to evaluate clinical outcomes and transcatheter heart valve hemodynamic parameters after transcatheter aortic valve replacement (TAVR) in low-risk patients with bicuspid aortic stenosis (AS).BackgroundTAVR is approved for low-risk patients in the United States. However, patients with bicuspid AS were excluded from the randomized cohorts of the pivotal low-risk trials.MethodsThe LRT (Low Risk TAVR) trial was an investigator-initiated, prospective, multicenter study and was the first and only U.S. Food and Drug Administration–approved investigational device exemption trial to evaluate the feasibility of TAVR with either balloon-expandable or self-expanding valves in low-risk patients with bicuspid AS. The primary endpoint was all-cause mortality at 30 days. Baseline and follow-up echocardiography and computed tomography to detect leaflet thickening were analyzed in an independent core laboratory.ResultsSixty-one low-risk patients with symptomatic, severe AS and bicuspid aortic valves (78.3% Sievers type 1 morphology) underwent TAVR at 6 centers from 2016 to 2019. The mean age was 68.6 years, and 42.6% were men. At 30 days, there was zero mortality and no disabling strokes. The rate of new permanent pacemaker implantation was 13.1%; just 1 patient had a moderate paravalvular leak at 30 days. Hypoattenuated leaflet thickening was observed in 10% of patients at 30 days.ConclusionsTAVR appears to be safe in patients with bicuspid AS, with short length of hospital stay, zero mortality, and no disabling strokes at 30 days. Subclinical leaflet thrombosis was observed in a minority of patients at 30 days but did not appear to be associated with clinical events.     

5-Year Outcomes Comparing Surgical Versus Transcatheter Aortic Valve Replacement in Patients With Chronic Kidney Disease

ObjectivesThe aim of this study was to compare 5-year cardiovascular, renal, and bioprosthetic valve durability outcomes in patients with severe aortic stenosis (AS) and chronic kidney disease (CKD) undergoing transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR).BackgroundPatients with severe AS and CKD undergoing TAVR or SAVR are a challenging, understudied clinical subset.MethodsIntermediate-risk patients with moderate to severe CKD (estimated glomerular filtration rate <60 mL/min/m²) from the PARTNER (Placement of Aortic Transcatheter Valve) 2A trial (patients randomly assigned to SAPIEN XT TAVR or SAVR) and SAPIEN 3 Intermediate Risk Registry were pooled. The composite primary outcome of death, stroke, rehospitalization, and new hemodialysis was evaluated using Cox regression analysis. Patients with and without perioperative acute kidney injury (AKI) were followed through 5 years. A core laboratory–adjudicated analysis of structural valve deterioration and bioprosthetic valve failure was also performed.ResultsThe study population included 1,045 TAVR patients (512 SAPIEN XT, 533 SAPIEN 3) and 479 SAVR patients. At 5 years, SAVR was better than SAPIEN XT TAVR (52.8% vs 68.0%; P = 0.04) but similar to SAPIEN 3 TAVR (52.8% vs 58.7%; P = 0.89). Perioperative AKI was more common after SAVR than TAVR (26.3% vs 10.3%; P < 0.001) and was independently associated with long-term outcomes. Compared with SAVR, bioprosthetic valve failure and stage 2 or 3 structural valve deterioration were significantly greater for SAPIEN XT TAVR (P < 0.05) but not for SAPIEN 3 TAVR.ConclusionsIn intermediate-risk patients with AS and CKD, SAPIEN 3 TAVR and SAVR were associated with a similar risk for the primary endpoint at 5 years. AKI was more common after SAVR than TAVR, and SAPIEN 3 valve durability was comparable with that of surgical bioprostheses.     

Challenges and Future Opportunities for Transcatheter Aortic Valve Therapy

Background

Transcatheter aortic valve replacement (TAVR) is a novel less-invasive therapy for high-risk patients with severe aortic stenosis (AS). Despite the impressive clinical growth of TAVR, there are many challenges as well as future opportunities.

Results

The heart valve team serves as the central vehicle for determining appropriate case selection. Considerations which impact clinical therapy decisions include frailty assessments and defining clinical “futility”. There are many controversial procedural issues; choice of vascular access site, valve sizing, adjunctive imaging, and post-dilatation strategies. Complications associated with TAVR (strokes, vascular and bleeding events, para-valvular regurgitation, and conduction abnormalities) must be improved and will require procedural and/or technology enhancements. TAVR site training mandates a rigorous commitment to established society and sponsor guidelines. In the future, TAVR clinical indications should extend to bioprosthetic valve failure, intermediate risk patients, and other clinical scenarios, based upon well conducted clinical trials. New TAVR systems have been developed which should further optimize clinical outcomes, by reducing device profile, providing retrievable features, and preventing para-valvular regurgitation. Other accessory devices, such as cerebral protection to prevent strokes, are also being developed and evaluated in clinical studies.

Summary

TAVR is a worthwhile addition to the armamentarium of therapies for patients with AS. Current limitations are important to recognize and future opportunities to improve clinical outcomes are being explored.     

Aortic Valve Surgery and Transcatheter Aortic Valve Replacement for the Very Old: Improved Interventional Therapeutic Options for Aortic Stenosis for Elderly

The older adult population in the U.S. (>75 years old) is growing rapidly with seniors living well into their 80s and 90s. Incidence of calcific valvular stenosis increases with age, and as a result, the prevalence of calcific valvular aortic stenosis (AS) is increasing. Elderly people with symptomatic AS are particularly vulnerable to mortality as well as to reduced quality of life and increased dependency. Trans-catheter aortic valve replacement (TAVR) has revolutionized the treatment options for those with AS, especially in older adults who were previously deemed non-surgical or high risk surgical candidates. Several reports have shown improvements in longevity, functional class and quality of life following TAVR in older adults. Surgical techniques for aortic valve replacement have also improved. This review will discuss clinical elements of AS and the dynamic field of interventional treatment options.     

Annual Budget Impact Analysis Comparing Self-Expanding Transcatheter and Surgical Aortic Valve Replacement in Low-Risk Aortic Stenosis Patients

BackgroundTranscatheter aortic valve replacement (TAVR) is approved for use across the entire spectrum of risk, including low-surgical-risk patients for severe aortic stenosis (AS). TAVR has been shown to be cost-effective compared with surgical aortic valve replacement (SAVR) in Canada. However, the affordability of implementing TAVR for low-risk AS patients from the hospital’s payers’ perspective is unknown.MethodsA budget impact analysis was conducted using a 1-year time horizon to quantify the total cost of health care resource utilisation to initially treat low-risk AS patients and manage subsequent adverse events. Differences in cost between TAVR and SAVR were calculated for 100 patients for various scenarios of TAVR uptake (10% to 70%) in low-risk AS patients. Event rates and associated costs were obtained from published literature and provincial datasets. Costs were reported in 2021 Canadian dollars. One-way sensitivity analysis on key TAVR input parameters was conducted.ResultsMean index hospitalisation costs of SAVR and TAVR per patient were $41,956 and $37,669, respectively. The average total costs of managing a low-risk AS patient in 1 year for TAVR and SAVR were $45,897 and $42,659, respectively. The incremental budget impacts of increasing TAVR uptake from 10% to 50% and 70% were 3% and 4.5%, respectively. One-way sensitivity analysis on key variables showed that the main contributors to the cost difference were the intensive care unit stay, permanent pacemaker rate, and hospital length of stay.ConclusionsThe incremental annual cost of implementing TAVR in low-risk AS patients was small, making TAVR likely an affordable strategy.     

Patient Evaluation and Selection for Transcatheter Aortic Valve Replacement: The Heart Team Approach

Transcatheter aortic valve replacement (TAVR) has been shown to significantly impact mortality and quality of life in patients with severe aortic stenosis (AS) who are deemed high risk for surgical aortic valve replacement (SAVR). Essential to these outcomes is proper patient selection. The multidisciplinary TAVR heart team was created to provide comprehensive patient evaluation and aid in proper selection. This review with outline the history and components of the heart team, and delineate the team’s role in risk and frailty assessment, evaluation of common co-morbidities that impact outcomes, and the complex multi-modality imaging necessary for procedural planning and patient selection. The heart team is critical in determining patient eligibility and benefit and the optimal operative approach for TAVR. The future of structural heart disease will certainly require a team approach, and the TAVR heart team will serve as the successful model.     

Postextrasystolic Potentiation in Low‐Gradient,Severe Aortic Stenosis: A Poor Man's Stress Echo?

An elderly man with dyspnea and syncope was found to have severe aortic stenosis (AS) by the continuity equation, despite a transaortic gradient that was only moderately elevated, in the setting of severe left ventricular dysfunction. The transaortic gradient increased during postextrasystolic beats, suggesting that his that his AS was truly severe; this was confirmed by dobutamine echocardiography. He underwent transcatheter aortic‐valve replacement (TAVR), with subsequent improvement in left ventricular systolic function. The diagnostic and prognostic significance of postextrasystolic potentiation, with associated increase in aortic stenosis gradient, deserves renewed attention in the TAVR era.     

Clinical Outcomes and Revascularization Strategies in Patients With Low-Flow,Low-Gradient Severe Aortic Valve Stenosis According to the Assigned Treatment Modality

ObjectivesThis study compared clinical outcomes and revascularization strategies among patients presenting with low ejection fraction, low-gradient (LEF-LG) severe aortic stenosis (AS) according to the assigned treatment modality.BackgroundThe optimal treatment modality for patients with LEF-LG severe AS and concomitant coronary artery disease (CAD) requiring revascularization is unknown.MethodsOf 1,551 patients, 204 with LEF-LG severe AS (aortic valve area <1.0 cm², ejection fraction <50%, and mean gradient <40 mm Hg) were allocated to medical therapy (MT) (n = 44), surgical aortic valve replacement (SAVR) (n = 52), or transcatheter aortic valve replacement (TAVR) (n = 108). CAD complexity was assessed using the SYNTAX score (SS) in 187 of 204 patients (92%). The primary endpoint was mortality at 1 year.ResultsLEF-LG severe AS patients undergoing SAVR were more likely to undergo complete revascularization (17 of 52, 35%) compared with TAVR (8 of 108, 8%) and MT (0 of 44, 0%) patients (p < 0.001). Compared with MT, both SAVR (adjusted hazard ratio [adj HR]: 0.16; 95% confidence interval [CI]: 0.07 to 0.38; p < 0.001) and TAVR (adj HR: 0.30; 95% CI: 0.18 to 0.52; p < 0.001) improved survival at 1 year. In TAVR and SAVR patients, CAD severity was associated with higher rates of cardiovascular death (no CAD: 12.2% vs. low SS [0 to 22], 15.3% vs. high SS [>22], 31.5%; p = 0.037) at 1 year. Compared with no CAD/complete revascularization, TAVR and SAVR patients undergoing incomplete revascularization had significantly higher 1-year cardiovascular death rates (adj HR: 2.80; 95% CI: 1.07 to 7.36; p = 0.037).ConclusionsAmong LEF-LG severe AS patients, SAVR and TAVR improved survival compared with MT. CAD severity was associated with worse outcomes and incomplete revascularization predicted 1-year cardiovascular mortality among TAVR and SAVR patients.