Transcatheter Aortic Valve Implantation: Current and Evolving Indications

Transcatheter Aortic Valve Replacement: The Experience of One Brazilian Health Care Center

Objective

Transcatheter aortic valve replacement has been an alternative to invasive treatment for symptomatic severe aortic stenosis in high risk patients. The primary endpoint was 30-day and 1-year mortality from any cause. Secondary endpoints were to compare the clinical and echocardiographic variation pre-and post- transcatheter aortic valve replacement, and the occurrence of complications throughout a 4-year follow-up period.

Methods

This prospective cohort, nestled to a multicenter study (Registro Brasileiro de Implante de Bioprótese por Cateter), describes the experience of a public tertiary center in transcatheter aortic valve replacement. All patients who underwent this procedure between October 2011 and February 2016 were included.

Results

Fifty-eight patients underwent transcatheter aortic valve replacement. The 30-day all-cause mortality was 5.2% (n=3) and after 1 year was 17.2% (n=10). A significant improvement in New York Heart Association functional classification was observed when comparing pre-and post- transcatheter aortic valve replacement (III or IV 84.4% versus 5.8%; P<0.001). A decline in peak was observed (P<0.001) and mean (P<0.001) systolic transaortic gradient. The results of peak and mean post-implant transaortic gradient were sustained after one year (P=0.29 and P=0.36, respectively). Left ventricular ejection fraction did not change significantly during follow-up (P=0.41). The most frequent complications were bleeding (28.9%), the need for permanent pacemaker (27.6%) and acute renal injury (20.6%).

Conclusion

Mortality and complications in this study were consistent with worldwide experience. Transcatheter aortic valve replacement had positive clinical and hemodynamic results, when comparing pre-and post-procedure, and the hemodynamic profile of the prosthesis was sustained throughout follow-up.

Transcatheter aortic valve replacement in patients with pure native aortic valve regurgitation: A systematic review and meta-analysis

This systematic review and meta-analysis sought to summarize the available evidence on the use of transcatheter aortic valve replacement (TAVR) in patients with Native Aortic Valve Regurgitation (NAVR) and compare outcomes between first and second generation valves. Owing to the improvements in transcatheter heart valve design and procedural success, TAVR has become increasingly performed in broader aortic valve pathologies. We searched Medline, Embase, Cochrane, and Scopus databases from 2007 to 2018 and performed a systematic review on reports with at least 10 patients with aortic valve regurgitation undergoing TAVR procedure. The main outcome of interest was all-cause mortality at 30 days. A total of 638 patients across 12 studies were included. Mean age ranged from 68 to 84. Society of Thoracic Surgeons score ranged from 5.4% to 13.1% and Logistic EuroSCORE ranged from 18.2% to 33%. The incidence rate of all-cause mortality at 30 days was found to be 11% (95% CI 7%-16%; I² = 20.86%). All-cause mortality at 30 days for first generation valves had an incidence rate of 15% (95% CI 10%-20%; I² = 10%) compared to 7% (95% CI 3%-13%; I² = 37%) in second generation valves with subgroup interaction analysis P = 0.059. Device success incidence rate in second generation valves was 92% (95% CI 83%-99%; I² = 67%) vs 68% (95% CI 59%-77%; I² = 53%) in first generation valves with P = 0.001. TAVR appears to be a feasible treatment choice for NAVR patients at high risk for surgical valve replacement. Second generation valves show promising results in terms of short-term outcomes.

A novel echocardiographic hemodynamic index for predicting outcome of aortic stenosis patients following transcatheter aortic valve replacement

Objective

Transcatheter aortic valve replacement (TAVR) reduces left ventricular (LV) afterload and improves prognosis in aortic stenosis (AS) patients. However, LV afterload consists of both valvular and arterial loads, and the benefits of TAVR may be attenuated if the arterial load dominates. We proposed a new hemodynamic index, the Relative Valve Load (RVL), a ratio of mean gradient (MG) and valvuloarterial impedance (Zva), to describe the relative contribution of the valvular load to the global LV load, and examined whether RVL predicted patient outcome following TAVR.

Methods

A total of 258 patients with symptomatic severe AS (indexed aortic valve area (AVA)<0.6cm²/m², AR≤2+) underwent successful TAVR at the University of Ottawa Heart Institute and had clinical follow-up to 1-year post-TAVR. Pre-TAVR MG, AVA, percent stroke work loss (%SWL), Zva and RVL were measured by echocardiography. The primary endpoint was all cause mortality at 1-year post TAVR.

Results

There were 53 deaths (20.5%) at 1-year. RVL≤7.95ml/m² had a sensitivity of 60.4% and specificity of 75.1% for identifying all cause mortality at 1-year post-TAVR and provided better specificity than MG<40 mmHg, AVA>0.75cm², %SWL≤25% and Zva>5mmHg/ml/m² despite equivalent or better sensitivity. In multivariable Cox analysis, RVL≤7.95ml/m² was an independent predictor of all cause mortality (HR 3.2, CI 1.8–5.9; p<0.0001). RVL≤7.95ml/m² was predictive of all cause mortality in both low flow and normal flow severe AS.

Conclusions

RVL is a strong predictor of all-cause mortality in severe AS patients undergoing TAVR. A pre-procedural RVL≤7.95ml/m² identifies AS patients at increased risk of death despite TAVR and may assist with decision making on the benefits of TAVR.

Transcatheter Aortic Valve Implantation (TAVI) for Native Aortic Valve Regurgitation - A Systematic Review

BACKGROUND

Transcatheter aortic valve implantation (TAVI) has become the standard of care for management of high-risk patients with aortic stenosis. Limited data is available regarding the performance of TAVI in patients with native aortic valve regurgitation (NAVR).Methods and Results:We performed a systematic review from 2002 to 2016. The primary outcome was device success as per VARC-2 criteria. Secondary endpoints included procedural complications, and 30-day and 1-year mortality rates. A total of 175 patients were included from 31 studies. Device success was reported in 86.3% of patients - with device failure driven by moderate aortic regurgitation (AR ≥3+) and/or need for a second device. Procedural complications were rare, with no procedural deaths, myocardial infarctions or annular ruptures reported. Procedural safety was acceptable with a low 30-day incidence of stroke (1.5%). The 30-day and 1-year overall mortality rates were 9.6% and 20.0% (cardiovascular death, 3.8% and 10.1%, respectively). Patients receiving 2nd-generation valves demonstrated similar safety profiles with greater device success compared with 1st-generation valves (96.2% vs. 78.4%). This was driven by the higher incidence of second-valve implantation (23.4% vs. 1.7%) and significant paravalvular leak (8.3% vs. 0.0%).

CONCLUSIONS

TAVI demonstrates acceptable safety and efficacy in high-risk patients with severe NAVR. Second-generation valves may afford a similar safety profile with improved device success. Dedicated studies are needed to definitively establish the efficacy of TAVI in this population.