Prosthesis-patient mismatch after transcatheter implantation of contemporary balloon-expandable and self-expandable valves in small aortic annuli

BACKGROUND

Evidence of clinical impact of PPM after TAVI is conflicting and might vary according to the type of valve implanted.

AIMS

To assess the clinical impact of prosthesis-patient mismatch (PPM) after transcatheter aortic valve implantation (TAVI) with balloon-expandable (BEV) and self-expandable valves (SEV) in patients with small annuli.

METHODS

TAVI-SMALL 2 enrolled 628 patients in an international retrospective registry, which included patients with severe aortic stenosis and small annuli (annular perimeter <72 mm or area <400 mm2 ) treated with transfemoral TAVI at 16 high-volume centers between 2011 and 2020. Analyses were performed comparing patients with less than moderate (n = 452), moderate (n = 138), and severe PPM (n = 38). Primary endpoint was incidence of all-cause mortality. Predictors of all-cause mortality and PPM were investigated.

RESULTS

At a median follow-up of 380 days (interquartile range: 210-709 days), patients with severe PPM, but not moderate PPM, had an increased risk of all-cause mortality when compared with less than moderate PPM (log-rank p = 0.046). Severe PPM predicted all-cause mortality in patients with BEV (hazard ratio [HR]: 5.20, 95% confidence interval [CI]: 1.27-21.2) and intra-annular valves (IAVs, HR: 4.23, 95% CI: 1.28-14.02), and it did so with borderline significance in the overall population (HR: 2.89, 95% CI: 0.95-8.79). Supra-annular valve (SAV) implantation was the only predictor of severe PPM (odds ratio: 0.33, 95% CI: 0.13-0.83).

CONCLUSIONS

Patients with small aortic annuli and severe PPM after TAVI have an increased risk of all-cause mortality at early term follow-up, especially after IAV or BEV implantation. TAVI with SAV protected from severe PPM.

Self-expanding vs. balloon-expandable transcatheter heart valves in small aortic annuli

Background

Clinical consequences of prosthesis-patient mismatch (PPM) after transcatheter aortic valve replacement (TAVR) is currently in the focus of clinical research. Patients with small aortic annulus are at higher risk to display PPM. Data on incidence and clinical consequences of PPM after TAVR with either balloon-expandable (BEV) or self-expanding (SEV) transcatheter heart valves in small aortic annulus are sparse.

Methods

Patients with small aortic annulus (perimeter < 72 mm or aortic annulus area < 400 mm2) who underwent BEV or SEV with contemporary transcatheter heart valve types were identified from the institutional TAVR database. Propensity score matching was applied for imbalanced baseline characteristics between patients undergoing BEV or SEV. Echocardiography and clinical follow-up beyond 3 years was reported following VARC-3 recommendations. Primary endpoint was the incidence of pre-discharge PPM and its association with 3-year mortality.

Results

From a total of 507 patients with small aortic annulus, 192 matched patient pairs with SEV or BEV were identified. Mean age was 81 ± 7 (SEV) vs. 81 ± 6 (BEV) years (p = 0.5), aortic annulus perimeter was 69 ± 3 vs.69 ± 3 mm, (p = 0.8), annulus area was 357 ± 27 vs.357 ± 27 mm2 (p = 0.8), and EuroScore II was 5.8 ± 6.6 vs.5.7 ± 7.2 (p = 0.9). SEV resulted in less moderate (20% vs. 31%, p < 0.001) and severe pre-discharge PPM (9% vs.18%, p < 0.001) compared to BEV. At discharge (7 ± 4 vs. 12 ± 9 mmHg, p = 0.003) and at 1-year follow-up (7 ± 5 vs.13 ± 3 mmHg, p < 0.001), SEV displayed lower mean gradients compared to BEV. Estimated survival after SEV was 85% (95% confidence interval (CI): 80%-90%) at 1 year, 80% (95% CI: 75%-86%) at 2 years, and 71% (95% CI: 65%-78%) at 3 years; estimated survival after BEV was 87% (95% CI: 82%-92%) at 1 year, 81% (95% CI: 75%-86%) at 2 years, and 72% (95% CI: 66%-79%) at 3 years, with no significant difference among the groups (p = 0.9) Body surface area (OR: 1.35, p < 0.001), implantation of BEV (odds ratio (OR): 3.32, p < 0.001), and the absence of postdilatation (OR: 2.16, p < 0.001) were independent risk factors for any PPM. At 3 years, patients without PPM had a higher 3-year survival compared with patients with ≥moderate PPM (77% vs. 67%, p = 0.03).

Conclusion

BEV implantation in patients with small annulus was associated with a twofold higher incidence of pre-discharge severe PPM compared to SEV implantation. Survival at 3 years after TAVR was similar after BEV and SEV. However, patients with the absence of pre-discharge PPM had a higher 3-year survival compared to patients with ≥moderate PPM.

5-Year Outcomes With Self-Expanding vs Balloon-Expandable Transcatheter Aortic Valve Replacement in Patients With Small Annuli

BACKGROUND

Self-expanding transcatheter heart valves (THVs) are associated with better echocardiographic hemodynamic performance than balloon-expandable THVs and are considered preferable in patients with small annuli.

OBJECTIVES

This study sought to compare 5-year outcomes between self-expanding vs balloon-expandable THVs in severe aortic stenosis (AS) patients with small annuli.

METHODS

Consecutive severe AS patients with an aortic valve annulus area <430 mm² who underwent transcatheter aortic valve replacement (TAVR) with either the CoreValve Evolut (Medtronic) or SAPIEN (Edwards Lifesciences) THV between 2012 and 2021 were enrolled from the Bern TAVI registry. A 1:1 propensity-matched analysis was performed to account for baseline differences between groups.

RESULTS

A total of 723 patients were included, and propensity score matching resulted in 171 pairs. Technical success was achieved in over 85% of both groups with no significant difference. Self-expanding THVs were associated with a lower transvalvular gradient (8.0 ± 4.8 mm Hg vs 12.5 ± 4.5 mm Hg; P < 0.001), a larger effective orifice area (1.81 ± 0.46 cm² vs 1.49 ± 0.42 cm²; P < 0.001), and a lower incidence of prosthesis-patient mismatch (19.7% vs 51.8%; P < 0.001) than balloon-expandable THVs. At 5 years, there were no significant differences in mortality (50.4% vs 39.6%; P = 0.269) between groups. Disabling stroke occurred more frequently in patients with a self-expanding THV than those with a balloon-expandable THV (6.6% vs 0.6%; P = 0.030). Similar results were obtained using inverse probability of treatment weighting in the Bern TAVI registry and the nationwide Swiss TAVI registry.

CONCLUSIONS

The echocardiographic hemodynamic advantage of self-expanding THVs was not associated with better clinical outcomes compared with balloon-expandable THVs up to 5 years in patients with small annuli. (Swiss TAVI Registry; NCT01368250).

Clinical and Technical Challenges of Prosthesis-Patient Mismatch After Transcatheter Aortic Valve Implantation

Prosthesis-patient mismatch (PPM) is present when the effective area of a prosthetic valve inserted into a patient is inferior to that of a normal human valve; the hemodynamic consequence of a valve too small compared with the size of the patient's body is the generation of higher than expected transprosthetic gradients. Despite evidence of increased risk of short- and long-term mortality and of structural valve degeneration in patients with PPM after surgical aortic valve replacement, its clinical impact in patients subject to transcatheter aortic valve implantation (TAVI) is yet unclear. We aim to review and update on the definition and incidence of PPM after TAVI, and its prognostic implications in the overall population and in higher-risk subgroups, such as small aortic annuli or valve-in-valve procedures. Last, we will focus on the armamentarium available in order to reduce risk of PPM when planning a TAVI procedure.

Predictors and Clinical Impact of Prosthesis-Patient Mismatch After Self-Expandable TAVR in Small Annuli

OBJECTIVES

The aim of this study was to define predictors of prosthesis-patient mismatch (PPM) and its impact on mortality after transcatheter aortic valve replacement (TAVR) with self-expandable valves (SEVs) in patients with small annuli.

BACKGROUND

TAVR seems to reduce the risk for PPM compared with surgical aortic valve replacement, especially in patients with small aortic annuli. Nevertheless, predictors and impact of PPM in this population have not been clarified yet.

METHODS

Predictors of PPM and all-cause mortality were investigated using multivariable logistic regression analysis from the cohort of the TAVI-SMALL (International Multicenter Registry to Evaluate the Performance of Self-Expandable Valves in Small Aortic Annuli) registry, which included patients with severe aortic stenosis and small annuli (annular perimeter <72 mm or area <400 mm² on computed tomography) treated with transcatheter SEVs: 445 patients with (n = 129) and without (n = 316) PPM were enrolled.

RESULTS

Intra-annular valves conferred increased risk for PPM (odds ratio [OR]: 2.36; 95% confidence interval [CI]: 1.16 to 4.81), while post-dilation (OR: 0.46; 95% CI: 0.25-0.84) and valve oversizing (OR: 0.53; 95% CI: 0.28-1.00) seemed to protect against PPM occurrence. At a median follow-up of 354 days, patients with severe PPM, but not those with moderate PPM, had a higher all-cause mortality rate compared with those without PPM (log-rank p = 0.008). Multivariable Cox regression confirmed severe PPM as an independent predictor of all-cause mortality (hazard ratio: 4.27; 95% CI: 1.34 to 13.6).

CONCLUSIONS

Among patients with aortic stenosis and small aortic annuli undergoing transcatheter SEV implantation, use of intra-annular valves yielded higher risk for PPM; conversely, post-dilation and valve oversizing protected against PPM occurrence. Severe PPM was independently associated with all-cause mortality.