Prosthesis-patient mismatch defined by cardiac computed tomography versus echocardiography after transcatheter aortic valve replacement

Backgrounds: Evaluation of prosthesis-patient mismatch (P-PM) after transcatheter aortic valve replacement (TAVR) by transthoracic echocardiography (TTE) has provided conflicting results regarding its impact on outcomes. Whether post-TAVR computed tomography angiography (CTA) evaluation of P-PM can improve our understanding is unknown. We aimed to evaluate the inter-modality (TTE vs. CTA) agreement, inter-valve platform (balloon-expanding valve [BEV] vs. self-expandable valve [SEV]) differences in P-PM severity, and outcomes related to P-PM after TAVR.

Methods: We analyzed patients with both CTA and TTE before and after TAVR. Indexed effective orifice area was calculated using two methods: TTE-derived left ventricular outflow tract (LVOT) area from measured diameter and post-TAVR CTA-measured area. Body size specific cut-offs for P-PM severity were used: for body mass index (BMI) ​< ​30 ​kg/m², moderate ​= ​0.66-0.85 ​cm²/m² and severe≤0.65 ​cm²/m²; for BMI ≥30 ​kg/m², moderate ​= ​0.56-0.70 ​cm²/m² and severe≤0.55 ​cm²/m².

Results: A total of 447 patients were included (median age, 83 years; 54% male). The prevalence of P-PM (moderate or severe) was lower with CTA vs. TTE (3.5% vs. 19.5%, p ​< ​0.001). The prevalence of P-PM measured by TTE was more common in BEV compared to SEV (p ​= ​0.002), while CTA assessment showed no difference in P-PM incidence and severity between TAVR platforms (p ​= ​0.40). In multivariable analysis, CTA-defined but not TTE-defined P-PM was associated with mortality after TAVR (HR:3.97; 95%CI,1.55-10.2; p ​= ​0.004). Both CTA-defined and TTE-defined P-PM were associated with the composite of death and heart failure rehospitalization.

Conclusion: Although post-TAVR CTA substantially downgraded the prevalence of P-PM compared to TTE, it identified a subset of patients with clinically relevant P-PM which associated with outcomes.