BACKGROUND: For patients with asymptomatic severe aortic stenosis (AS), the EARLY TAVR trial demonstrated that early transcatheter aortic valve replacement (TAVR) was superior to clinical surveillance (CS).
OBJECTIVES: In this study, the authors sought to evaluate whether baseline left ventricular (LV) health altered the treatment effect of early intervention and to examine longitudinal LV health under different treatment strategies.
METHODS: At 75 centers in the United States and Canada, 901 patients underwent randomization to TAVR (n = 455) or CS (n = 446). Echocardiographic measurements were made in a core laboratory. The protocol defined integrated LV health as the composite of absolute LV global longitudinal strain (GLS) ≥15%, LV mass index (LVMi) <115 g/m2 (men) or <95 g/m2 (women), and left atrial volume index (LAVi) ≤34 mL/m2. Integrated LV health was a prespecified secondary endpoint and the protocol outlined longitudinal measurements to be made in the intention-to-treat (ITT) and valve implant populations. As a stratification variable for effect-modification testing, LV health was not prespecified, so those analyses are exploratory. The trial's primary endpoint and 2 secondary composites were examined.
RESULTS: At randomization, in the ITT population, 27% had normal integrated LV health (64% normal LVMi, 42% normal LAVi, 88% normal GLS). Abnormal integrated LV health and each component were generally associated with higher event rates across several composite endpoints. Benefit of early TAVR, compared with CS, was consistently observed regardless of whether LV health (evaluated as an integrated measure and as individual components) was normal or not. In the ITT population, the CS group exhibited normal LV health less frequently at 2 years than those treated early according to the integrated LV health measure (35.9% vs 48.1%; P < 0.001) and component measures. Among CS patients undergoing delayed AVR, LV health tended to decline from randomization to preprocedure (P < 0.10 for all measures except GLS), but baseline LV health did not predict timing of conversion to AVR nor severity of presentation.
CONCLUSIONS: For patients with asymptomatic severe AS, the benefit of early TAVR, compared with CS, is consistent regardless of baseline LV health according to integrated or individual measures. These exploratory findings suggest limited value for measures of LV health to guide the timing of TAVR in asymptomatic patients. Whether the worsening of LV health associated with CS and delayed aortic valve replacement underlies increased clinical events in that treatment arm requires further study. (Evaluation of TAVR Compared to Surveillance for Patients With Asymptomatic Severe Aortic Stenosis [EARLY TAVR]; NCT03042104).