Clinical and Echocardiographic Characteristics of Flow-Based Classification Following Balloon-Expandable Transcatheter Heart Valve in PARTNER Trials.

BACKGROUND: Current expected normal echocardiographic measures of transcatheter heart valve (THV) function were derived from pooled cohorts of the randomized trials; however, THV function by flow state before or following transcatheter aortic valve replacement (TAVR) has not been previously reported.

OBJECTIVES: This study sought to assess the expected normal echocardiographic hemodynamics for the balloon-expandable THV grouped by stroke volume index (SVI).

METHODS: Patients with severe aortic stenosis enrolled in PARTNER (Placement of Aortic Transcatheter Valves) 1 (high/extreme surgical risk), PARTNER 2 (intermediate surgical risk), or PARTNER 3 (low surgical risk) trials with complete core laboratory echocardiography were included. Patients were grouped by low-flow (SVILOW  <35 mL/m2 ) and normal-flow (SVINORMAL  ≥35 mL/m2 ). Mean gradient, effective orifice area (EOA), and Doppler velocity index (DVI) were collected at baseline and at 30 days post-TAVR. Prosthesis-patient mismatch (PPM) was both calculated and predicted from normative data, using defined criteria.

RESULTS: In the entire population (N = 4,991), mean age was 81.8 years, 58% of patients were male, and 42% had low flow. Compared with patients with baseline SVINORMAL , those with SVILOW were more likely to be male; have more comorbidities; and lower left ventricular ejection fraction, mean gradient, and EOA. Post-TAVR, SVILOW increased to SVINORMAL in 17.3% and SVINORMAL decreased to SVILOW in 12.3% of patients. Using baseline SVI, follow-up EOA, mean gradient, and DVI for patients with SVILOW tended to be lower than for patients with SVINORMAL . Using the post-TAVR SVI, follow-up EOA, mean gradient, and DVI were significantly lower for patients with SVILOW than for those with SVINORMAL (P < 0.001 for all). The incidence of calculated, but not predicted, severe PPM was higher in patients with low flow than it was in patients with normal flow, suggesting pseudo-PPM in the presence of low flow.

CONCLUSIONS: This study demonstrates that flow affects THV hemodynamics and both baseline and follow-up SVI should be considered when predicting THV hemodynamics prior to TAVR, as well as assessing valve function following valve implantation.