Relative amplitude index: a new tool for hemodynamic evaluation of periprosthetic regurgitation after transcatheter valve implantation.

OBJECTIVE: The impact of paravalvular aortic regurgitation (PAR) on hemodynamic performance after transcatheter aortic valve implantation (TAVI) remains disputable. Common parameters such as the diastolic blood pressure or the blood pressure amplitude do not provide reproducible results. The aim of our study was to evaluate the impact of PAR on hemodynamics and outcome using the relative amplitude index (RAI).

METHODS: PAR was prospectively evaluated by echocardiography before discharge in 110 patients. The RAI was calculated according to the formula: RAI = [(Post-TAVI BP amplitude)/(Post-TAVI SBP) - (Pre-TAVI BP amplitude)/(Pre-TAVI SBP)] × 100%, where BP is blood pressure and SBP is systolic blood pressure. Correlations of increased RAI with perioperative outcome were investigated and factors influencing mortality were isolated.

RESULTS: The incidence of moderate and severe PAR after TAVI was 9% and 1%, respectively. Diastolic pressure or post-TAVI amplitude did not correlate to perioperative outcome. RAI increased from 2 when PAR was <2+ to 7 when PAR was ≥2+ (P = .006). A cut-off value of RAI ≥14 was associated with increased perioperative mortality (29 vs 5%; P = .013) and acute renal injury requiring dialysis (71 vs 18%; P = .001). RAI ≥14 was also associated with higher follow-up mortality at 1 year (57 vs 16%; P = .007). RAI ≥14 (odds ratio [OR], 3.390; 95% confidence interval [CI], 1.6-7.194; P = .00146), PAR ≥2+ (OR, 4.717; 95% CI, 1.828-12.195; P = .00135), and perioperative renal replacement therapy (OR, 12.820; 95% CI, 5.181-31.250; P = .00031) were found to be independent predictors of mortality at 1 year.

CONCLUSIONS: The RAI is a useful tool to predict perioperative and 1-year outcome in patients with PAR after TAVI.