Abstract 11602: Impact of Pre-Operative Type-B Natriuretic Peptide Level on Survival After Aortic Valve Replacement for Aortic Stenosis

Abstract

Introduction: Levels of type-B natriuretic peptide (BNP) adjusted for age and sex are a powerful predictor of mortality after the diagnosis of aortic stenosis (AS). Objective: To assess whether BNP activation (compared to normal values) affects mortality after aortic valve replacement (AVR). Methods: In 494 patients with AS, plasma level of BNP was measured pre-operatively at the time of Doppler-Echocardiography. BNP was normalized as BNPratio (BNP measured/BNP maximum normal value for age and sex) to evaluate the impact of BNP activation on post-operative outcomes. Results: Mean age was73±11 years and 300 (61%) patients were male. Mean aortic valve area was 0.82±0.20cm2, mean gradient 51±16mmHg, and mean Left Ventricular Ejection Fraction 59±15%. Incidence of hypertension was 65%, diabetes 27% and chronic kidney disease 22%. Median of BNP was 211 (interquartile: 87-508) and BNPratio 2.2 (1.0-5.2). After adjustment age, gender, body surface area, Charlson score index, presence of symptoms, creatinine, hemoglobin, systolic blood pressure, indexed aortic valve area and left ventricular ejection fraction, the BNPratio (log transformed) was a predictor of long-term mortality (p<0.0001) with an hazard ratio 1.34 (1.14-1.60). Moreover, stratification by BNPratio showed increasing long-term post-operative mortality with BNPratios>2 (Figure). Conclusions: BNP activation defined using BNPratios (normalized for age and sex) is a powerful independent predictor of long-term mortality after aortic valve replacement for AS. Furthermore, patients with a BNPratio>2 before aortic valve replacement incur excess mortality during follow-up in relation to the increasing BNPratio. These data support the use of the BNPratio to guide the timing of AVR.