Abstract 12950: Measurement of Type-B Natriuretic Peptide in Aortic Stenosis: Normalization by age and sex predicts Survival After diagnosis
Background: Plasma level of type-B natriuretic peptide (BNP) is highly influence by age and sex. However, BNP level has never been controlled for age and sex, in order to use as a predictor of mortality in aortic stenosis (AS). The objective of this study was to assess the impact of increments in BNP compared to normal/expected values on mortality in a large population of AS patients.
Methods: In 2104 patients with AS, plasma BNP level was measured at the time of Doppler-Echocardiography and divided by the expected BNP level according to age and sex to evaluate the BNP increment for each patient (BNPratio).
Results: The Baseline characteristics of our cohort were standard in AS patients with a mean age of 76±12 years and 1158 (55%) male. Mean aortic valve area was 1.04±0.26cm2, mean gradient 35±19mmHg, mean LVEF 57±15% and incidence of hypertension was 70%, diabetes 32% and chronic kidney disease 37%. Median of BNP was 274 (interquartile: 102-652) and BNPratio 2.6 (1.1-6.1). After adjustment for age, gender, body surface area, Charlson score index, presence of symptoms, creatinine, hemoglobin, systolic blood pressure, indexed aortic valve area, left ventricular ejection fraction and aortic valve replacement (as a time dependent variable), BNPratio (log transformed) was a powerful predictor of mortality (p≤0.0001) with an hazard ratio 1.54 (1.47-1.61) per one logarithm increase. Moreover, when stratifying groups by elevated BNPratio, each group had increases in risk of death compared to the precedent one (Figure).
Conclusion: In patients with AS, abnormal BNP level normalized for age and sex is a powerful independent predictor of long-term mortality. Each doubling of observed/expected BNPratio predicts higher mortality. Thus, BNP level interpretation should be quantitative (i.e. corrected for expected level) and integrated into the clinical decision-making process.
- © 2013 by American Heart Association, Inc.