Prognostic value of B-type natriuretic peptide in elderly patients with aortic valve stenosis: the COFRASA–GENERAC study

Objective Previous studies suggested an independent prognostic value of B-type natriuretic peptide (BNP) in aortic valve stenosis (AS) but were impeded by small sample sizes and inclusion of relatively selected young patients. We aimed to evaluate the relationship among N-terminal fragment of proBNP (Nt-proBNP), AS severity, symptoms and outcome in a large cohort of elderly patients with AS. Design Observational cohort study, COhorte Francaise de Retrecissement Aortique du Sujet Age (clinicalTrial.gov number-[NCT00338676][1]) and GENEtique du Retrecissement Aortique (clinicalTrial.gov number-[NCT00647088][2]). Setting Single-centre study. Patients Patients older than 70 years with at least mild AS. Interventions None. Measurements A comprehensive clinical, biological and echocardiographic evaluation was performed at study entry. Asymptomatic patients were prospectively followed on a 6-months basis and AS-related events (sudden death, congestive heart failure or new onset of AS-related symptoms) collected. Results We prospectively enrolled 361 patients (79±6 years, 230 severe AS). Nt-proBNP increased with the grade of AS severity and the NYHA class (all p<0.0001) but there was an important overlap between grades/classes. Consequently, diagnostic value of Nt-proBNP for the diagnosis of severe symptomatic AS was only modest (area under the curve of the receiver operator characteristic analysis=0.73). At 2 years, 28 AS-related events occurred among 142 asymptomatic patients prospectively followed. Nt-proBNP was associated with outcome in univariate analysis (p=0.04) but not after adjustment for age, gender and AS severity (p=0.40). Conclusions The present study clearly highlights the limitations of Nt-proBNP for the evaluation and management of AS patients. Our results suggest that Nt-proBNP should be considered cautiously, at least as a single criterion, in the decision-making process of AS patients especially in the elderly population. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00338676&atom=%2Fheartjnl%2F99%2F7%2F461.atom [2]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00647088&atom=%2Fheartjnl%2F99%2F7%2F461.atom