Relation between serum N-terminal pro-brain natriuretic peptide and prognosis in patients with hypertrophic cardiomyopathy

Abstract

To determine the relation between serum concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) and prognosis in patients with hypertrophic cardiomyopathy (HCM). In total, 847 patients (53 ± 15 years; 67% male) with HCM (28% with left ventricular outflow tract obstruction ≥ 30 mmHg at rest) were followed for 3.5 years (IQR 2.5-4.5 years). The median NT-proBNP concentration was 78 pmol/L (range < 5-1817 pmol/L and IQR 31-183 pmol/L). Sixty-eight patients (8%) reached the primary endpoint of all-cause mortality or cardiac transplantation. NT-proBNP concentration predicted long-term survival from the primary endpoint [area under the receiver operating characteristic curve of 0.78 (95% confidence interval 0.73-0.84)]. A serum concentration of ≥ 135 pmol/L was associated with an annual event rate of 6.1% (95% CI 4.4-7.7). Three independent predictors of primary outcome were identified in a multivariable Cox model: New York Heart Association class III/IV (HR 2.10, 95% CI 1.21-3.65, P = 0.008), ejection fraction (HR 0.98, 95% CI 0.96-1.00, P = 0.035), log NT-proBNP (HR 2.04, 95% CI 1.56-2.66, P < 0.001). Log NT-proBNP was a significant predictor of heart failure (HF) and transplant-related deaths (n = 23; HR 3.03, 95% CI 1.99-4.60, P < 0.001) but not sudden death or appropriate implantable cardioverter defibrillator shock (n = 11; HR 1.54, 95% CI 0.91-2.60, P = 0.111). In patients with ejection fraction ≥ 50% (n = 673), log NT-proBNP remained an independent predictor of the primary outcome (HR 2.11, 95% CI 1.54-2.90, P < 0.001). In patients with HCM, elevated NT-proBNP concentration is a strong predictor of overall prognosis, particularly HF-related death and transplantation.