Predictive value of NT-proBNP in non-obstructive hypertrophic cardiomyopathy

Abstract

Abstract Background We studied the prognostic value of serum NT-proBNP in nonobstructive hypertrophic cardiomyopathy (nHCM) patients. Methods We studied 777 nHCM patients (55±13 years, 54% men, maximal left ventricular outflow tract gradient [LVOTG] <30 mm Hg) with serum NT-proBNP measured at baseline. We excluded patients with prior septal myectomy (SM) & LV ejection fraction (LVEF) <55%. NT-proBNP was adjusted for age & sex & converted to a log NT-proBNP ratio. Clinical & echo variables were recorded. Primary endpoint was death, appropriate implantable defibrillator (ICD) discharge or heart transplant. Results NT-proBNP ratio was high in 473 and low in 304 patients. Median [interquartile range] LVEF, LVOTG & NT-proBNP were 61% [59, 66], 7 [4, 12] mm Hg & 481 [137–1361] pg/dl. 31% had functional class ≥II & 32% had ≥1 sudden cardiac death risk factor. At 5.3 [3–9] years, 139 (18%) met the primary endpoint (107 deaths). On spline analysis, log NT-proBNP ratio >2.75 was associated with higher events. Cox & Kaplan-Meier survival analyses showed that high NT-proBNP ratio was independently associated with events (Figures 1A-B). In the subgroup of asymptomatic patients, NT-proBNP ratio remained associated with the primary outcome (adjusted HR 1.45, 95% CI 1.10–1.93, P=0.009). Conclusions Higher NT-proBNP ratio (>2.75) is independently associated with adverse outcomes in nHCM, including asymptomatic patients, suggesting risk stratification even in earlier disease stages. Funding Acknowledgement Type of funding sources: None.