Combined Measurements of Cardiac Troponin I and Brain Natriuretic Peptide Are Useful for Predicting Adverse Outcomes in Hypertrophic Cardiomyopathy

Abstract

Background: Although serum cardiac troponin I (cTnI) and plasma brain natriuretic peptide (BNP) have become clinically important tools as diagnostic and prognostic markers for ischemic heart disease and heart failure, the usefulness of these biomarkers for risk stratification of hypertrophic cardiomyopathy (HCM) is not clear. Methods and Results: We studied 167 patients with HCM, and cTnI and BNP were measured. During follow-up (38.5 months), 20 patients suffered from cardiovascular events: HCM-related deaths in 6, hospitalization for heart failure in 8, embolic stroke in 5 and 1 patient with spontaneous sustained ventricular tachycardia. Patients with high cTnI values (≥0.04ng/ml) had more frequent cardiovascular events than did those with low cTnI values (P=0.008). Similarly, there were more frequent adverse events in the high BNP group (≥200pg/ml) than in the low BNP group (P=0.002). When groups were allocated according to both cTnI and BNP measurements, serum cTnI used in conjunction with BNP further improved the prognostic value; patients with both high cTnI and BNP values had an 11.7-fold increased risk of cardiovascular events compared with those with both low cTnI and BNP values. Conclusions: CTnI and BNP are useful parameters for identifying patients at risk for clinical deteriorations, and combined measurements of these biomarkers further improves the prognostic value of increased cardiovascular events in HCM. (Circ J 2011; 75: 919-926)