Ongoing myocardial injury in stable severe heart failure -: Value of cardiac troponin T monitoring for high-risk patient identification

Background - The progression of chronic heart failure (CHF) is related to ongoing myocyte loss, which can be detected by cardiac troponin T (cTnT). We examined the prevalence and prognostic value of increased cTnT concentrations in serial blood specimens from patients with severe CHF. Methods and Results - Clinical, echocardiographic, and 6-minute walk test data were collected prospectively at baseline and at 1 year in 115 outpatients ( mean age, 61 +/- 11 years; 75% men; 62% coronary heart disease) with CHF and a left ventricular ejection fraction < 40%. Blood samples were collected at baseline and at 3, 6, and 12 months of follow-up. cTnT concentrations ≥ 0.02 ng/mL were considered abnormal, and a Tn index ( highest cTnT measurement/0.02 ng/mL) was calculated. In 62 patients (54%), cTnT was consistently <0.02 ng/mL (group 1); 28 (24%) had a single abnormal cTnT result (group 2); and 25 (22%) had greater than or equal to2 abnormal cTnT results ( group 3). At 18 months, CHF hospitalization-free survival was 63%, 46%, and 17%, respectively ( P = 0.0001). In a Cox proportional-hazards model, hospitalization for worsening CHF in the previous year (HR = 2.1; 95% CI, 1.1 to 4.1), functional class III - IV ( HR = 2.3; 95% CI, 1.1 to 4.6), and number of abnormal cTnT samples ( HR = 1.6; 95% CI, 1.1 to 2.4) were independently associated with prognosis. A cTnT rise of 0.020 ng/mL in any sample was associated with an excess of 9% ( 95% CI, 1% to 18%) in the incidence of combined end point. Conclusions - Abnormal cTnT concentrations were detected in > 50% of outpatients with advanced CHF. This ongoing myocardial necrosis was a strong predictor of worsening CHF, suggesting a role of cTnT-based monitoring to identify high-risk patients.