Profiles of serial changes in cardiac troponin T concentrations and outcome in ambulatory patients with chronic heart failure.

OBJECTIVES: The purpose of this study was to determine whether different profiles of cardiac troponin T (cTnT) values assessed over time would yield incremental prognostic information on clinically stable outpatients with heart failure (HF).
BACKGROUND: cTnT levels were used to estimate prognosis in HF; however, most studies evaluated hospitalized patients using single measurements.
METHODS: A cohort of 172 New York Heart Association functional class III to IV outpatients was prospectively studied with serial cTnT measurements collected every 3 months over a 2-year period. The primary end point was death or cardiac transplantation, and secondary end points included HF hospitalization.
RESULTS: Of the 172 patients, 22 (13%) died or underwent transplantation during the first year. Therefore, 150 patients were included in the second-year analysis of 3 pre-determined groups: 1) no serial cTnT elevations (defined as <0.01 ng/ml); 2) 1 or more, but not all cTnT values elevated > or =0.01 ng/ml; and 3) all cTnT values elevated during the first year. During the second year, 30 events occurred: 53 patients had persistently normal cTnT levels (<0.01 ng/ml) with 6 primary events (11%); 57 patients had 1 or more but not all cTnT levels elevated with 11 events (19%); 40 patients demonstrated persistently elevated cTnT levels with 13 (33%) primary events (odds ratio: 3.77; 95% confidence interval: 1.28 to 11.07, p = 0.02).
CONCLUSIONS: Elevations in cTnT, even using a low threshold of 0.01 ng/ml, detected during routine clinical follow-up of ambulatory patients with HF, are highly associated with an increased risk of events, particularly with frequent or persistent cTnT elevations of > or =0.01 ng/ml. Therefore, the ability to monitor clinical change through serial cTnT measurements may add to risk assessment in the ambulatory HF population.