High-sensitivity cardiac troponin I and risk of heart failure in patients with suspected acute coronary syndrome: a cohort study

Abstract

Aims: Heart failure may occur following acute myocardial infarction, but with the use of high-sensitivity cardiac troponin assays we increasingly diagnose patients with minor myocardial injury. Whether troponin concentrations remain a useful predictor of heart failure in patients with acute coronary syndrome is uncertain.

Methods and results: We identified all consecutive patients (n = 4748) with suspected acute coronary syndrome (61 ± 16 years, 57% male) presenting to three secondary and tertiary care hospitals. Cox-regression models were used to evaluate the association between high-sensitivity cardiac troponin I concentration and subsequent heart failure hospitalization. C-statistics were estimated to evaluate the predictive value of troponin for heart failure hospitalization. Over 2071 years of follow-up there were 83 heart failure hospitalizations. Patients with troponin concentrations above the upper reference limit (URL) were more likely to be hospitalized with heart failure than patients below the URL (118/1000 vs. 17/1000 person years, adjusted hazard ratio: 7.0). Among patients with troponin concentrations <URL the rate of heart failure hospitalization was 2.80-fold higher [95% confidence interval (95% CI 1.81-4.31)] per doubling of troponin concentration. On adding troponin to a model with demographic, cardiovascular risk factor, and clinical variables, the prediction of heart failure hospitalization improved considerably (C-statistic 0.80 vs. 0.86, P < 0.001).

Conclusion: Cardiac troponin is an excellent predictor of heart failure hospitalization in patients with suspected acute coronary syndrome. The strongest associations were observed in patients with troponin concentrations in the normal reference range, in whom high-sensitivity cardiac troponin assays identify those at increased risk of heart failure who may benefit from further investigation and treatment.

Keywords: Acute coronary syndrome; Heart failure; High-sensitivity cardiac troponin.

Figure 1

Association between peak cardiac troponin concentration and time to first event for heart failure hospitalization, and heart failure hospitalization or cardiac death. Departures from linearity were explored using penalized spline smoothing functions (grey band). The association was also analysed after stratifying patients into those with a peak troponin concentration less than the upper reference limit (URL) (red line), and those with troponin concentrations above the URL, with a specific index diagnosis (type 1 myocardial infarction, green line; type 2 myocardial infarction, blue; myocardial injury, purple).