Patients with unstable angina or non ST-segment elevation myocardial infarction (NSTEMI) may be four times more likely to suffer advanced heart failure (HF) if their plasma troponin T (TnT) levels are high, report researchers at the Heart Failure 2002 meeting in Oslo, Norway.
Although TnT levels are already useful predictors of outcome in these patients, little is known about their ability to predict the development of heart failure.
To investigate further, Antonio Salvador, and colleagues from Hospital Universitario Dr Peset in Valencia, Spain, examined whether elevated TnT concentrations during an acute episode of unstable angina or NSTEMI related to the subsequent development of New York Heart Association (NYHA) class III or IV HF.
TnT levels were measured in 352 patients between five and 24 hours after they were admitted to hospital with a suspected acute coronary syndrome (ACS), with Q-wave MI patients excluded from the study.
Based on these measurements, patients were divided into two groups; TnT+ patients (n=135) had TnT levels equal to or above 0.1 ng/ml, while TnT- patients (n=217) had levels below 0.1 ng/ml.
After three months, patients were followed up by telephone or personal interview, or information from relatives was obtained. Those who had signs or symptoms of advanced HF were then invited into hospital for further examination.
The researchers found that 8.1% of TnT+ patients had developed NYHA III or IV HF, compared with just 2.3% of TnT- patients, giving an odds ratio of 3.76 (p<0.03). Altogether, 5.9% of TnT+ patients developed NYHA IV HF, compared with 0.9% of TnT- patients, giving an odds ratio of 6.77 (0<0.02).
Three patients died of class IV HF, all in the TnT+ group.
Explaining the results, Salvador told InCirculation.net: 'Troponin T levels relate with microvascular thrombosis and consecutive cell death. Some of the clinic implications from this could be increased MI and more HF.'
He added that this study is part of a larger investigation into the predictive prognostic power of TnT in these ACS patients.