Cardiac Troponin I Release in Noncoronary Critical Illness Reflects Underlying Myocardial Disease

Cardiac troponin I release is common in the intensive care unit and portends increased short term mortality. We sought to identify factors associated with myocardial injury as evidenced by elevated cardiac troponin I. Forty-nine consecutive patients with respiratory failure not due to coronary ischemia were studied prospectively. Data on various clinical variables were correlated with cardiac troponin I measurements. A separate group with elevated cardiac troponin I during a non-cardiac illness and non-flow limiting coronary disease by angiography was identified retrospectively. Reduced ejection fraction was significantly associated with cardiac troponin I release (p=0.02) as were left ventricular hypertrophy (p=0.03) and hypoxia (p=0.04). The presence of coronary disease, however, was similar in the troponin positive and troponin negative groups. Patients in the retrospective arm all had easily identifiable heart disease with most having elevated left ventricular filling pressure. Non-coronary critical illness commonly produces cardiac troponin I release. Structural myocardial disease is present in nearly all such patients. Increased left ventricular filling pressure may be the underlying factor associated with such myocardial injury.