Importance of myocardial ischemia detected with protocol-based measurements of high-sensitivity troponin, ECG and echocardiography in critically ill patients without acute coronary syndrome—a prospective study

Abstract

Elevated cardiac troponin is detected in the majority of critically ill patients. This study aimed to evaluate the prognostic value of protocol-guided detection of myocardial ischemia (MI) (serial 12-lead electrocardiograms (ECG), high-sensitivity troponin T (hsTnT) measurements, and echocardiography) and compare it with a retrospective cohort with only clinically driven detection of MI. In a prospective observational study, 95 patients hospitalized ≥48 hours for reasons other than acute coronary syndrome in medical or surgical intensive-care unit (ICU) were enrolled. A protocol-based approach, with regular 12-lead ECG recordings, hsTnT measurements and admission echocardiography was conducted. All events possibly indicating MI were documented, and ECG, hsTnT, echocardiography were repeated. The protocol-based approach was compared to a retrospective group with only clinically driven detection of MI. In the prospective group, 95.8% of patients had at least one elevated hsTnT value. A hsTnT ＞70 ng/L was associated with the use of inotropes (OR 3.35 (95% CI: 1.184, 9.472), p = 0.022), left ventricular ejection fraction <30% (OR 9.65 (95% CI: 1.172, 76.620), p = 0.035), regional wall motion abnormalities (OR 3.87 (95% CI: 1.032, 14.533), p = 0.045), ICU mortality (OR 8.38 (95% CI: 1.004, 69.924), p = 0.0495), hospital mortality (OR 3.05 (95% CI: 1.133, 8.230), p = 0.027) and 1-year mortality (OR: 5.43 (95% CI: 2.1099, 13.971), p = 0.005). The incidence of MI was higher in the prospective, as compared to the retrospective group (22.1% vs 5.3%; p = 0.001). MI, compared to the high “hsTnT positive only” group, predicted hospital mortality (OR 3.33 (95% CI: 1.190, 9.329), p = 0.02) and 1-year mortality (OR 4.66 (95% CI: 1.647, 13.222), p = 0.0037). A protocol-based compared to a clinically driven approach for the detection of MI reveals more patients with MI. The majority of critically ill patients have elevated hsTnT levels. Detected MI additionally stratifies patients with elevated hsTnT to higher hospital and 1-year mortality.