Prognosis Based on Creatine Kinase Isoenzyme MB, Cardiac Troponin I, and Right Ventricular Size in Stable Patients With Acute Pulmonary Embolism

Prognosis of stable patients with acute pulmonary embolism (PE) has been assessed with cardiac troponin I (cTnI) and right ventricular (RV) function or size. Whether creatine kinase-MB isoenzyme (CK-MB) would add to the prognostic assessment is uncertain. We retrospectively assessed in-hospital mortality from PE in 392 stable patients to test the hypothesis that CK-MB would be of greater prognostic value than cTnI or RV size and we assessed whether combinations would increase prognostic value. CK-MB was high in 29 patients (7.4%); cTnI was high in 76 patients (19%) and intermediate in 78 patients (20%). The right ventricle was dilated in 128 patients (33%). Trends showed highest in-hospital mortality from PE in 4 of 29 (14%) with high CK-MB compared to 6 of 76 (7.9%) with high cTnI and 8 of 128 (6.3%) with RV dilatation (differences NS). High CK-MB and high cTnI provided added prognostic information only in patients with RV dilatation. Mortality with high CK-MB plus RV dilatation (4 of 19, 21%) tended to exceed mortality with high cTnI plus RV dilatation (5 of 39, 13%, NS). When CK-MB and cTnI were high and the right ventricle was dilated, PE mortality tended to be highest (4 of 14, 29%, NS). In conclusion, cardiac biomarkers contributed to prognosis only in patients with RV dilatation. CK-MB was the strongest predictor of death from PE but its prevalence was low, thus limiting its value as a single prognostic indicator. The combination of high CK-MB, high cTnI, and RV dilatation tended to indicate the highest mortality.