PURPOSE: Elevation of cardiac troponin I (TnI) is a common finding in the intensive care unit (ICU). While these elevations reflect myocardial necrosis, the correlation with significant obstructive coronary artery disease (CAD) in this patient population remains unclear.The purpose of this study is to describe the incidence and time to diagnostic evaluation for obstructive CAD in patients with modest TnI elevation (peak between 0.4–10 ng/dL) admitted to ICUs for both cardiac and non-cardiac causes.
METHODS: Retrospective analysis of patients admitted to adult ICUs with modest TnI elevation between July and December 2005.
RESULTS: 177/829 (21%) patients were identified with peak TnI between 0.4-10 ng/dL. 54/177 patients (31%) were admitted with a primary cardiac diagnosis (group 1) and 123/177 patients (69%) with a non-cardiac diagnosis (group 2). 46/54 of patients (85%) in group 1 as opposed to 17/123 (14%) in group 2 had work-up for CAD (p < 0.001). Obstructive CAD was 82% (38/46) in group 1 and 29% (5/17) in group 2 (P<0.001). In-hospital mortality was 11% and 34% in group 1 and group 2, respectively (p<0.01). The percentage of patients with work up for obstructive CAD within 24 hrs was 70% vs 35% in group 1 and group 2, respectively (p < 0.05).Comparison of different relevant variables between the 2 groups is shown in Table 1.
CONCLUSION: Though the incidence of obstructive CAD is higher in patients admitted with cardiac diagnoses and modest TnI elevation, patients with non-cardiac diagnoses and modest TnI elevation admitted to ICU have a higher mortality. The true incidence of obstructive CAD in this patient population remains unclear, largely because of lack of available accurate bedside techniques. Bedside stress myocardial contrast echocardiography can be broadly applied to all patients and may lead to an earlier diagnosis and treatment.
CLINICAL IMPLICATIONS: Modest TnI elevation in ICU patients with non-cardiac diagnosis has serious implications and should be taken seriously. Timely and proper diagnostic work for obstructive CAD should be done in this patient population as well.
DISCLOSURE: Ather Anis, None.