Chronic Elevation of Troponin I Predicts the Extent of Coronary Artery Disease in Hemodialysis Patients Presenting with Acute Enzyme Elevation

Abstract

Background Chronic elevation of cardiac troponin I (cTn-I) has been associated with severe angiographic coronary artery disease (CAD) in asymptomatic patients with end-stage renal disease (ESRD) on hemodialysis. However, for patients presenting with an acute rise in serum cTn-I levels, the association is less clear. Methods We performed a single-center retrospective analysis of 364 hemodialysis patients. Using coronary angiography, we correlated the asymptomatic baseline elevation of cTn-I with the severity of coronary artery stenosis when hemodialysis patients present with acute symptomatic elevation in serum cTn-I above baseline levels. Results In hemodialysis patients presenting with a rise in serum cTn-I above baseline levels, 59% had severe CAD, and 17% had no angiographic evidence of CAD. Hemodialysis patients with severe CAD had significantly higher baseline cTn-I levels compared to patients with non-severe CAD or normal coronaries (p < 0.0001). Baseline elevation of cTn-I in the severe CAD group was correlated with the degree of CAD occlusion (R2 of 0.56, p < 0.0001), fitting a positive linear model. Furthermore, baseline cTn-I differentiates between patients with and without severe CAD with a test accuracy of 0.72 (95% CI, 0.69–0.75, p < 0.001). At a value of ≥ 0.2 ng/mL (cutoff value for myocardial necrosis), the specificity of baseline cTn-I for underlying severe CAD was 0.95. Conclusions Elevated baseline cTn-I has good accuracy for anticipating more advanced angiographic CAD when hemodialysis patients present with a symptomatic rise in serum cTn-I above baseline levels. Baseline elevation of cTn-I can be used for cardiac disease risk management in hemodialysis patients presenting with symptoms suggestive of CAD.