Background: The significance of troponin I (TnI) elevations in patients with renal failure (RF) admitted for possible myocardial ischemia is unclear. We therefore compared outcomes in patients with and without TnI elevations based on renal function.
Methods: Consecutive patients without ST elevation admitted for exclusion of ischemia underwent serial assessment of cardiac markers including TnI. Coronary angiography, significant disease, and revascularization were determined, and 1-year cardiac mortality and all-cause mortality were assessed. Mortality was assessed based on TnI elevations in patients with no (creatinine clearance [CrCl] > or = 60 mL/min), moderate (CrCl 30-59 mL/min), and severe (CrCl < 30 mL/min) RF.
Results: Troponin I elevations were present in 17% of the 3774 consecutive patients and were significantly more frequent in patients with RF (CrCl < 30 mL/min: 26%; CrCl 30-59 mL/min: 19%; CrCl > 60 mL/min: 13%, all P < or = .01). Coronary angiography was performed significantly less frequently in patients with RF, whether TnI elevations were present. One-year all-cause mortality increased with both RF and TnI positivity (TnI [+] vs TnI [-], CrCl < 30 mL/min: 52% vs 26%; CrCl 30-59 mL/min: 21% vs 14%; CrCl > 60 mL/min: 8.9% vs 4.9%, all P < .001) . Troponin I was the most important independent predictor of mortality in the 3 RF groups (odds ratio 3.3 for CrCl < 30 mL/min, 2.2 for CrCl 30-59 mL/min, and 3.3 for CrCl > 60 mL/min).
Conclusions: Troponin I elevations identified a high-risk cohort, and its prognostic value was not diminished in patients with RF.