Background: Clinicians face uncertainty about the prognostic value of troponin testing in patients with chronic kidney disease (CKD) without suspected acute coronary syndrome (ACS).
Purpose: To systematically review the literature on troponin testing in patients with CKD without ACS.
Data sources: MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials through May 2014.
Study selection: Studies examining elevated versus normal troponin levels in patients with CKD without ACS.
Data extraction: Paired reviewers selected articles for inclusion, extracted data, and graded strength of evidence (SOE). Meta-analyses were conducted when studies had sufficient homogeneity of key variables.
Data synthesis: Ninety-eight studies met inclusion criteria. Elevated troponin levels were associated with all-cause and cardiovascular mortality among patients receiving dialysis (moderate SOE). Pooled hazard ratios (HRs) for all-cause mortality from studies that adjusted for age and coronary artery disease or a risk equivalent were 3.0 (95% CI, 2.4 to 4.3) for troponin T and 2.7 (CI, 1.9 to 4.6) for troponin I. The pooled adjusted HRs for cardiovascular mortality were 3.3 (CI, 1.8 to 5.4) for troponin T and 4.2 (CI, 2.0 to 9.2) for troponin I. Findings were similar for patients with CKD who were not receiving dialysis, but there were fewer studies. No study tested treatment strategies by troponin cut points.
Limitation: Studies were heterogeneous regarding assays, troponin cut points, covariate adjustment, and follow-up.
Conclusion: In patients with CKD without suspected ACS, elevated troponin levels were associated with worse prognosis. Future studies should focus on whether this biomarker is more appropriate than clinical models for reclassifying risk of patients with CKD and whether such classification can help guide treatment in those at highest risk for death.
Primary funding source: Agency for Healthcare Research and Quality.