High-Sensitivity Troponin for Suspected Acute Coronary Syndrome in Patients With Chronic Kidney Disease Versus Patients Without Chronic Kidney Disease

BACKGROUND: Heart disease is the leading cause of death in the United States. Patients with acute coronary syndrome (ACS) who have chronic kidney disease (CKD) have a twofold increase in mortality compared to patients with normal kidney function. Patients with CKD tend to have elevated baseline high-sensitivity cardiac troponin-T (hs-cTnT) levels. We studied patients with or without CKD to find out if a higher baseline hs-cTnT influenced the change in hs-cTnT (delta) when ruling in or ruling out ACS. METHODS: Eighty-nine patients were included in this study (29 with CKD; 60 without CKD). Delta hs-cTnT was dichotomized based on those who had delta of ≥ 5, or < 5. We calculated the positive predictive values, negative predictive values, sensitivities and specificities. Shapiro-Wilk test and independent t-test were used for the continuous variables. Mann-Whitney U test was used to examine the variables between the two groups. Chi-square test was used to compare the categorical variables between the two groups. RESULTS: The mean ages of patients with CKD and without CKD were 61.2 and 58.9 years, respectively (P = 0.508). We found that although there were differences in the sensitivities, specificities, positive predictive values and negative predictive values of delta hs-cTnT > 5 for ACS between the patients with CKD and without CKD, the differences were not statistically significant. Subgroup analysis showed that in patients with CKD, the positive predictive values and sensitivities of delta hs-cTnT > 5 for CAD requiring percutaneous coronary intervention (PCI) and stent were significantly higher compared to the patients without CKD (82.4% vs. 27.3%, and 82.4% vs. 40.0%, respectively) (P < 0.05). CONCLUSIONS: In calculating delta hs-cTnT to rule in or rule out ACS, the presence of CKD does not influence the delta. Patients with CKD and a delta hs-cTnT > 5 have significantly higher risk of undergoing PCI.