Abstract 4056: Elevated Troponins in Heart Failure Patients: Is there an Association with Kidney Function?
Background. Cardiac troponin Ts (cTnT) are often increased in asymptomatic patients with end-stage renal disease and are predictors of higher mortality. This increase in cTnT is likely related to left ventricular hypertrophy and the release of cTnT from failing myocytes. Whether the elevation of cTnT is correlated to a decrease in kidney function in patients with heart failure is unknown.
Methods. We examined the association between cTnT and glomerular filtration rate (GFR) in all patients hospitalized with a diagnostic of heart failure between 2004 and 2005. Of 1042 observations, 541 had complete records for cTnT, serum creatinine, clinical and demographic variables. GFR was estimated with the Modification of Diet in Renal Disease equation. Chronic kidney disease (CKD) was defined as GFR<60/mL/min/1.73m2. Hematocrit<30% was a marker of anemia. Non-parametric tests were used because the distribution of cTnT was highly skewed. Logistic regression was used to estimate the association between cTnT≥0.1 ng/mL (dependent variable) and GFR after adjusting for age, race, sex, diabetes (DM), hypertension (HTN), anemia.
Results. Among the 541 patients, 22.2% were blacks, 50.1% males, 45.1% had DM, 47.3% HTN, 31.0% had cTnT≥0.1, 70.0% CKD,10.4% anemia. The population characteristics according to GFR are described below. The Spearman correlation between cTnT and GFR was significant (p<0.0001 r = −0.189). Compared to GFR≥ 60, and after adjusting for the covariates, patients with GFR < 30 were more likely to have high cTnT (Odds ratio (OR) = 1.92, 95% Confidence Interval (CI)= 1.15–3.19). This association was not significant in patients with GFR 30 to 60 (OR=1.05, 95% CI= 0.66–1.66). None of the other covariates were significant predictors of high cTnT except DM (OR=1.55, 95% CI=1.05–2.28).
Conclusion. These results confirm the hypothesis that cTnT concentration is related to GFR levels. The mechanism, abnormal cTnT renal clearance or elevated cTnT leakage, should be explored.