Baseline creatinine level and long-term outcomes in patients with heart failure undergoing cardiac resynchronization therapy

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Renal dysfunction has been shown as an independent predictor of mortality in patients with heart failure (HF). However, data on the long-term outcomes of cardiac resynchronization therapy (CRT) in patients with chronic kidney disease is scarce due to underrepresentation of such patients in clinical trials on CRT. AIM: To determine outcome and mortality predictors in patients with HF and elevated creatinine level treated with cardiac resynchronization therapy. METHODS: Study population consisted of 1059 consecutive patients with CRT implanted between 2002 and 2019 in a tertiary care university hospital, in a densely inhabited, urban region of Poland (949 subjects [89.6%] with CRT-D; 110 patients with CRT-P [10.4%]; 832 men [78.6%]). RESULTS: The median creatinine level before CRT implantation was 96 umol/L (10th and 90th percentile: 67-160). We divided all CRT patients into quartiles per creatinine level: I <79 umol/L, II 79 to less than 96 umol/L, III 96 to less than 118 umol/L, and IV ≥118 umol/L. During the median follow-up of 1661 days (10th and 90th percentile: 323-3995), mortality rates for quartiles I-IV were 36.8, 44.9, 60.1, and 71.7%, respectively (P<0.05) [Figure 1]. The creatinine level ≥118 umol/L (quartile IV) appeared to be an independent risk factor for death (HR 1.004, 95%CI 1.003-1.006, P<0.001). On multivariable analysis, lower left ventricular ejection fraction (HR 0.97, 95%CI 0.95-0.99, P=0.04), higher NT-proBNP level (HR 1.00, 95%CI 1.0001-1.0005, P=0.04), and diabetes treated with insulin (HR 1.64, 95%CI 1.07-2.53, P=0.02) were independent risk factors for death in quartile IV. The mortality rate in those with creatinine level ≥118 umol/L and left ventricular ejection fraction ≤ 20% was 88% during the observation. CONCLUSIONS: Compared to patients without renal dysfunction prior to CRT implantation, mortality rates of those with creatinine level ≥118 umol/L are significantly higher and reach 70% in 4.5 years of median observation. Almost 9 out of 10 CRT recipients with creatinine level ≥118 umol/L and left ventricular ejection fraction ≤ 20% die within 4.5 years since CRT implantation. Figure 1. Kaplan-Meier curves for survival of patients treated with cardiac resynchronization therapy as a function of creatinine level [Figure: see text]