Study objectives: The purpose of this study was to quantify the impact of baseline renal dysfunction on incidence and occurrence of cardiac arrhythmias in the coronary ICU.
Background: Renal dysfunction is an established predictor of all-cause mortality in the ICU setting. We set out to evaluate the independent contributory effect of renal dysfunction to arrhythmias and mortality in this population.
Design and setting: We analyzed a prospective coronary care unit registry of 12,648 admissions by 9,557 patients over 8 years at a single, tertiary center. An admission serum creatinine level was available for 9,544 patients. Those patients not receiving long-term dialysis were classified into quartiles of corrected creatinine clearance with cutpoints of 46.2 mL/min/72 kg (group 1), 63.1 mL/min/72 kg, and 81.5 mL/min/72 kg. Dialysis patients (n = 527) were considered as a fifth comparison group (group 5).
Measurements and results: Baseline characteristics including older age, African-American race, diabetes, hypertension, history of previous coronary disease, and heart failure were incrementally more common with increasing renal dysfunction strata. There were graded, independent increased risks for accelerated idioventricular rhythm (relative risk [RR], 2.43; 95% confidence interval [CI], 1.40 to 4.20; p = 0.002), sustained ventricular tachycardia (RR, 2.07; 95% CI, 1.02 to 4.22; p = 0.04), ventricular fibrillation (RR, 2.42; 95% CI, 1.13 to 5.15; p = 0.02), and complete heart block (RR, 3.64; 95% CI, 1.77 to 7.48; p = 0.0004, group 5 vs group 1).
Conclusions: We conclude that baseline renal function is a powerful, independent predictor of cardiac arrhythmias in the coronary ICU population.