Background: optimal utilization of therapies effective at preventing arrhythmic death but not nonarrhythmic death, for example, the implantable cardioverter-defibrillator (ICD), is challenging in patients with concomitant heart failure (HF) and chronic kidney disease (CKD), given the association of both conditions with competing risks of death.
Objectives: we examined the risk of arrhythmic and nonarrhythmic mortality in patients with different severities of HF and CKD.
Methods: using individual patient data from the SOLVD, we categorized HF by New York Heart Association class and CKD severity by estimated glomerular filtration rate. Cox models with HF and CKD stages as time-dependent covariates were used to calculate hazard ratios for arrhythmic and nonarrhythmic death adjusted for age, gender, and enalapril allocation.
Results: among 6,378 patients without an ICD (age 60 ± 10, left ventricular ejection fraction 27 ± 6, male 86%), there were 421 arrhythmic and 1188 nonarrhythmic deaths over a median follow-up of 34 months. Worse HF or CKD stages were associated with increased risk of both arrhythmic and nonarrhythmic death. The increase in the risk of nonarrhythmic death in the worst HF stage was disproportionately higher than that of arrhythmic death, and this disproportionate effect was more exaggerated in the presence of more advanced CKD.
Conclusion: while advanced CKD and HF stages are associated with increased risk of arrhythmic and nonarrhythmic death, benefits of ICDs in patients with more advanced disease may be limited by the preponderance of nonarrhythmic death.