SAN DIEGO — Statin therapy slashed appropriate implantable cardioverter-defibrillator shocks by 54% and all-cause mortality by 95% in a nonrandomized observational study of patients with advanced heart failure on combined ICD and cardiac resynchronization therapy.
The clinical implication of these findings is that patients with heart failure treated with combined ICD and CRT ought to be placed on a statin, whether they're dyslipidemic or not, according to Dr. Harit Desai of New York Medical College, Valhalla.
The study involved 209 heart failure patients who received dual device therapy based on the current indications. During a mean 35 months of follow-up, appropriate ICD shocks occurred in 18% of the 122 patients on statin therapy and in 34% of those who were not on statins, Dr. Desai reported at the annual meeting of the American College of Chest Physicians.
Death occurred in 2% of the group on statin therapy, compared with 10% of those who weren't. Two-thirds of patients not on a statin were dyslipidemic.
The use of beta-blockers and amiodarone was similar in the statin users and nonusers. However, angiotensin-converting enzyme or angiotensin receptor blocker therapy was significantly more common in the statin-treated group, by a margin of 75%-63%.
In a stepwise Cox regression analysis adjusted for potential confounding variables, the three factors associated with the rate of appropriate ICD shocks were statin therapy, which reduced the rate by 54%; diabetes, which reduced appropriate shocks by 66%; and smoking, which increased the likelihood of appropriate shocks 3.5-fold.
Diabetes was independently associated with a 4.3-fold risk of all-cause mortality during the follow-up period. Hypertension conferred a 14.2-fold risk. Digoxin therapy was associated with a 4.2-fold risk of mortality.
The mechanism by which statin therapy protects against appropriate ICD shocks is unclear but does not appear to involve lipid lowering.
Dr. Desai reported having no financial conflicts in connection with this study.