CTO linked to ventricular arrhythmia recurrence in patients with ICDs
Coronary chronic total occlusion was associated with higher risk for ventricular arrhythmia recurrence among patients who received an implantable cardioverter defibrillator for secondary prevention of sudden cardiac death, according to published findings.
The long-term follow-up of the VACTO secondary study, published in JACC: Cardiovascular Interventions, suggested that angiographic and ventricular arrhythmia patterns may affect future interventions designed to reduce ICD shocks in patients in high-risk populations.
“Despite the survival benefit conferred by ICD, appropriate and inappropriate shocks have a negative impact on prognosis and may impair quality of life, causing significant psychological effects,” Luis Nombela-Franco, MD, PhD, from the Cardiovascular Institute at Hospital Universitario Clinico San Carlos, Madrid, and colleagues wrote. “Thus, it is of utmost importance to determine predictors of ICD to the baseline cardiac disease.”
Researchers enrolled 425 patients across eight centers who had survived a ventricular arrhythmia occurrence and had ICD implantation for secondary prevention. Specifically, researchers monitored and analyzed coronary angiogram, CTO angiogram characteristics and ventricular arrhythmia pattern.
The primary and secondary endpoints of the study were appropriate ICD therapies and mortality, respectively, during a follow-up of 4.1 years, stratified by presence of CTO at baseline angiogram.
The study showed that patients with CTO had a higher rate of appropriate ICD therapies (51.7% vs. 36.3%; P = .001 at 4 years).
Appropriate ICD therapy was independently predicted by left ventricular ejection fraction (P = .015) and CTO (P = .001).
Ventricular arrhythmia onset was associated with shorter coupling interval and lower prematurity index in patients with CTO.
Defibrillator therapies were linked to worse LVEF (P = .046) and renal dysfunction (P = .023) among patients with CTO.
The data showed a higher mortality rate among patients with poorer renal function (P = .029), worse LVEF (P = .041) and CTO (P = .033).
In a related editorial, Vasim Farooq, MBChB, PhD, from the department of cardiology at St. Georges University Hospital in London, and Patrick W. Serruys, MD, PhD, emeritus professor of cardiology at the University of Rotterdam in the Netherlands, wrote that the most important finding “is the apparent independent association of CTOs with life-threatening arrhythmias in patients with ischemic cardiomyopathy, with the suggestion that maintaining the viability of myocardial territories through collateral vessels is insufficient, and that untreated CTOs may actually fuel ischemia-driven malignant arrhythmias and ultimately have an adverse impact on long-term mortality.”
“If future trials targeted these high-risk patients, then perhaps one day, we may show the potential prognostic impact of CTO revascularization in appropriately selected patients,” they wrote. – by Dave Quaile
Disclosure: Farooq, Nombela-Franco and Serruys report no relevant financial disclosures. One researcher reports serving on steering committees or advisory boards for Boston Scientific, Medtronic, Sorin and St. Jude Medical.