Risk vs Benefit of Atrial Fibrillation Ablation Procedures
Abstract & Commentary
By John P. DiMarco, MD, PhD, Professor of Medicine, Division of Cardiology, University of Virginia, Charlottesville. Dr. DiMarco does research for Medtronic, is a consultant for Medtronic, Novartis, and St. Jude, and is a speaker for Boston Scientific.
Source: Shah RU, et al. Procedural complications, rehospitalizations, and repeat procedures after catheter ablation for atrial fibrillation. J Am Coll Cardiol 2012;59:143-149.
Shah et al used an administrative database, the California State Inpatient Database from the Healthcare Utilization Project, to analyze the short and intermediate success and complication rates associated with catheter ablation for atrial fibrillation (AF). The authors identified patients who underwent an initial AF ablation in California between January 1, 2005, and November 31, 2008. Search methods identified patients who underwent ablation for only AF and excluded patients having other electrophysiologic procedures. Comorbidities were identified through the database. Acute procedural complications were also obtained from the database and included: cardiac perforation and/or tamponade, pneumothorax, hemothorax, procedure-related stroke, transient ischemic attack, vascular access complications, and in-hospital death. Thirty-day and long-term rehospitalization rates were also identified.
During the 4-year study period, the authors identified 4156 patients who received an initial ablation for AF in the state of California. There was a steady increase in the number of initial procedures annually, with 684 cases in 2005 and 1332 in 2008. AF ablations were performed in 98 unique hospitals with a mean annual volume of 15.4 throughout the study. The mean patient age was 61.7 years, with hypertension (50.3%) and coronary artery disease (14.7%) the most common cardiac diagnoses. Only a minority of patients (20.9%) had been hospitalized with a primary diagnosis of AF during the year before ablation. The mean observation time from the initial ablation to the close of the study was 1.5 years.
During the initial hospitalization, complications were noted after 5.1% of AF ablations. The complication rate was constant during the course of the study. More than half of the complications were vascular. There was, however, only one death. In addition to these early complications, 9.4% of patients discharged were rehospitalized within 30 days after discharge. Recurrent atrial arrhythmias and late procedural complications accounted for 47% of these repeat admissions. The risk of an inpatient complication or 30-day rehospitalization was associated with the following: increased age; female gender; primary payer (Medicare vs private insurance); a history of heart failure, hypertension, renal, or lung disease; the prior number of AF hospitalizations; and hospital AF ablation volume. The latter was a strong predictor of rehospitalization with a 50% increase in the odds of complication or rehospitalization in hospitals in the lowest frequency quartile compared to those in the highest frequency quartile. After 30 days, rehospitalizations continued to be frequent. At 1 year, 39% of the patients had been rehospitalized at least once and 22% of patients had been hospitalized for either recurrent arrhythmia or a repeat ablation. Repeat ablations were performed in 17.4% of the study group with most receiving a single additional procedure.
The authors conclude that during the period of study, AF ablation procedures had only modest efficacy with a significant risk for complications and need for rehospitalization.
AF ablation is now one of the more common procedures performed by electrophysiologists. Evaluating the efficacy of AF ablation has been difficult. If one uses the criterion of no detectable AF off all antiarrhythmic therapy during intensive periodic monitoring, single procedure success rates are less than 65% for patients with paroxysmal AF and less than 50% for patients with persistent AF, even in experienced centers. This paper suggests that the success rates may be even lower in general practice. AF is usually managed on an outpatient basis and this report only captured recurrences if they resulted in hospitalization or a repeat ablation procedure. The observation that success rates were higher and complication rates lower in higher volume centers is also important, although not surprising. AF ablation techniques continue to evolve and only centers and operators who do enough procedures to remain current are likely to have the best outcomes.