Patients Treated with Catheter Ablation for Atrial Fibrillation Have Long-Term Rates of Death, Stroke, and Dementia Similar to Patients Without Atrial Fibrillation

Cryoballoon ablation for atrial fibrillation

Focal point-by-point radiofrequency catheter ablation has shown considerable success in the treatment of paroxysmal atrial fibrillation. However, it is not without limitations. Recent clinical and preclinical studies have demonstrated that cryothermal ablation using a balloon catheter (Artic Front©, Medtronic CryoCath LP) provides an effective alternative strategy to treating atrial fibrillation. The objective of this article is to review efficacy and safety data surrounding cryoballoon ablation for paroxysmal and persistent atrial fibrillation. In addition, a practical step-by-step approach to cryoballoon ablation is presented, while highlighting relevant literature regarding: 1) the rationale for adjunctive imaging, 2) selection of an appropriate cryoballoon size, 3) predictors of efficacy, 4) advanced trouble-shooting techniques, and 5) strategies to reduce procedural complications, such as phrenic nerve palsy.

Health Outcomes With Catheter Ablation or Antiarrhythmic Drug Therapy in Atrial Fibrillation

Background—

Patients with atrial fibrillation (AF) face significant risks of stroke and heart failure. The objective of this study was to determine whether AF ablation reduces the long-term risk of stroke or heart failure compared with antiarrhythmic drug therapy.

Methods and Results—

A coding algorithm was used to identify AF patients treated with catheter ablation (n=3194) or antiarrhythmic drugs without ablation (n=6028) between 2005 and 2009 using The MarketScan Research Database from Thomson Reuters From this sample, 801 pairs were propensity matched, based on 15 demographic and clinical characteristics and baseline medication use. Rates of stroke/transient ischemic attack (TIA) and heart failure hospitalizations for up to 3 years were examined. Patients treated with catheter ablation had a significantly lower rate of stroke or TIA (3.4% per year) than a group of patients with AF managed with antiarrhythmic drugs only (5.5% per year), with an unadjusted hazard ratio of 0.62 (95% CI, 0.44–0.86; P =0.005). The rates for heart failure hospitalization were 1.5% per year in the ablation group and 2.2% per year in the antiarrhythmic drug group, with an unadjusted hazard ratio of 0.69 (95% CI, 0.42–1.15; P =0.158). These results were minimally altered in Cox proportional hazards models, which further adjusted for potential confounders not well balanced by the propensity matching.

Conclusions—

In a large propensity-matched community sample, AF ablation was associated with a reduced risk of stroke/TIA and no significant difference in heart failure hospitalizations compared with antiarrhythmic drug therapy. These findings require confirmation with randomized study designs.

Atrial fibrillation and risk of dementia: a prospective cohort study

OBJECTIVES

To determine whether atrial fibrillation (AF) is associated with risk of incident dementia or Alzheimer's disease (AD), beyond its effect on stroke.

DESIGN

Prospective cohort study.

SETTING

An integrated healthcare delivery system.

PARTICIPANTS

A population-based sample of 3,045 community-dwelling adults aged 65 and older without dementia or clinical stroke followed from 1994 to 2008.

MEASUREMENTS

AF was identified from health plan electronic data using International Classification of Diseases, Ninth Revision, codes from inpatient and outpatient encounters. Covariates came from self-report, study measures, and health plan data. Participants were screened every 2 years using the Cognitive Abilities Screening Instrument (range 0-100), with detailed neuropsychological and clinical assessment of those scoring less than 86. A multidisciplinary consensus committee determined diagnoses of all-cause dementia and possible or probable AD using standard research criteria.

RESULTS

AF was present in 132 (4.3%) participants at baseline and was diagnosed in 370 (12.2%) more over a mean of 6.8 years of follow-up; 572 participants (18.8%) developed dementia (449 with AD). The adjusted hazard ratio associated with AF was 1.38 (95% confidence interval (CI)=1.10-1.73) for all-cause dementia and 1.50 (95% CI=1.16-1.94) for possible or probable AD. Results were similar for participants with and without clinically recognized stroke during follow-up and in sensitivity analyses examining only probable AD.

CONCLUSION

AF is associated with higher risk of developing AD and dementia. Future studies should examine whether specific treatments, including optimal anticoagulation, can decrease this risk.