External cardioversion of atrial fibrillation and flutter in patients with cardiac implantable electrical devices.

BACKGROUND: Atrial fibrillation and flutter are often treated with external electrical cardioversion (ECV) in patients with potentially electrically sensitive cardiovascular implantable electronic devices (CIED). Long-term follow-up data on contemporary CIED undergoing ECV is sparse. The aim is to investigate shock-related complications and impact on CIEDs. METHODS: All ECV procedures from 2010 to 2020 in patients with CIED performed at a tertiary university hospital were identified in the Danish National Patient Registry. Changes in device measurements after ECV were retrospectively studied and procedure-related complications were identified by review of medical records. RESULTS: We analyzed 763 ECV procedures in 372 patients, median device implant time 1.9 years. The mean age of patients was 69.9 ± 9.9 years of which 73.4% were men. We identified two cases of device programming changes and four cases of premature battery depletion (≤3 years after device implant). Minor changes in device measurements were found for impedances, sensing, and pacing thresholds. No patients died due to ECV-related device dysfunctions within the first 12 months after cardioversions. CONCLUSION: External cardioversion in patients with contemporary pacemakers and implantable cardioverter-defibrillators seems safe in the majority of patients. Clinically important changes in device function following cardioversion were rarely observed but may be critical for device function. In an observational study, causality between cardioversion and device dysfunction cannot be established. For patient safety, we suggest that routine device interrogation after cardioversion still should be part of standard care.

Long-term risk of cardiovascular implantable electronic device reinterventions following external cardioversion of atrial fibrillation and flutter: A nationwide cohort study.

BACKGROUND: External cardioversion (ECV) is an essential part of rhythm control of atrial fibrillation and flutter in patients with and without cardiovascular implantable electronic devices (CIEDs). Long-term follow-up data on ECV-related CIED dysfunctions are limited. OBJECTIVE: The purpose of this study was to investigate the risk of CIED reintervention following ECV in a nationwide cohort. METHODS: We identified CIED implants and surgical reinterventions from 2005 to 2021 in the Danish Pacemaker and ICD Register. We included CIED patients undergoing ECV from 2010 to 2019 from the Danish National Patient Registry. For each ECV-exposed generator, 5 matched generators without ECV were identified, and for each ECV-exposed lead, 3 matched leads were identified. The primary endpoints were generator replacement and lead reintervention. RESULTS: We compared 2582 ECV-exposed patients with 12,910 matched patients with a pacemaker (47%), implantable cardioverter-defibrillator (ICD) (29%), cardiac resynchronization therapy-pacemaker (6%), or cardiac resynchronization therapy-defibrillator (18%). During 2 years of follow-up, 210 ECV-exposed generators (8.1%) vs 670 matched generators (5.2%) underwent replacements, and 247 ECV-exposed leads (5.6%) vs 306 matched leads (2.3%) underwent reintervention. Unadjusted hazard ratios were 1.61 (95% confidence interval [CI] 1.37-1.91; P <.001) for generator replacement and 2.39 (95% CI 2.01-2.85; P <.001) for lead reintervention. One-year relative risks were 1.73 (95% CI 1.41-2.12; P <.001) for generator replacement and 2.85 (95% CI 2.32-3.51; P <.001) for lead reintervention, and 2-year relative risks were 1.39 (95% CI 1.19-1.63; P <.001) and 2.18 (95% CI 1.84-2.57; P <.001), respectively. CONCLUSION: ECV in patients with a CIED is associated with a higher risk of generator replacement and lead reintervention. The risks of reinterventions were more pronounced within the first year after cardioversion.

Patterns of adipose tissue fatty acids and the risk of atrial fibrillation: A case-cohort study.

Fatty acids in adipose tissue share dietary sources and metabolic pathways and therefore occur in patterns. The aim of the present study was to investigate the association between adipose tissue fatty acid patterns identified by the data-driven dimension-reducing method treelet transform and the risk of atrial fibrillation. A total of 57,053 Danish men and women aged 50-64 years participating in the Diet, Cancer and Health cohort had an adipose tissue biopsy taken at baseline. During a median follow-up of 14.6 years, a total of 4,710 participants developed atrial fibrillation or atrial flutter. Adipose tissue biopsies were analysed for fatty acid content by gas chromatography for all cases of atrial fibrillation and for a randomly drawn subcohort (n = 3,500) representative for the entire cohort. Hazard ratios with 95% confidence intervals for atrial fibrillation according to quintiles of factor scores were determined by weighted Cox proportional hazards regression analyses for men and women separately. From the 32 fatty acids measured, 7 major factors/patterns of fatty acids were identified using treelet transform. We found that a pattern consisting of n-6 polyunsaturated fatty acids (PUFA) (except linoleic acid) was associated with a lower hazard of atrial fibrillation. Patterns consisting of marine n-3 PUFA and containing n-9 fatty acids were associated with a lower hazard of atrial fibrillation in women. In conclusion, patterns of fatty acids in adipose tissue identified by treelet transform may be differentially associated with the risk of atrial fibrillation.

Effect of Dietary Intake of Saturated Fatty Acids on the Development of Atrial Fibrillation and the Effect of Replacement of Saturated With Monounsaturated and Polyunsaturated Fatty Acids.

The aim of the present study was to explore substitution of intake of saturated fatty acids (FAs) with monounsaturated and polyunsaturated FAs and incident atrial fibrillation (AF) in men and women. A total of 57,053 Danish participants aged 50 to 64 years were enrolled in the Diet, Cancer and Health cohort study in 1993 to 1997 and completed a semiquantitative food frequency questionnaire at baseline. Follow-up was registry-based and data were analyzed using Cox proportional hazards regression. The statistical model was formulated in such a way that 1 g/day of saturated FAs was replaced with 1 g/day of monounsaturated or polyunsaturated FAs while keeping total fat intake, total energy intake, and energy intake from protein and carbohydrates constant. During a median follow-up of 17 years, 5,175 incident cases of AF occurred. In men, there was a higher hazard of AF when total n-3 polyunsaturated FAs replaced dietary saturated FAs-hazard ratio per 1-g substitution of FAs of 1.08 (95% confidence interval 1.02 to 1.14) in a model adjusted for lifestyle factors. For other substitutions of FAs (monounsaturated, total or n-6 polyunsaturated FAs), no consistent nor statistically significant associations were found. In conclusion, we found a moderately higher risk of AF in men, but not in women, when total n-3 polyunsaturated FAs replaced dietary saturated FAs. Substitution of saturated FAs with monounsaturated, total or n-6 polyunsaturated FAs was not associated with the risk of AF.