Background
We evaluated scar lesions following initial and repeat catheter ablation of atrial fibrillation (AF) and correlated these regions to low-voltage tissue on repeat electroanatomical (EA) mapping. We also identified gaps in lesion sets that could be targeted and closed during repeat procedures.
Methods and Results
One hundred forty-four patients underwent AF ablation and received a delayed-enhancement MRI (DE-MRI) at three months post-ablation. The number of pulmonary veins (PV) with circumferential lesions were assessed and correlated with procedural outcome. Eighteen patients with AF recurrence underwent repeat ablation. MRI scar regions were compared to electroanatomical (EA) maps during the repeat procedure. Regions of incomplete scar around the PVs were then identified and targeted during repeat ablation in order to ensure complete circumferential lesions. Following the initial procedure, complete circumferential scarring of all 4 PVA was achieved in only 7% of patients, with the majority of patients (69%) having <2 completely scarred PVA. After the first procedure, the number of PVs with complete circumferential scarring and total LA wall scar burden was associated with better clinical outcome. Patients with successful AF termination had higher average total LA wall scar of 16.4% ± 9.8 (p = 0.004) and percent PVA scar of 66.2 ± 25.4 (p = 0.01) compared to patients with AF recurrence who had an average total LA wall scar 11.3% ± 8.1 and PVA percent scar 50.0 ± 24.7. In patients who underwent repeat ablation, the PV antra scar percentage was 56.1% ± 21.4 after the first procedure compared to 77.2% ± 19.5 after the second procedure. The average total LA scar after the first ablation was 11.0% ± 4.1, while the average total LA scar after second ablation was 21.2% ± 7.4. All patients had increased number of completely scarred pulmonary vein antra after the second procedure. MRI scar after the first procedure and low voltage regions on EA obtained during repeat ablation demonstrated a positive quantitative correlation of R2 = 0.57.
Conclusions
Complete circumferential PV lesions is difficult to achieve but is associated with better clinical outcome. DE-MRI can accurately define scar lesions following AF ablation and can be used to target breaks in lesion sets during repeat ablation.
Pathologic remodeling in the septal and posterior walls of the LA helps form the pathogenic substrate for AF, and these early results suggest that more aggressive treatment of these regions appears to correlate with improved ablation outcomes. Noninvasive imaging to characterize tissue changes after ablation may prove essential to stratifying recurrence risk.
Background-Esophageal wall thermal injury after atrial fibrillation ablation is a potentially serious complication.However, no noninvasive modality has been used to describe and screen patients to examine whether esophageal wall injury has occurred. We describe a noninvasive method of using delayed-enhancement MRI to detect esophageal wall injury and subsequent recovery after atrial fibrillation ablation. Methods and Results-We analyzed the delayed-enhancement MRI scans of 41 patients before ablation and at 24 hours and 3 months after ablation to determine whether there was evidence of contrast enhancement in the esophagus after atrial fibrillation ablation. In patients with contrast enhancement, 3D segmentation of the esophagus was performed using a novel image processing method. Upper gastrointestinal endoscopy was then performed. Repeat delayedenhancement MRI and upper gastrointestinal endoscopy was performed 1 week later to track changes in lesions. The wall thickness of the anterior and posterior wall of the esophagus was measured at 3 time points: before ablation, 24 hours after ablation, and 3 months after ablation.
BackgroundImplantable cardioverter‐defibrillators (ICDs) are commonly implanted in older patients, including those with multiple comorbidities. There are few prospective studies assessing the clinical course and end‐of‐life circumstances for these patients.Methods and ResultsWe prospectively followed 51 patients with ICDs for up to 18 months to longitudinally assess in terms of (1) advance care planning, (2) health status, (3) healthcare utilization, and (4) end‐of‐life circumstances through quarterly phone interviews and electronic medical record review. The mean age was 71.1±8.3, 74.5% were men, and 19.6% were non‐white. Congestive heart failure was predominant (82.4%), as was chronic kidney disease (92%). At baseline, a total of 12% of subjects met criteria for major depression, and 78.4% met criteria for mild cognitive impairment. From this initial study cohort, 76% survived to 18 months and completed all follow‐up interviews, 18% died, and 19% withdrew or were lost to follow‐up. Though living will completion and healthcare proxy assignment were common (cumulative outcome at 18 months 88% and 98%, respectively), discussions of prognosis were uncommon (baseline, 9.8%; by 18 months, 22.7%), as were conversations regarding ICD deactivation (baseline, 15.7%; by 18 months, 25.5%). Five decedents with available data received shocks in the days immediately prior to death, including 3 of whom ultimately had their ICDs deactivated prior to death.ConclusionsWe demonstrated the feasibility of prospective enrollment and follow‐up of older, vulnerable ICD patients. Early findings suggest a high burden of cognitive and psychological impairment, poor communication with providers, and frequent shocks at the end of life. These findings will inform the design of a larger cohort study designed to further explore the experiences of living and dying with an ICD in this important patient population.
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