Pablo B. Nery

Aims: The 2024 American Heart Association statement recommends fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) for patients with high clinical suspicion of cardiac sarcoidosis even without late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR), but this recommendation has been challenged. We determined the frequency of LGE-negative CMR at first presentation of clinically manifest, metabolically active, treatment-naïve cardiac sarcoidosis. Methods and results: In this single-centre sub-study of the prospective Cardiac Sarcoidosis Multi-Center Prospective Cohort Study, we analysed 46 consecutive treatment-naïve patients with de novo clinically manifest cardiac sarcoidosis and core-laboratory-defined abnormal cardiac and extracardiac FDG uptake, imaged within a 6-month interval, before immunosuppression. Four of 46 patients had no LGE on CMR (8.7%; exact 95% CI, 2.4–20.8%). All four presented with advanced atrioventricular conduction disease and none had ventricular tachycardia; three of four started immunosuppressive therapy. Compared with LGE-positive patients, LGE-negative patients had preserved left ventricular ejection fraction and lower cardiac inflammatory burden (left ventricular maximum standardized uptake value 3.9 ± 0.9 vs. 9.6 ± 5.2; P = 0.037). Conclusion: An LGE-negative phenotype can occur in clinically relevant, treatment-naïve, FDG-avid cardiac sarcoidosis. These findings suggest considering FDG-PET in selected patients with high clinical suspicion of cardiac sarcoidosis, even when CMR shows no LGE.

Aims: Cardiac implantable electronic device (CIED) infection carries a substantial burden of morbidity, mortality, and cost. The Prevention of Arrhythmia Device Infection Trial (PADIT) risk score improves identification of high-risk patients and may guide targeted strategies to reduce infection. Recent work has categorized CIED infection into localized pocket vs. systemic infection, with early reports suggesting different risk factors for each. However, no current risk score has been validated for infection subtypes. ObjectivesIndependently validate the PADIT infection risk score.Compare risk factors for infection subtypes.Assess PADIT performance in predicting subtype-specific infection. Methods and results: A prospective registry was initiated at the University of Ottawa Heart Institute in 2007 to capture all CIED procedures and prospectively identify infections in collaboration with the infection prevention team. PADIT risk score components were documented for each procedure. All suspected infections were adjudicated independently by two physicians (with a third if required), blinded to PADIT score and baseline variables, and subclassified as pocket or systemic infection. Logistic regression models were generated to validate PADIT performance for each subtype, with evaluation using Akaike and Bayesian information criteria (AIC/BIC), C-statistics, and calibration slope. Between 2007 and 2020, 14,225 procedures were performed (mean age 72 ± 14 years, 35% female, 70% new implants, 18% generator changes, 11% upgrades). A total of 103 infections (0.73%) were adjudicated, of which 71 (69%) were pocket and 32 (31%) systemic. The PADIT score showed good predictive performance with a C-statistic of 0.687 (95% CI 0.655–0.743), similar to the derivation cohort (0.702, 95% CI 0.661–0.741). Notably, the number of prior procedures was strongly associated with pocket infection but not systemic infection. PADIT discrimination was consistent across subtypes: pocket infection C-statistic 0.691 (95% CI 0.649–0.761) and systemic infection 0.746 (95% CI 0.707–0.848). Calibration slopes demonstrated good agreement between predicted and observed events, with the best fit for systemic infection. Conclusion: The PADIT score was independently validated with discrimination and calibration similar to the original derivation cohort. Importantly, prior procedures predicted pocket but not systemic infection. Overall, PADIT performed well in predicting both subtypes, with the strongest model fit observed for systemic infection.

Introduction: Pulmonary vein isolations (PVI) are being performed using a high‐power, short‐duration (HPSD) strategy. The purpose of this study was to compare the clinical efficacy and safety outcomes of an HPSD versus low‐power, long‐duration (LPLD) approach to PVI in patients with paroxysmal atrial fibrillation (AF).Methods: Patients were grouped according to a HPSD (≥40 W) or LPLD (≤35 W) strategy. The primary endpoint was the 1‐year recurrence of any atrial arrhythmia lasting ≥30 s, detected using three 14‐day ambulatory continuous ECG monitoring. Procedural and safety endpoints were also evaluated. The primary analysis were regression models incorporating propensity scores yielding adjusted relative risk (RR_a) and mean difference (MD_a) estimates.Results: Of the 398 patients included in the AWARE Trial, 173 (43%) underwent HPSD and 225 (57%) LPLD ablation. The distribution of power was 50 W in 75%, 45 W in 20%, and 40 W in 5% in the HPSD group, and 35 W with 25 W on the posterior wall in the LPLD group. The primary outcome was not statistically significant at 30.1% versus 22.2% in HPSD and LPLD groups with RR_a 0.77 (95% confidence interval [CI]) 0.55–1.10; p = .165). The secondary outcome of repeat catheter ablation was not statistically significant at 6.9% and 9.8% (RR_a 1.59 [95% CI 0.77–3.30]; p = .208) respectively, nor was the incidence of any ECG documented AF during the blanking period: 1.7% versus 8.0% (RR_a 3.95 [95% CI 1.00–15.61; p = .049) in the HPSD versus LPLD group respectively. The total procedure time was significantly shorter in the HPSD group (MD_a 97.5 min [95% CI 84.8–110.4)]; p < .0001) with no difference in adjudicated serious adverse events.Conclusions: An HPSD strategy was associated with significantly shorter procedural times with similar efficacy in terms of clinical arrhythmia recurrence. Importantly, there was no signal for increased harm with a HPSD strategy.

Background: The effectiveness, safety, and pulmonary vein (PV) reconnection patterns of point‐by‐point high‐power, short‐duration (HPSD) ablation relative to conventional force‐time integral (FTI)‐guided strategies for atrial fibrillation (AF) ablation are unknown.Objectives: To compare 1‐year freedom from atrial arrhythmia (AA), complication rates, procedural times, and PV reconnection patterns with HPSD AF AF ablation versus an FTI‐guided low‐power, long‐duration (LPLD) strategy.Methods: We compared consecutive patients undergoing a first ablation procedure for paroxysmal or persistent AF. The HPSD protocol utilized a power of 50 W and durations of 6–8 s posteriorly and 8–10 s anteriorly. The LPLD protocol was FTI‐guided with a power of ≤25 W posteriorly (FTI ≥ 300g·s) and ≤35 W anteriorly (FTI ≥ 400g·s).Results: In total, 214 patients were prospectively included (107 HPSD, 107 LPLD). Freedom from AA at 1 year was achieved in 79% in the HPSD group versus 73% in the LPLD group (p = .339; adjusted hazard ratio with HPSD, 0.67; 95% confidence interval, 0.36–1.23; p < .004 for non‐inferiority). Procedure duration was shorter in the HPSD group (229 ± 60 vs. 309 ± 77 min; p < .005). Patients undergoing repeat ablation had a higher propensity for reconnection at the right PV carina in the HPSD group compared with the LPLD group (14/30 = 46.7% vs. 7/34 = 20.6%; p = .035). There were no differences in complication rates.Conclusion: HPSD AF ablation resulted in similar freedom from AAs at 1 year, shorter procedure times, and a similar safety profile when compared with an LPLD ablation strategy. Patients undergoing HPSD ablation required more applications at the right carina to achieve isolation, and had a significantly higher rate of right carinal reconnections at redo procedures.