Combining contact force and local impedance to treat idiopathic premature ventricular contractions from the outflow tracts: impact of ablation strategy on outcomes.

BACKGROUND: Contact force (CF)-sensing catheters have not proved superior to standard catheters in the ablation of premature ventricular contractions (PVCs) from the right and left ventricular outflow tract (RVOT, LVOT). In this context, the utility of measuring local impedance (LI) is not known. We aimed to ascertain whether the use of a catheter combining LI and CF information was associated with superior outcomes in comparison with other catheter technologies. METHODS: We compared three groups of 40 propensity-matched patients with PVCs from the OTs, ablated by means of different catheter technologies: a CF-plus LI-featured catheter, an LI-featured catheter, and a standard irrigated catheter. RESULTS: The CF + LI group displayed a significantly lower risk of PVC recurrence than the standard ablation group (HR, 0.22; 95%CI, 0.07-0.71; p = 0.01). In the CF + LI group, LI drop and RF time were the only predictors of successful lesions (OR = 1.19, CI: 1.13-1.26, p < 0.001; OR = 1.06 CI: 1.01-1.07, p = 0.044, respectively). In the coronary cusps, unlike the RVOT/LVOT region, CF was not associated with LI drop (p = 0.48), and RF duration showed a linear relationship with LI drop (p < 0.001). CONCLUSIONS: The use of ablation catheters that combine CF and LI information is associated with increased success in the RF ablation of PVCs from the OTs. LI drop is the most important predictor of effective lesions, but its behavior depends on the ablation site: in the coronary cusps, unlike the RVOT/LVOT region, longer RF application times are needed in order to achieve LI drops associated with successful outcomes. REGISTRY AND REGISTRATION NO. OF THE STUDY/TRIAL: NCT03793998.

One-year outcomes in patients undergoing very high-power short-duration ablation for atrial fibrillation.

BACKGROUND: The very high-power short-duration (vHPSD) temperature-controlled ablation (vHPSD) improves the efficiency of pulmonary vein isolation (PVI) procedures. We evaluated the procedural and 12-months outcomes in atrial fibrillation (AF) patients undergoing PVI by means of vHPSD ablation. In patients with AF or atrial tachyarrythmia (AT) recurrence undergoing a redo procedure the durability of the PVI was investigated. METHODS: Consecutive paroxysmal/persistent AF patients undergoing PVI with the vHPSD ablation strategy (90 W, for 4 s) were enrolled. The rate of PVI, first-pass isolation, acute reconnection, and procedural complications were evaluated. Follow-up examinations and EKG were scheduled at 3,6, and 12 months. In case of AF/AT recurrence, patients underwent a redo procedure. RESULTS: Overall, 163 AF patients (29 persistent and 134 paroxysmal) were enrolled. The PVI was reached in 100% of patients (88% at the first pass). The rate of acute reconnection was 2%. The radiofrequency, fluoroscopy and procedural times were respectively 5.5 ± 1 min, 9 ± 1 min and 75 ± 20 min. No death, tamponade nor steam pops occurred; however, 5 patients had vascular complications. The 12-months freedom from AF/AT recurrence was 86% in both paroxysmal and persistent patients. Overall, 9 patients underwent a redo procedure, and in 4 all veins were still isolated, whereas in 5 pulmonary vein reconnections were found. The PVI durability was 78%. No overt clinical complications were observed in the follow-up. CONCLUSIONS: The vHPSD ablation represents an effective and safe ablation strategy to achieve PVI. The 12-months follow-up showed high freedom from AF/AT recurrence and a good safety profile.

Non-conducted premature atrial complexes: A new independent predictor of atrial fibrillation in cryptogenic stroke.

INTRODUCTION: Atrial fibrillation (AF) is the main cardiac cause of stroke, but it frequently remains undetected. In patients with cryptogenic stroke an Holter electrocardiogram (ECG) monitoring for AF is recommended. OBJECTIVE: To evaluate the prognostic role of Non-Conducted Premature Atrial Complexes (ncPACs) recorded on Holter ECG. METHODS: We prospectively enrolled consecutive patients admitted to the Stroke Unit of our hospital with a diagnosis of cryptogenic stroke between December 2018 and January 2020; all patients underwent 24-h Holter ECG monitoring during hospitalization. Two follow-up visits were scheduled, including a 24-h Holter ECG at 3 and 6 months to detect AF. RESULTS: Among 112 patients, 58% were male with an average age of 72.2 ± 12.2 years. At follow-up, AF was diagnosed in 21.4% of the population. The baseline 24-h Holter ECG burden of ncPACs and Premature Atrial Complexes (PACs) was higher in patients with AF detected on follow-up (13.5 vs 2, p = 0.001; 221.5 vs 52; p = 0.01). ROC analysis showed that ncPACs had the best diagnostic accuracy in predicting AF (AUC:0.80; 95% CI 0.68-0.92). Cut-off value of ≥7 for ncPACs burden showed the highest accuracy with sensitivity of 62.5% and specificity 97.7% to predict AF onset at follow-up. Moreover, at multivariate Cox-proportional hazard analysis ncPACs burden ≥7 was a powerful independent predictor of AF onset (HR 12.4; 95% CI 4.8-32.8; p < 0.0001). CONCLUSIONS: NcPACs burden ≥7 represents a new predictor of AF that could guide the screening of this arrhythmia in cryptogenic stroke patients.