Acute oesophageal safety and long-term follow-up of AI-guided high-power short-duration with 50 W for atrial fibrillation ablation.

AIMS: Pulmonary vein isolation using radiofrequency ablation is an effective treatment option for patients with symptomatic atrial fibrillation (AF). Application of high power over a short period of time (HPSD) is reported to create more efficient lesions and may prevent collateral thermal oesophageal injury. This study aims to compare efficacy and safety of two different HPSD ablation approaches using different ablation index settings. METHODS AND RESULTS: Consecutive patients undergoing AF ablation with HPSD (50 W; ablation index-guided) using the ThermoCool SmartTouch SF catheter were included. Patients were grouped by ablation protocol: ablation with target ablation index (AI) of 400 on the anterior left atrial wall vs. 300 at the posterior left atrial wall (AI 400/300) or AI 450/350 was performed upon the operator's preference and compared. Peri-procedural parameters and complications were recorded, and incidences of endoscopically detected thermal oesophageal lesions (EDEL) analysed. Recurrence rates after a mean follow-up of 25 ± 7 months and reconnection patterns in patients undergoing redo procedures were investigated. A total of 795 patients (67 ± 10 years; 58% male; 48% paroxysmal AF) underwent a first AF ablation with HPSD (211 in group AI 400/300 and 584 in group 450/350). Median procedure time was 82.9 ± 24.6 min with longer ablation times in patients with target AI 400/300 due to higher intraprocedural reconnection rates, increased box lesions, and additional right atrial isthmus ablations. EDEL rates among target AI 400/300 procedures were significantly lower (3% vs. 7%; P = 0.019). Correspondingly, AI 450/350 was the strongest independent predictor of post-ablation EDEL (OR 4.799, CI 1.427-16.138, P = 0.011). Twelve-month (76% vs. 76%; P = 0.892) and long-term ablation single procedure success (68% vs. 71%; log-rank P = 0.452) after a mean of 25 ± 7 months were comparable among both target AI groups; however, long-term success was significantly higher for paroxysmal AF compared to persistent AF (12 months: 80% vs. 72%; P = 0.010; end of follow-up: 76% vs. 65%; log-rank P = 0.001). One hundred three patients (16%) underwent a redo procedure during follow-up documented comparable pulmonary vein (PV) reconnection among groups. Multivariate predictors of AF recurrence were age, left atrium (LA) size, persistent AF, and extra-PV ablation targets. CONCLUSION: High-power short-duration AF ablation with target AI of 400 for non-posterior wall and 300 for posterior wall lesions resulted in comparable long-term results compared to higher AI (450/350) ablations with significantly lower risk for thermal oesophageal lesions. Older age, larger LA size, persistent AF, and extra-PV ablation targets were identified in a multivariate analysis as independent risk factors for recurrences of atrial arrhythmias.

Efficacy and safety of high-power short duration atrial fibrillation ablation in elderly patients.

INTRODUCTION: Data about atrial fibrillation (AF) ablation using high-power short duration (HPSD) radiofrequency ablation in the elderly population is still scarce. The aim of our study was to investigate the efficacy and safety of HPSD ablation in patients over 75 years compared to younger patients. METHODS: Consecutive patients older than 75 years with paroxysmal or persistent AF undergoing a first-time AF ablation using 50 W HPSD ablation approach were analyzed in this retrospective observational analysis and compared to a control group <75 years. Short-term endpoints included intraprocedural reconnection of at least one pulmonary vein (PV) and intrahospital and AF recurrence during 3 months blanking period, as well as a long-term endpoint of freedom from atrial arrhythmias of antiarrhythmic drugs after 12 months. RESULTS: A total of 540 patients underwent a first AF ablation with HPSD (66 ± 10 years; 58% male; 47% paroxysmal AF). Mean age was 78 ± 2.4 and 63 ± 6.3 years (p < .001), respectively. Elderly patients were significantly more often women (p < .001). The procedure, fluoroscopy, and ablation were comparable. Elderly patients revealed significantly more often extra-PV low-voltage areas requiring additional left atrial ablations (p < .001). Overall complication rates were low; however, elderly patients revealed higher major complication rates mainly due to unmasking sick sinus syndrome (p = .003). Freedom from arrhythmia recurrences was comparable (68% vs. 76%, log-rank p = .087). Only in the subgroup of paroxysmal AF, AF recurrences were more common after 12 months (69% vs. 82%; log-rank p = .040; hazard ratio: 1.462, p = .044) in the elderly patients. In multivariable Cox regression analysis of the whole cohort persistent AF, female gender, diabetes mellitus and presence of left atrium low-voltage areas, but not age >75 years were associated with AF recurrences. CONCLUSION: HPSD AF ablation of patients >75 years in experienced centers is safe and effective. Therefore, age alone should not be the reason to withhold AF ablation from vital elderly patients due to only a slightly worse outcome and safety profile. In paroxysmal AF, elderly patients have more recurrences compared to the younger control group.

Radiofrequency ablation of atrial fibrillation-50 W or 90 W?

BACKGROUND: This study sought to evaluate the short and midterm efficacy and safety of the novel very high power very short duration (vHPvSD) 90 W approach compared to HPSD 50 W for atrial fibrillation (AF) ablation as well as reconnection patterns of 90 W ablations. METHODS AND RESULTS: Consecutive patients undergoing first AF ablation with vHPvSD (90 W; predefined ablation time of 3 s for posterior wall ablation and 4 s for anterior wall ablation) were compared to patients using HPSD (50 W; ablation index-guided; AI 350 for posterior wall ablation, AI 450 for anterior wall ablation) retrospectively. A total of 84 patients (67.1 ± 9.8 years; 58% male; 47% paroxysmal AF) were included (42 with 90 W, 42 with 50 W) out of a propensity score-matched cohort. 90 W ablations revealed shorter ablation times (10.5 ± 6.7 min vs. 17.4 ± 9.9 min; p = .001). No major complication occurred. 90 W ablations revealed lower first pass PVI rates (40% vs. 62%; p = .049) and higher AF recurrences during blanking period (38% vs. 12%; p = .007). After 12 months, both ablation approaches revealed comparable midterm outcomes (62% vs. 70%; log-rank p = .452). In a multivariable Cox regression model, persistent AF (hazard ratio [HR]: 1.442, 95% confidence interval [CI]: 1.035-2.010, p = .031) and increased procedural duration (HR: 1.011, 95% CI: 1.005-1.017, p = .001) were identified as independent predictors of AF recurrence during follow-up. CONCLUSIONS: AF ablation using 90 W vHPvSD reveals a similar safety profile compared to 50 W ablation with shorter ablation times. However, vHPvSD ablation was associated with lower rates of first-pass isolations and increased AF recurrences during the blanking period. After 12 months, 90 W revealed comparable efficacy results to 50 W ablations in a nonrandomized, propensity-matched comparison.

Epicardial ventricular tachycardia ablation: safety and efficacy of access and ablation using low-iodine content.

BACKGROUND: Epicardial ablation has become an integral part of the treatment of ventricular tachycardias (VT). This study reports the safety of epicardial access as well as the efficacy of epicardial ablation of structural heart disease in a tertiary single-center experience. METHODS: Between January 2016 and February 2022, consecutive patients undergoing an epicardial access for VT ablation were included. Different puncture techniques and occurrence of epicardial access-related complications as well as the safety of ablation using non-ionic 5% dextrose in water (D5W) compared to standard 0.9% normal saline (NS) irrigation were analyzed. VT recurrence rates during a mean follow-up of 37 ± 23 months were reported. RESULTS: In total, 197 patients undergoing a total of 239 procedures were included (59.8 ± 15.3 years, 86% males). A total of 154 patients (78%) had non-ischemic cardiomyopathies with a mean LVEF of 37 ± 14. Anterior-oriented epicardial access was aimed for in all cases and was successful in 217 (91%) of all procedures, whereas access was achieved in 19 procedures (8%) only using an inferior oriented access and in three procedures (1%) using surgical access due to severe adhesions or anatomical requirements. Overall epicardial puncture-related complications occurred in 18 (8%) of all procedures with minor pericardial bleeding in nine, pericardial tamponade in one, pneumothorax in five, pneumopericardium in one, and abdominal puncture in two cases. Presence of adhesions could be identified as the only independent predictor of epicardial access-related complications. D5W was used in 79 cases and regular 0.9% saline in 117 procedures. No differences were seen regarding acute ablation success or complications. During follow-up, 47% of all patients were free from any VTs (56% D5W vs. 40% NS; log-rank p = 0.747) and 92% of clinical VTs (98% D5W vs. 91% NS; log-rank p = 0.139). CONCLUSIONS: In this large single-centre experience, epicardial access and ablation were safe and feasible. Although long-term clinical VT recurrence rates were low, overall VT recurrences as well as mortality were high advocating for a highly experienced, interdisciplinary approach including intense management of underlying cardiac disease/heart failure. Routine usage of D5W was safe and associated with comparable short- or long-term clinical or overall VT freedom.

Electrical Storm Has Worse Prognosis Compared to Sustained Ventricular Tachycardia after VT Ablation.

BACKGROUND: Electrical storm (ES) represents a serious heart rhythm disorder. This study investigates the impact of ES on acute ablation success and long-term outcomes after VT ablation compared to non-ES patients. METHODS: In this large single-centre study, patients presenting with ES and undergoing VT ablation from June 2018 to April 2021 were compared to patients undergoing VT ablation due to ventricular tachyarrhythmias but without ES. The primary prognostic outcome was VT recurrence, and secondary endpoints were rehospitalization rates and cardiovascular mortality, all after a median follow-up of 22 months. RESULTS: A total of 311 patients underwent a first VT ablation due to ventricular tachyarrhythmias and were included (63 ± 14 years; 86% male). Of these, 108 presented with ES. In the ES cohort, dilated cardiomyopathy as underlying heart disease was significantly higher (p = 0.008). Major complications were equal across both groups (all p > 0.05). Ablation of the clinical VT was achieved in 94% of all patients (p > 0.05). Noninducibility of any VT was achieved in 91% without ES and in 76% with ES (p = 0.001). Patients with ES revealed increased VT recurrence rates during follow-up (65% vs. 40%; log rank p = 0.001; HR 1.841, 95% CI 1.289-2.628; p = 0.001). Furthermore, ES patients suffered from increased rehospitalization rates (73% vs. 48%; log rank p = 0.001; HR 1.948, 95% CI 1.415-2.682; p = 0.001) and cardiovascular mortality (18% vs. 9%; log rank p = 0.045; HR 1.948, 95% CI 1.004-3.780; p = 0.049). After multivariable adjustment, ES was a strong independent predictor of VT recurrence and rehospitalization rates, but not for mortality. In a propensity score-matched cohort, patients with ES still had a higher risk of VT recurrences and rehospitalizations compared to non-ES patients. CONCLUSIONS: VT ablation in patients with ES is challenging and these patients reveal the highest risk for recurrent VTs, rehospitalization and cardiovascular mortality. These patients need close follow-ups and optimal guideline-directed therapy.

Adverse Prognosis of Patients With Septal Substrate After VT Ablation Due to Electrical Storm.

BACKGROUND: Data about ventricular tachycardia (VT) ablation in patients with electrical storm (ES) is limited. OBJECTIVES: This study sought to compare the prognostic outcome of patients undergoing VT ablation after ES with and without a septal substrate. METHODS: In this large single-center study, consecutive patients presenting with ES and undergoing VT ablation from June 2018 to April 2021 were included. Patients with septal substrate were compared with patients without septal substrate regarding endpoints of cardiovascular mortality, VT recurrences, recurrences of the clinical VT, and rehospitalization rates. RESULTS: A total of 107 patients undergoing a first VT ablation because of electrical storm (ES) were included (age 65 ± 13 years, 86% male, 45% ischemic cardiomyopathy). Major complications occurred in 11% of all patients with increased postinterventional third-degree atrioventricular blocks among patients with septal substrate (9% vs 0%; P = 0.063). Partial ablation successes were similar (95% with a septal substrate vs 100% without a septal substrate; P = 0.251). Complete ablation success was achieved in 63% with a septal substrate and in 87% without a septal substrate (P = 0.004). After a median 22 months of follow-up, patients with septal substrate died significantly more often from cardiovascular causes (26% vs 7%; log-rank P = 0.018). In univariate analysis cardiovascular mortality for ES patients with septal substrate was 4.1-fold higher (HR: 4.192; CI: 1.194-14.719; P = 0.025). Independent predictors of adverse outcome in multivariable regression analysis were presence of septal substrate (HR: 5.723; P = 0.025) and increased age (HR: 1.104; P = 0.003). Recurrences of any ventricular arrhythmia (67% vs 56%; log rank P = 0.554) and rehospitalization rates (80% vs 66%; log rank P = 0.515) were similar between groups. Recurrences of clinical VT were similar (7% vs 2%; P = 0.252). CONCLUSIONS: Presence of a septal substrate is associated with adverse long-term cardiovascular mortality in patients admitted for VT ablation after ES. Despite decreased acute ablation successes in these patients, VT recurrence rates were similar to those without a septal substrate during follow-up.

Long-Term Outcomes after Catheter Ablation of Ventricular Tachycardia in Dilated vs. Ischemic Cardiomyopathy.

Ischemic (ICM) and dilated cardiomyopathy (DCM) represent the two main underlying heart diseases in patients referred for catheter ablation of ventricular tachycardia (VT). While VT ablation in ischemic cardiomyopathy is relatively well-studied, data in patients with DCM are still scarce. The study aimed to compare the acute and long-term outcomes in patients with ICM and DCM who underwent VT ablation at a high-volume center. Consecutive patients who underwent VT ablation from April 2018 to April 2021 were included retrospectively. Patients with ischemic cardiomyopathy were compared to those with dilated cardiomyopathy. The primary endpoint was rate of VT recurrences, the secondary endpoints included overall mortality, rehospitalization because of cardiac condition (VT, acute heart failure, acute myocardial infarction, heart transplantation or implantation of left ventricular assisting device), and major adverse cardiac events (MACE) at long-term follow-up. A total of 225 patients admitted for first VT ablation were included. A total of 156 patients (69%) revealed ICM and 69 (31%) DCM. After a mean follow-up of 22 months, the primary endpoint of VT recurrence occurred significantly more often in the patients with dilated cardiomyopathy (ICM n = 47; 37% vs. DCM n = 34; 64%; p = 0.001). In regard to the secondary endpoint of overall mortality, there was no difference between the two patient cohorts (DCM n = 9; 15% vs. ICM n = 22; 16%; p = 0.677); the patients with DCM showed significantly higher rehospitalization rates due to cardiac conditions (75% vs. 59%; p = 0.038) and more frequent MACE (68% vs. 52%; p= 0.036). In a Cox regression model, electrical storm at admission was shown to be a predictor for VT recurrence after successful catheter ablation (HR = 1.942: 95% CI 1.237-3.050; p = 0.004), while the ablation of every induced VT morphology during the procedure (HR = 0.522; 95% CI = 0.307-0.885; p = 0.016) contributed to a positive long-term outcome. DCM is associated with a higher risk of VT recurrence after catheter ablation compared to ICM. Furthermore, patients with DCM are more frequent re-hospitalized in the majority of cases due the VT recurrence. There is no difference in the long-term mortality between the two cohorts.