Oesophageal safety in voltage-guided atrial fibrillation ablation using ablation index or contact force only: a prospective comparison.

AIMS: Left atrial ablation using radiofrequency (RF) is associated with endoscopically detected thermal oesophageal lesions (EDELs). The aim of this study was to compare EDEL occurrence after conventional contact force-guided (CFG) RF ablation vs. an ablation index-guided (AIG) approach in clinical routine of voltage-guided ablation (VGA). Predictors of EDEL were also assessed. METHODS AND RESULTS: This study compared CFG (n = 100) with AIG (n = 100) in consecutive atrial fibrillation ablation procedures, in which both pulmonary vein isolation and VGA were performed. In the AIG group, AI targets were ≥500 anteriorly and ≥350-400 posteriorly. Upper endoscopy was performed after ablation.The CFG and AIG groups had comparable baseline characteristics. The EDEL occurred in 6 and 5% (P = 0.86) in the CFG and AIG groups, respectively. Category 2 lesions occurred in 4 and 2% (P = 0.68), respectively. All EDEL healed under proton pump inhibitor therapy. The AI > 520 was the only predictor of EDEL [odds ratio (OR) 3.84; P = 0.039]. The more extensive Category 2 lesions were predicted by: AI max > 520 during posterior ablation (OR 7.05; P = 0.042), application of posterior or roof lines (OR 5.19; P = 0.039), existence of cardiomyopathy (OR 4.93; P = 0.047), and CHA2DS2-VASc score (OR 1.71; P = 0.044). The only Category 2 lesion with AI max < 520 (467) occurred in a patient with low body mass index. CONCLUSIONS: Both methods were comparable with respect to clinical complications and EDEL. In consideration of previous reconnection data and our study results regarding oesophageal safety, optimal AI target range might be between 400 and 450.

Voltage-guided ablation in persistent atrial fibrillation-favorable 1-year outcome and predictors.

INTRODUCTION: Pulmonary vein isolation (PVI) in persistent atrial fibrillation (AF) has a low success rate. A newer ablation concept targets left atrial (LA) low voltage zones (LVZ) which correlate with fibrosis and predict recurrence after PVI. We aimed to determine the success of combined PVI- and LVZ-guided ablation and to identify the predictors for LVZ and for ablation success. METHODS AND RESULTS: A total of 119 consecutive patients who underwent their first ablation procedure due to persistent AF were included. After acquisition of a high-resolution LA voltage map, PVI- and LVZ-guided ablation were performed. Mean age was 69 ± 8 years, 53% were men, and 8% had longstanding persistent AF. We found LVZ in 55% of patients. Twelve-month freedom from recurrences off drugs was 69%. The only independent predictor for recurrence was the existence of LVZ (OR 4.2, 95% CI 1.54-11.41, p = 0.005). Existence of LVZ was predicted positively by age ≥ 67 years (OR 4.4, 95% CI 1.4-13.7, p = 0.011), LA volume index ≥ 68 ml/m2 (OR 3.9, 95% CI 1.4-10.5, p = 0.008), and GFR ≤ 85 ml/min/1.73 m2 (OR 12.5, 95% CI 2.0-76.6, p = 0.006). BMI ≥ 26 kg/m2 (OR 0.06, 95% CI 0.01-0.30, p = 0.001) was a negative predictor of LVZ. CONCLUSION: LVZ-guided ablation in combination with PVI results in comparably high success rates. However, the existence of LVZ remains the strongest predictor of ablation success.

Pulmonary vein isolation using second-generation single-shot devices: not all the same?

INTRODUCTION: Single-shot devices have been developed to simplify pulmonary vein isolation (PVI). Randomized studies of the second-generation cryoballoon (CB 2nd) demonstrated excellent results. There are limited data comparing results of circular pulmonary vein ablation catheter (PVAC) with conventional RF ablation or CB for PVI. OBJECTIVE: Using a sequential registry cohort and a prospective randomized study, we aimed to compare the acute and long-term results of CB 2nd and PVAC Gold. METHODS: In the registry, consecutive patients with paroxysmal atrial fibrillation (AF) undergoing their first PVI were included. The preferred method used was PVAC Gold in 2014 and CB 2nd in 2015. Subsequently, a randomized study (PVAC vs. CB 2nd) was performed. Ablation success was measured as freedom of AF or atrial tachycardias (AT) off antiarrhythmic drugs. RESULTS: In the registry cohort, PVAC Gold was used in 60 patients and CB 2nd in 56 patients (age 66 ± 11 years, 52% male, LAD 43 ± 6). In the randomized study, 20 patients were treated with PVAC Gold and 22 with CB 2nd (age 67 ± 9; 43% men, LAD 40 ± 7 mm). During a mean follow up of 13.2 ± 3.6 months, success was 54% in PVAC Gold patients and 81% in CB 2nd cases (p = 0.001). In the randomized study 12 months success was 50% versus 86%, p < 0.05. Complications occurred rare in both groups. CONCLUSIONS: Our registry data and the randomized study both suggest superiority of PVI using CB 2nd as compared with PVI using PVAC Gold.

Low rate of access site complications after transradial coronary catheterization: A prospective ultrasound study.

BACKGROUND: Transradial artery (TRA) left heart catheterization is an increasingly used technique for both diagnostic and interventional coronary procedures. This study evaluates the incidence of access site complications in the current interventional era. METHODS AND RESULTS: A total of 507 procedures were performed under standardized conditions. Each procedure was performed using high levels of anticoagulation, hydrophilic sheaths, and short post-procedural compression times. Vascular complications were assessed one day after TRA catheterization using Duplex sonography and classified according to the necessity of additional medical intervention. A simple questionnaire helped identifying upper extremity neurologic or motor complications. Vascular complications were detected in 12 patients (2.36%): radial artery occlusion was detected in 9 patients (1.77%), 1 patient developed an AV-fistula (0.19%), and 2 patients had pseudoaneurysms (0.38%). None of the patients required specialized medical or surgical intervention. Under our procedural conditions, small radial artery diameter was the only significant predictor for the development of post-procedural vascular complications (2.11 ± 0.42 mm vs 2.52 ± 0.39 mm, p = 0.001). None of the previously reported risk factors, namely, advanced renal failure, diabetes, acuteness/complexity of procedure, or sheath and catheter size significantly influenced the rate of vascular complications. No major hematoma or local neurologic or motor complications were identified. CONCLUSIONS: Using current techniques and materials, we report a very low rate of local complications associated with TRA catheterization.

Glycolytic oscillations in single ischemic cardiomyocytes at near anoxia.

Previous studies have shown that oscillations of the metabolism can occur in cardiomyocytes under conditions simulating ischemia/reperfusion. It is not known whether they can also occur during real ischemia with near-anoxic oxygen tension. Here, using oxygen clamp in on-chip picochambers, we exposed single resting cardiomyocytes to near anoxia (pO(2) < 0.1 mm Hg). We show that at near anoxia, the mitochondrial membrane potential (DeltaPsi) was kept by the F(1)F(0)-ATPase reversal, using glycolytic adenosine triphosphate (ATP). In many cells, activation of current through sarcolemmal K(ATP) channels (I(KATP)) started after a delay with one or several oscillations (frequency of 0.044 +/- 0.002 Hz). These oscillations were time correlated with oscillations of DeltaPsi. Metabolic oscillations at near anoxia are driven by glycolysis because (a) they were inhibited when glycolysis was blocked, (b) they persisted in cells treated with cytoplasmic reactive oxygen species scavengers, and (c) the highest rate of ATP synthesis during an oscillation cycle was associated with the generation of reducing equivalents. Glycolytic oscillations could be initiated upon rapid, but not slow, transition to near anoxia, indicating that the speed of ATP/ADP ratio drop is a determinant of their occurrence. At enhanced oxidative stress, the rate of ATP consumption was increased as indicated by rapid I(KATP) activation with large-scale oscillations. These results show that metabolic oscillations occur in cardiomyocytes at near anoxia and are driven by glycolysis and modulated by mitochondria through the rate of ATP hydrolysis, which, in turn, can be accelerated by oxidative stress.