Less Pulmonary Vein Reconnection at Redo Procedures Following Radiofrequency Point-by-Point Antral Pulmonary Vein Isolation With the Use of Contemporary Catheter Ablation Technologies.

OBJECTIVES: This study investigated whether real-world use of contemporary technologies changed pulmonary vein (PV) reconnection and redo pulmonary vein isolation (PVI) procedure frequencies. BACKGROUND: Previous studies consistently reported that following PVI recurrence of PV conduction is observed in >80% of patients. METHODS: Consecutive patients undergoing 529 first and/or redo radiofrequency point-by-point PVI between January 2013 and December 2016 were included. RESULTS: Between 2013 and 2016, redo PVI rate in atrial fibrillation significantly decreased (p < 0.001); in ≤12 months, first redo PVI rate decreased from 19% to 4%. The percentage of patients having PV reconnection at second PVI significantly decreased from 90% to 29% (p = 0.001). One PVI was performed in 393 and >1 in 79 patients. Female sex was associated with >1 PVI (hazard ratio [HR]: 1.86; 95% confidence interval [CI]: 1.10 to 3.13; p = 0.02). Sixty patients underwent first and second PVI in the study period. Female sex (HR: 2.79; 95% CI: 1.67 to 4.64; p < 0.001) and left atrial diameter (HR: 1.05; 95% CI: 1.01 to 1.08; p = 0.01) were associated with more and use of automatic ablation annotation algorithm during first PVI with fewer (HR: 0.54; 95% CI: 0.32 to 0.92; p = 0.02) redo PVI procedures. In 31 of 60 patients, ≥1 PV was reconnected at second PVI. The need for "touch-up" applications at the first PVI was the only predictor of PV reconnection. CONCLUSIONS: Redo rate in atrial fibrillation and PV reconnection at redo PVI significantly decreased in recent years. Male sex, left atrial diameter, and use of automatic ablation annotation algorithm at first PVI were associated with fewer redo procedures. First-pass isolation was associated with lower PV reconnection rate at second procedure. Female sex was associated with more redo procedures but not higher PV reconnection frequencies.

Cerebral micro-embolization during pulmonary vein isolation: Relation to post-ablation silent cerebral ischemia.

BACKGROUND: High incidences of silent cerebral ischemia (SCI) have been revealed by diffusion-weighted magnetic resonance imaging (DW MRI) after pulmonary vein isolation (PVI) for atrial fibrillation. A high number of mostly gaseous micro-embolic signals (MESs) was detected by transcranial Doppler (TCD) during PVI. In this investigation the possible relationship between MESs detected intraoperatively by TCD and new SCI on DW MRI post-ablation is reported. METHODS: 27 consecutive atrial fibrillation patients (6 female, age median: 64 interquartile range: 13.23) undergoing PVI with the pulmonary vein ablation catheter, pre- and post-ablation DW MRI and intra-operative MES detection by TCD were included in the study. Procedures were performed on a therapeutic international normalized ratio (2-3) and with a target activated clotting time ≥ 350 s in all patients. DW MRI scans performed pre- and post-ablation revealed new SCI in 6 out of 27 (22%) patients. RESULTS: The median (interquartile range) MES count recorded during the whole procedure was 1642 (912) in patients with and 1019 (529) in those without SCI (p = 0.129). The number of MESs recorded during pulmonary vein angiography was significantly higher in patients as compared to those without a new lesion on the post-ablation DW MRI: 257 (249) vs. 110 (71), respectively (p = 0.0009). On mul-tivariate logistic regression, the total MES count was predictive of SCI in patients older than 68 years. CONCLUSIONS: Micro-embolus generation detected by TCD during pulmonary vein angiography significantly correlates with new SCI on DW MRI post-ablation.

Phased RF Ablation: Results and Concerns.

Treatment of atrial fibrillation (AF) with catheter ablation has proven to be a safe and effective treatment modality which is offered to an increasing number of patients in many centers. Pulmonary vein isolation (PVI) is an established cornerstone of AF ablation strategies. Athough the isolation of the pulmonary veins (PVs) with irrigated focal radiofrequency (RF) catheters using a point-by-point method is considered as the gold standard, it can be challenging to create contiguous lesions, time consuming, and require advanced three dimensional (3D) mapping and navigational systems. The phased RF ablation system was designed to address many of these challenges associated with conventional focal RF ablation. In this review, we describe the main features of phased RF ablation and summarize the data available on clinical outcome with this technology.

Learning curve in circular multipolar phased radiofrequency ablation of atrial fibrillation.

BACKGROUND: Although atrial fibrillation (AF) ablation is considered a technically challenging procedure, studies on the learning curve of different pulmonary vein isolation (PVI) techniques are limited. We investigated the time-dependent changes in procedural parameters, complication rates, and in the 1-year clinical outcome during our initial experience with circular multipolar phased radiofrequency (RF) ablation. METHODS AND RESULTS: The first 132 consecutive patients (40 female; age: 56.6 ± 10.4 years) who underwent PVI with phased RF ablation for paroxysmal or persistent AF at our center were included in the study. Procedural parameters and atrial arrhythmia-free survival were compared in the first, second and third group of 44 successive patients. All pulmonary veins were successfully isolated in 44 (100%), 41 (93.8%) and 42 (95.5%) patients in Tierce 1, 2 and 3, respectively (p = 0.233). The number of RF applications (per vein) required for isolation and fluoroscopy times demonstrated a significant decrease with experience, and a trend towards lower procedure times in Tierces 2 and 3 was also observed. Atrial arrhythmia-free survival rates at 12 months postablation were 68.18%, 75%, and 70.75% in Tierce 1, Tierce 2 and Tierce 3, respectively (p = 0.772). Pericardial tamponade requiring percutaneous subxiphoid drainage occurred in 1 patient (Tierce 3) as the only significant procedural complication. CONCLUSIONS: A learning curve effect was demonstrated in fluoroscopy times and in the number of RF applications but not in the acute success and in the long-term arrhythmia-free survival with circular multipolar RF ablations.

New perspectives in the renin-angiotensin-aldosterone system (RAAS) IV: circulating ACE2 as a biomarker of systolic dysfunction in human hypertension and heart failure.

BACKGROUND: Growing evidence exists for soluble Angiotensin Converting Enzyme-2 (sACE2) as a biomarker in definitive heart failure (HF), but there is little information about changes in sACE2 activity in hypertension with imminent heart failure and in reverse remodeling. METHODS, FINDINGS: Patients with systolic HF (NYHAII-IV, enrolled for cardiac resynchronisation therapy, CRT, n = 100) were compared to hypertensive patients (n = 239) and to a healthy cohort (n = 45) with preserved ejection fraction (EF>50%) in a single center prospective clinical study. The status of the heart failure patients were checked before and after CRT. Biochemical (ACE and sACE2 activity, ACE concentration) and echocardiographic parameters (EF, left ventricular end-diastolic (EDD) and end-systolic diameter (ESD) and dP/dt) were measured. sACE2 activity negatively correlated with EF and positively with ESD and EDD in all patient's populations, while it was independent in the healthy cohort. sACE2 activity was already increased in the hypertensive group, where signs for imminent heart failure (slightly decreased EF and barely increased NT-proBNP levels) were detected. sACE2 activities further increased in patients with definitive heart failure (EF<50%), while sACE2 activities decreased with the improvement of the heart failure after CRT (reverse remodeling). Serum angiotensin converting enzyme (ACE) concentrations were lower in the diseased populations, but did not show a strong correlation with the echocardiographic parameters. CONCLUSIONS: Soluble ACE2 activity appears to be biomarker in heart failure, and in hypertension, where heart failure may be imminent. Our data suggest that sACE2 is involved in the pathomechanism of hypertension and HF.

Cerebral microembolization during atrial fibrillation ablation: comparison of different single-shot ablation techniques.

BACKGROUND: Clinically silent cerebral ischemia (SCI) detected by diffusion-weighted MRI has been reported in 5-40% of patients undergoing pulmonary vein isolation (PVI). Although initial reports suggested a high rate of SCI with phased radiofrequency (RF) ablation on use of the pulmonary vein ablation catheter (PVAC), the incidence was subsequently markedly reduced in consequence of procedural modifications in recent studies. We analyzed cerebral microembolization as assessed with transcranial Doppler during phased RF ablation and with two other single-shot AF ablation technologies: the cryoballoon (CB) and the nMARQ™ multipolar irrigated RF ablation system. METHODS AND RESULTS: A total of 89 patients (mean age: 57, SD: 12years; 62 males) with paroxysmal or persistent AF underwent PVI. Phased RF was used according to the initial protocol in 7 patients (PVAC Group I), with procedural modifications and a newer (14.4) version of the RF generator in 37 patients (PVAC Group II) and with the most recent (version 15.1) generator in 18 patients (PVAC Group III). Ablation was performed with the CB in 13 and with the nMARQ system in 14 patients. The number of microemboli (mean+(SD)) detected in the middle cerebral arteries was 2703 (918) in PVAC Group I, 1087 (542) in PVAC Group II, 719 (469) in PVAC Group III, 1057 (784) with CB and 2166 (1047) with nMARQ (p<0.01). CONCLUSION: Significant decreases in MES counts were observed thanks to the procedural modifications and newer RF generator with phased RF. High MES counts comparable to those with the initial phased RF resulted from the use of nMARQ.

Electrical storm in the brain and in the heart: epilepsy and Brugada syndrome.

We describe a patient with the coincidence of 2 ion channel disorders with autosomal dominant inheritance: Brugada syndrome, a potentially fatal cardiac condition, and cryptogenic focal epilepsy, likely due to a neurologic channelopathy. Although Brugada syndrome was discovered incidentally, most of the clinical features of epilepsy in this patient shared the risk factor characteristics of sudden unexplained death in epilepsy syndrome. This case provides additional information on the potential interaction between ion channel abnormalities in the heart and in the brain. Furthermore, it may suggest that patients with epilepsy at increased risk for sudden unexplained death in epilepsy syndrome should undergo a careful cardiac evaluation.

The Seattle Heart Failure Model predicts survival in patients with cardiac resynchronization therapy: a validation study.

BACKGROUND: The Seattle Heart Failure Model (SHFM) predicts mortality in patients with heart failure, but no study has investigated model performance in subjects with cardiac resynchronization therapy (CRT). METHODS AND RESULTS: Prospectively collected registry data of 427 patients with CRT were used for the evaluation of the discrimination and calibration performance of the SHFM. The primary end point was all-cause mortality. Calibration profile was assessed with the use of Hosmer-Lemeshow tests, and discrimination was assessed by calculating areas under receiver operating characteristic curves (AUCs) derived from the model. Mean (SD) age of the study population was 61.2 (11.1) years (72.6% male). During a median follow-up of 24.7 months, 16.9% (72/427) of the patients reached the primary end point, with observed outcomes of 34/303, 54/234, and 72/97 at years 1, 2, and 5, respectively. No evidence of insufficient fit was found in any calibration tests. AUC estimates in all subjects were 0.7377 (95% CI 0.6575-0.8179) at year 1, 0.7936 (95% CI 0.7317-0.8556) at year 2, and 0.7572 (95% CI 0.6455-0.8689) at year 5. CONCLUSIONS: SHFM offers an accurate prediction of survival in patients with CRT, with good observed calibration and AUC estimates indicating discrimination performance similar to those found by earlier validation studies.