Evaluation of microembolic signals on carotid ultrasound during pulmonary vein isolation with high-power short-duration and cryoballoon ablations: When and where do bubble and solid emboli arise?

INTRODUCTION: The underlying risks of asymptomatic embolization during high-power short-duration (HPSD) ablation for atrial fibrillation remain unclear. We aimed to evaluate microembolic signals (MESs) during HPSD ablation with power settings of 50 and 90 W in comparison with those during cryoballoon (CB) ablation using a novel carotid ultrasound-Doppler system that classifies solid and air bubble signals using real-time monitoring. METHODS AND RESULTS: Forty-seven patients underwent HPSD ablation using radiofrequency (RF), and 13 underwent CB ablation. MESs were evaluated using a novel pastable soft ultrasound probe equipped with a carotid ultrasound during pulmonary vein isolation. We compared the detailed MESs and their timing between RF and CB ablations. The number of MESs and solid signals were significantly higher in the RF group than in CB group (209 ± 229 vs. 79 ± 32, p = .047, and 83 ± 89 vs. 28 ± 17, p = .032, respectively). In RF ablation, the number of MESs, solid, and bubble signals per ablation point, or per second, was significantly higher at 90 W than at 50 W ablation. The MESs, solid, and bubble signals were detected more frequently in the bottom and anterior walls of the left pulmonary vein (LPV) ablation. In contrast, many MESs were observed before the first CB application and decreased chronologically as the procedure progressed. Signals were more prevalent during the CB interval rather than during the freezing time. Among the 28 patients, 4 exhibited a high-intensity area on postbrain magnetic resonance imaging (MRI). The MRI-positive group showed a trend of larger signal sizes than did the MRI-negative group. CONCLUSION: The number of MESs was higher in the HPSD RF group than in the CB group, with this risk being more pronounced in the 90 W ablation group. The primary detection site was the anterior wall of the LPV in RF and the first interval in CB ablation.

Clinical Outcomes and Predictors of All-Cause Mortality After Complex High-Risk and Indicated Revascularization Using Percutaneous Coronary Intervention.

The concept of complex and high-risk indicated procedures using percutaneous coronary intervention (CHIP-PCI) has recently been defined. However, few studies have investigated the prognosis of patients after CHIP-PCI. We enrolled 322 consecutive patients who underwent CHIP-PCI. CHIP-PCI was defined as a procedure satisfying at least one criterion each for both patient and procedure characteristics, as follows: patient characteristics [age ≥ 75 years old, low left ventricular ejection fraction (LVEF), diabetes mellitus, acute coronary syndrome, previous coronary artery bypass surgery, peripheral arterial disease, severe chronic kidney disease (CKD), chronic obstructive pulmonary disease (COPD), and severe valvular disease] and procedure characteristics [unprotected left main disease, degenerated saphenous or radial artery grafts, severely calcified lesions, last patent conduit, chronic total occlusions, multivessel disease, and use of mechanical circulatory support]. On Kaplan-Meier analysis, 1-, 2-, and 3-year survival rates following CHIP-PCI was 93.8%, 89.2%, and 85.4%, respectively. Moreover, on Cox multivariate hazard analysis, age (≥ 75 years old) (hazard ratio: 4.01, 95% confidence interval: 1.92-8.38, P < 0.01), COPD (hazard ratio: 2.95, 95% confidence interval: 1.38-6.32, P < 0.01), low LVEF (hazard ratio: 3.35, 95% confidence interval: 1.55-7.22, P < 0.01), severe CKD (hazard ratio: 3.02, 95% confidence interval: 1.44-6.36, P < 0.01), and use of mechanical circulatory support (hazard ratio: 5.97, 95% confidence interval: 2.72-13.10, P < 0.01) remained significant predictors of mortality. In conclusion, we revealed the clinical outcomes after CHIP-PCI. The presence of advanced age, COPD, low LVEF, severe CKD, and mechanical circulatory support use might lead to worse clinical outcomes.

Evaluation of the direction and extent of ice formation during cryoballoon ablation: an experimental study.

BACKGROUND: The distal hemisphere of a balloon is generally cooled during cryoapplication. However, a wide ablation area can be acquired after cryoballoon ablation. This study aimed to evaluate the extent of ice formation on two types of balloon surfaces through experimental and simulation studies. METHODS: A standard cryoballoon (SCB; Arctic Front Advance Pro, Medtronic) and novel cryoballoon (NCB; POLARx, Boston Scientific) were frozen for 240 s in 36 °C normal saline solution to observe ice formation on the balloon surface. Pieces of porcine tissue were placed between the upper and lower sides of the balloon, and the balloon was frozen in the horizontal direction for 240 s in 20 attempts (10 for SCB and NCB each). The measured areas of ice formation were evaluated and compared between the upper and lower sides of each balloon. RESULTS: Ice formation was greater on the lower side of the balloon than on the upper side. A larger area of ice formation in the tissue slab was observed on the lower side than on the upper side in both balloons, and the ice formation extended to the proximal hemisphere on the lower side of the balloon. The ice formation area in the NCB was significantly larger than that in SCB. CONCLUSIONS: Ice formation was significantly greater on the lower side of the cryoballoon than on the upper side and extended to the proximal hemisphere of the balloon, which might facilitate the acquisition of a wide ablation area on the left atrial posterior wall after cryoballoon ablation. Different ice formation after cryoballoon ablation Greater ice formation on the lower side of cryoballoon and an extensive ice formation in the proximal hemisphere, especially in novel cryoballoon.

A case of successful catheter ablation of blocked atrial bigeminy and bradycardia with the recovery of normal sinus rhythm and myocardial reverse remodeling.

A 69-year-old man presented bradycardia with a constant blocked atrial bigeminy and heart failure. Successful catheter ablation of blocked atrial bigeminy with bradycardia resulted in myocardial reverse remodeling and restoration of the normal sinus rhythm from the ectopic atrial rhythm.

Efficacy and feasibility of cryoballoon ablation for atrial fibrillation in patients with heart failure: A large-scale multicenter study.

INTRODUCTION: Data are limited regarding outcomes of cryoballoon ablation for atrial fibrillation (AF) in patients with heart failure (HF). This large-scale multicenter study aimed to evaluate the prognosis of patients with HF after cryoballoon ablation for AF. METHODS: Among 3655 patients undergoing cryoballoon ablation at 17 institutions, 549 patients (15%) (391 with paroxysmal AF and 158 with persistent AF) diagnosed with HF preoperatively were analyzed. Clinical endpoints were recurrence, mortality, and HF hospitalization after ablation. RESULTS: Most patients had a preserved left ventricular ejection fraction (LVEF) ≥ 50%. During a mean follow-up period of 25.7 months, recurrence, all-cause death, and HF hospitalization occurred in 29%, 4.0%, and 4.8%, respectively. Cardiac function on echocardiography and B-type natriuretic peptide (BNP) levels significantly improved postoperatively, and the effect was more pronounced in the nonrecurrence group. Major complications occurred in 33 patients (6.0%), but most complications were phrenic nerve palsy (3.6%). Although death and HF hospitalization occurred more frequently in patients with LVEF ≤ 40% (n = 73) and New York Heart Association (NYHA) class III-IV (n = 19) than other subgroups, the BNP levels, and LVEF significantly improved after ablation in all LVEF and NYHA class subgroups. High BNP levels, NHYA class, CHADS2 score, and structural heart disease, but not postablation recurrence, independently predicted death, and HF hospitalization on multivariate analysis. The patients with tachycardia-induced cardiomyopathy had better recovery of BNP levels and LVEF after ablation than those with structural heart disease. CONCLUSIONS: Cryoballoon ablation for AF in HF patients is feasible and leads to significantly improved cardiac function.

Usefulness of the Snare Technique During Leadless Pacemaker Implantation for a Patient with a Severely Dilated Right Atrium.

We report here the case of a 92-year-old woman with atrial fibrillation bradycardia in which leadless pacemaker implantation was performed with a difficult delivery of the catheter sheath due to an extremely large right atrium. Using a snare technique with correction of the direction of the force on the catheter toward the right ventricle (RV) can result in successful delivery of the pacemaker catheter and stable placement of the pacemaker system in the RV septum. This specific snare technique has the potential to facilitate leadless pacemaker implantation safely in a severely dilated chamber of the heart, making this technique effective to use in clinical practice.

Cryoballoon ablation for atrial fibrillation without the use of a contrast medium: a combination of the intracardiac echocardiography and pressure wave monitoring guided approach.

In cryoballoon ablation (CBA), a contrast medium is commonly used to confirm balloon occlusion of the pulmonary veins (PVs). However, a contrast medium cannot always be used in patients with renal dysfunction and allergy. The present study aimed to assess the efficacy and safety of CBA without the use of a contrast medium. We retrospectively examined consecutive patients with paroxysmal atrial fibrillation (PAF) who underwent first-time CBA. We compared the procedural results and outcomes in patients for whom a contrast medium was used (contrast group) and those from whom a contrast medium was not used (non-contrast group). In the non-contrast group, we used saline injection on the intracardiac echocardiography and pressure wave monitoring for PV occlusion. Fifty patients (200 PVs) and 22 patients (88 PVs) underwent CBA with and without a contrast medium, respectively. The success rate of PV isolation with CBA alone was 93% and 90% in the non-contrast and contrast groups, respectively (p = 0.40). The fluoroscopy time and nadir temperature were significantly lower in the non-contrast group as compared to that in the contrast group. The recurrence rate 1 year after ablation did not differ between the two groups (18% vs. 18%, p > 0.99). Furthermore, the number of reconnected PVs in patients with recurrence was significantly lower in the non-contrast group than in the contrast group (6% vs. 36%, p = 0.017). In conclusion, CBA using the intracardiac echocardiography and pressure monitoring approach without the use of a contrast medium was safe and efficient.

Difficulty removing a leadless pacemaker in a post-transfusion patient.

A 99-year-old woman with atrial fibrillation bradycardia and symptomatic long pauses underwent a leadless pacemaker implantation after red blood cell transfusion due to anaemia. The patient's blood tests after transfusion showed hypercoagulability; haematocrit, haemoglobin and fibrinogen levels were increased from 24.5% to 33.2%, 76 g/L to 111g/L, and 346 mg/dL to 646 mg/dL, respectively. Blood tests showed no hereditary hypercoagulability disorder and she had no history of thrombophilia. A leadless pacemaker was implanted in the correct position in the right ventricle. Heparin was administered after sheath insertion and the leadless pacemaker system was thoroughly flushed with heparinised saline before the tether was cut; however, removing the tether after leadless pacemaker implantation was difficult because clots had formed on the tether.

Earliest pulmonary vein potential-guided cryoballoon ablation is associated with better clinical outcomes than conventional cryoballoon ablation: A result from two randomized clinical studies.

INTRODUCTION: With regard to short-term outcome in atrial fibrillation (AF), the benefit of cryoballoon ablation (CBA) by pressing a balloon against the earliest pulmonary vein (PV) potential site during PV isolation (earliest potential [EP]-guided CBA) has been previously demonstrated. The present study aimed to evaluate the long-term outcome of the EP-guided CBA. METHODS AND RESULTS: This study included 136 patients from two randomized studies, who underwent CBA for paroxysmal AF for the first time. Patients were randomly assigned to the EP-guided and conventional CBA groups in each study. In the EP-guided CBA group, we pressed a balloon against the EP site when the time-to-isolation (TTI) after cryoapplication exceeded 60 and 45 s in the first and second studies, respectively. We compared the clinical outcomes for 1 year after the procedure between the EP-guided CBA group (68 patients) and the conventional CBA group (68 patients). The primary endpoint was the recurrence of atrial arrhythmia after ablation. No significant differences in baseline characteristics were observed between the two groups. Compared with the conventional CBA group, the EP-guided CBA group had a significantly higher success rate at TTI ≤ 90 s (98.5% vs. 90.0%, p < .001); lower touch-up rate and total cryoapplication; and shorter procedure time, and fluoroscopy time. The recurrence at 1 year after ablation was significantly lower in the EP-guided CBA group than in the conventional CBA group (6.0% vs. 19.4%; p = .019). CONCLUSIONS: The EP-guided CBA approach can facilitate the ablation procedure and achieve low recurrence at 1 year after ablation.

Reverse-Type Left Posterior Fascicular Ventricular Tachycardia: A New Electrocardiographic Entity.

OBJECTIVES: This study sought to demonstrate a new type of verapamil-sensitive fascicular ventricular tachycardia (VT) with a reverse circuit. BACKGROUND: Left posterior fascicular ventricular tachycardia (LPFVT) is the most common form of verapamil-sensitive fascicular VT. Reverse-type LPFVT has not been reported. METHODS: We searched for a reverse-type LPFVT among 242 patients with verapamil-sensitive VT from February 2006 to September 2019. RESULTS: Three patients had a reverse-type LPFVT (cycle lengths: 340, 360, and 340 ms). QRS configuration during VT was narrow (140, 150, and 140 ms) and exhibited rSr' morphology in V1 with an early precordial transition and inferior axis. Two of 3 patients had common-type LPFVT. During reverse-type LPFVT, the earliest ventricular activation was the left superior middle septum. Fragmented Purkinje potentials (P1) buried within the local ventricular electrogram were recorded with an activation sequence from the apex to the base and were linked to the subsequent left ventricular septal activation. After radiofrequency catheter ablation at P1 during LPFVT, the reverse-type LPFVT also became noninducible. In 1 patient with only the reverse-type LPFVT, radiofrequency catheter ablation at the earliest LV activation site suppressed VT. These findings suggest that this new type of verapamil-sensitive fascicular VT shares a re-entrant circuit with a reverse direction of common LPFVT with an intramural exit site at the superior middle septum. CONCLUSIONS: Reverse-type LPFVT can occur. If common LPFVT exists, diastolic P1 during LPFVT can be a common target of ablation. If only reverse-LPFVT is inducible, the earliest ventricular activation site can be a target.

Disappearance pattern and the last remaining earliest pulmonary vein potential during cryoballoon ablation in predicting recurrence and conduction gap site of pulmonary veins.

Electrophysiological studies have rarely evaluated the sites prone to pulmonary vein (PV) conduction gap during cryoballoon ablation (CBA) for atrial fibrillation (AF). In addition, no studies have analyzed the sequence of PV potentials just before PV isolation during CBA for AF. Of the 238 patients who underwent first-time CBA for paroxysmal AF, 115 PVs of 29 patients who underwent repeat session due to recurrence after the procedure were retrospectively evaluated in the study. We evaluated the disappearance pattern of PV potential and PV reconnection on intracardiac electrograms and investigated whether the conduction gap site of the PV was related to the last remaining earliest PV potential (EP) and sequence pattern during the first-time CBA. Time to isolation was observed in 81 PVs during the first-time CBA. At the repeat session, PV reconnection was only observed in 22 of 81 PVs. PV potentials disappeared with sequence changes in 36 PVs and without sequence changes in 38 PVs. Multivariate analysis demonstrated that disappearance of PV potentials without change in the EP site but with delay or disappearance of other PV potentials was independently associated with PV reconnection (12/22 PVs [55%] vs. 4/59 PVs [6.8%]; odds ratio 14.4; 95% confidence interval 3.75-55.5; p < 0.001). In 19 of 22 (86%) reconnected PVs, PV conduction gap sites at repeat ablation corresponded with the last remaining EP sites during first-time CBA. In conclusion, disappearance pattern of the PV potential and the last remaining EP during the CBA can predict PV reconnection and gap site.

Impact of the clinical frailty scale on clinical outcomes and bleeding events in patients with ST-segment elevation myocardial infarction.

The Clinical Frailty Scale (CFS) is a simple tool to assess patients' frailty and may help to predict adverse outcomes in elderly patients. The aim of the present study was to examine the impact of CFS on clinical outcomes and bleeding events after successful percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI). We enrolled 266 consecutive patients with STEMI who underwent primary PCI in between January 2015 and June 2018. Patients were categorized into two groups based on the CFS stages: CFS 1-3 and CFS ≥ 4. We collected the data and evaluated the relationship between the CFS grade and the incidence of major adverse cardiovascular events (MACE) and Bleeding Academic Research Consortium 3 or 5 bleeding events. Of these patients, CFS ≥ 4 was present in 59 (22.2%). During the follow-up, 37.3% in the CFS ≥ 4 group and 8.2% in the CFS 1-3 group experienced MACE. In Kaplan-Meier analysis, the proportion of MACE-free survival for 4 years was significantly lower in the CFS ≥ 4 group (log-rank P < 0.001). Additionally, the proportion of bleeding event-free survival was significantly lower in the CFS ≥ 4 group (log-rank P < 0.001). The CFS (per 1-grade increase) remained an independent significant predictor of MACE on multivariate Cox proportional hazard analysis [hazard ratio 1.39 (95% confidence interval: 1.08 to 1.79, P = 0.01)]. In conclusion, CFS was an independent predictor of future adverse cardiac events in patients with STEMI. Therefore, the assessment of CFS is crucial in this population.

Impact of skeletal muscle mass on clinical outcomes in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement.

Low skeletal muscle mass is one of the components of sarcopenia. However, the prognostic impact of skeletal muscle mass on clinical outcomes in patients after transcatheter aortic valve replacement (TAVR) remains unclear. Therefore, we assessed the impact of skeletal muscle mass on future cardiovascular events in patients undergoing TAVR. We enrolled 71 consecutive patients who underwent TAVR for symptomatic severe aortic stenosis. We applied bilateral psoas muscles as an indicator of skeletal muscle mass. Psoas muscle volumes were measured from the origin of psoas at the level of the lumbar vertebrae to its insertion in the lesser trochanter on three-dimensional computed tomography datasets. Psoas muscle mass index (PMI) was calculated as psoas muscle volume/height2 (cm3/m2). According to the median value of PMIs (79.8 and 60.0 cm3/m2 for men and women), the enrolled patients were divided into two groups. During the follow-up, 11 (31.4%) patients in low PMI group and 4 (11.1%) in high PMI group experienced major adverse cardiovascular events (MACE) defined as a composite of death from any cause, myocardial infarction, heart failure hospitalization, and stroke. The proportion of MACE-free survival was significantly lower in low PMI group (log-rank P = 0.033), mainly due to the difference of hospital readmission for congestive heart failure. On multivariate Cox proportional hazard analysis, PMI remained an independent negative predictor of MACE [hazard ratio 0.95 (95% confidence interval 0.92-0.98, P = 0.002)]. In conclusion, low skeletal muscle mass independently predicted MACE in patients undergoing TAVR.

Safety and efficacy of first-line cryoablation for para-hisian ventricular arrhythmias using a cryomapping protocol approach: A case series.

A first-line cryoablation for para-Hisian VAs using a strict cryomapping protocol is useful and safe, even if the His bundle potential is recorded on the ablation catheter.

Earliest pulmonary vein potential-guided cryoballoon ablation for atrial fibrillation.

No studies have evaluated both the time-to-isolation (TTI) and the sequence of pulmonary vein (PV) potentials in cryoballoon ablation (CBA) for atrial fibrillation (AF). This study aimed to prospectively evaluate the acute results of pulmonary vein isolation (PVI) using a novel CBA technique-the earliest potential (EP) of PV-guided CBA-in paroxysmal AF. We pressed a balloon against the earliest PV potential site during PVI when TTI could not be achieved within 60 s (EP-guided CBA group). We compared 32 patients consecutively treated by EP-guided CBA to 32 patients treated without pressing the balloon against the EP site (conventional CBA group). The cryoapplication protocol was the same, except with regard to the pressing of the balloon. All 256 PVs (EP-guided CBA group, 128 PVs; conventional CBA group, 128 PVs) were isolated successfully. The TTI observation rate was similar in both groups. Compared with conventional CBA, EP-guided CBA was associated with a lower non-success rate of TTI ≤ 90 s (9% vs. 26%; P = 0.040) and shorter left atrial dwell time (38 ± 9 vs. 46 ± 19 min; P = 0.036), total procedure time (76 ± 15 vs. 87 ± 23 min; P = 0.043), and fluoroscopy time (23 ± 8 vs. 30 ± 11 min; P = 0.006). This novel EP-guided CBA approach may help facilitate the ablation procedure.

Vagal response in cryoballoon ablation of atrial fibrillation and autonomic nervous system: Utility of epicardial adipose tissue location.

BACKGROUND: Mechanism and effects of vagal response (VR) during cryoballoon ablation procedure on the cardiac autonomic nervous system (ANS) are unclear. The present study aimed to evaluate the relationship between VR during cryoballoon catheter ablation for atrial fibrillation and ANS modulation by evaluating epicardial adipose tissue (EAT) locations and heart rate variability (HRV) analysis. METHODS: Forty-one patients with paroxysmal atrial fibrillation (11 with VR during the procedure and 30 without VR) who underwent second-generation cryoballoon ablation were included. EAT locations and changes in HRV parameters were compared between the VR and non-VR groups, using Holter monitoring before ablation, immediately after ablation and one month after ablation. RESULTS: The total EAT volume surrounding the left atrium (LA) in the VR and non-VR groups was 29.0±18.4 cm3 vs 27.7±19.7 cm3, respectively (p=0.847). The VR group exhibited greater EAT volume overlaying the LA-left superior pulmonary vein (PV) junction (6.1±3.6 cm3 vs 3.6±3.3 cm3, p=0.039) than the non-VR group. HRV parameters similarly changed following ablation in both the groups. EAT volume overlaying LA-right superior PV junction was significantly correlated with the relative changes in root-mean-square successive differences (r=-0.317, p=0.043) and high frequency (r=-0.331, p=0.034), immediately after the ablation. CONCLUSIONS: Changes in HRV parameters following ablation were similarly observed in both the groups. EAT volume on the LA-PV junction is helpful for interpretation of VR occurrence and ANS modulation.