Importance of the relative epicardial connection locations and right-sided pulmonary vein isolation line for successful pulmonary vein isolation.

INTRODUCTION: The presence of an epicardial connection (EC) decreases the success rate of pulmonary vein isolation (PVI); however, the effect of designing isolation lines has not been evaluated. We sought to clarify the effects of designing an anterior line for right-sided PVI considering the presence and location of the EC. METHODS: Seventy-four consecutive patients who underwent initial catheter ablation for atrial fibrillation were retrospectively included in this study. The presence of the EC was determined by the left atrial (LA) activation map during right atrial pacing, and patients were divided into EC-positive (n = 23, 31%) and EC-negative (n = 51, 69%) groups. EC-positive patients were further subdivided based on the EC location: on-the-line group, (EC on the PVI line, n = 11); inside-line group (EC on the pulmonary vein [PV] side, n = 10); and outside-line group (EC on the LA side, n = 2). The PVI parameters were compared among the three groups. RESULTS: The success rates of the first-pass isolation were comparable between the EC-negative and EC-positive groups (70.6% vs. 60.9%, ns), but the success rate was significantly higher in the on-the-line group than in the inside-line group (91% vs. 20%, p = 0.002). First-pass isolation was successful in both patients in the outside-line group. Additional carina ablation was required only in the inside-line group. CONCLUSIONS: The association between the EC site and the right-sided PV anterior isolation line affected the success rate of first-pass isolation. For successful right-sided PVI, it is important to consider the EC site when designing the PVI line.

Comparison of Cryoballoon and Contact Force-Sensing Radiofrequency Ablation for Persistent Atrial Fibrillation in Clinical Practice.

BACKGROUND: Outcomes of cryoballoon ablation for persistent atrial fibrillation (AF) are unclear, especially in Japanese patients, so the effectiveness and safety of cryoballoon ablation in clinical practice were retrospectively compared with those of contact force-sensing radiofrequency (CFRF) ablation including the high-power protocol.Methods and Results:Consecutive patients with persistent AF were reviewed, and 253 and 265 patients who underwent cryoballoon and CFRF ablation, respectively, were enrolled. The primary endpoint was atrial arrhythmia recurrence. The secondary endpoints were periprocedural complications and repeat ablation. The rate of additional left atrial (LA) ablation after pulmonary vein isolation (PVI) was similar between groups (68.8% cryoballoon vs. 74.0% CFRF, P=0.19). Freedom from atrial arrhythmia recurrence was comparable between groups over a follow-up of 25.5±12.5 months (72.3% cryoballoon vs. 69.8% CFRF; adjusted hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.59-1.21, P=0.36). Outcomes were similar in the subgroups of PVI alone and PVI plus additional LA ablation. LA posterior wall isolation, absence of defragmentation, and low creatine clearance, but not catheter selection, were associated with the primary endpoint. Periprocedural complications (adjusted HR 0.73, 95% CI 0.34-1.54, P=0.41) and repeat ablation (adjusted HR 1.11, 95% CI 0.71-1.74, P=0.64) were similar for both procedures. CONCLUSIONS: Cryoballoon ablation for persistent AF in Japanese clinical practice had acceptable outcomes comparable to those of advanced CFRF ablation.

Trends Over Time in the Incidences of ST-Segment Elevation Myocardial Infarction and Non-ST-Segment Elevation Myocardial Infarction During the Past Decade in a Rural Japanese High-Aged Population.

BACKGROUND: In developed countries, the incidence of non-ST-segment elevation myocardial infarction (NSTEMI) has outpaced that of ST-segment elevation myocardial infarction (STEMI). However, whether this trend is observed in Japan, in which the aging of society is rapidly progressing, remains to be elucidated.Methods and Results:This study retrospectively investigated the trends over time in the incidence of acute coronary syndrome (ACS) between August 2009 and July 2019 at 2 institutions in Izumo City (in rural Japan), which has an elderly population. Crude and age-sex-adjusted incidences of total ACS, STEMI, and non-ST-segment elevation-ACS (NSTE-ACS; including NSTEMI and unstable angina pectoris) were calculated for each year. In the total population, factors associated with the development of NSTEMI were evaluated by multivariate analysis. In total, 1,087 patients were enrolled. The age-adjusted incidence of NSTE-ACS in male patients aged ≥75 years showed a significantly increasing trend. The proportion of NSTEMI per total ACS cases showed a significantly increasing trend over the entire study period. In the multivariate analysis, pre-development use of ≥3 medications for comorbidities was associated with the development of NSTEMI, independent of high-sensitivity cardiac troponin assay use. CONCLUSIONS: This study demonstrated an increasing trend in the incidence of NSTEMI in a rural high-aged Japanese population. In addition to the widespread use of high-sensitivity cardiac troponin assays, early medication use for comorbidities might have contributed to this trend.

Association Between Atrial High-Rate Episodes and Ischemic/Major Bleeding Events in Patients With a Cardiac Implantable Electronic Device　- A 10-Year, Single-Center Historical Cohort Study.

BACKGROUND: An association between atrial high-rate episode (AHRE) and stroke has been reported, although data for the Asian population are limited. This study aimed to investigate the role of AHRE in ischemic and major bleeding events in patients who underwent a cardiac implantable electronic device (CIED) procedure.Methods and Results:This single-center historical cohort study included 710 patients (age: 78±11 years, 374 women) who underwent a CIED-related procedure between October 2009 and September 2019 at Shimane Prefectural Central Hospital (median follow-up period: 4.5 [2.5, 7] years, 3439 person-years). Based on the maximum AHRE burden, patients were divided into: (1) <6 min; (2) ≥6 min to 24-h; and (3) ≥24-h groups. The cumulative incidence of ischemic (ischemic stroke, systemic embolism, and transient ischemic attack) and major bleeding (≥3 Bleeding Academic Research Consortium bleeding criteria) events after the procedure were compared. Uni- and multivariate analyses were performed to identify factors associated with these events. The incidence of both events increased with the rising AHRE burden, being significantly higher in the ≥24-h group than in the <6 min group. Multivariate analysis found age ≥85 years to be the only independent factor associated with both events. CONCLUSIONS: Longer AHRE duration is associated with a high number of major bleeding and ischemic events. Monitoring these bleeding risks is mandatory when clinicians are considering anticoagulation therapy for such patients.

Successful ablation of biatrial tachycardia with preserved electrical activation of left atrial appendage by unidirectional connection via Bachmann's bundle: A case report.

A 57-year-old man underwent his seventh ablation session for atrial tachycardia (AT). His previous ablations involved several regions of the right atrium (RA) and left atrium (LA). The AT was characterized as biatrial tachycardia with a circuit involving the mitral annulus and septal RA. The AT was terminated by ablation through the insertion site of Bachmann's bundle (BB) in both atria. After 3 months, the patient underwent his eighth ablation session because of AT recurrence. Activation maps showed that the connection from the RA to LA and vice versa was maintained via BB and the coronary sinus, respectively. The ablation target to interrupt the AT circuit was the mitral isthmus (MI), not BB, because BB supplied the electrical activation of the left atrial appendage (LAA) via a unidirectional electrical connection from the RA to LA. Ablation attempts from within the coronary sinus were performed to target the epicardial connection in the MI and led to complete blockage of the connection from the LA to RA. Otherwise, the connection from the RA to LA was preserved via BB. The patient was free of symptoms and anti-arrhythmic drugs at the 4-month follow-up. However, he had a high risk of electrical isolation of the LAA because extensive ablations had been performed; the strategy of targeting the MI contributed to the balance between preserving the electrical activation of the LAA and treating the biatrial tachycardia. Verification of the connective pathway between the two atria might be helpful to determine the optimal target.

Effectiveness of a manual dragging laser irradiation technique using the first-generation endoscopic laser balloon ablation system for pulmonary vein isolation.

Background: Although high efficacy of laser balloon (LB) ablation for atrial fibrillation (AF) has been shown, the conventional point-by-point technique requires a long procedure time. We investigated the clinical effectiveness of the manual dragging laser technique. Methods: We enrolled 51 consecutive patients with paroxysmal AF who underwent pulmonary vein isolation (PVI) using first-generation LB (LB1) at our institution. The first 25 patients underwent PVI using a point-by-point laser irradiation maneuver (point-by-point group). The latter 26 patients underwent PVI using a manually dragging laser irradiation maneuver (dragging group). The power and delivery time for the laser energy were selected from a preset protocol with 5.5-12 W and 20-30 s for each application. The dragging irradiation method was performed by manually rotating approximately 1.5°/s during one irradiation application. Results: PVI was successful in all cases. The duration of PVI was shorter (66 ± 20 vs. 116 ± 39 min, p < 0.0001), and the number of laser irradiations for the 4PVs were significantly less in the dragging group. There were four recurrent cases (16%) in the point-by-point group and 1 (4%) in the dragging group. There was no significant difference in the survival rate free from recurrence after the blanking period between the two groups (log-rank p = 0.1570). The complications were similar between the groups (4% vs. 4%, ns). Conclusions: The manual dragging laser irradiation technique using LB1 could shorten the PVI procedure time while preserving clinical effectiveness.

Development of Alveolar Hemorrhage in a Patient with Acute Myocardial Infarction Complicated with Essential Thrombocythemia.

BACKGROUND Essential thrombocythemia (ET) is a risk factor both for bleeding caused by abnormal platelet function and for thrombus formation caused by excessive platelet proliferation. We present a rare case of alveolar hemorrhage after dual antiplatelet therapy (DAPT), a serious bleeding complication of antithrombotic therapy, in a patient with an acute myocardial infarction complicated by ET. CASE REPORT A 75-year-old man was treated for ET. He experienced an acute myocardial infarction, and an emergent percutaneous coronary intervention was subsequently performed. DAPT was started just before stent implantation. Because a left ventricular thrombus was suspected in spite of DAPT, anticoagulant therapy with heparin was added. On day 7, a large amount of hemoptysis was observed, and alveolar hemorrhage was diagnosed. Although the antithrombotic treatment was de-escalated from DAPT to single antiplatelet therapy, no stent thrombosis or recurrence of alveolar hemorrhage was observed. CONCLUSIONS In ET patients, reduced platelet function due to thrombocytosis and strong antithrombotic therapy may cause an excessive bleeding risk. Switching from DAPT to antiplatelet monotherapy at the early stage of stent implantation is a treatment option in situations in which excessive bleeding risk is a concern.

Clarithromycin-induced Coronary Vasospasms Caused Acute Coronary Syndrome in a 19-year-old Male Patient.

A 19-year-old-man was admitted to our hospital with intermittent chest pain. The day before admission, he had been diagnosed with enteritis and prescribed clarithromycin. He had experienced severe chest pain three times after taking clarithromycin; thus, acute coronary syndrome (ACS) was suspected. Emergent coronary angiography showed normal coronary arteries; however, the result of a subsequent acetylcholine provocation test was positive. We diagnosed him to have ACS caused by coronary vasospasms and suspected clarithromycin-induced Kounis syndrome. Although more common in older patients, Kounis syndrome must be suspected and a thorough medication history should be taken whenever a patient complains of chest pain.

Incidence and Demographic Trends for Acute Coronary Syndrome in a Non-Epidemic Area During the Coronavirus Disease Pandemic in Japan　- A 2-Institutional Observational Study.

Background: We investigated the incidence of acute coronary syndrome (ACS) in a non-epidemic area of coronavirus disease-2019 (COVID-19) in Japan. Methods and Results: This observational study included consecutive patients admitted for ACS at 2 tertiary hospitals in Izumo City during the pandemic in Japan (n=42, March-July 2020). Although the monthly ACS incidence was comparable, the proportions of delayed admissions and high Killip class (III/IV) were significantly higher in this population than in historical cohorts (n=197, 2015-2019). Conclusions: Our findings stress the importance of encouraging patients with ACS-related symptoms to visit medical services promptly, especially in non-epidemic areas.

Incidence and risk factors for cardiac implantable electronic device infection in current clinical settings in a Japanese population: A 20-year single-center observational study.

BACKGROUND: The incidence of cardiac implantable electronic device (CIED) infection is increasing worldwide. However, data regarding this phenomenon in Japan and information on factors associated with developing CIED infection are limited. Our aim was to compare the incidence of CIED infection between pre-current (past 10-20 years) and current (past 10 years) clinical settings and to investigate risk factors for CIED infection in current clinical settings in a Japanese population. METHODS: This observational study included 1749 patients (age 77 ± 12 years, 824 males) who underwent a CIED-related procedure between August 1999 and July 2019 at our institution. We defined the pre-current and current clinical setting periods as August 1999-July 2009 (period I) and August 2009-July 2019 (period II), respectively. We compared the incidence rate of CIED infection between periods and evaluated the risk factors for CIED infection in period II by multivariate analysis. RESULTS: A CIED infection was identified in 0.7% (5/709 patients) and 1.7% (17/1040) of patients in periods I and II, respectively. Notably, the rate of late (>6 months since last procedure) CIED infection was significantly increased in period II (1.3% vs. 0.1%, p < 0.01), despite the rate of early infection (≤6 months) being comparable (0.4% vs. 0.6%, p = 0.58). On multiple logistic regression, revision [odds ratio (95% confidence interval): 5.2 (1.6-16.3), p = 0.005] and age [0.96, (0.93-0.99), p = 0.007] were identified as independent risk factors for CIED infection in period II. CONCLUSIONS: Our findings suggest that the increasing incidence of CIED infection in current clinical settings was due to an increase in late CIED infection. Furthermore, revision and younger age were identified as independent risk factors for CIED infection in current clinical settings. Our data indicate that clinicians should consider whether the merit of a procedure can overcome the risk of infection when planning revision or implantation in younger patients.