Yasutoshi Nagata

Atrial defibrillation threshold as a novel predictor of clinical outcome of catheter ablation for persistent atrial fibrillation

AIMS Catheter ablation for persistent atrial fibrillation (AF) is currently performed with different procedural endpoints. When AF did not terminate during ablation procedure, electrical cardioversion was performed at different defibrillation threshold (DFT) according to AF characteristics and atrial electrophysiologic substrates. We sought to evaluate the impact of atrial DFT after catheter ablation for persistent AF on clinical outcome. METHODS AND RESULTS We studied 128 patients with persistent AF (age 63±9 years, 106 men). After completion of circumferential pulmonary vein isolation, the left atrial substrate ablation was performed until AF terminated or all identified complex fractionated electrograms were eliminated. If AF did not terminate during ablation, an internal cardioversion protocol was started at 5J and was increased incrementally in 5 J steps until successful cardioversion was accomplished. Procedural AF termination was achieved in 50 patients (Group A). Atrial fibrillation was terminated by cardioversion with DFT≤10 J in 47 patients (Group B) and with DFT>10 J in 31 patients (Group C). At 14±7 follow-up months after 1.3±0.5 sessions, 47 (94%) Group A patients, 42 (89%) Group B patients, and 14 (45%) Group C patients remained in sinus rhythm. In multivariate analysis of Group B and Group C, DFT (hazard ratio 5.54, P<0.001) and AF duration (hazard ratio 3.74, P=0.011) were independent predictors of recurrent arrhythmia. CONCLUSION When AF does not terminate after the completion of predetermined stepwise ablation, further extensive ablation to terminate AF might be unnecessary if the AF can be successfully terminated by electrical cardioversion at low DFT.

Atrial fibrillation type matters: greater infarct volume and worse neurological defects seen in acute cardiogenic cerebral embolism due to persistent or permanent rather than paroxysmal atrial fibrillation

Aims Some studies have shown that the type of atrial fibrillation (AF), whether paroxysmal AF (PAF) or persistent or permanent AF (PeAF), affects the incidence of ischaemic stroke. This study sought to determine the relationship between the AF pattern and the severity and brain volume of infarction in an AF population including transient ischaemic attack (TIA) patients. Methods and results This was a retrospective observational study. We studied 161 consecutive patients who were admitted to our stroke care unit with cardiogenic embolism or TIA related to non-valvular AF (age 79 ± 9.5, 78 females, and 87 PAF patients). We evaluated the differences in severity and infarct volume between the types of AF. Additionally, we divided the patients into three groups according to severe stroke (n = 38), TIA (n = 28), and those who were neither (stroke, n = 95) for the assessment of the predictors of severe stroke and TIA. Persistent or permanent atrial fibrillation patients with acute cardiogenic stroke or TIA had worse peak National Institute of Health Stroke Scale (NIHSS) scores [PAF median 4 (range 3-14), PeAF 17 (5.8-25); P < 0.0001] and worse NIHSS scores at discharge [PAF 2.0 (1-7), PeAF 11 (3-22); P < 0.0001]. Their infarct brain volume assessed by computed tomography or magnetic resonance imaging was also larger [PAF 4.4 (1.1-32) mL, PeAF 64 (6.9-170) mL; P < 0.0001]. Multivariate analysis of severe stroke vs. non-severe stroke patients showed that having PeAF was the only independent predictor of severe stroke [odds ratio (OR) 4.27, 95% confidence interval (CI) 1.91-10.2; P = 0.0003]. Comparison of TIA vs. non-TIA patients showed that PeAF (OR 0.120, 95% CI 0.0230-0.444; P = 0.0008) and anticoagulant use (OR 8.24, 95% CI 2.15-40.8; P = 0.0018) were independent predictors of TIA. Conclusion Cardiogenic emboli due to non-valvular PeAF are associated with a worse acute clinical course and greater volume of infarction than those due to PAF.

Effect of Optimizing Guideline-Directed Medical Therapy Before Discharge on Mortality and Heart Failure Readmission in Patients Hospitalized With Heart Failure With Reduced Ejection Fraction

Guideline-directed medical therapy (GDMT) is recommended for patients with heart failure with reduced ejection fraction (HFrEF). However, the prognostic impact of medication optimization at the time of discharge in patients hospitalized with heart failure (HF) is unclear. We analyzed 534 patients (73 ± 13 years old) with HFrEF. The status of GDMT at the time of discharge (prescription of angiotensin converting enzyme inhibitor [ACE-I]/angiotensin receptor blocker [ARB] and β blocker [BB]) and its association with 1-year all-cause mortality and HF readmission were investigated. Patients were divided into 3 groups: those treated with both ACE-I/ARB and BB (Both group: n = 332, 62%), either ACE-I/ARB or BB (Either group: n = 169, 32%), and neither ACE-I/ARB nor BB (None group: n = 33, 6%), respectively. One-year mortality, but not 1-year HF readmission rate, was significantly different in the 3 groups, in favor of the Either and Both groups. A favorable impact of being on GDMT at the time of discharge on 1-year mortality was retained even after adjustment for covariates (Either group: hazard ratio [HR] 0.44, 95% confidence interval [CI] 0.21 to 0.90, p = 0.025 and Both group: HR 0.29, 95% CI 0.13-0.65, p = 0.002, vs None group). For 1-year HF readmission, no such association was found. In conclusion, optimization of GDMT before the time of discharge was associated with a lower 1-year mortality, but not with HF readmission rate, in patients hospitalized with HFrEF.

Prognosis of super-elderly healthy Japanese patients after pacemaker implantation for bradycardia

BACKGROUND The prognosis of super-elderly patients (age≥85 years) who undergo bradycardia pacemaker (PM) implantation remains unknown. METHODS We retrospectively enrolled 868 patients (men 49.0%, 76.6±10.6 years) who could walk unassisted and whose expected life expectancy was more than 1 year, receiving their first bradycardia PM implantation between January 1, 2006, and June 30, 2013. Clinical outcomes were compared between super-elderly patients (n=201, mean age 88.6±3.2 years) and younger patients (n=667, 73.0±9.3 years). RESULTS At the end of a median 1285-day follow-up, 128 patients (14.7%) died, of which 54 were cardiac deaths (42.2%). Mortality rates were similar between the groups (16.4% vs. 14.2%, log-rank p=0.56) and across different indications for implantation (atrio-ventricular conduction disturbance or sick sinus syndrome, p=0.59), initial rhythms (sinus rhythm or persistent atrial fibrillation, p=0.62), pacing modes (dual chamber pacing or VVI pacing, p=0.26), and ventricular lead positions (septum or apex, p=0.52). On Cox proportional hazard model analysis, hypertension [hazard ratio (HR)=1.74, 95% confidence interval (CI)=1.19-2.54, p=0.004], diabetes mellitus (HR=2.18, 95% CI=1.51-3.14, p<0.001), history of myocardial infarction (HR=3.59, 95% CI=2.49-5.16, p<0.001), and history of stroke (HR=2.26, 95% CI=1.51-3.37, p<0.001) were independent predictors for mortality. CONCLUSIONS The mortality rate of super-elderly patients who had no critical illnesses and were healthy enough to walk unassisted at the time of PM implantation was not inferior to that of younger patients. Prognosis was determined by comorbidities, but not by age, PM indication, initial rhythm, pacing leads, or mode.

Hemorrhagic shock due to branch injury of the left internal thoracic artery two days after pericardiocentesis

Pericardiocentesis is a definitive strategy to remove pericardial effusion. In this report, we present a rare case of a 23-year-old man with sudden delayed hemorrhagic shock due to branch bleeding of the left internal thoracic artery (LITA) two days after undergoing pericardiocentesis. Angiography, embolization, and drainage were effective. As far as we know, this is the first report that shows delayed bleeding due to branch injury of the LITA as a possible complication after pericardiocentesis. <Learning objective: Pericardiocentesis using an apical approach under echocardiography is considered safe; however, in this case, unexpected complications after pericardiocentesis for hemorrhagic shock occurred. Patients who undergo pericardiocentesis should be observed in the hospital for several days. If sudden changes in vital signs occur, the underlying complications should also be considered, and it is important to act promptly and review the patients prior procedures.>.

Impact of impedance decrease during radiofrequency current application for atrial fibrillation ablation on myocardial lesion and gap formation

The clinical impact of a decrease in impedance during radiofrequency catheter ablation (RFCA) has not been fully clarified. The aim of the study was to analyze the impact of impedance decrease and to determine its optimal cutoff value during RFCA.

Comparison of direct oral anticoagulants and warfarin regarding midterm adverse events in patients with atrial fibrillation undergoing catheter ablation

Oral anticoagulants, including direct oral anticoagulants (DOACs), are usually required in atrial fibrillation (AF) patients who are at a high risk of thromboembolism (TE), even if they had undergone catheter ablation (CA). Although several studies have reported the safety and efficacy of DOACs around CA in AF patients, there are only limited data regarding the midterm incidence of TE and bleeding complications post‐CA among AF patients treated with warfarin or DOACs.

Cardiac Magnetic Resonance Imaging of Very Late Intrapericardial Hematoma 8 Years after Coronary Artery Bypass Grafting

A 55-year-old man presented with dyspnea, edema, and appetite loss. He had undergone coronary artery bypass grafting 8 years previously. He had jugular venous distention and Kussmauls sign. Contrast-enhanced cardiac magnetic resonance imaging (CMRI) demonstrated an intrapericardial mass compressing the right ventricular (RV) cavity. T1- and T2-weighted black-blood images showed a mass with heterogeneous high signal intensity and a thick and dark rim. The mass was considered to be a chronic hematoma. After pericardiotomy with surgical removal of the hematoma, CMRI showed the marked improvement of the RV function. Late intrapericardial hematoma is rare and CMRI is useful for making a differential diagnosis.

Treatment Outcomes of Anticoagulant Therapy and Temporary Inferior Vena Cava Filter Implantation for Pregnancy Complicated by Venous Thrombosis

Objective: Although deep vein thrombosis (DVT) followed by pulmonary thromboembolism (PE) is a critical complication during pregnancy, there have been few reports about its intrapartum management. We evaluated intrapartum management by using a temporary inferior vena cava filter (IVCF) in pregnant women with PE/DVT. Materials and Methods: Eleven women with PE/DVT during pregnancy between January 2004 and December 2016 were included. The patients were hospitalized for intravenous unfractionated heparin infusion after acute PE/DVT onset. Seven patients were discharged and continued treatment with subcutaneous injection of heparin at the outpatient unit. IVCF was implanted 1–3 days before delivery in 10 patients. Anticoagulant therapy was discontinued 6–12 h before delivery. We retrospectively analyzed rates of maternal or perinatal death, and recurrence of symptomatic PE/DVT. Results: One patient was diagnosed as having PE/DVT and 10 had DVT alone. One patient suffered hemorrhagic shock during delivery; however, maternal or perinatal death and recurrence of symptomatic PE/DVT did not occur in any patient. Conclusion: Maternal or perinatal death and recurrence of symptomatic PE/DVT was not seen in women diagnosed as having PE/DVT during pregnancy and treated with anticoagulant therapy and IVCF.

Successful treatment of a massive pulmonary embolism using rivaroxaban in a patient with antithrombin III deficiency

We report a case of acute massive pulmonary embolism in a patient with antithrombin III deficiency. The patient was treated with rivaroxaban. The patient responded well to the therapy, and contrast-enhanced computed tomography showed nearly complete disappearance of the pulmonary embolism. Patients with low antithrombin III activity may have resistance to heparin therapy, leading to insufficient anticoagulation during the acute phase of thromboembolism. This case suggests that direct oral anticoagulants, such as rivaroxaban, may be effective first-line agents for treating venous thromboembolism in patients with antithrombin III deficiency. <Learning objective: Recently, direct oral anticoagulants represent a novel treatment option for venous thromboembolism with several practical advantages over conventional therapy. Antithrombin-III deficiency may lead to insufficient anticoagulation during the acute phase of thromboembolism. The present case suggests that rivaroxaban is a direct Factor Xa inhibitor and does not require cofactors such as antithrombin-III, thus it is suitable for anticoagulation therapy in patients with low antithrombin-III activity.>.