JCS/JHRS 2020 Guideline on Pharmacotherapy of Cardiac Arrhythmias

Chained occurrences of early afterdepolarizations may create a directional triggered activity to initiate reentrant ventricular tachyarrhythmias

BACKGROUND AND OBJECTIVE

It has been believed that polymorphic ventricular tachycardia (VT) such as torsades de pointes (TdP) seen in patients with long QT syndromes is triggered by creating early afterdepolarization (EAD)-mediated triggered activity (TA). Although the mechanisms creating the TA have been studied intensively, characteristics of the arrhythmogenic (torsadogenic) substrates that link EAD developments to TA formation are still not well understood.

METHODS

Computer simulations of excitation propagation in a homogenous two-dimensional ventricular tissue with an anisotropic conduction property were performed to characterize torsadogenic substrates that potentially form TA. We examined how the configuration of islands (clusters) of myocytes with synchronously chained occurrence of EADs within the tissue, each EAD cluster size and stimulation from different directions impact the TA creation.

RESULTS

The presence of EAD clusters within the tissue created local regions of cardiomyocytes maintained at a depolarized membrane potential above 0 mV due to the chained occurrence of EADs. When the local area contained a concave surface border, the TA was created depending on its curvature. We found that the distance of EAD clusters was a critical factor for the development of EAD-mediated TA and polymorphic VT in long QT syndromes, that there existed a region of the distance favorable for the development of TA and VT, and that the TA was always created along the myocardial fiber orientation regardless of stimulating directions.

CONCLUSION

The chained occurrences of EADs may create a directional TA. Our findings provide deeper understandings of the cardiac arrhythmogenic substrates for preventing and treating arrhythmias.

Impact of Antibacterials on the Quality of Anticoagulation Control in Patients Initiating Warfarin Therapy

BACKGROUND

Warfarin interacts with antibacterials to prolong the prothrombin time international normalized ratio (PT-INR) and increase the risk of bleeding. Patients initiating warfarin therapy often undergo precise dosage adjustments; however, the clinical implications of these interactions with antibacterials remain unclear. This study aimed to clarify the effect of antibacterials on PT-INR during the warfarin induction phase.

METHODS

This was a retrospective, observational study. Patients who were newly treated with warfarin after cardiovascular surgery were included. The primary endpoint was the comparison of the maximum PT-INR and time in therapeutic range (TTR) after warfarin initiation between the antibacterial-treated (ABx) and non-treated (non-ABx) groups.

RESULTS

The maximum PT-INR was significantly higher in the ABx group (which included β-lactams, glycopeptides, quinolones, tetracyclines, and aminoglycosides) than in the non-ABx group (median [interquartile range] 2.37 [2.03-2.71] vs. 2.08 [1.93-2.33]; P = 0.005); however, the TTR did not differ significantly (65% [44-76] vs. 71% [43-85]; P = 0.150). The odds ratio for maximum PT-INR > 2.6 with antimicrobial therapy was 2.51 (95% confidence interval 1.21-5.21).

DISCUSSION

Antibacterial therapy was a risk factor for a maximum PT-INR >2.6. However, there was no association with the TTR, which is a marker of good outcomes. This was due to the strict warfarin dosing regimen according to the algorithm, which immediately and appropriately adjusted for PT-INR overexpansion.

CONCLUSIONS

Antibacterials have been suggested to increase PT-INR during the induction phase of warfarin. However, with strict dose adjustments, the clinical impact on the PT-INR and TTR is likely limited.

Prevalence, Patient Characteristics, and Treatment of Patients with Hypertrophic Cardiomyopathy: A Nationwide Payer Database Study

INTRODUCTION

Data on the prevalence of hypertrophic cardiomyopathy (HCM), characteristics of patients with HCM, and treatment patterns in Japan are limited. This study aimed to estimate the prevalence of HCM and describe the patient characteristics, treatment patterns, and utilization of medical expense subsidies in Japan, using payer claims data from insurers.

METHODS

This retrospective study of patients with HCM in Japan utilized payer claims data from insurers (Advanced Elderly Medical Service System [AEMSS], Kokuho, and Kempo) from January 1, 2017, to December 31, 2021. The prevalence of HCM was calculated annually; while medication use, comorbidities, and usage of medical expense subsidies were described for 2021 as representative data.

RESULTS

The estimated prevalence of HCM increased from 9.3/10,000 people in 2017 to 11.1/10,000 people in 2021. In 2021, the highest prevalence was observed in patients aged 85-89 years (39.0/10,000 people). For patients with HCM, mean (standard deviation) age was 82.5 (5.5) years (AEMSS), 66.7 (9.2) years (Kokuho), and 53.4 (14.0) years (Kempo). Hypertension was the most common comorbidity (AEMSS, 90.7%; Kokuho, 85.7%; Kempo, 71.4%), followed by heart failure (AEMSS, 77.3%; Kokuho, 64.4%; Kempo, 56.9%). Mental health disorders were reported in 22.4% (AEMSS), 16.3% (Kokuho), and 11.3% (Kempo) of patients with HCM. Beta-blockers were the most frequently prescribed medications (AEMSS, 65.1%; Kokuho, 63.2%; Kempo, 56.6%). A small proportion of patients whose HCM was diagnosed in 2021 received medical expense subsidies (AEMSS, 2.6%; Kokuho, 4.6%).

CONCLUSIONS

This study is the first to evaluate the prevalence of HCM in Japan using data from the general population as the denominator. It indicated that patients with HCM are typically > 50 years old, have a high prevalence of comorbidities, are commonly treated with beta-blockers, and rarely receive medical expense subsidies for designated intractable diseases. About one-fifth of the patients had mental health disorders.

The Characteristics and Clinical Analysis of Lorenz Plot of Neonatal Atrial Tachycardia

BACKGROUND

Lorenz plot (LP) analysis enhances the accuracy of arrhythmia diagnosis and serves as an attractive diagnostic tool for patients with arrhythmias. We explored the utility of the LP in the classification of various types of neonatal atrial tachycardia and evaluated the treatment effects and prognosis.

METHODS

Ninety-six newborns with atrial tachycardia had their dynamic electrocardiograms and clinical data collected between January 2018 and June 2023. They were divided into different atrial tachycardia groups based on the morphological characteristics of the LP. The clinical features of the patients in each group were also analyzed.

RESULTS

Neonates were divided into multifocal (30%, 31.25%), parasystole (19%, 19.79%), and atrial premature beat-induced atrial tachycardia (47%, 48.96%) groups. It was demonstrated that the prevalence of cardiac structural abnormalities, viral infections, myocardial injury, and heart failure was significantly increased in the multifocal atrial tachycardia group.

CONCLUSIONS

The analysis of distinct LP patterns allowed for the identification and classification of neonatal atrial tachycardia, which could improve the diagnostic efficiency of neonatal atrial tachycardia and assist clinical physicians in making better management strategies based on the type of atrial tachycardia.

Impact of polypharmacy on 3-year mortality in patients with heart failure: a retrospective study

BACKGROUND

Guideline-directed medical therapy (GDMT) is important in heart failure management; however, polypharmacy itself may impact heart failure. Although measures against polypharmacy are needed, current discussion on unilateral drug tapering (including the drugs that should be tapered) is insufficient. In this study, we investigated the relationship between the number of prescribed GDMT drugs and prognosis in patients with heart failure.

METHODS

In this single-centre retrospective study, 3,146 eligible patients with heart failure were included and divided into four groups based on the median number of prescribed GDMT drugs and the median number of drugs not included in the GDMT (ni-GDMT) at the time of hospital discharge. The definition of GDMT was based on various Japanese guidelines. The primary outcome was all-cause mortality within 3 years of hospital discharge.

RESULTS

A total of 252 deaths were observed during the 3-year follow-up period. Kaplan-Meier analysis revealed that groups with GDMT drug count ≥ 5 and ni-GDMT drug count < 4 had the lowest mortality, and those with GDMT drug count < 5 and ni-GDMT drug count ≥ 4 had the highest mortality (log-rank, P < 0.001). Cox regression analysis revealed a significant association between ni-GDMT drug count and all-cause mortality, even after adjustment for number of GDMT medications, age, male, left ventricular ejection function < 40%, hemoglobin, albumin levels, and estimated glomerular filtration rate [HR = 1.06 (95% CI: 1.01-1.11), P = 0.020]. Conversely, the GDMT drug count was not associated with increased mortality rates.

CONCLUSIONS

The ni-GDMT drug count was significantly associated with 3-year mortality in patients with heart failure. Conversely, the GDMT drug count did not worsen the prognosis. Polypharmacy measures should consider ni-GDMT drug quantity to improve the prognosis and outcomes in patients with heart failure.

Treatment of thrombotic cardiovascular diseases in people with haemophilia: A Japanese consensus study

INTRODUCTION

Cardiovascular diseases (CVD) that require long-term anticoagulant and antiplatelet therapy presents a problem in people with haemophilia (PWH) who receive factor replacement therapy to reduce bleeding risk. Currently, there are no Japanese guidelines for the management of PWH with CVD.

AIM

To develop expert guidance on managing CVD in PWH in Japan.

METHODS

A steering committee of four experts (two haemophilia specialists, one thrombosis specialist, one cardiologist) identified 44 statements related to five key themes. An online questionnaire was produced comprising a mix of 4-point Likert scale and multiple-choice questions that was sent to specialists in the management of PWH with CVD in Japan. Consensus was defined as high or very high if a respective ≥75% or ≥90% of respondents agreed with a statement.

RESULTS

Of 16 potential respondents, responses were received from 15 specialists. Of the Likert scale questions, 71% (29/41) achieved ≥90% agreement (very strong agreement), 17% (7/41) achieved 75%-89% agreement (strong agreement) and 15% (6/41) did not achieve consensus agreement. The three multiple-choice questions failed to identify a strong preference. Agreement on specific target trough clotting factor levels for managing certain clinical situations, such as when in the presence of non-valvular atrial fibrillation or myocardial infarction, was also achieved.

CONCLUSION

The results of this consensus study provide a framework for cardiologists and haematologists to manage PWH who are at risk of, or who have, CVD. Implementation of the recommendations provided herein may improve outcomes for PWH with CVD.

Impact of left ventricular diastolic function and direct oral anticoagulant use for predicting embolic events in patients with heart failure and atrial fibrillation

Background

Patients with atrial fibrillation (AF) and heart failure (HF) have high stroke risk owing to left atrial dysfunction. However, anticoagulation is a concern in patients with high bleeding risk. We aimed to identify independent predictors of stroke in HF patients with AF.

Methods

We retrospectively examined 320 patients (mean age 79 ± 12 years, 163 women) hospitalized with acute HF complicated by AF between January 2014 and December 2018. Patients were followed from admission until ischemic stroke or systemic embolism (SSE) onset or death or were censored at the last contact date or September 2023.

Results

SSE occurred in 40 patients (median follow-up of 528 days). Multivariate Cox regression analysis identified age (hazard ratio [HR] 1.04, 95% confidence interval [CI] 1.00-1.07, p = .034), direct oral anticoagulant (DOAC) use (HR 0.26, 95% CI 0.11-0.60, p = .002), and early diastolic peak flow velocity to early diastolic peak annular velocity (E/e'; HR 1.05, 95% CI 1.02-1.08, p < .001) to be independent predictors of SSE, whereas left atrial reservoir strain was not. After determining an appropriate E/e' cutoff by receiver-operating characteristic curve analysis and adjusting the multivariate Cox model, E/e' ≥17.5 (HR 3.30, 95% CI 1.56-6.83, p = .001) independently predicted SSE. The results were consistent with no interaction in the subanalysis except for gender.

Conclusion

Elderly patients not on DOACs with elevated E/e' may be at higher risk of stroke, suggesting that DOACs should be the first choice for patients with elevated E/e' and aggressive additional prophylaxis and careful follow-up are needed.

Acute myocardial infarction following radiofrequency catheter ablation in a child: a case report on the mechanism of coronary artery occlusion assessed by cardiovascular imaging

Background

Radiofrequency ablation is a common treatment for atrioventricular nodal re-entrant tachycardia, even in paediatric patients weighing ≥15 kg, where outcomes are similar to those in adults. However, reports of acute coronary artery occlusion after radiofrequency ablation for atrioventricular nodal re-entrant tachycardia are rare.

Case summary

An 11-year-old girl with symptomatic atrioventricular nodal re-entrant tachycardia refractory to drug treatment underwent radiofrequency ablation. During the procedure, ST elevation was observed, and coronary angiography revealed occlusion of the right coronary artery at the segment 4 atrioventricular branch. Intravascular ultrasonography showed a narrowed lumen and an abnormal area of low echogenicity in the adjacent myocardium. After dilation with a 1.5 mm diameter balloon, blood flow was successfully restored. Follow-up coronary computed tomography angiography revealed residual stenosis in the right coronary artery at the segment 4 atrioventricular branch; however, blood flow to the distal occlusion was preserved. The patient was discharged without further complications.

Discussion

To the best of our knowledge, this is the first report of coronary artery occlusion following radiofrequency ablation for atrioventricular nodal re-entrant tachycardia, evaluated using intravascular ultrasonography and coronary computed tomography angiography. Based on the imaging findings, direct thermal injury was considered the cause of occlusion.

Antithrombotic therapy for stable coronary artery disease and atrial fibrillation in patients with and without revascularisation: the AFIRE trial

BACKGROUND

The Atrial Fibrillation and Ischemic Events with Rivaroxaban in Patients with Stable Coronary Artery Disease (AFIRE) trial demonstrated non-inferior efficacy endpoints for rivaroxaban monotherapy versus combination therapy (rivaroxaban plus a single antiplatelet) and superior safety endpoints in patients with atrial fibrillation and stable coronary artery disease.

AIMS

This post hoc analysis investigated whether the AFIRE trial results reflected the presence or absence of prior revascularisation.

METHODS

Among 2,215 patients, 1,697 (76.6%) had previously undergone revascularisation, and the remaining 518 (23.4%) had not undergone prior revascularisation. The primary efficacy endpoint was a composite of stroke, systemic embolism, myocardial infarction, unstable angina requiring revascularisation, or death from any cause, while the primary safety endpoint was major bleeding.

RESULTS

In 1,697 patients with prior revascularisation, the efficacy and safety endpoints were superior for monotherapy versus combination therapy (efficacy: hazard ratio [HR] 0.62, 95% confidence interval [CI]: 0.45-0.85; p=0.003; safety: HR 0.62, 95% CI: 0.39-0.98; p=0.042). Among 518 without prior revascularisation, there were no significant differences in endpoints (efficacy: HR 1.19, 95% CI: 0.67-2.12; p=0.554; safety: HR 0.47, 95% CI: 0.18-1.26; p=0.134). There was borderline interaction of the efficacy endpoints (p=0.055) between two treatments. The safety benefit of monotherapy on any bleeding was significant in patients without prior revascularisation (HR 0.59, 95% CI: 0.38-0.93; p=0.022).

CONCLUSIONS

In high-risk thrombosis patients with a history of prior revascularisation, rivaroxaban monotherapy versus combination therapy demonstrated favourable safety and efficacy outcomes.

External Validation of the HELT-E2S2 Score in Japanese Patients With Nonvalvular Atrial Fibrillation - A Pooled Analysis of the RAFFINE and SAKURA Registries

BACKGROUND

The HELT-E2S2score, which assigns 1 point to Hypertension, Elderly aged 75-84 years, Low body mass index <18.5 kg/m2, and Type of atrial fibrillation (AF: persistent/permanent), and 2 points to Extreme Elderly aged ≥85 years and previous Stroke, has been proposed as a new risk stratification for strokes in Japanese AF patients, but has not yet undergone external validation.

METHODS AND RESULTS

We evaluated the prognostic performance of the HELT-E2S2score for stroke risk stratification using 2 large-scale registries in Japanese AF patients (n=7,020). During 23,241 person-years of follow-up (mean follow-up 1,208±450 days), 287 ischemic stroke events occurred. The C-statistic using the HELT-E2S2score was 0.661 (95% confidence interval [CI], 0.629-0.692), which was numerically higher than with the CHADS2score (0.644, 95% CI 0.613-0.675; P=0.15 vs. HELT-E2S2) or CHA2DS2-VASc score (0.650, 95% CI, 0.619-0.680; P=0.37 vs. HELT-E2S2). In the SAKURA AF Registry, the C-statistic of the HELT-E2S2score was consistently higher than the CHADS2and CHA2DS2-VASc scores across all 3 types of facilities comprising university hospitals, general hospitals, and clinics. However, in the RAFFINE Study, its superiority was only observed in general hospitals.

CONCLUSIONS

The HELT-E2S2score demonstrated potential value for risk stratification, particularly in a super-aged society such as Japan. However, its superiority over the CHADS2or CHA2DS2-VASc scores may vary across different hospital settings.

Thoracoscopic surgery for atrial fibrillation in a patient with persistent left superior vena cava: a case report

BACKGROUND

A persistent left superior vena cava (PLSVC) is an anomaly of the thoracic venous system that flows into the right atrium via an enlarged coronary sinus. When performing pulmonary vein isolation and left atrial appendage closure, the PLSVC can interfere with the procedure. We have performed thoracoscopic surgery on such a patient and would like to share our experience.

CASE PRESENTATION

The patient is a 70-year-old male with a 1-year history of repeated tachycardia with chest discomfort due to paroxysmal atrial fibrillation. Contrast-enhanced computed tomography revealed the presence of a PLSVC that flows into the right atrium. The hepatic vein flows directly into the right atrium, whereas the inferior vena cava enters the thoracic cavity next to the descending aorta and flows into the parazygous vein and PLSVC. We performed thoracoscopic stapler closure of the left atrial appendage and epicardial clamp-isolation of the pulmonary veins and the PLSVC. There was concern that the PLSVC would interfere with the visual field needed to perform the procedure. We carefully removed the adhesions to the surrounding tissue and provided mobility to the PLSVC and expanded it ventrally. As a result, the procedure could be performed safely and without complications.

CONCLUSIONS

Our results demonstrate that in cases where catheter ablation is difficult for anatomical reasons, thoracoscopic stapler closure of the LAA and epicardial clamp-isolation of pulmonary veins may be a viable option.

Risk factor profile for newly diagnosed atrial fibrillation: 4-year follow-up of annual health examinations in a Japanese Adult Cohort

Background

Detecting unknown atrial fibrillation (AF) would provide an opportunity to prevent ischemic stroke by instituting appropriate anticoagulation. Although opportunistic screening of older patients is recommended in current guidelines, which patients may benefit from intensive AF screening remains unclear. We sought to clarify the risk factor profile for newly diagnosed AF in annual health examinations of a Japanese adult cohort.

Methods

Among 141 441 Japanese patients who underwent annual health examinations in 2014, 87 872 patients aged ≥20 years without known AF who had undergone electrocardiography were analyzed (mean age: 47 ± 12 years; 64% men). The absence of known AF was confirmed by prior electrocardiography in 2012 and/or 2013. Newly diagnosed AF was observed in 244 patients in 2014-2017 (mean age: 62 ± 12 years; 83% men).

Results

In the multivariable analysis, waist circumference obesity (hazard ratio [HR], 1.5; 95% confidence interval [CI], 1.13-1.99; p = .005) high blood pressure (HR, 1.9; 95% CI, 1.01-3.59; p = .047), on-treatment hypertension (HR, 1.53; 95% CI, 1.01-2.31; p = .046), and daily alcohol drinking (HR, 2.18; 95% CI, 1.52-3.12; p < .001) were significantly associated with newly diagnosed AF.

Conclusions

In this Japanese cohort, waist circumference obesity, hypertension, and alcohol drinking were independent predictors of newly diagnosed AF in annual medical examinations. This finding encourages further evaluation of systematic AF screening programs in at-risk populations.

Optimal use of intravenous landiolol in acute cardiac care

INTRODUCTION

B-blockers are regarded as beneficial pharmacologic agents in cardiac care, but their role in the acute setting remains ambiguous. Increasing evidence supports the important role of landiolol in critical care, a highly cardioselective intravenous b-blocker with rapid onset of action and short elimination time. Among its most valuable properties, which may aid to overcome special reservations related to b-blocker therapy in the acute setting, landiolol has a potent negative chronotropic effect while at the same time it exhibits a mild negative inotropic effect.

AREAS COVERED

This expert opinion review aims to present basic pharmacologic aspects of landiolol and provide current clinical research focused on its efficacy and safety.

EXPERT OPINION

Landiolol is a valuable and safe pharmacologic agent in acute cardiac care. Japanese and European guidelines have incorporated its use for the management of atrial tachyarrhythmia in patients with cardiac dysfunction. Although emerging clinical trials have experimented its use in patients with sustained ventricular tachycardia/fibrillation, acute myocardial infarction undergoing primary percutaneous intervention and in patients with septic cardiomyopathy, more studies are needed in order to establish its value in such cardiac conditions.