Stereotactic arrhythmia radioablation: A novel therapy for cardiac arrhythmia

Sex-based differences and risk of recurrence in patients with atrial fibrillation undergoing pulmonary vein isolation

INTRODUCTION

Studies suggest increased likelihood of atrial fibrillation (AF) recurrence after catheter ablation (CA) in women than in men, indicating that sex may be an independent risk factor for recurrence. Nevertheless, the influence of sex on AF recurrence and underlying mechanisms remains unclear.

METHODS

Retrospective, single-centre study including patients undergoing AF CA between 2017 and 2021. Late recurrence (LR) was defined as AF recurrence ≥90 days after ablation, whereas early recurrence (ER) occurred within 90 days.

RESULTS

656 patients (32% women) were included, with a median follow-up period of 26 months. Compared to men, women undergoing CA were older, had higher body mass indexes, and had higher rates of hypertension, thyroid dysfunction, and valvular disease. Women also had increased LR risk after CA (HR 1.76, 95% CI [1.19, 2.59]). A time-split multivariable analysis at one year of follow-up showed no difference in LR risk during the first 12 months after CA (HR 1.19, 95% CI [0.73, 1.94]); however, LR risk increased in women (HR 2.90, 95% CI [1.68, 5.01]) after 12 months. In a sex-stratified analysis, coronary calcium score (CCS) >100 was associated with increased LR risk in men (HR 1.81, 95% CI [1.06, 3.08]), but not in women. Cardiac adipose tissue volume was not associated with increased LR risk.

CONCLUSIONS

Fewer women underwent CA than men and LR was more frequent in women, particularly one year after the procedure. CCS was associated with increased LR risk in men.

A Refractory Electrical Storm after Acute Myocardial Infarction: The Role of Temporary Ventricular Overdrive Pacing as a Bridge to ICD Implantation

An electrical storm (ES) is defined as the presence of at least three episodes of sustained ventricular tachycardia or ventricular fibrillation within 24 h. This patient had a previously known arterial hypertension, type II diabetes mellitus, and chronic kidney disease and has presented to the Emergency Department (ED) with symptoms of retrosternal chest pain lasting for several hours prior. The initial 12-lead electrocardiogram revealed ST segment elevation in the anterior leads (V1-V6). Emergent coronary angiography revealed an acute occlusion of the proximal left anterior descending artery (pLAD) and percutaneous coronary intervention was performed with successful implantation of one drug-eluting stent in the pLAD. On day 8 of hospitalization, the patient developed a refractory ES for which he received 50 DC shocks and did not respond to multiple lines of antiarrhythmic medications. Due to a failure of medical therapy, we decided to implant a temporary pacemaker and initiate ventricular overdrive pacing (VOP) that was successful in terminating ES. Following electrical stabilization, the patient underwent a successful ICD implantation. This case demonstrates that VOP can contribute to hemodynamic and electrical stabilization of a patient that suffers from refractory ES and this treatment modality might serve as a temporary bridge to ICD implantation.

Linear accelerator-based stereotactic arrhythmia radioablation for paroxysmal atrial fibrillation in elderly: a prospective phase II trial

AIMS

Stereotactic arrhythmia radioablation (STAR) is a novel therapeutic approach for cardiac arrhythmias. The aim of this trial is to investigate the feasibility of STAR for the treatment of paroxysmal atrial fibrillation (AF) in elderly patients.

METHODS AND RESULTS

Inclusion criteria were age >70 years, symptomatic AF, antiarrhythmic drugs failure, or intolerance. All patients underwent to 4D cardiac computed tomography simulation. The clinical target volume was identified in the area around pulmonary veins (PV). Stereotactic arrhythmia radioablation was performed with a total dose of 25 Gy (single fraction) delivered in 3 min. Twenty patients were enrolled and 18 underwent STAR. One patient withdrew informed consent before treatment and one patient was excluded due to unfavourable oesophagus position. With a median follow-up (FU) of 16 months (range 12-23), no acute toxicity more than Grade 3 was reported. Five patients had a Grade 1 oesophagitis 24 h after STAR; eight patients had an asymptomatic Grade 1 pericardial effusion, and one patient had a torsade de pointes treated effectively by electrical cardioversion and subsequent cardiac implantable cardioverter-defibrillator implantation. Most patients had a significant reduction in AF episodes. Five patients, due to arrhythmias recurrences after STAR, performed electrophysiological study documenting successful PV isolation. Finally, a significant improvement of quality of life was documented (48 ± 15 at enrolment vs. 75 ± 15 at 12 months FU; P < 0.001).

CONCLUSION

The present phase II trial demonstrated the feasibility of STAR in paroxysmal AF elderly patients and its potential role in increasing the quality of life. Surely, more robust data are needed about safety and efficacy.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04575662.

Cardiac Arrhythmias in Patients Treated for Lung Cancer: A Review

Cardio-oncology currently faces one of the greatest challenges in the field of health care. The main goal of this discipline is to ensure that patients treated for cancer do not suffer or die from cardiovascular disease. The number of studies on the mechanisms of heart injury during cancer treatment is constantly increasing. However, there is insufficient data on heart rhythm disorders that may result from this treatment. This issue seems to be particularly important in patients with lung cancer, in whom anticancer therapy, especially radiotherapy, may contribute to the onset of cardiac arrhythmias. The observed relationship between cardiac dosimetry and radiotherapy-induced cardiotoxicity in lung cancer treatment may explain the increased mortality from cardiovascular causes in patients after chest irradiation. Further research is essential to elucidate the role of cardiac arrhythmias in this context. Conversely, recent reports have highlighted the application of stereotactic arrhythmia radioablation (STAR) in the treatment of ventricular tachycardia. This review of available studies on the epidemiology, pathogenesis, diagnosis, and treatment of arrhythmias in patients treated for lung cancer aims to draw attention to the need for regular cardiological monitoring in this group of patients. Improving cardiac care for patients with lung cancer has the potential to enhance their overall therapeutic outcomes.