Stereotactic Radioablation for Ventricular Tachycardia in the Setting of Electrical Storm.

BACKGROUND: Stereotactic body radiotherapy (SBRT) has been reported as a safe and efficient therapy for treating refractory ventricular tachycardia (VT) despite optimal medical treatment and catheter ablation. However, data on the use of SBRT in patients with electrical storm (ES) is lacking. The aim of this study was to assess the clinical outcomes associated with SBRT in the context of ES. METHODS: This retrospective study included patients who underwent SBRT in the context of ES from March 2020 to March 2021 in one tertiary center (CHU Lille). The target volume was delineated according to a predefined workflow. The efficacy was assessed with the following end points: sustained VT recurrence, VT reduced with antitachycardia pacing, and implantable cardioverter defibrillator shock. RESULTS: Seventeen patients underwent SBRT to treat refractory VT in the context of ES (mean 67±12.8 age, 59% presenting ischemic heart disease, mean left ventricular ejection fraction: 33.7± 9.7%). Five patients presented with ES related to incessant VT. Among these 5 patients, the time to effectiveness ranged from 1 to 7 weeks after SBRT. In the 12 remaining patients, VT recurrences occurred in 7 patients during the first 6 weeks following SBRT. After a median 12.5 (10.5-17.8) months follow-up, a significant reduction of the VT burden was observed beyond 6 weeks (-91% [95% CI, 78-103]), P<0.0001). The incidence of implantable cardioverter defibrillator shock and antitachycardia pacing was 36% at 1 year. CONCLUSIONS: SBRT is associated with a significant reduction of the VT burden in the event of an ES; however, prospective randomized control trials are needed. In patients without incessant VT, recurrences are observed in half of patients during the first 6 weeks. VT tolerance and implantable cardioverter defibrillator programming adjustments should be integrated as part of an action plan defined before SBRT for each patient.

Usefulness of remote monitoring for the early detection of back-up mode in implantable cardioverter defibrillators.

BACKGROUND: Reversion of an implantable cardioverter defibrillator (ICD) to back-up mode degrades the operating capabilities of the device, puts patients at risk and requires rapid intervention by a manufacturer's technician. AIM: To illustrate the usefulness of remote monitoring of ICDs for the early detection of reversion to back-up mode. METHODS: In our centre, all patients implanted with an ICD, with or without resynchronisation, were offered remote monitoring as soon as the technology became available. Alerts triggered by the remote monitoring system were included prospectively in a register. During a mean follow-up of 5.7±1.3 years, a total of 1594 patients with an ICD (441 with resynchronisation function) followed with remote monitoring were included in the register. RESULTS: Among 15,874 alerts, only 10 were related to a reversion to back-up mode. Among those, seven reversions were caused by radiotherapy, two were fake events and one was caused by magnetic resonance imaging. Except for the two fake events, the eight other patients had an emergency admission for the resetting and reprogramming of their ICD. None of the reversion to back-up mode alerts was followed by a clinical alert (i.e. a shock alert) before the ICD problem was resolved. CONCLUSIONS: Reversion to back-up mode is a very rare event, accounting for 0.06% of total alerts; remote monitoring facilitates the early detection of this critical event to resolve the problem faster than the next scheduled follow-up. Remote monitoring can prevent serious damage to the patient and avoids systematic ambulatory control of the ICD after each radiotherapy session.

Daytime variation of perioperative myocardial injury in cardiac surgery and its prevention by Rev-Erbα antagonism: a single-centre propensity-matched cohort study and a randomised study.

BACKGROUND: On-pump cardiac surgery provokes a predictable perioperative myocardial ischaemia-reperfusion injury which is associated with poor clinical outcomes. We determined the occurrence of time-of-the-day variation in perioperative myocardial injury in patients undergoing aortic valve replacement and its molecular mechanisms. METHODS: We studied the incidence of major adverse cardiac events in a prospective observational single-centre cohort study of patients with severe aortic stenosis and preserved left ventricular ejection fraction (>50%) who were referred to our cardiovascular surgery department at Lille University Hospital (Lille, France) for aortic valve replacement and underwent surgery in the morning or afternoon. Patients were matched into pairs by propensity score. We also did a randomised study, in which we evaluated perioperative myocardial injury and myocardial samples of patients randomly assigned (1:1) via permuted block randomisation (block size of eight) to undergo isolated aortic valve replacement surgery either in the morning or afternoon. We also evaluated human and rodent myocardium in ex-vivo hypoxia-reoxygenation models and did a transcriptomic analysis in myocardial samples from the randomised patients to identify the signalling pathway(s) involved. The primary objective of the study was to assess whether myocardial tolerance of ischaemia-reperfusion differed depending on the timing of aortic valve replacement surgery (morning vs afternoon), as measured by the occurrence of major adverse cardiovascular events (cardiovascular death, myocardial infarction, and admission to hospital for acute heart failure). The randomised study is registered with ClinicalTrials.gov, number NCT02812901. FINDINGS: In the cohort study (n=596 patients in matched pairs who underwent either morning surgery [n=298] or afternoon surgery [n=298]), during the 500 days following aortic valve replacement, the incidence of major adverse cardiac events was lower in the afternoon surgery group than in the morning group: hazard ratio 0·50 (95% CI 0·32-0·77; p=0·0021). In the randomised study, 88 patients were randomly assigned to undergo surgery in the morning (n=44) or afternoon (n=44); perioperative myocardial injury assessed with the geometric mean of perioperative cardiac troponin T release was significantly lower in the afternoon group than in the morning group (estimated ratio of geometric means for afternoon to morning of 0·79 [95% CI 0·68-0·93; p=0·0045]). Ex-vivo analysis of human myocardium revealed an intrinsic morning-afternoon variation in hypoxia-reoxygenation tolerance, concomitant with transcriptional alterations in circadian gene expression with the nuclear receptor Rev-Erbα being highest in the morning. In a mouse Langendorff model of hypoxia-reoxygenation myocardial injury, Rev-Erbα gene deletion or antagonist treatment reduced injury at the time of sleep-to-wake transition, through an increase in the expression of the ischaemia-reperfusion injury modulator CDKN1a/p21. INTERPRETATION: Perioperative myocardial injury is transcriptionally orchestrated by the circadian clock in patients undergoing aortic valve replacement, and Rev-Erbα antagonism seems to be a pharmacological strategy for cardioprotection. Afternoon surgery might provide perioperative myocardial protection and lead to improved patient outcomes compared with morning surgery. FUNDING: Fondation de France, Fédération Française de Cardiologie, EU-FP7-Eurhythdia, Agence Nationale pour la Recherche ANR-10-LABX-46, and CPER-Centre Transdisciplinaire de Recherche sur la Longévité.