Prognostic impact of left ventricular ejection fraction in patients with electrical storm

Management of patients with an electrical storm or clustered ventricular arrhythmias: a clinical consensus statement of the European Heart Rhythm Association of the ESC-endorsed by the Asia-Pacific Heart Rhythm Society, Heart Rhythm Society, and Latin-American Heart Rhythm Society

Electrical storm (ES) is a state of electrical instability, manifesting as recurrent ventricular arrhythmias (VAs) over a short period of time (three or more episodes of sustained VA within 24 h, separated by at least 5 min, requiring termination by an intervention). The clinical presentation can vary, but ES is usually a cardiac emergency. Electrical storm mainly affects patients with structural or primary electrical heart disease, often with an implantable cardioverter-defibrillator (ICD). Management of ES requires a multi-faceted approach and the involvement of multi-disciplinary teams, but despite advanced treatment and often invasive procedures, it is associated with high morbidity and mortality. With an ageing population, longer survival of heart failure patients, and an increasing number of patients with ICD, the incidence of ES is expected to increase. This European Heart Rhythm Association clinical consensus statement focuses on pathophysiology, clinical presentation, diagnostic evaluation, and acute and long-term management of patients presenting with ES or clustered VA.

Electrical storm treatment by percutaneous stellate ganglion block: the STAR study

BACKGROUND AND AIMS

An electrical storm (ES) is a clinical emergency with a paucity of established treatment options. Despite initial encouraging reports about the safety and effectiveness of percutaneous stellate ganglion block (PSGB), many questions remained unsettled and evidence from a prospective multicentre study was still lacking. For these purposes, the STAR study was designed.

METHODS

This is a multicentre observational study enrolling patients suffering from an ES refractory to standard treatment from 1 July 2017 to 30 June 2023. The primary outcome was the reduction of treated arrhythmic events by at least 50% comparing the 12 h following PSGB with the 12 h before the procedure. STAR operators were specifically trained to both the anterior anatomical and the lateral ultrasound-guided approach.

RESULTS

A total of 131 patients from 19 centres were enrolled and underwent 184 PSGBs. Patients were mainly male (83.2%) with a median age of 68 (63.8-69.2) years and a depressed left ventricular ejection fraction (25.0 ± 12.3%). The primary outcome was reached in 92% of patients, and the median reduction of arrhythmic episodes between 12 h before and after PSGB was 100% (interquartile range -100% to -92.3%). Arrhythmic episodes requiring treatment were significantly reduced comparing 12 h before the first PSGB with 12 h after the last procedure [six (3-15.8) vs. 0 (0-1), P < .0001] and comparing 1 h before with 1 h after each procedure [2 (0-6) vs. 0 (0-0), P < .001]. One major complication occurred (0.5%).

CONCLUSIONS

The findings of this large, prospective, multicentre study provide evidence in favour of the effectiveness and safety of PSGB for the treatment of refractory ES.

Distribution and prognostic impact of coronary artery disease and nonischemic cardiomyopathies in patients with electrical storm

BACKGROUND

The distribution and prognostic impact of coronary artery disease (CAD) in ES are still under debate.

METHODS

Consecutive ES patients with implantable cardioverter-defibrillator (ICD) were included retrospectively from 2002 to 2016. Three analyses were applied to characterize ES patients: (a) ES patients without CAD (non-CAD), (b) ES patients with CAD (CAD), and (c) diagnostic findings assessed by coronary angiography (CA) at the time of ES (immediate CA). CAD was compared with non-CAD ES patients, and progressive CAD was compared with stable CAD ES patients. The primary endpoint was all-cause mortality at 2.5 years. Secondary endpoints were the composite endpoint of first recurrent ventricular tachyarrhythmias and appropriate ICD therapies, and recurrence of ES (ES-R) at 2.5 years.

RESULTS

Within a total of 87 consecutive ES patients. CAD was present in more than two-thirds (67%). However, only 52% patients underwent immediate CA at the time of ES. Here, 84% had CAD, of which 39% revealed progressive CAD with the need of target vessel revascularization (TVR) or cardiac transplantation (n = 1). At long-term follow-up, neither the presence (or absence) of CAD (41% vs. 34%; log rank P = 0.708) nor of progressive CAD (33% vs. 26%; log rank P = 0.372) was associated with all-cause mortality at 2.5 years, and further secondary endpoints including the composite of recurrent ventricular tachyarrhythmias plus appropriate ICD therapies, or ES-R.

CONCLUSION

In ES patients, CAD was more common than non-CAD-related cardiac diseases, accompanied by an underinvestigated rate of CA despite increasing rates of progressive CAD. CAD had no prognostic impact in ES.