Electrical storm in the early phase of HeartMate II device implantation: Incidence, risk factors and prognosis.

Background: Ventricular arrhythmia is common after left ventricular assist device (LVAD) implantation, especially in the early postoperative phase (<30 days).

Aim: To identify the incidence of and risk factors for electrical storm (ES) occurring within 30 days of HeartMate II implantation.

Methods: We reviewed data from all consecutive patients undergoing HeartMate II device implantation at our institution from January 2008 to December 2014. Patient demographic data, pharmacotherapies and outcomes were collected. The primary endpoint was occurrence of early ES (within 30 days of surgery), defined as three or more separate episodes of sustained ventricular arrhythmia within a 24-hour interval, requiring appropriate therapy.

Results: Forty-three patients (mean age 56.7±11.2 years; 39 men) were included. At HeartMate II implantation, mean left ventricular ejection fraction was 20±5%, 32 (74.4%) patients had ischaemic cardiomyopathy and 31 (72.1%) were implanted with an indication of bridge to cardiac transplantation. During follow-up, 12 (27.9%) patients experienced early ES after HeartMate II implantation (median delay 9.1±7.8 days). Early ES was more frequent in larger patients (body surface area 1.99 vs 1.81 m; P<0.01), tended to be associated with previous sustained ventricular tachycardia (50.0% vs 22.6%; P=0.08), previous implantable cardioverter-defibrillator implantation (66.7% vs 38.7%; P=0.09), discontinuation of long-term beta-blocker therapy (75.0% vs 45.2%; P=0.08), weaning of adrenergic drugs after the third day (66.7% vs 35.5%; P=0.06) and the use of extracorporeal life support (50% vs 22.6%; P=0.079), but was not associated with the cardiomyopathy aetiology or the indication for assistance. Catheter ventricular tachycardia ablation was performed in six (14.0%) patients. Early ES was associated with a significantly higher all-cause mortality rate at the 30th day (33.3% vs 6.5%; P=0.02).

Conclusion: ES is a common and pejorative feature in the early postoperative period.