麻豆传媒

Early ventricular arrhythmias (VAs) commonly occur after left ventricular assist device (LVAD) implantation, researchers found, although whether inherently dangerous or merely a marker of disease severity remained unclear.

A quarter of the 652 LVAD recipients in the observational ASSIST-ICD study suffered early VAs in the form of sustained ventricular tachycardia (VT) and/or ventricular fibrillation (VF) within 30 days and required appropriate implantable cardioverter-defibrillator (ICD) therapy, external electric shock, or medical therapy.

The strongest predictor of 30-day mortality after LVAD surgery was an early VA with electrical storm (OR 7.36, 95% CI 2.71-20.00).

Early VAs without electrical storm did not have a significant relationship with mortality, reported Raphael Martins, MD, PhD, of Centre Hospitalier Universitaire de Rennes, France, and colleagues in the August issue of .

Martins' group advocated for a multidisciplinary "LVAD Heart Team" (which would include electrophysiologists) to make decisions, such as whether the patient should get combination surgery.

"Patients with a history of VAs should be evaluated by electrophysiologists prior to LVAD implantation and a VT ablation could be discussed in selected patients," the ASSIST-ICD study authors said. "An aggressive management of arrhythmias should be pursued, using antiarrhythmic drugs and proposing catheter ablation of VAs in selected patients."

In addition, ICU physicians should be trained to remain vigilant about VAs in the post-operative period and to contact electrophysiologists when one occurs, they suggested.

"Indeed, despite the continuous flow generated by the LVAD, early VAs can lead to right ventricular failure and hemodynamic deterioration in this high-risk post-operative period," the group noted.

Lower odds of death were also observed among LVAD recipients with ICDs (OR 0.04, 95% CI 0.02-0.09).

However, while it is plausible that early post-operative VAs (particularly with electrical storm) may contribute to worse outcomes, it is also possible that early VAs are merely a marker for patients who were more ill, according to Joshua Moss, MD, of the University of California San Francisco.

"Another issue common to many analyses of this distinctive patient population is the way 'survival' is defined. From a statistical standpoint, termination of LVAD support at the time of heart transplantation is treated as an equivalent outcome to death; patients experiencing either outcome are censored from further follow-up," Moss noted in an .

He pointed out that the ASSIST-ICD investigators likewise combined transplantation and death in survival analyses from which they concluded no significant transplant-free survival difference in patients with or without (beyond 30 days).

Their observational study collected data on people with end-stage heart failure who received LVADs in 2006-2016.

This 652-person cohort had a median age of 59.8 years; 86.0% were men; and left ventricular ejection fraction averaged 20.7%. For more than half the group, the indication for LVAD placement was bridge to transplantation.

Devices most commonly used were the HeartMate 2 (72.8%), followed by the HeartWare (19.5%) and Jarvik 2000 (7.7%).

Of the 24.8% of patients who had VAs in the 30 days after LVAD placement, more than half had their first event within the first week.

Early VAs were predicted by a history of VAs (OR 2.36, 95% CI 1.57-3.56) and any combined surgery with LVAD implantation (OR 1.75, 95% CI 1.05-2.93).

While death during hospitalization occurred in 21.2% of patients overall, patients who survived to discharge saw no worse long-term survival with the occurrence of early VAs.

Mortality was less likely for those who got amiodarone during their ICU stay (OR 0.46, 95% CI 0.23-0.92) -- at a median of 2 days after LVAD implantation, possibly for the occurrence of VAs or atrial fibrillation, according to Martins and colleagues.

The investigators cited the observational and retrospective nature of the study as a major limitation. French LVAD recipients also tend to be sicker than U.S. peers at device implantation, they cautioned, limiting the generalizability of the results.

The finding that temporary right extracorporeal life support during LVAD surgery was associated with a halving of early VA risk (OR 0.48, 95% CI 0.24-0.95) could not be explained by Martins' group.

"What we need next are more prospective, randomized studies on interventions to treat and prevent VAs in this population, to see whether there is a positive impact on morbidity and/or mortality," Moss concluded.