乌鸦传媒

ORLANDO -- A wearable cardioverter defibrillator (WCD) didn't help prevent sudden cardiac deaths in the immediate post-MI period, the 2,300-patient VEST trial found, but it did provide benefit in secondary outcomes including all-cause mortality and stroke death.

Participants randomized to the Zoll LifeVest for primary prevention defibrillation had a rate of 1.6% for the primary outcome of sudden cardiac death or mortality due to ventricular arrhythmias within 90 days, versus 2.4% for controls (P=0.18), said Jeffrey Olgin, MD, of University of California San Francisco, at the annual (ACC) meeting here.

Nor was there any advantage regarding non-sudden deaths during that time (1.4% versus 2.2%, P=0.15).

Rates of stroke death, however, did favor LifeVest use (0% versus 0.5%, P=0.01), according to Olgin's late-breaking trial presentation. And death from any cause was significantly less likely when patients got the WCD (3.1% versus 4.9%, P=0.04).

These advantages led the investigator to suggest that the LifeVest may confer additional protection beyond sudden death, providing earlier intervention for bradycardia, non-sustained ventricular tachycardia, and aborted shocks.

Based from the VEST findings, "prescribing the WCD is reasonable to protect high-risk patients with a low LVEF post-MI until evaluation for an ICD at 40-90 days," Olgin concluded.

Current guidelines recommend implantable cardioverter defibrillator (ICD) therapy only after at least 40 days post-MI and 90 days post-revascularization for patients with left ventricular ejection fraction (LVEF) 35% or less due to ischemic heart disease. DINAMIT and IRIS were two studies that demonstrated no benefit to getting an ICD early on in this population.

After all, said Olgin, early mortality isn't always due to arrhythmias and therefore not preventable by an ICD; LVEF may recover on its own over time as well.

was experienced by 1.4% of LifeVest recipients. Another 0.6% had an inappropriate shock and 4.6% an aborted one. Olgin noted that 70% of participants that got an appropriate shock survived to 90 days.

Compared to controls, the WCD group suffered more rashes and itches. There was no difference in the rehospitalization rate.

It was a limitation to the VEST trial that participants and investigators weren't blinded, Olgin said.

Also of note was the fact that it took 10 years to enroll the necessary patients for this study -- an "incredible long time," in the words of ACC president Mary Norine Walsh, MD, of St. Vincent Heart Center in Indianapolis.

"The assumption is it had a really hard time enrolling ... that patients were not interested," she said in an interview. A new blow to the LifeVest is that a significant number of patients with a vest did have sudden death in this "long-awaited" data, she suggested.

"This is not a practice-changing trial," Walsh said. "This vest has been available a long time and has been used for other indications – like a patient with sepsis who needs an ICD taken out and you have to clear the sepsis before another device. That is a reason for using the vest. In that patient population – in the absence of data -- some clinicians have been using the vest."

After VEST, it seems "reasonable" to keep WCD therapy as a "reasonable" option for some, Olgin concluded.

The LifeVest may make sense for some higher-risk groups, Allen agreed. "But exactly who these patients are is not immediately apparent, so it remains an area of possible future research. In the meantime, it may be even more appropriate to include patient preferences, where a small potential reduction in sudden death while waiting to decide about ICD implantation is weighed against out-of-pocket costs and lifestyle burdens."

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