OMNI Support for Tighter Postshock Driving Restrictions

November 23, 2011

November 22, 2011 (Orlando, Florida) — Current recommendations to stop driving vehicles for six months after a ventricular arrhythmia triggers a response from a primary-prevention implantable cardioverter defibrillator (ICD), whether for the first time since implantation or not, should perhaps become more restrictive if the device goes off again in the future, conclude the authors of a retrospective analysis from a registry [1].

About 28% of ICD recipients will receive appropriate device therapy, either shocks or antitachycardia pacing (ATP), an average of about a year after the device is implanted, suggest data from 2255 patients who received their devices in 2005 and 2006 in the Medtronic-sponsored OMNI registry, according to a presentation here at the American Heart Association (AHA) 2011 Scientific Sessions . Three-quarters of the registry's patients received primary-prevention devices.

The analysis further suggests that a much higher percentage of patients with a first ICD therapy go on to have a second one, and it will likely strike sooner than the first one did, presenter Dr Michael H Kim (Northwestern University, Chicago, IL) told heartwire . "And then once you've had a second episode, you're going to have the third one sooner."

So the current joint AHA and Heart Rhythm Society guidelines, which recommend six months off from driving after a primary-prevention device delivers either a shock or ATP for the first time or any subsequent time, should be reconsidered, according to Kim.

"I think it should be more restrictive," he said. The data say someone with a first shock has a 62% chance of having a second one in a mean of 5.4 months, "so if more than half are going to have an event within the restriction period, then [the six months] doesn't make sense."

Likelihood of First, Second, and Third Appropriate Therapies and Times Since Last Event in the OMNI Registry

End point Mean months from implant to 1st device therapy (% of all patients) Mean months from 1st to 2nd device therapy (% of patients with a 1st device therapy) Mean months from 2nd to 3rd device therapy (% of patients with a 2nd device therapy)
Appropriate therapy* 13 (27.7) 5.4 (62) 3.1 (74)
Appropriate shocks 14.8 (14.5) 4.1 (56) 3.2 (64)

*includes both shocks and antitachycardia pacing

Kim acknowledges that efforts to further restrict driving in ICD patients who've received therapy are likely to be controversial. But if the guidelines are going to recommend such restrictions in the first place, they should be consistent with the data, "to the point that I would argue that if you have a second or third event, maybe you shouldn't be driving."

Kim discloses being on speaker's bureaus for Sanofi-Aventis and Boehringer Ingelheim and consulting or being on an advisory board for Medtronic and Sanofi-Aventis. Coauthor Dr Fang Yang is an employee of Medtronic.