Restrictions on Driving by Heart Patients May Be Unwarranted
Aug. 8, 2001 -- Each year about 100,000 people with potentially life-threatening heart rhythm problems receive a device called a pacemaker-defibrillator -- like the one implanted in Vice President Dick Cheney five weeks ago. Many others are treated with drugs, also given to reduce the risk of death from sudden cardiac arrest.
Because patients with irregular heart rhythms, or arrhythmias, often lose consciousness with little or no warning when an attack occurs, the question of whether it is safe for them to drive is a controversial one. Many medical groups recommend that people treated for arrhythmias refrain from driving for six months or more. And such patients are prohibited from driving by law in some areas.
But there is little medical evidence to support such prohibitions, and a new study published in the Aug. 9 issue of TheNew England Journal of Medicine suggests they may not be warranted. L. Brent Mitchell, MD, and colleagues found that patients who had recently received treatment for life-threatening arrhythmias had the same risk of having an accident while driving as the general population.
"When we looked for evidence justifying these driving prohibitions, we were not able to find it," Mitchell tells WebMD. "We are not suggesting that physicians tell their patients to ignore these guidelines, or that patients ignore the advice of their doctors. But we definitely believe that all guidelines and legal restrictions need to be revisited."
The researchers asked about 750 patients with life-threatening irregular heartbeats about their driving habits. All of the patients had been resuscitated from a near fatal heart arrhythmia and recently been placed on drugs to control the condition or had received a pacemaker/defibrillator.
More than half of those completing the anonymous survey said they resumed driving within three months of receiving treatment and over three-quarters were driving within six months. Approximately 9% of those surveyed acknowledged having had an accident during an average follow-up period of 35 months, but the accidents were preceded by symptoms of possible arrhythmia in only one in 10 of them.
"While many patients are ignoring these guidelines, some are doing so at their own risk with regard to the law and insurers," Mitchell says. " Most insurers will take the position that they should not be driving, and they may not be covered if something happens."
Of the approximately 40,000 deaths related to motor vehicle accidents occurring in the U.S. each year, only a very small percentage of them are caused by medical conditions, according to the U.S. Department of Transportation. But it is impossible to pinpoint exactly how many accidents are due to arrhythmias because data on such accidents are sparse. In a scientific statement published in 1996, the American Heart Association called for the establishment of a database to define the risk of driving accidents among patients treated for arrhythmias.
Timothy W. Smith, MD, of the Washington University School of Medicine in St. Louis, says limitations of the newly published study prevent it from being the definitive word on whether people who are newly treated for heart arrhythmias should drive. Smith wrote an editorial on the study, also published in TheNew England Journal of Medicine.
"I don't think that this study in and of itself is strong enough to recommend that patients and their doctors ignore established guidelines," Smith tells WebMD. "In some cases the data are so strong that it makes sense to reject such guidelines, but this is not the case with this study."