Driving restrictions advised by midwestern cardiologists implanting cardioverter defibrillators: present practices, criteria utilized, and compatibility with existing state laws

Resumption of driving after life-threatening ventricular tachyarrhythmia

BACKGROUND

Although the privilege of driving must be respected, it may be necessary to restrict driving when it poses a threat to others. The risks associated with allowing patients with life-threatening ventricular tachyarrhythmias to drive have not been quantified.

METHODS

The Antiarrhythmics versus Implantable Defibrillators (AVID) trial compared antiarrhythmic-drug therapy with the implantation of defibrillators in patients resuscitated from near-fatal ventricular arrhythmias. In the current study, we sent patients who participated in the AVID trial a questionnaire, to be completed anonymously, requesting information about driving habits and experiences.

RESULTS

The questionnaire was returned by 758 of 909 patients (83 percent). Of these, 627 patients drove during the year before their index episode of ventricular tachyarrhythmia. A total of 57 percent of these patients resumed driving within 3 months after randomization in the AVID trial, 78 percent within 6 months, and 88 percent within 12 months. While driving, 2 percent had a syncopal episode, 11 percent had dizziness or palpitations that necessitated stopping the vehicle, 22 percent had dizziness or palpitations that did not necessitate stopping the vehicle, and 8 percent of the 295 patients with an implantable cardioverter-defibrillator received a shock. Fifty patients reported having at least 1 accident, for a total of 55 accidents during 1619 patient-years of follow-up after the resumption of driving (3.4 percent per patient-year). Only 11 percent of these accidents were preceded by symptoms of possible arrhythmia (0.4 percent per patient-year).

CONCLUSIONS

Most patients with ventricular tachyarrhythmias resume driving early. Although it is common for them to have symptoms of possible arrhythmia while driving, accidents are uncommon and occur with a frequency that is lower than the annual accident rate of 7.1 percent in the general driving population of the United States.

Baseline factors predicting early resumption of driving after life-threatening arrhythmias in the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial

BACKGROUND

In the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial, patients with ventricular fibrillation or hemodynamically unstable ventricular tachycardia were randomly assigned to receive either an implantable cardioverter-defibrillator (ICD) or antiarrhythmic drug therapy. As part of the trial, patients were asked to participate in a prospective driving survey. The purpose of the survey was to determine what baseline factors and patient characteristics specifically predicted resumption of driving earlier than advised by current guidelines.

METHODS

Patients were surveyed anonymously as to their driving habits in the initial period after random assignment and every 6 months thereafter. AVID study coordinators were independently asked to assess their patients' driving status as well. The relation between baseline factors and time to resumption of driving was explored by means of Kaplan-Meier estimates for univariate analyses and the stepwise Cox proportional hazards regression model for multivariate analyses.

RESULTS

There were 802 patients who were eligible for assessment of driving status. The majority of patients (58%) resumed driving an automobile within 6 months of their index arrhythmia regardless of whether they received drug therapy or an ICD. By multivariate analysis, patients who were younger than 65 years of age, male, and college educated were more likely to drive early, as were patients whose index arrhythmia was ventricular tachycardia.

CONCLUSIONS

Younger, college-educated men and those whose index arrhythmia is ventricular tachycardia are most likely to resume driving <6 months after the initiation of therapy for a potentially life-threatening ventricular arrhythmia. Patients with an ICD did not appear to resume driving later than those who were discharged on antiarrhythmic drugs alone.

Should patients with implantable cardioverter-defibrillators be allowed to drive? Observations in 291 patients from a single center over an 11-year period

Motor-vehicle driving restrictions for patients with implantable cardioverter-defibrillators (ICDs) vary widely throughout the world because safety concerns have never been adequately resolved in this patient population. To address this issue, we examined the driving behavior of 291 ICD patients to correlate the frequency of device therapy during driving, the occurrence of syncopal symptoms, and the incidence of traffic accidents. Fifty of the 291 patients had never driven. Of the remaining 241 patients, 171 (59%) continued driving postimplant and 70 (24%) elected to stop prior to (n = 30) or at the time of ICD implantation (n = 40). Patients were followed for a mean of 38 +/- 26 months (range < 1-124). During this period, no patients died while driving. Of 11 accidents involving 11 driving patients (6%), only 1 was caused by the driver, and none was related to syncopal symptoms or ICD therapy. Although 2 accidents (8%) occurred within 12 months postimplant, the majority (50%) took place after more than 36 months. ICD therapy was delivered in 8 patients (5%) while driving: 13% (1 episode) of the discharges occurred within the first year postimplant, 13% (1 episode) occurred between 1-2 years, and 74% (6 episodes) occurred > 2 years. None of these patients experienced syncope before or during these episodes. A multivariate analysis was unable to identify any variables that might predict increased risk of ICD therapy (with or without sudden death) while driving and consequent motor vehicle accidents. Our data suggest that such events occur only rarely.

Syncope in patients with an implantable cardioverter-defibrillator: incidence, prediction and implications for driving restrictions

OBJECTIVES

This retrospective study was undertaken to provide information on occurrence, risk prediction and prevention of syncope in patients with an implantable cardioverter-defibrillator (ICD).

BACKGROUND

ICDs effectively terminate ventricular tachycardia and fibrillation (VT/VF). Incapacitating symptoms, such as syncope, may still occur.

METHODS

We performed a retrospective analysis of data from 421 patients (clinical history, outpatient chart reviews and episode data) with mean (+/-SD) follow-up of 26 +/- 18 months.

RESULTS

Of 421 patients, 229 (54.4%) had recurrent VT/VF, and 62 (14.7%) had syncope. The actuarial survival rate free of VT/VF was 58%, 45% and 37% and that for survival free of syncope was 90%, 85% and 81% at 12, 24 and 36 months after implantation, respectively. Once VT/VF had occurred, 76%, 68% and 62% of patients remained free of syncope during the following 12, 24 and 36 months, and 68%, 64% and 56% remained free of second syncope 12, 24 and 36 months after first syncope, respectively. In cases of syncope, the mean cycle length (CL) of VT was 251 +/- 56 ms. A low baseline left ventricular ejection fraction (LVEF), induction of fast VT (CL <300 ms) during programmed ventricular stimulation and chronic atrial fibrillation (AF) were associated with an increased risk of syncope. If the LVEF was >40%, fast VT had not been induced, and patients had no chronic AF; 96%, 92% and 92% of patients remained free of syncope after 12, 24 and 36 months, respectively. Once patients had a VT recurrence, syncope during the first VT and a high VT rate were the strongest risk predictors of future syncope.

CONCLUSIONS

Identification of patients with an ICD with a low and high risk of syncope seems to be feasible and might help as a guide to driving restrictions in such patients.

Modification of patient driving behavior after implantation of a cardioverter defibrillator

Driving habits among recipients of ICDs have not been well characterized previously, yet such information may have implications for development of national policy. This study was undertaken to characterize driving behavior after defibrillator implantation in our patient population. From 1988-1993, 82 ICDs were implanted at the University of Florida. All patients received defibrillator teaching preoperatively and postoperatively with particular emphasis placed on driving restrictions. A standardized questionnaire was developed to ascertain driving behavior, compliance with restrictions, and occurrence of motor vehicle accidents following implantation. The patients were divided into two groups according to whether or not they had received a shock from their device since implantation. Group I patients did, and Group II patients did not. Fifty-two out of 82 (63%, Group I) patients had at least one shock. The remaining 30 patients had received no shocks. Mean age and gender were no different between the two groups. Mean time since implantation was 6 +/- 1.3 years in Group I, compared to 4 +/- 1.5 years in Group II (P = 0.001). Forty-seven out of 52 (90%) and 26 out of 30 (87%) in Groups I and II, respectively, resumed driving after defibrillator implantation. There was no difference in the amount of time that passed prior to resumption of driving. Group I patients drove more, 20.5 +/- 27 miles/day compared to patients in Group II, 8.3 +/- 9.7 miles/day (P = 0.02). No patient experienced device discharge during driving; likewise, no patient was involved in a motor vehicle accident secondary to their device firing. Sixty-seven out of 82 (82%) patients complied with the instructions they thought they heard; seven patients in Group I and eight patients in Group II deliberately did not follow our advice. The majority of patients do comply with physician instructions, although the instructions they remember are not always the instructions given. If a national policy is created to prohibit driving after ICD implantation, effective enforcement may be difficult.

Motor vehicle accidents in patients with an implantable cardioverter-defibrillator

OBJECTIVES

This study was designed to examine driving safety in patients at risk for sudden death after implantation of a cardioverter-defibrillator.

BACKGROUND

Cardioverter-defibrillators are frequently implanted in patients at high risk for sudden death. Despite concern about the safety of driving in these patients, little is known about their actual motor vehicle accident rates.

METHODS

Surveys were sent to all 742 physicians in the United States involved in cardioverter-defibrillator implantation and follow-up. Physicians were questioned about numbers of patients followed up, numbers of fatal and nonfatal accidents, physician recommendations to patients about driving and knowledge of state driving laws.

RESULTS

Surveys were returned by 452 physicians (61%). A total of 30 motor vehicle accidents related to shocks from implantable defibrillators were reported by 25 physicians over a 12-year period from 1980 to 1992. Of these, nine were fatal accidents involving eight patients with a defibrillator and one passenger in a car driven by a patient. No bystanders were fatally injured. There were 21 nonfatal accidents involving 15 patients, 3 passengers and 3 bystanders. The estimated fatality rate for patients with a defibrillator, 7.5/100,000 patient-years, is significantly lower than that for the general population (18.4/100,000 patient-years, p < 0.05). The estimated injury rate, 17.6/100,000 patient-years, is also significantly lower than that for the general public (2,224/100,000 patient-years, p < 0.05). Only 10.5% (30 of 286) of all defibrillator discharges during driving resulted in accidents. Regarding physician recommendations, most physicians (58.1%) ask their patients to wait a mean (+/- SD) of 7.3 +/- 3.4 months after implantation or a shock before driving again.

CONCLUSIONS

The motor vehicle accident rate caused by discharge from an implantable cardioverter-defibrillator is low. Although restricting driving for a short period of time after implantation may be appropriate, excessive restrictions or a total ban on driving appears to be unwarranted.

Legal and ethical aspects of driving and working in patients with an implantable cardioverter defibrillator

Automobile driving is essential to work and leisure for many people, and patients with implantable cardioverter defibrillators (ICDs) are no exception. Whether patients who may suffer sudden incapacitation should be allowed to drive raises important ethical and legal issues. The opinion of physicians regarding when or if it is safe to drive with an ICD varies, and most countries have no regulations to assist such decisions. Such regulations can best be developed by actuarial analysis of the risks involved, although the limited volume of published data on the ICD hinders this process. A policy based on very low levels of social risk from driving by patients with ICDs or a comparison with epileptic patients suggests a ban on driving for 12 to 24 months after ICD implantation. Patients who have received therapy from the ICD within this period would not be granted a driver's licence. As further data from actuarial studies become available, these guidelines could be relaxed for patients at low risk of therapy delivery.