Driving and Implantable Cardioverter-Defibrillator Shocks for Ventricular Arrhythmias

Driving following defibrillator implantation: a nationwide register-linked survey study

AIMS

Patients are restricted from driving following implantable cardioverter defibrillator (ICD) implantation or shock. We sought to investigate how many patients are aware of, and adhere to, the driving restrictions, and what proportion experience an ICD shock or other cardiac symptoms while driving.

METHODS AND RESULTS

We performed a nationwide survey of all living Danish residents 18 years or older who received a first-time ICD between 2013 and 2016 (n = 3913) and linked their responses with nationwide registers. Of 2741 respondents (47% primary prevention, 83% male, median age 67 years), 2513 (92%) held a valid driver's license at ICD implantation, 175 (7%) of whom had a license for professional driving. Many drivers were unaware of driving restrictions: primary prevention 58%; secondary prevention 36%; post-appropriate shock 28%; professional drivers 55%. Almost all (94%) resumed non-professional driving after ICD implantation, more than one-third during the restricted period; 35% resumed professional driving. During a median follow-up of 2.3 years, 5 (0.2%) reported receiving an ICD shock while driving, one of which resulted in a traffic accident. The estimated risk of harm was 0.0002% per person-year.

CONCLUSION

In this nationwide study, many ICD patients were unaware of driving restrictions, and more than one third resumed driving during a driving restriction period. However, the rate of reported ICD shocks while driving was very low.

A Review of Driving Restrictions in Patients at Risk of Syncope and Cardiac Arrhythmias Associated with Sudden Incapacity: Differing Global Approaches to Regulation and Risk

The ability to drive is a highly valued freedom in the developed world. Sudden incapacitation while driving can result in injury or death for the driver and passengers or bystanders. Cardiovascular conditions are a primary cause for sudden incapacitation and regulations have long existed to restrict driving for patients with cardiac conditions at high risk of sudden incapacitation. Significant variation occurs between these rules in different countries and legislatures. Quantification of the potential risk of harm associated with various categories of drivers has attempted to make these regulations more objective. The assumptions on which these calculations are based are now old and less likely to reflect the reality of modern driving. Ultimately, a more individual assessment of risk with a combined assessment of the medical condition and the patient's driving behaviour may be appropriate. The development of driverless technologies may also have an impact on decision making in this field.

Ambient and controlled exposures to particulate air pollution and acute changes in heart rate variability and repolarization

Previous studies have reported increased risks of myocardial infarction in association with elevated ambient particulate matter (PM) in the previous hour(s). However, whether PM can trigger mechanisms that act on this time scale is still unclear. We hypothesized that increases in PM are associated with rapid changes in measures of heart rate variability and repolarization. We used data from panel studies in Augsburg, Germany, and Rochester, New York, USA, and two controlled human exposure studies in Rochester. Data included ECG recordings from all four studies, controlled exposures to (concentrated) ultrafine particles (UFP; particles with an aerodynamic diameter <100 nm) and ambient concentrations of UFP and fine PM (PM_2.5, aerodynamic diameter <2.5 μm). Factor analysis identified three representative ECG parameters: standard deviation of NN-intervals (SDNN), root mean square of successive differences (RMSSD), and T-wave complexity. Associations between air pollutants and ECG parameters in the concurrent and previous six hours were estimated using additive mixed models adjusting for long- and short-term time trends, meteorology, and study visit number. We found decreases in SDNN in relation to increased exposures to UFP in the previous five hours in both of the panel studies (e.g. Augsburg study, lag 3 hours: −2.26%, 95% confidence interval [CI]: −3.98% to −0.53%; Rochester panel study, lag 1 hour: −2.69%; 95% CI: −5.13% to −0.26%) and one of the two controlled human exposure studies (1-hour lag: −13.22%; 95% CI: −24.11% to −2.33%). Similarly, we observed consistent decreases in SDNN and RMSSD in association with elevated PM_2.5 concentrations in the preceding six hours in both panel studies. We did not find consistent associations between particle metrics and T-wave complexity. This study provided consistent evidence that recent exposures to UFP and PM_2.5 can induce acute pathophysiological responses.

Driving with cardiac devices in Australia. Does a review of recent evidence prompt a change in guidelines?

Australian Driving Guidelines for patients with pacemakers and implanted cardioverter defibrillators are in line with many around the world, with some minor differences. Some aspects of these guidelines lack contemporary evidence in key decision-making areas and make broad recommendations regarding groups with heterogeneous populations. In addition, more recent studies suggest lower rates of adverse events in some patients with these devices than previously thought. Through a systematic literature review, along with discussion of current guidelines, we combine new evidence with well established risk assessment tools to ask the following questions: (i) Given the heterogeneity of patient risk within the defibrillator population, should guidelines allow for further individualisation of risk and subsequent licensing restrictions?; and (ii) Could some patients with primary prevention automated cardioverter defibrillators be able to hold a commercial driving licence?

Inappropriate implantable cardioverter defibrillator shocks-incidence, effect, and implications for driver licensing

Purpose

Patients with implantable cardioverter defibrillators (ICDs) have an ongoing risk of sudden incapacitation that may cause traffic accidents. However, there are limited data on the magnitude of this risk after inappropriate ICD therapies. We studied the rate of syncope associated with inappropriate ICD therapies to provide a scientific basis for formulating driving restrictions.

Methods

Inappropriate ICD therapy event data between 1997 and 2014 from 50 Japanese institutions were analyzed retrospectively. The annual risk of harm (RH) to others posed by a driver with an ICD was calculated for private driving habits. We used a commonly employed annual RH to others of 5 in 100,000 (0.005%) as an acceptable risk threshold.

Results

Of the 4089 patients, 772 inappropriate ICD therapies occurred in 417 patients (age 61 ± 15 years, 74% male, and 65% secondary prevention). Patients experiencing inappropriate therapies had a mean number of 1.8 ± 1.5 therapy episodes during a median follow-up period of 3.9 years. No significant differences were found in the age, sex, or number of inappropriate therapies between patients receiving ICDs for primary or secondary prevention. Only three patients (0.7%) experienced syncope associated with inappropriate therapies. The maximum annual RH to others after the first therapy in primary and secondary prevention patients was calculated to be 0.11 in 100,000 and 0.12 in 100,000, respectively.

Conclusions

We found that the annual RH from driving was far below the commonly cited acceptable risk threshold. Our data provide useful information to supplement current recommendations on driving restrictions in ICD patients with private driving habits.

Electronic supplementary material

The online version of this article (doi:10.1007/s10840-017-0272-4) contains supplementary material, which is available to authorized users.

Driving restrictions in patients with implantable cardioverter defibrillators and pacemakers

Implantable cardioverter-defibrillators (ICDs) improve the survival in patients at risk of sudden cardiac death. However, these patients have an ongoing risk of sudden incapacitation that may cause harm to individuals and others when driving. Considerable disagreement exists about whether and when these patients should be allowed to resume driving after ICD therapies. This information is critical for the management decisions to avoid future potentially lethal incidents and unnecessary restrictions for ICD patients. The cardiac implantable device committee of the Japanese Heart Rhythm Society reassessed the risk of driving for ICD patients based on the literature and domestic data. We reviewed the driving restrictions of ICD patients in various regions and here present updated Japanese driving restrictions.

Sports and Driving With an Implantable Cardioverter-Defibrillator

Many patients with implantable cardioverter-defibrillators (ICD) want to participate in sports and many need or wish to operate a personal motor vehicle. Healthcare providers need to advise patients regarding restrictions related to these activities in the context of the clinical indication for the ICD. Ethical considerations need to be considered when advising ICD patients of restrictions to reduce risk of injury to themselves and to others when participating in either sports or driving. Shared decision-making is necessary to have ICD patients understand and comply with recommended restrictions. Guidelines have been developed based on available studies; however, studies assessing the need for ICD patients to restrict these activities are observational and often out of date. More recent studies challenge driving and sports restrictions that are recommended by the guidelines. Recommendations to ICD patients must be individualized yet be compliant with the guidelines, and need to adapt to changes in a patients' condition.

Syncope and Driving

The occurrence of syncope while driving has obvious implications for personal and public safety. Neurally mediated syncope is the most common type of syncope in general and, thereby, also while driving. The presence of structural heart disease (reduced ejection fraction, previous myocardial infarction, significant congenital heart disease) potentially leads to high risk and should determine driving restrictions pending clarification of underlying heart disease and etiology of syncope. The clinical approach to syncope evaluation and recommendations for driving should not differ, whether or not the syncopal spell occurred while driving.

Public health and components of particulate matter: the changing assessment of black carbon

In 2012, the WHO classified diesel emissions as carcinogenic, and its European branch suggested creating a public health standard for airborne black carbon (BC). In 2011, EU researchers found that life expectancy could be extended four to nine times by reducing a unit of BC, vs reducing a unit of PM2.5. Only recently could such determinations be made. Steady improvements in research methodologies now enable such judgments. In this Critical Review, we survey epidemiological and toxicological literature regarding carbonaceous combustion emissions, as research methodologies improved over time. Initially, we focus on studies of BC, diesel, and traffic emissions in the Western countries (where daily urban BC emissions are mainly from diesels). We examine effects of other carbonaceous emissions, e.g., residential burning of biomass and coal without controls, mainly in developing countries. Throughout the 1990s, air pollution epidemiology studies rarely included species not routinely monitored. As additional PM2.5. chemical species, including carbonaceous species, became more widely available after 1999, they were gradually included in epidemiological studies. Pollutant species concentrations which more accurately reflected subject exposure also improved models. Natural "interventions"--reductions in emissions concurrent with fuel changes or increased combustion efficiency; introduction of ventilation in highway tunnels; implementation of electronic toll payment systems--demonstrated health benefits of reducing specific carbon emissions. Toxicology studies provided plausible biological mechanisms by which different PM species, e.g, carbonaceous species, may cause harm, aiding interpretation of epidemiological studies. Our review finds that BC from various sources appears to be causally involved in all-cause, lung cancer and cardiovascular mortality, morbidity, and perhaps adverse birth and nervous system effects. We recommend that the US. EPA rubric for judging possible causality of PM25. mass concentrations, be used to assess which PM2.5. species are most harmful to public health.

IMPLICATIONS

Black carbon (BC) and correlated co-emissions appear causally related with all-cause, cardiovascular, and lung cancer mortality, and perhaps with adverse birth outcomes and central nervous system effects. Such findings are recent, since widespread monitoring for BC is also recent. Helpful epidemiological advances (using many health relevant PM2.5 species in models; using better measurements of subject exposure) have also occurred. "Natural intervention" studies also demonstrate harm from partly combusted carbonaceous emissions. Toxicology studies consistently find biological mechanisms explaining how such emissions can cause these adverse outcomes. A consistent mechanism for judging causality for different PM2.5 species is suggested.

Cardiac Resynchronization Therapy With and Without Defibrillator in a Commercial Truck Driver with Ischemic Cardiomyopathy and New York Heart Association Class III Heart Failure

Commercial drivers warrant tighter restrictions to their driving privileges than private drivers. Patients with cardiac disease who are at risk of consciousness-impairing arrhythmias are not allowed to drive commercially. Patients with left ventricular systolic dysfunction and/or heart failure symptoms are permanently disqualified from commercial driving. A biventricular pacemaker without defibrillator can improve symptoms and mortality in selected patients with heart failure. Biventricular pacing may have antiarrhythmic effects that may reduce the added benefit of a defibrillator. Motor vehicle collisions resulting from arrhythmic events are infrequent. The interests of public safety must outweigh individual liberties when driving safety is in question.

Driving restrictions after implantable cardioverter defibrillator implantation: an evidence-based approach

Aims

Little evidence is available regarding restrictions from driving following implantable cardioverter defibrillator (ICD) implantation or following first appropriate or inappropriate shock. The purpose of the current analysis was to provide evidence for driving restrictions based on real-world incidences of shocks (appropriate and inappropriate).

Methods and results

A total of 2786 primary and secondary prevention ICD patients were included. The occurrence of shocks was noted during a median follow-up of 996 days (inter-quartile range, 428–1833 days). With the risk of harm (RH) formula, using the incidence of sudden cardiac incapacitation, the annual RH to others posed by a driver with an ICD was calculated. Based on Canadian data, the annual RH to others of 5 in 100 000 (0.005%) was used as a cut-off value. In both primary and secondary prevention ICD patients with private driving habits, no restrictions to drive directly following implantation, or an inappropriate shock are warranted. However, following an appropriate shock, these patients are at an increased risk to cause harm to other road users and therefore should be restricted to drive for a period of 2 and 4 months, respectively. In addition, all ICD patients with professional driving habits have a substantial elevated risk to cause harm to other road users during the complete follow-up after both implantation and shock and should therefore be restricted to drive permanently.

Conclusion

The current analysis provides a clinically applicable tool for guideline committees to establish evidence-based driving restrictions.

Reduction in heart rate variability with traffic and air pollution in patients with coronary artery disease

INTRODUCTION

Ambient particulate pollution and traffic have been linked to myocardial infarction and cardiac death risk. Possible mechanisms include autonomic cardiac dysfunction.

METHODS

In a repeated-measures study of 46 patients 43-75 years of age, we investigated associations of central-site ambient particulate pollution, including black carbon (BC) (a marker for regional and local traffic), and report of traffic exposure with changes in half-hourly averaged heart rate variability (HRV), a marker of autonomic function measured by 24-hr Holter electrocardiogram monitoring. Each patient was observed up to four times within 1 year after a percutaneous intervention for myocardial infarction, acute coronary syndrome without infarction, or stable coronary artery disease (4,955 half-hour observations). For each half-hour period, diary data defined whether the patient was home or not home, or in traffic.

RESULTS

A decrease in high frequency (HF; an HRV marker of vagal tone) of 16.4% [95% confidence interval (CI), 20.7 to 11.8%] was associated with an interquartile range of 0.3-microg/m3 increase in prior 5-day averaged ambient BC. Decreases in HF were independently associated both with the previous 2-hr averaged BC (10.4%; 95% CI, 15.4 to 5.2%) and with being in traffic in the previous 2 hr (38.5%; 95% CI, 57.4 to 11.1%). We also observed independent responses for particulate air matter with aerodynamic diameter < or = 2.5 microm and for gases (ozone or nitrogen dioxide).

CONCLUSION

After hospitalization for coronary artery disease, both particulate pollution and being in traffic, a marker of stress and pollution, were associated with decreased HRV.

Cardiovascular health and particulate vehicular emissions: a critical evaluation of the evidence

A major public health goal is to determine linkages between specific pollution sources and adverse health outcomes. This paper provides an integrative evaluation of the database examining effects of vehicular emissions, such as black carbon (BC), carbonaceous gasses, and ultrafine PM, on cardiovascular (CV) morbidity and mortality. Less than a decade ago, few epidemiological studies had examined effects of traffic emissions specifically on these health endpoints. In 2002, the first of many studies emerged finding significantly higher risks of CV morbidity and mortality for people living in close proximity to major roadways, vs. those living further away. Abundant epidemiological studies now link exposure to vehicular emissions, characterized in many different ways, with CV health endpoints such as cardiopulmonary and ischemic heart disease and circulatory-disease-associated mortality; incidence of coronary artery disease; acute myocardial infarction; survival after heart failure; emergency CV hospital admissions; and markers of atherosclerosis. We identify numerous in vitro, in vivo, and human panel studies elucidating mechanisms which could explain many of these cardiovascular morbidity and mortality associations. These include: oxidative stress, inflammation, lipoperoxidation and atherosclerosis, change in heart rate variability (HRV), arrhythmias, ST-segment depression, and changes in vascular function (such as brachial arterial caliber and blood pressure). Panel studies with accurate exposure information, examining effects of ambient components of vehicular emissions on susceptible human subjects, appear to confirm these mechanisms. Together, this body of evidence supports biological mechanisms which can explain the various CV epidemiological findings. Based upon these studies, the research base suggests that vehicular emissions are a major environmental cause of cardiovascular mortality and morbidity in the United States. As a means to reduce the public health consequences of such emissions, it may be desirable to promulgate a black carbon (BC) PM(2.5) standard under the National Ambient Air Quality Standards, which would apply to both on and off-road diesels. Two specific critical research needs are identified. One is to continue research on health effects of vehicular emissions, gaseous as well as particulate. The second is to utilize identical or nearly identical research designs in studies using accurate exposure metrics to determine whether other major PM pollutant sources and types may also underlie the specific health effects found in this evaluation for vehicular emissions.

T-wave alternans, air pollution and traffic in high-risk subjects

Particulate pollution has been linked to risk for cardiac death; possible mechanisms include pollution-related increases in cardiac electrical instability. T-wave alternans (TWA) is a marker of cardiac electrical instability measured as differences in the magnitude between adjacent T waves. In a repeated-measures study of 48 patients aged 43 to 75 years, associations of ambient and home indoor particulate pollution, including black carbon (BC) and reports of traffic exposure, with changes in 0.5-hourly maximum TWA (TWA-MAX), measured by 24-hour Holter electrocardiographic monitoring, were investigated. Each patient was observed up to 4 times within 1 year after percutaneous intervention for myocardial infarction, acute coronary syndromes without infarction, or stable coronary artery disease, for a total of 5,830 0.5-hour observations. Diary data for each 0.5-hour period defined whether a patient was home or not home, or in traffic. Increases in TWA-MAX were independently associated with the previous 2-hour mean ambient BC (2.1%, 95% confidence interval 0.9% to 3.3%) and with being in traffic in the previous 2 hours (6.1%, 95% confidence interval 3.4% to 8.8%). When subjects were home, indoor home BC effects were largest and most precise; when subjects were away from home, ambient central site BC effects were strongest. Increases in pollution increased the odds of TWA-MAX > or =75th percentile (odds ratio 1.4, 95% confidence interval 1.2 to 1.6 for a 1 microg/m(3) increase in 6-hour mean BC). In conclusion, after hospitalization for coronary artery disease, being in traffic and short-term ambient or indoor BC exposure increased TWA, a marker of cardiac electrical instability.

Consensus statement of the European Heart Rhythm Association: updated recommendations for driving by patients with implantable cardioverter defibrillators

Patients with an implantable cardioverter defibrillator (ICD) have an ongoing risk of sudden incapacitation that might cause harm to others while driving a car. Driving restrictions vary across different countries in Europe. The most recent recommendations for driving of ICD patients in Europe were published in 1997 and focused mainly on patients implanted for secondary prevention. In recent years there has been a vast increase in the number of patients with an ICD and in the percentage of patients implanted for primary prevention. The EHRA task force on ICD and driving was formed to reassess the risk of driving for ICD patients based on the literature available. The recommendations are summarized in the following table and are further explained in the document. [table: see text] Driving restrictions are perceived as difficult for patients and their families, and have an immediate consequence for their lifestyle. To increase the adherence to the driving restrictions, adequate discharge of education and follow-up of patients and family are pivotal. The task force members hope this document may serve as an instrument for European and national regulatory authorities to formulate uniform driving regulations.

[Update on arrhythmias and cardiac electrophysiology]

This article contains a review of the most important developments in clinical arrhythmology and interventional cardiac electrophysiology that have been reported during the past year. Special emphasis has been placed on clinical conditions that are most prevalent in the general population as well as on progress that has been achieved using the main therapeutic approaches, whether pharmacologic or interventional.

Is it safe to allow patients with implantable cardioverter-defibrillators to drive? Learnings from a single center experience

BACKGROUND

Implantable cardioverter-defibrillator (ICD) implant indications have widened in recent years after the publication of the Multicenter Automatic Defibrillator Implantation Trial 2 and the Sudden Cardiac Death in Heart Failure Trial. On the contrary, guidelines on resumption of driving after ICD implant were published almost 10 years ago when the ICD implant rate was much lower and candidates were generally older.

AIM OF THE STUDY

The overall objective of our study was to evaluate whether patients implanted with ICDs have higher risk than the general driving population. The specific aim of the study was to verify the rate of car accidents in patients implanted with an ICD, both for primary and secondary indication, and compare this with the rate of accidents in the general population. The primary end point of the study was the annual car accident rate; the secondary end point was to determine if there were subgroups of patients with a higher risk of car accidents.

METHODS

All patients (612) followed up in our outpatient clinic were sent a questionnaire in which they were asked five questions regarding their driving habits before and after ICD implant and, specifically, whether they had been involved in a car accident after the implant.

RESULTS

Two hundred eighty-six patients (47%) responded to the questionnaire. Seventy-one patients had never driven; two patients were forbidden to drive for professional reasons (one bus and one truck driver). Two hundred thirteen (74.5% of all responding) patients (201 men, mean age 62 +/- 11 years) continued to drive after ICD implant. During the follow-up (1430 +/- 920 days) 11 patients had been involved in car accidents and, importantly 10 out of 11 were innocent bystanders. Thus, in 996 patient-years, 11 events happened, yielding an annual event rate of 1.1% per patient-years (and only 0.1% in which the driver could had been responsible).

CONCLUSION

Car accidents are infrequent in patients implanted with an ICD, and - in any case - not more frequent than in the general population. The old guidelines need to be updated and specific restrictions on car driving in ICD patients need to be revised to reflect the current data.