Drivers with AF hospitalized after a car accident are at greater risk of death than those without AF. Who gets a red light?
A recent study from the Mayo Clinic suggests that persons with nonvalvular atrial fibrillation (AF) may have significantly higher mortality from motor vehicle accidents compared with drivers without AF.
The retrospective observational analysis studied about 2.9 million motor vehicle accidents (MVAs) from 2003-2012 cataloged in the National Inpatient Sample and results were presented at the CARDIOSTIM-Europace meeting in Nice in mid-June. The study reported that the rate of in-hospital mortality for AF patients was 7.8% compared to 2.6% for non-AF patients and that, even after adjustment for age, gender, Charlson Comorbidity Score, Injury Severity score, and hospital characteristics, there was a 52% increase in relative risk of dying from an MVA if AF was present. The authors noted that among the patients with AF, a higher CHA2DS2-Vasc stroke score was correlated with higher mortality and increased risk for receiving a blood transfusion. They theorize that increased mortality may be a result of the increased bleeding risk with anticoagulant use for AF patients. In addition to the mortality signal, the average length of stay for MVA victims with AF was 3.2 days longer and hospitalization cost an average of $8602 more than non-affected persons.
Although these findings are preliminary and need prospective validation, this study provides another example of increased morbidity and mortality and costs associated with a diagnosis of AF. We can hardly tell every patient with AF to stop driving based on these results. However, this study does raise the question of whether driving restrictions may be indicated for those who are at very high risk for bleeding or those who have particularly bad driving records. Given the differences in bleeding risk, and the ongoing paucity of antidotes for newer oral anticoagulants, it will also be important for future studies to stratify mortality risk in a number of ways to more effectively select out those AF patients at highest risk of death after an MVA; these include by patient characteristics (age, demographics, etc), AF characteristics (paroxysmal, persistent, etc) as well as provider characteristics (ie, type of oral anticoagulant prescribed).
Deshmukh A. Impact of atrial fibrillation on patients with motor vehicle accidents. CARDIOSTIM-EUROPACE 2016; Nice, France.