Author + information
- Received September 2, 2015
- Revision received October 15, 2015
- Accepted October 22, 2015
- Published online April 1, 2016.
- Vern Hsen Tan, MD,
- Debbie Ritchie, MN,
- Connor Maxey, BSc,
- Robert Sheldon, MD, PhD∗ (, )
- POST Investigators
- ↵∗Reprint requests and correspondence:
Dr. Robert Sheldon, University of Calgary, 3280 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada.
Objectives This study sought to estimate the likelihood of a motor vehicle accident causing serious risk or harm in patients with frequent vasovagal syncope, and compare this with international accident data.
Background Recurrent vasovagal syncope poses a risk because of fainting while driving, but prospective, benchmarked estimates of this risk have not been reported.
Methods Data were from the POST (Prevention of Syncope Trial)-1 and -2, which were multicenter randomized studies of patients with ≥3 lifetime vasovagal syncope spells. POST-1 patients (reported in 2005) received metoprolol or placebo for ≤1 year between 1998 and 2004; POST 2 patients received fludrocortisone or placebo for ≤1 year between 2006 and 2011. Accident data were recovered from Internet reports from the United States, United Kingdom, and Canada.
Results A total of 418 patients (age 38 ± 17 years) had a median of 10 lifetime faints and a median of 3 faints in the previous year. Total follow-up time was 323 years, or 0.77 years per person. A total of 174 subjects fainted, having a total of 615 faints. Two patients fainted while driving, without fatality or injury, with a likelihood of 0.62% per person-year. The risk of serious harm or death was <0.0035% per person-year, and 0.0018% per faint. In the general U.S., U.K., and Canadian driving populations, the risk of serious harm or death was 0.067% per driver-year, and the risk of death was 0.009%.
Conclusions The estimated risk of serious harm or death was <0.0035% per person-year in highly symptomatic patients, less than the risk of serious harm or death in the general population. (A Randomized Clinical Trial of Fludrocortisone for Vasovagal Syncope: The Second Prevention of Syncope Trial [POST II]; NCT00118482)
The parent clinical trials were supported by Operating Grants from the Canadian Institutes of Health Research, Ottawa, Canada. The funder had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication. All authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received September 2, 2015.
- Revision received October 15, 2015.
- Accepted October 22, 2015.
- 2016 American College of Cardiology Foundation