Roadway proximity and risk of sudden cardiac death in women.

BACKGROUND Sudden cardiac death (SCD) is a major source of mortality and is the first manifestation of heart disease for the majority of cases. Thus, there is a definite need to identify risk factors for SCD that can be modified at the population level. Exposure to traffic, measured by residential roadway proximity, has been shown to be associated with an increased risk of cardiovascular disease. Our objective was to determine whether roadway proximity was associated with an increased risk of SCD and to compare that risk with the risk of other coronary heart disease outcomes. METHODS AND RESULTS A total of 523 cases of SCD were identified over 26 years of follow-up among 107 130 members of the prospective Nurses' Health Study. We calculated residential distance to roadways at all residential addresses from 1986 to 2012. In age- and race-adjusted models, women living within 50 m of a major roadway had an elevated risk of SCD (hazard ratio=1.56; 95% confidence interval, 1.18-2.05). The association was attenuated but still statistically significant after controlling for potential confounders and mediators (hazard ratio=1.38; 95% confidence interval, 1.04-1.82). The equivalent adjusted hazard ratios for nonfatal myocardial infarction and fatal coronary heart disease were 1.08 (95% confidence interval, 0.96-1.23) and 1.24 (95% confidence interval, 1.03-1.50), respectively. CONCLUSIONS Among this sample of middle-aged and older women, roadway proximity was associated with elevated and statistically significant risks of SCD and fatal coronary heart disease, even after controlling for other cardiovascular risk factors.