Abstract
Background
Although the risk of recurrent events among adults with coronary heart disease (CHD) has declined considerably from the 1970's in the US and many Western countries, studies from the 2000's show that rates remain high. Women have lower rates of incident CHD but little is known about sex differences in recurrent events in adults with CHD.
Purpose
To examine trends in rates of recurrent myocardial infarction (MI), recurrent CHD, and all-cause mortality following a MI hospitalization between 2008 and 2015 among US men and women. Also, we compared sex differences in event rates among individuals with a MI hospitalization versus their counterparts without a history of CHD.
Methods
Data were used from 1,232,024 (53% women) US adults <65 years of age with commercial health insurance in the MarketScan database and US adults ≥66 years of age with government health insurance through Medicare who had a MI hospitalization between January 1, 2008 and December 31, 2015. For each calendar year, age-standardized sex-specific rates of recurrent MI, recurrent CHD (i.e., recurrent MI or coronary revascularization), and all-cause mortality (in Medicare only) were calculated through 365 days following the hospital discharge date for MI. In a secondary analyses, we assessed the rate of recurrent MI, CHD events and all-cause mortality among women versus men with a history of MI (n=324,283) and without a history of CHD (n=1,297,132) in 2014–2015. For these analyses, adjusted hazard ratios (95% confidence intervals) were calculated using follow-up through December 31, 2016.
Results
From 2008 to 2015, age-standardized rates over 365 days of follow-up for recurrent MI declined by 15%, from 94 to 80 per 1000 person-years, in men and by 14%, from 89 to 77 per 1000 person-years, in women. Age-standardized recurrent CHD rates decreased by 16%, from 163 to 138 per 1000 person-years, in men and by 17%, from 142 to 118 per 1000 person-years, in women. In the Medicare population, age-standardized all-cause mortality rates following MI decreased by 6%, from 446 to 421 per 1000 person-years, in men and by 3%, from 412 to 398 per 1000 person-years, in women. In the secondary analyses, the women-to-men hazard ratios for those with a history of MI and those without prior CHD were 0.97 (0.94–0.99) and 0.67 (0.65–0.69), respectively, for MI, 0.89 (0.87–0.91) and 0.52 (0.51–0.54), respectively, for CHD, and 0.84 (0.83–0.85) and 0.74 (0.73–0.75) respectively, for all-cause mortality.
Conclusion
Reductions in rates of recurrent MI, recurrent CHD, and all-cause mortality within 365 days after hospitalization for MI have been similar for US women and men. The lower risk for events comparing women versus men without prior CHD is attenuated after a MI.
Acknowledgement/Funding
The design and conduct of the study was supported through a research grant from Amgen, Inc.
Sex differences in cardiovascular and total mortality among diabetic and non-diabetic individuals with or without history of myocardial infarction
