Race and Sex Differences in Post-Myocardial Infarction Angina Frequency and Risk of 1-Year Unplanned Rehospitalization.

BACKGROUND

Race and sex disparities in in-hospital treatment and outcomes of patients with acute myocardial infarction (MI) have been described, but little is known about race and sex differences in post-MI angina and long-term risk of unplanned rehospitalization. We examined race and sex differences in post-MI angina frequency and 1-year unplanned rehospitalization to identify factors associated with unplanned rehospitalization, testing for whether race and sex modify these relationships.

METHODS

Using TRANSLATE-ACS (Treatment With Adenosine Diphosphate Receptor Inhibitors: Longitudinal Assessment of Treatment Patterns and Events after Acute Coronary Syndrome) data, we examined 6-week and 1-year angina frequency and 1-year unplanned rehospitalization stratified by race and sex among MI patients treated with percutaneous coronary intervention. We used multivariable logistic regression to assess factors associated with unplanned rehospitalization and tested for interactions among angina frequency, race, and sex.

RESULTS

A total of 11 595 MI patients survived to 1 year postdischarge; there were 66.6% white male patients, 24.3% white female patients, 5.3% black male patients, and 3.8% black female patients. Overall, 29.7% had angina at 6 weeks, and 20.6% had angina at 1 year postdischarge. Relative to white patients, black patients were more likely to have angina at 6 weeks (female: 44.2% versus 31.8%; male: 33.5% versus 27.1%; both P<0.0001) and 1 year (female: 49.4% versus 38.9%; male: 46.3% versus 31.1%; both P<0.0001). Rates of 1-year unplanned rehospitalization were highest among black female patients (44.1%), followed by white female patients (38.4%), black male patients (36.4%), and white male patients (30.2%, P<0.0001). In the multivariable model, 6-week angina was most strongly associated with unplanned rehospitalization (hazard ratio, 1.49; 95% confidence interval, 1.36-1.62; P<0.0001); this relationship was not modified by race or sex (adjusted 3-way Pinteraction=0.41).

CONCLUSIONS

One-fifth of MI patients treated with percutaneous coronary intervention report 1-year postdischarge angina, with black and female patients more likely to have angina and to be rehospitalized. Better treatment of post-MI angina may improve patient quality of life and quality of care and help to lower rates of rehospitalization overall and particularly among black and female patients, given their high prevalence of post-MI angina.

CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01088503.