A meta-analysis of randomized trials has shown a significant reduction of mortality rate in patients receiving
aspirin for
secondary prevention after acute
myocardial infarction (AMI). However, a significant number of patients do not receive
aspirin after AMI. Little is known about why
aspirin is withheld or the long-term outcome of these patients today.
METHODS: Of 4902 patients, 509 (10%) did not receive
aspirin at the time of discharge from the hospital. The mean follow-up period for these patients was 17 months. Relative
contraindications to
aspirin were significantly associated with the withholding of
aspirin (in-hospital
bleeding: odds ratio [OR], 3.56; 95% CI, 1.86-6.80; history of
peptic ulcer: OR, 2.49; 95% CI, 1.62-3.83). Absolute
contraindications to
aspirin were rare (2.2%). Other medications of proven benefit were also given less often in these patients (beta-blockers: 49.0% vs 61.9%, P <.001;
angiotensin-converting enzyme inhibitors: 65.6% vs 70.2%, P =.06;
statins: 12.2% vs 15.1%, P =.10). Patients who were not given
aspirin were at high risk for vascular events. They were more likely to have a history of prior AMI (OR, 1.34; 95% CI, 1.02-1.79), were in critical clinical condition at admission more often (
cardiogenic shock: OR, 1.98; 95% CI, 1.09-3.56; overt
heart failure: OR, 1.6; 95% CI, 1.05-2.3), and received acute revascularization less often (OR, 1.32; 95% CI, 1.05-1.67). The 1-year mortality was 2-times higher in patients who did not receive
aspirin than in patients who did receive
aspirin (16.5% vs 8.3%, P <.001). A significant association of withheld
aspirin at discharge with a higher long-term mortality rate was confirmed with multivariate analysis (OR, 1.62; 95% CI, 1.15-2.29).
CONCLUSIONS: Ten percent of patients who sustained an AMI did not receive
aspirin at the time of hospital discharge. Most of these patients were at high risk for cardiovascular events. Withheld
aspirin was significantly associated with higher mortality rate during follow up.