Comparison of Outcomes in Patients Having Acute Myocardial Infarction With Versus Without Sickle-Cell Anemia

Sickle-cell disease (SCD) affects millions worldwide. Sickle-cell anemia (SCA), the most severe form of this disease, is the most common inherited blood disorder in the United States. There are limited data on the incidence, clinical characteristics, and outcomes of acute myocardial infarction (AMI) in these patients. Using data from the National Inpatient Sample database, we matched cases (AMI with SCA) with controls (AMI without SCA) in a 1:1 ratio for age, gender, race, and year of admission. We compared both groups in terms of clinical characteristics and inpatient outcomes and performed a logistic regression with mortality as the primary outcome. Using weighted samples, we also described trends of SCA in the general population of patients with AMI. Of the 2,386,657 admissions with AMI, SCA was reported in 501 (0.02%) patients, and 495 were successfully matched to controls. Patients with SCA were less likely to have risk factors for coronary artery disease than those without SCA. Patients with SCA were more likely to develop pneumonia, respiratory failure, and acute renal failure, and require mechanical ventilation, hemodialysis for acute renal failure and blood transfusion. In-hospital mortality was significantly higher in patients with SCA. In a multivariate analysis, SCA was an independent predictor of mortality (odds ratio 3.49; 95% confidence interval 1.99 to 6.12; p = <.001). In conclusion, myocardial infarction occurs in patients with SCA at a relatively early age. These patients do not typically have the traditional risk factors for the acute coronary syndrome. Mortality in these patients is significantly higher in age-, gender-, and race-matched controls.