Risk Factors and Timing of Acute Myocardial Infarction Associated With Pregnancy: Insights From the National Inpatient Sample

Background Pregnancy increases the risk of acute myocardial infarction (AMI). The purpose of this study was to examine timing and risk factors for AMI in pregnancy and poor outcome. Methods and Results National Inpatient Sample (2003–2015) was screened in pregnancy, labor and delivery, and postpartum. There were 11 297 849 records extracted with 913 instances of AMI (0.008%). One hundred eleven (12.2%) women experienced AMI during labor and delivery, 338 (37.0%) during pregnancy and most during the postpartum period (464; 50.8%). The prevalence of AMI in pregnancy has increased (P=0.0005). Most major adverse cardiovascular and cerebrovascular events occurred in the postpartum period (63.5%). Inpatient mortality was 4.5%. Predictors of AMI include known coronary artery disease (odds ratio [OR], 517.4; 95% CI, 420.8–636.2), heart failure (OR, 8.2; 95% CI, 1.9–35.2), prior valve replacement (OR, 6.4; 95% CI, 2.4–17.1), and atrial fibrillation (OR, 2.7; CI, 1.5–4.7; P