Pregnancy-Associated Spontaneous Coronary Artery Dissection in the Third Trimester Requiring Multistent Percutaneous Coronary Intervention: A Case Report.

Background: Pregnancy-associated spontaneous coronary artery dissection (P-SCAD) is an uncommon cause of acute coronary syndrome (ACS) in young women. Although SCAD accounts for less than 1% of ACS cases, it causes up to 40%-50% of myocardial infarctions during pregnancy and the postpartum period. Third-trimester cases requiring complex percutaneous coronary intervention (PCI) are particularly rare. Case Presentation: A 33-year-old gravida 5, para 3 woman at 27 weeks' gestation presented with sudden severe substernal chest pain. Electrocardiographic findings and elevated cardiac biomarkers confirmed an anterior ST-segment elevation myocardial infarction (STEMI). Coronary angiography demonstrated spontaneous coronary artery dissection involving the mid-to-distal left anterior descending artery. Owing to ongoing ischemia and extensive dissection, she underwent intravascular ultrasound-guided PCI with four overlapping drug-eluting stents, restoring TIMI III flow. Following revascularization, she remained hospitalized for maternal and fetal monitoring because of concerns for preeclampsia and severe fetal growth restriction. Although expectant management was initially pursued, worsening fetal heart-rate concerns necessitated cesarean delivery at 29 weeks' gestation without maternal cardiac complications. Although left ventricular function initially improved with guideline-directed medical therapy (GDMT), discontinuation of several medications because she felt symptomatically better contributed to progressive left ventricular dysfunction and NYHA class III heart failure, ultimately requiring cardiac rehabilitation and prophylactic implantable cardioverter-defibrillator placement. Discussion: This case highlights the complexity of managing extensive third-trimester P-SCAD requiring multistent PCI while balancing maternal cardiovascular stabilization with ongoing obstetric complications. It further emphasizes the importance of longitudinal imaging, sustained GDMT, medication adherence, and coordinated multidisciplinary follow-up after significant myocardial injury. Conclusion: Third-trimester P-SCAD requiring complex PCI is rare. Early recognition, individualized revascularization strategies, multidisciplinary obstetric and cardiovascular management, and close long-term follow-up are essential to optimize maternal and fetal outcomes while reducing the risk of adverse ventricular remodeling and heart failure progression.