Abstract 4136274: A Case of Myocardial Infarction with Non-obstructive Coronary Arteries (MINOCA) Complicated by a Ventricular Septal Defect (VSD)

Case: A 69-year-old woman with a history of hypertension and tobacco use disorder presented with acute chest pain. The patient was found to have classic anterior ST elevation myocardial infarction (STEMI) pattern on electrocardiogram (ECG) with high-sensitivity troponin of 12,772 ng/L and was taken emergently to the catheterization laboratory. Coronary angiography showed tortuous coronary vessels though without evidence of obstructive coronary artery disease, plaque rupture, ulceration, dissection, or vasospasm. Transthoracic echocardiogram showed an apical ventricular septal defect (VSD) with normal left ventricular systolic function of 60%. Cardiac computed tomography (CT), confirmed a discrete apical VSD that was 7.93 mm in diameter and multiple small VSDs distally in the septum. Right heart catheterization revealed severe left-to-right shunting with a ratio of pulmonary blood flow to systemic blood flow (Qp:Qs) of 2.8. Early surgical repair of the apical VSD was pursued despite known high operative risk given the hemodynamic significance of the shunt. The patient developed ongoing hemodynamic instability from cardiogenic shock with inability to ween from intra-aortic balloon pump (IABP). Unfortunately, because of the location of the residual VSDs and elevated panel-reactive antibody testing of 98%, the patient was deemed to not be a candidate for percutaneous closure or heart transplantation, respectively. Discussion: An acquired ventricular septal defect (VSD) is a rare and catastrophic complication of myocardial infarction, typically with a culprit obstructive coronary artery lesion identified on coronary angiography. Acquired VSDs in myocardial infarction with nonobstructive coronary arteries (MINOCA) is an even more rare phenomenon. Possible causes include low flow, inflammation, intimal disruption, or vasospasm of coronary arteries. Our case highlights that MINOCA can present with life-threatening complications similar to obstructive STEMI. The timing of intervention and treatment approach of acquired VSDs remains an area of debate. The life-threatening effects of VSDs make it critical to manage in a multidisciplinary manner involving advanced imagers, interventional cardiologists, cardiothoracic surgeons, and heart failure specialists. This case emphasizes the importance of maintaining a high index of suspicion for abnormal coronary anatomy, even in patients with MINOCA, and prompt interdisciplinary decision making to reduce mortality.