Waqas Ali, MD, MBBBS
Resident Physician, University of Pittsburgh-McKeesport
UPMC McKeesport
McKeesport, Pennsylvania
Disclosure information not submitted.
Khubaib Ahmad, MBBS
Medical Student
Services Institute of Medical Sciences, United States
Disclosure information not submitted.
Asmi Chattaraj, MD
Resident Physician
University of Pittsburgh- McKeesport, United States
Disclosure information not submitted.
Anjana Pillai, MD
Faculty
University of Pittsburgh- McKeesport, United States
Disclosure information not submitted.
Title: A Tale of Two Arteries- A Case of NSTEMI due to Coronary Artery Compression by Pulmonary Artery
Case Report Body:
Introduction: Severe pulmonary artery (PA) dilatation in patients with pulmonary hypertension can rarely cause extrinsic left main coronary artery (LMCA) compression. We present an interesting case of non-ST elevation myocardial infarction (NSTEMI) caused LMCA compression from enlarged pulmonary artery.
Description: 56-year-old man with medical history of ESRD on hemodialysis, Group V pulmonary hypertension due to ESRD and heart failure with preserved ejection fraction presented for elective orthopedic surgery under general anesthesia. His post-op course was complicated by acute left-sided chest pain and shock. He developed new ST elevations in aVR and ST depressions in anterolateral leads, and elevated cardiac enzymes consistent with NSTEMI. CTA chest revealed enlarged PA (diameter 4.5 cm). Urgent left heart catheterization (LHC) revealed ostial eccentric 70% stenosis of LMCA with hemodynamically significant instantaneous wave-free ratio (iFR) of 0.84. Right heart catheterization revealed severe pulmonary hypertension with mean PA pressure of 55 mm Hg (84/39), pulmonary capillary wedge pressure of 12 mm Hg, and cardiac output of 3.8 L/min. He underwent intra-aortic balloon pump placement for hemodynamic support and CRRT for fluid removal resulting in resolution of chest pain and EKG changes. Repeat LHC with intravascular ultrasound (IVUS) showed 70% eccentric ostial stenosis of LMCA measuring 4.5 mm x 7.6 mm with no evidence of atherosclerotic disease. Interestingly now his iFR was 0.97 which was considered not hemodynamically significant. It was determined that NSTEMI was caused by acute worsening of pulmonary hypertension in the setting of general anesthesia leading to eccentric compression of LMCA by enlarged PA. Repeat LHC showed adequate coronary flow due to improvement in PA pressures and LMCA compression, therefore PCI was not performed.
Discussion: Anatomic origin of LMCA, PA diameter >40 mm, and PA trunk/aorta ratio >1.2 are important factors in the development of extrinsic LMCA compression by PA. Anginal chest pain in patients with pre-existing pulmonary hypertension should raise concern for the development of this condition. Coronary angiography with IVUS can distinguish between extrinsic LMCA compression and intrinsic atherosclerotic CAD. Most of the patients receive coronary revascularization by PCI.