Amjad Khanfar

MRI, MFT, United Kingdom

Abstract Title: Left Main Coronary Artery Spasm Mimicking Severe Ostial Stenosis Presenting as NSTEMI

Biography: Amjad Khanfar is currently completing IMT3 training in the United Kingdom and is pursuing a long-term career in Cardiology. He has completed a one-year cardiology fellowship alongside extensive Internal Medicine training with continuous cardiology exposure. His clinical interests include heart failure, acute cardiology, echocardiography, and interventional cardiology. Dr. Khanfar has been actively involved in cardiovascular research, international presentations, quality improvement projects, and medical education for junior doctors and medical students. He is passionate about advancing patient-centred cardiovascular care through clinical practice, research, and innovation.

Research Interest: Coronary artery spasm is an important non-atherosclerotic cause of acute coronary syndrome but rarely involves the left main stem (LMS). We report a 49-year-old male smoker presenting with chest pain, dynamic troponin elevation, and electrocardiographic changes consistent with non–ST elevation myocardial infarction (NSTEMI). Invasive coronary angiography demonstrated apparent severe ostial LMS stenosis with pressure dampening, raising concern for high-risk coronary disease. However, myocardial perfusion scintigraphy confirmed reversible ischemia, while computed tomography coronary angiography (CTCA) showed a zero calcium score and no evidence of atherosclerosis. Repeat CTCA following calcium channel blocker therapy demonstrated significant improvement in LMS calibre, supporting a diagnosis of coronary vasospasm. This case highlights the importance of multimodality imaging in distinguishing dynamic coronary vasospasm from fixed stenosis to avoid unnecessary revascularization. Background: Coronary artery vasospasm is a recognized cause of myocardial ischaemia and infarction, particularly in younger patients and smokers. It typically affects focal segments of epicardial coronary arteries, most commonly the right coronary artery. Involvement of the left main stem (LMS) is rare but clinically significant due to the large myocardial territory at risk. Distinguishing LMS vasospasm from fixed atherosclerotic stenosis is critical, as the latter often necessitates urgent revascularisation. However, angiographic appearances may be misleading, and further imaging is often required to clarify the diagnosis. Case Presentation: A 49-year-old man with a significant smoking history and no prior medical conditions presented with acute central chest pain. There was no previous history of cardiovascular disease. Initial investigations revealed a high-sensitivity troponin rise from 20 ng/L to 257 ng/L. Electrocardiography demonstrated T wave inversion in leads V1–V2. He was managed as a non–ST elevation myocardial infarction. Transthoracic echocardiography showed normal left ventricular systolic function with no regional wall motion abnormalities and no significant valvular disease. Investigations: Coronary Angiography Invasive coronary angiography demonstrated marked pressure dampening on engagement of the LMS. There appeared to be severe ostial LMS stenosis. The left anterior descending artery was angiographically normal. The left circumflex artery initially appeared normal but subsequently showed significant reduction in calibre in certain projections, suggestive of vasospasm. The right coronary artery was dominant with mild disease. Myocardial Perfusion Scintigraphy: Myocardial perfusion imaging demonstrated a moderate reversible perfusion defect at the apex and mild reversible defects in the anterior, anteroseptal, and anterolateral walls. A total of 9/20 myocardial segments were ischaemic. Global myocardial perfusion reserve was preserved, and left ventricular systolic function was normal. CT Coronary Angiography: Initial CTCA demonstrated a calcium score of 0 Agatston units and no evidence of coronary atherosclerosis. The LMS ostium and proximal segment appeared small in calibre. A repeat CTCA following initiation of calcium channel blocker therapy demonstrated significant improvement in LMS calibre, although mild relative narrowing persisted. Differential Diagnosis: • Severe atherosclerotic stenosis of the LMS • Coronary artery vasospasm (most likely) • Congenital small calibre LMS • Catheter-induced spasm The absence of coronary calcification or plaque, along with improvement following vasodilator therapy, supported coronary vasospasm as the underlying diagnosis. Treatment: The patient was initially treated according to NSTEMI protocols. Invasive revascularisation was deferred in view of the uncertainty regarding the LMS lesion. He was commenced on calcium channel blocker therapy (diltiazem) for presumed coronary vasospasm. Outcome and Follow-Up: Repeat CTCA demonstrated improved calibre of the LMS following initiation of vasodilator therapy, supporting a dynamic process. The patient was managed conservatively with medical therapy. Discussion: This case illustrates a rare presentation of left main stem coronary vasospasm mimicking severe ostial stenosis and presenting as NSTEMI. Angiographic findings of LMS narrowing and pressure dampening are typically 6 | P a g e associated with critical disease and often prompt urgent revascularisation. However, coronary vasospasm can produce similar appearances, particularly in smokers with endothelial dysfunction. In this case, multimodality imaging was essential in establishing the diagnosis. While myocardial perfusion scintigraphy confirmed inducible ischaemia, it did not distinguish between fixed and dynamic causes. CTCA played a pivotal role by demonstrating the absence of atherosclerosis and a zero calcium score, which is highly suggestive of non-atherosclerotic pathology in this clinical context. The most compelling evidence for vasospasm was the demonstrable improvement in LMS calibre following calcium channel blocker therapy. This reversibility effectively excluded fixed stenosis and avoided unnecessary high-risk revascularisation. This case highlights the importance of considering coronary vasospasm in patients with apparent LMS disease, particularly when imaging findings are discordant. Failure to recognise this entity may lead to inappropriate intervention, including coronary artery bypass grafting. Learning Points: Left main stem coronary spasm is a rare but important cause of acute coronary syndrome • Angiographic appearances may mimic severe atherosclerotic stenosis • A zero calcium score should prompt consideration of non-atherosclerotic causes • Multimodality imaging is essential when findings are discordant • Demonstration of reversibility with vasodilator therapy supports the diagnosis and can prevent unnecessary revascularisation