Case Presentation: A 55-year-old woman with a history of hypothyroidism presented with exertional retrosternal chest pain radiating to the neck and left arm. Vital signs were stable and physical exam was unremarkable. Chest x-ray was normal and ECG revealed T-wave inversions in the inferior leads. Laboratory testing demonstrated normal levels of cardiac troponin. Lipid profile was normal and HbA1C was 5.4%. Echocardiography revealed a left ventricular ejection fraction (LVEF) of 60-65% without regional wall motion abnormalities. The patient underwent nuclear stress testing which was not completed due to a severe reaction to the regadenoson. Rest images were normal. The plan was to perform left heart catheterization (LHC) with coronary angiogram which revealed 70% stenosis of the distal portion of the left main coronary artery (LMCA) (Figure 1-A). Patient was referred to cardiothoracic surgery for possible coronary artery bypass grafting (CABG), however given the high suspicion of LMCA spasm in the setting of no coronary artery disease (CAD) risk factors and lack of even mild disease in the other coronaries, the decision was to obtain a coronary CT angiography (CCTA) which showed normal LMCA without stenosis. Repeated LHC showed normal LMCA (Figure 1-B), which supported the diagnosis of coronary artery spasm .
Discussion: LMCA vasospasm is extremely rare with only a few cases reported in the literature (1). LMCA spasm can cause demand-supply mismatch that can mimic CAD. Coronary artery spasm (CAS) can be challenging to diagnose because it has a wide range of presentations from silent ischemia, chest pain, to sudden cardiac death (1). Our patient had isolated LMCA stenosis which was misdiagnosed with severe left main disease requiring surgical referral. CCTA unmasked spasm as the underlying cause and prevented unnecessary surgery.
Conclusions: CAS can angiographically mimic CAD potentially leading to misdiagnosis and, in cases of LMCA stenosis, inappropriate referral for surgery. Physicians should have a high suspicion for coronary spasm especially in patients with anginal chest pain who lack CAD risk factors and have no coronary atherosclerosis in the unspammed coronary arteries. CCTA is a non-invasive tool that can unmask LMCA vasospasm and help prevent unnecessary surgery in such cases (2).
