Acute coronary syndrome due to intermittent right coronary artery obstruction by an ascending aortic thrombus in a cancer patient: a case report

Background: ST-elevation myocardial infarction (STEMI) is most commonly caused by atherosclerotic coronary artery occlusion. In some instances, non-atherosclerotic mechanisms should also be considered. We present a case of a floating thrombus in the aortic root moving in and out of the right coronary ostium, leading to STEMI. Case summary: A 70-year-old man with stage IIIA lung adenocarcinoma receiving ongoing chemotherapy presented with syncope. The ECG revealed ST-segment elevation in the inferior leads and intermittent complete atrioventricular block with a heart rate of 40 bpm. A temporary transjugular pacemaker was inserted because of haemodynamic instability. Coronary angiography showed patent coronary arteries but cyclic radiolucency at the right coronary artery (RCA) ostium during RCA injections. Transoesophageal echocardiography identified a 2.5-3.0 cm pedunculated, mobile mass consistent with thrombus attached to the right coronary sinus, intermittently prolapsing into the RCA ostium. Surgical thrombectomy or fibrinolysis was deemed high risk because of prior thoracic radiotherapy and active malignancy with cranial metastases. A pre-emptive RCA guidewire was placed, and the thrombus obstructing the RCA ostium was successfully removed with multiple-pass aspiration using a 10F PRONTO.035 extraction catheter, achieving TIMI 3 flow. Haemodynamic status and rhythm improved subsequently. The patient was discharged on apixaban. Discussion: This case illustrates dynamic RCA obstruction caused by an aortic root thrombus managed with catheter-based aspiration. However, this approach should be considered on a case-by-case basis, given its high thromboembolic potential.