AN UNUSUAL CASE OF NON SMALL CELL LUNG CANCER PRESENTING AS NON-ST SEGMENT ELEVATION MYOCARDIAL INFARCTION

Abstract

SESSION TITLE: Monday Abstract Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: Non-ST-elevation myocardial infarction (NSTEMI) is a mismatch in the myocardial oxygen demand and consumption. Common causes include poor coronary flow, unmet increased oxygen demand, and cardiac inflammation. We present a case of NSTEMI as a result of a cause not yet reported in the literature. CASE PRESENTATION: An 84-year-old man with a history of coronary artery disease (CAD), coronary artery bypass grafting, hypertension, 10 pack-year smoking history presented with a 1-week history of typical chest pain. Review of systems was otherwise non-contributory. He reported medication adherence and denied illicit drug use. Initial vitals were stable. Electrocardiogram (EKG) was unchanged from prior with no dynamic ST changes. Cardiac enzymes showed a troponin of 0.720 ng/ml, CKMB of 72.50 ng/ml and CK of 585 IU/L. Heparin drip was started for presumed NSTEMI. Troponins subsequently rose to 22.530 ng/ml and peaked at 49.160 ng/ml after which they trended downwards. Serial EKGs were unchanged. His chest pain resolved with the initiation of heparin drip. Given the downtrend in troponins and lack of EKG changes, cardiac catheterization was not performed. The echocardiogram revealed a right ventricular mass obstructing the right ventricular outflow tract (RVOT) without evidence of right ventricular strain. As the position of the mass was unclear a CT chest and cardiac MRI were done which showed an anterior mediastinal mass 5.0 cm x 5.5 cm x 6.5 cm effacing the right ventricle and pulmonary artery and also encasing the left main coronary artery, the left internal mammary artery and left anterior descending artery graft with invasion of the superficial epicardial margin of the left ventricle basal anterior segment. The heparin drip was discontinued at this point given the risk of hemorrhagic conversion of the mass. Biopsy of the mass revealed a non-small cell lung cancer (NSCLC). Further imaging revealed no metastatic lesions. Due to the size of the mass and cardiac invasion, he was not a candidate for cardiothoracic surgery. Given that he was stable from a cardiac standpoint, he was discharged with followup with hematology-oncology. DISCUSSION: Cardiac metastasis has been reported in 9% of NSCLC cases. It typically presents as dyspnea and pleuritic chest pain. While myocardial metastasis has been reported to be associated with acute STEMI [2], its presentation as NSTEMI has not been previously reported [1]. We hypothesize that this unusual presentation may have resulted from the encasement of the coronary vessels by the tumor, which led to disruption and stasis of blood flow promoting a prothrombotic state. This may have resulted in a thrombus causing ischemia which responded to heparin as treatment. CONCLUSIONS: Cardiac metastasis should be considered as a differential diagnosis for NSTEMI in patients with CAD presenting with typical chest pain given the potential to alter treatment Reference #1: Chiles, C., Woodard, P., Gutierrez, F., Link, K. (2001). Metastatic involvement of the heart and pericardium: CT and MR imaging. Radiographics, 21(2), 439-449. Reference #2: Suga, T., Akuzawa, N., Hatori, T., Imai, K., Kitahara, Y., & Kurabayashi, M. (2015). ST segment elevation in secondary cardiac cancer: a case report and review of the literature. International journal of clinical and experimental medicine, 8(5), 7719-27. DISCLOSURES: No relevant relationships by Hassaan Arshad, source=Web Response No relevant relationships by Aishwarya Bhardwaj, source=Web Response No relevant relationships by Dayna Panchal, source=Web Response no disclosure on file for Kumar Satya; No relevant relationships by Umar Jamshed Sharif Khawaja, source=Web Response No relevant relationships by Rehan Umar, source=Web Response No relevant relationships by Jun Chih Wang, source=Web Response