Difference between Outcome of Left Circumflex Artery and Right Coronary Artery Related Acute Inferior Wall Myocardial Infarction in Patients Undergoing Adjunctive Angioplasty after Fibrinolysis

Introduction: Prognostic differences between anterior and inferior wall Myocardial Infarction (MI) has been extensively investigated, but there is limited information about similar comparison between inferior wall MI caused by right coronary artery (RCA) and left circumflex artery (LCX) occlusion. The aim of present study was to compare prognostic differences between LCX- and RCA-related acute inferior wall ST-segment elevation MI (STEMI) treated by routine adjunctive angioplasty after receiving thrombolytic therapy (TLT). Methods: Between March 2012 and June 2013 one hundred fifty consecutive patients with acute inferior wall STEMI were studied. Patients were divided into two groups according to the infarct related artery (LCX vs. RCA). All patients underwent routine adjunctive angioplasty after TLT during the index hospitalization and clinical characteristics and outcomes were compared. Results: RCA and LCX arteries were occluded in 97 (64.7%) and 53 (35.3%) of patients, respectively. Two groups were similar in baseline characteristics except multiple-vessel disease was more prevalent with LCX occlusion (p= 0.008). There was a higher cardiac enzyme release (p< 0.001), more significant mitral regurgitation (MR) (p= 0.015), and lower left ventricular ejection fraction (LVEF) (p= 0.01) in patients with LCX occlusion. Multivariate analysis showed cTn-I release, occurrence of MR, and lower LVEF as independent factors leading to poor outcome. Conclusions: There were higher cTn-I release, MR occurrence, and lower LVEF in LCX-related acute inferior wall STEMI, all associated with poor outcome. Therefore, patients with ECG finding in favour of LCX occlusion should be considered as high risk and an invasive approach should be planned.