Electrocardiographic predictors of poor outcome in acute myocardial infarction

Shirley, Samantha Shirley

Electrocardiographic predictors of poor outcome in acute myocardial infarction

Thesis / Dissertation

2024

Publisher

University of Cape Town

Department

Department of Medicine

Faculty

Faculty of Health Sciences

Abstract

Introduction: Myocardial infarction (MI) is a major cause of death worldwide. An ECG is indicated in all patients with suspected MI. The aim of this study was to evaluate electrocardiographic predictors of outcome in acute coronary syndrome (ACS). Methods: We analyzed 12-lead ECGs of 301 consecutive patients admitted to the coronary care unit (CCU) at a tertiary centre during 2016 with a diagnosis of ACS. ECGs were done on admission, and after that daily throughout the hospitalisation. Poor outcome was defined as all-cause mortality within a three-year period after the index MI. Results: This cohort of 301 patients (42.2% female) with a mean age of 57.4±11.9 years, presented with either ST-elevation myocardial infarction (STEMI, 57.5%) or non-ST elevation myocardial infarction (NSTEMI, 42.5%). Fifty-one (16.9%) patients died within three years after their index presentation. Multivariable regression analyses revealed that left atrial enlargement (LAE, odds ratio [OR] 3.91 [95% confidence interval [CI] 1.39-11.02], p=0.010) and ST depression (OR 3.64 [95% CI 1.33-9.93], p=0.012) were predictive of poor outcome, wheras sinus rhythm with normal rate was associated with a better prognosis (OR 0.33 [95% CI 0.12- 0.91] p=0.032). Patients with two or more risk factors (i.e., LAE, ST depression, sinus tachycardia) experienced higher mortality rates (p<0.001).Conclusion: Our study showed that the ECG has prognostic value in patients presenting with acute MI. ECG features that were independently associated with increased mortality within the first three years of MI (LAE, ST depression and/or sinus tachycardia) could assist with risk stratification of patients presenting with ACS.