Risk Assessment of Patients After ST-Segment Elevation Myocardial Infarction by Killip Classification: An Institutional Experience

Introduction The Killip classification system was introduced for clinical assessment of patients with acute myocardial infarction (MI). It stratifies individuals according to the severity of their post-MI heart failure. This system provides effective stratification of long-term and short-term outcomes in patients with acute MI and influences the treatment strategies. Revalidation of Killip class in our local population is mandatory. We planned this study to increase cardiologist's readiness to tackle the risks associated with increased mortality in each class post ST-segment elevation MI (STEMI). Objectives were to determine the frequency of Killip classes I, II, III, and IV and in-hospital mortality in each Killip class in patients with left ventricular failure secondary to STEMI. Methods A retrospective cross-sectional study was conducted in the Department of Cardiology, Jinnah Hospital, Lahore, over a period of three years. Patients with STEMI were stratified using Killip classification, and validation was performed by determining the within 15 days in-hospital mortality in each Killip class. Results The frequency (percentage) of patients with STEMI in each Killip class from I to IV was 395 (81.4%), 46 (9.5%), 27 (5.6%), and 17 (3.5%), respectively, while the in-hospital mortality in each Killip class came out to be 39 (9.9%), 4 (8.7%), 25 (92.6%) and 17 (100%), respectively. The presence of diabetes, history of smoking, and body mass index (BMI) of more than 30 kg/m2 were significant contributors to mortality, along with higher Killip class and age of presentation. Conclusions It is concluded that the Killip classification system is a valid tool for risk stratification for patients after STEMI, especially in resource-limited countries.