HIGH KILLIP CLASS (≥II), ITS PREDICTORS AND IN HOSPITAL OUTCOMES AMONG PATIENTS WITH STEMI

Abstract

Objective: To determine the incidence of high Killip class (≥II) and its associated risk factors and in hospital outcome on admission for ST elevation myocardial infarction (STEMI) patients in a tertiary cardiac centre. Background: ST-Elevation myocardial infarction (STEMI) continues to be one of the most important cardiac emergencies worldwide, and in-hospital outcome is sensitive to the extent of haemodynamic derangements at presentation. The Killip classification is a bedside assessment of the severity of the heart failure, which is a well established predictor of short-term mortality in STEMI. Adverse outcomes, like mortality and arrhythmias/cardiogenic shock, are independently associated with higher Killip classes (≥II) at admission. It has been, however, inadequately defined to have local predictors which correspond to the presence of high Killip class in the Pakistani STEMI population at high-volume centres, like NICVD Karachi. Place & Duration of Study: Department of Cardiology, NICVD, Karachi from April 01, 2026  to   July 03, 2026. Methodology: This descriptive cross-sectional study was conducted in 196 patients with symptoms of first episode STEMI aged 18-80 years by non-probability consecutive sampling. Killip class category was found at admission and split into high (Killip class ≥II) or low (Killip class I). Demographic and clinical characteristics such as age, sex, diabetes mellitus, hypertension, dyslipidaemia, smoking, anaemia, chronic kidney disease (CKD) and symptom to door time were collected. Up to 7 days, in hospital outcomes such as mortality, intubation, arrhythmias, inotropic support and the utilization of intra aortic balloon pump (IABP) were documented. We used multivariate logistic regression, using all available parameters, to determine if any parameters were independent predictors of high Killip class. IBM SPSS 21.0 was used for data analysis. Results: The mean age was 58.4 ± 12.6 years and the incidence of male was higher (76.5%). High Killip class (≥II) was present in 18.4% (36/196) of patients. On multivariate analysis, independent predictors of high Killip class were female sex (OR 3.24; 95% CI: 1.47–7.13; p=0.004), anaemia (OR 3.42; 95% CI: 1.61–7.26; p=0.001), CKD (OR 2.89; 95% CI: 1.27–6.59; p=0.011), diabetes mellitus (OR 2.31; 95% CI: 1.08–4.96; p=0.031) and symptom-to-door time >12 hours (OR 3.87; 95% CI: 1.78–8.41; p<0.001). The high Killip group had significantly higher incidences of in-hospital mortality (22.2% vs 3.1%), arrhythmias (36.1% vs 13.1%) and inotropic support requirement (27.8% vs 5.0%) (all p<0.001). Conclusion: Roughly 20% of STEMI patients at NICVD Karachi have high Killip class ≥ II which is independent of female sex, anaemia, CKD, delay or diabetes. It has been found to be associated with significantly poorer in-hospital outcomes, and early risk stratification of these patients and providing targeted intervention are imperative.