Impact of the Killip class of heart failure on treatment times and intrahospital mortality among STEMI patients

Aims While timely reperfusion is known to reduce mortality, the extent to which the severity of heart failure, as classified by the Killip system, influences treatment delays remains unclear. Our study aims to address the existing gap in evidence regarding the relationship between Killip classification at presentation and treatment times in ST-elevation myocardial infarction (STEMI) patients. Methods We conducted a correlative analysis using data from patients treated in our hospital and enrolled in the FITT-STEMI Register from 2009 to 2022. We focused on the relation of treatment times allocating patients into the four Killip classes and used an ANOVA test (significance level: P < 0.05). Killip class and intrahospital mortality were studied via binary logistic regression. Results In total, 1264 patients were identified. Door-to-balloon time among Killip I patients was 54 (±35) min (mean ± SD) and 53 (±26) min among Killip II and prolonged up to 77.5 (±46) min for class III and 79.7 (±45) min for class IV (overall P -value < 0.001). This remained statistically significant even after the exclusion of patients with out-of-hospital cardiac arrest (OHCA) (overall P -value: <0.001). Post hoc analysis showed a significant difference between Killip II and III classes for both all-comers ( P = 0.014) as well as after the exclusion of OHCA patients ( P = 0.012). Intrahospital mortality increased from <5% for classes I and II up to 10.3% for class III and 35.4% for class IV. Conclusion The severity of heart failure among STEMI patients significantly affects the duration of treatment times. Patients presenting with Killip class III and IV demonstrate high intrahospital mortality rates.