IN-HOSPITAL OUTCOMES OF MECHANICALLY VENTILATED PATIENTS WITH ADVANCED KILLIP CLASS UNDERGOING PRIMARY PERCUTANEOUS CORONARY INTERVENTION

Background: Patients with acute ST-elevation myocardial infarction (STEMI) who present in advanced Killip class and require mechanical ventilation represent a critically ill population with a heightened risk of adverse in-hospital outcomes. Understanding the prognostic impact of interventions in this group is essential for guiding management and improving outcomes. Objective: To determine in-hospital outcomes among mechanically ventilated patients with Killip class III or IV undergoing primary percutaneous coronary intervention (PPCI). Methods: This descriptive cross-sectional study was conducted at the National Institute of Cardiovascular Diseases (NICVD), Karachi, over a six-month period. A total of 295 patients meeting inclusion criteria—age ≥18 years, STEMI diagnosis, Killip class III/IV, and requiring mechanical ventilation—were enrolled through non-probability consecutive sampling. Demographic, clinical, procedural, and outcome data were collected and analyzed using SPSS version 24. Chi-square and Fisher’s exact tests were applied for stratified outcome comparison, with a significance threshold of p ≤ 0.05. Results: The mean age of patients was 61.4 ± 11.2 years, with 72.2% males. Invasive ventilation was used in 68.1% of cases. Overall in-hospital mortality was 13.9%, with significantly higher mortality in patients receiving invasive ventilation (17.4% vs. 6.4%, p = 0.011). Arrhythmias occurred in 28.1%, stroke in 12.2%, and RRT was needed in 14.9% of cases. Use of intra-aortic balloon pump (IABP) was significantly associated with increased arrhythmia rates (p = 0.002) and prolonged ICU stays (p < 0.001). Conclusion: Mechanically ventilated patients with advanced Killip class undergoing PPCI have high rates of in-hospital complications and mortality. Invasive interventions and supportive measures correlate with adverse outcomes, underscoring the need for timely risk stratification and individualized management strategies.