Factors Contributing to Prolonged Total Ischemic Time in ST-Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention: A Quasi-Experimental Clinical Audit of In-Hospital Process Improvement

Abstract

Objectives: To identify factors contributing to prolonged total ischemic time (TIT) in patients presenting with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) and to evaluate the impact of an audit-guided, process-based quality-improvement intervention on in-hospital reperfusion delays. Methodology: This quasi-experimental before–after quality-improvement study was conducted at a tertiary cardiac center in South Punjab, Pakistan. A total of 545 consecutive STEMI patients undergoing primary PCI were included (pre-intervention n = 272; post-intervention n = 273). Prolonged TIT was defined as ≥360 minutes. Following a clinical audit of workflow inefficiencies, a targeted in-hospital intervention was implemented, comprising structured emergency triage, direct Cath-lab activation, and deferral of non-essential administrative processes. Results: The mean age of the cohort was 52.4 ± 11.4 years, and 79.6% of patients were male. Mean TIT decreased significantly following the intervention (525.4 ± 177.5 vs. 461.3 ± 193.6 minutes; p < 0.001), primarily due to reductions in system-related in-hospital delays. Door-to-balloon time improved substantially (108.8 ± 28.1 vs. 73.7 ± 10.9 minutes; p < 0.001), along with significant reductions in door-to-ECG and ECG-to-Cath-lab transfer times. Prehospital delay remained the dominant contributor to prolonged TIT and did not change significantly between phases. Cath-to-balloon time showed no significant difference. Conclusion: In this cohort, prolonged TIT among STEMI patients was driven largely by prehospital delays. However, simple, audit-guided, low-cost in-hospital quality-improvement measures resulted in significant reductions in system-related reperfusion delays and improved adherence to guideline-recommended timelines.