Frequency and Determinants of ST-Segment Resolution Failure Following Primary Percutaneous Coronary Intervention in Patients with ST-Segment Elevation Myocardial Infarction.

Abstract

Background: This study aimed to determine the frequency of ST-segment resolution (STR) failure following primary percutaneous coronary intervention (PCI) in patients presenting with ST-segment elevation myocardial infarction (STEMI) and to evaluate its association with selected demographic and clinical characteristics.

Methodology: This prospective observational study was conducted in the Department of Cardiology, Hayatabad Medical Complex, Peshawar, Pakistan, from July 2025 to December 2025. A total of 103 patients aged 30–70 years diagnosed with STEMI and undergoing primary PCI were enrolled through consecutive sampling. ST-segment resolution was assessed using a standard 12-lead electrocardiogram within 30 minutes after PCI. STR failure was defined as a reduction of less than 30% in summed ST-segment elevation compared with baseline measurements. Demographic and clinical data were collected using a structured proforma. Statistical analysis was performed using SPSS version 25.

Results: Among the 103 enrolled patients, 55 (53.4%) experienced STR failure following primary PCI (95% CI: 43.5%–63.1%). The study population comprised 55 (53.4%) males and 48 (46.6%) females, with a mean age of 50.3 ± 11.4 years. No statistically significant associations were observed between STR failure and gender (p=0.693), smoking status (p=1.000), diabetes mellitus (p=0.555), hypertension (p=0.691), dyslipidaemia (p=0.425), or socioeconomic status (p=0.559). Rural residence demonstrated a borderline association with STR failure (p=0.074).

Conclusion: More than half of the STEMI patients in this cohort experienced ST-segment resolution failure despite undergoing primary PCI. Traditional cardiovascular risk factors were not significantly associated with STR failure, suggesting that procedural, angiographic, and microvascular determinants may play a more important role in post-PCI myocardial reperfusion. Larger multicenter studies incorporating comprehensive clinical and procedural variables are required to identify modifiable predictors and improve outcomes among STEMI patients.