OUTCOMES OF PATIENTS WITH ACUTE CORONARY SYNDROME UNDERGOING PRIMARY PCI – 03 MONTHS FOLLOW-UP

Abstract

Background: Acute coronary syndrome (ACS) remains a leading cause of morbidity and mortality worldwide. Primary percutaneous coronary intervention (PCI) is the preferred re-perfusion strategy for ST‐elevation myocardial infarction (STEMI) and a key component of invasive management in non–ST‐elevation acute coronary syndrome (NSTEMI) among high‐risk patients [1–3]. However, data on short-term outcomes, particularly up to three months post-procedure, are limited in many low- and middle-income countries, including Pakistan. This study aims to determine procedural success rates and major adverse cardiovascular events (MACE) at three months in ACS patients undergoing primary PCI at a tertiary cardiac center in Peshawar, Pakistan. Methods: In this prospective descriptive study, 219 consecutive ACS patients (both STEMI and NSTEMI) who presented within 24 hours of symptom onset and underwent primary PCI between 10 December 2023 and 10 June 2024 were enrolled. Sample size was calculated using the WHO formula for single-proportion studies, assuming a procedural success rate of 90% from prior regional data, 5% precision, and 95% confidence, yielding a minimum of 138 patients; we enrolled 219 to account for potential losses and subgroup analyses [4, 5]. Baseline demographics, risk factors, angiographic data,nd in-hospital outcomes were recorded. Procedural success was defined as <20% residual stenosis with TIMI (Thrombolysis In Myocardial Infarction) grade 3 flow in the infarct‐related artery without in‐hospital death. emergent coronary artery bypass grafting (CABG) or major complication [6]. MACE (composite of cardiac death, reinfarction, target-vessel revascularization, and stroke) up to three months post-PCI was documented through outpatient visits and phone follow-ups. Results: The mean age of participants was 55.78 ± 7.23 years, with 59.4% males and 40.6% females. Hypertension (54.8%), diabetes mellitus (41.1%), and smoking (36.5%) were the predominant risk factors. STEMI accounted for 65.3% of cases; NSTEMI comprised 34.7% (Figure 1). Procedural success was achieved in 83.6% (n=183) (Figure 2). MACE at three months occurred in 6.8% (n=15), including cardiac death (2.3%), reinfarction (1.8%), target-vessel revascularization (1.4%), and stroke (1.4%). On stratified analysis, age ≥60 years (p=0.03), baseline left ventricular ejection fraction (LVEF) <40% (p=0.01), and diabetes mellitus (p=0.02) were significantly associated with higher MACE. Procedural failure correlated with the the presence of multivessel disease (p=0.04) and symptom-to-balloon time >180 minutes (p=0.02). Conclusions: Primary PCI in ACS patients demonstrated a high procedural success rate (83.6%) with relativelyy low three-month MACE (6.8%). Delays in reperfusion and comorbid diabetes and reduced LVEF are key determinants of adverse outcomes. These findings reinforce the need for rapid triage and optimization of modifiable risk factors tohance short-term outcomes in Pakistan.