ST-Segment Elevation in Lead aVR as a Marker of Left Main Coronary Artery Disease in Acute Coronary Syndrome: Frequency and Associated Clinical Factors

Objectives: This study aimed to determine the frequency of LMCA disease among ACS patients presenting with ≥1 mm ST-segment elevation in lead aVR and to identify associated clinical risk factors. Methodology: A descriptive cross-sectional study was conducted at the Peshawar Institute of Cardiology from February to July 2025. Adults aged 18–60 years with ACS and ST-segment elevation ≥1 mm in lead aVR were consecutively enrolled. Patients with prior CABG, congenital heart disease, or major comorbidities were excluded. All participants underwent coronary angiography, and LMCA disease was defined as ≥50% stenosis. Data were analyzed using SPSS v26, with chi-square and Fisher’s exact tests applied to assess associations. Results: Of 384 enrolled patients (mean age 39.5 ± 12.5 years; 60.2% male), 132 (34.4%; 95% CI: 29.6–39.1%) demonstrated LMCA stenosis ≥50%. Smoking (55.0% vs. 23.7%, p < 0.001) and hypertension (54.7% vs. 19.7%, p < 0.001) were significantly associated with LMCA disease, whereas age, sex, diabetes, BMI, residence, and lifestyle showed no significant relationships. Conclusion: ST-segment elevation in lead aVR was frequently associated with LMCA disease in ACS patients, with smoking and hypertension emerging as the most relevant correlating risk factors. These findings highlight the potential clinical value of aVR assessment during early ACS evaluation.