Severity of Chest Pain among Acute Myocardial Infarction Patients with Diagonal Branch Vessel Disease: A Pilot Study.

INTRODUCTION:  Acute myocardial infarction (AMI) patients present with variable clinical manifestations such as shortness of breath, nausea, etc. among which chest pain is the most common. Previous studies have reported that the clinical presentation of AMI patients with branch vessel disease is indistinguishable from epicardial coronary vessel disease. However, our experience suggests patients with branch vessel disease experience severe chest pain, especially those with a diagonal branch. Therefore, we aim to study the association of chest pain severity with isolated diagonal branch vessel disease as a culprit vessel in AMI patients. METHODS:  It is a retrospective case-control design, where 10 cases and 40 historic controls were recruited in the study. Cases were patients with isolated diagonal branch disease, whereas controls were patients with epicardial vessel disease in AMI. We reviewed Coronary Angiograms of adult patients who presented with acute myocardial infarction and had undergone coronary angiography at Aga Khan University Hospital, Karachi (AKUH). Information on pain scores was measured using the Numeric Pain Rating Scale (NRS) before administration of analgesics. Other relevant variables were also recorded on a pre-structured questionnaire. RESULTS: The mean age of all the participants in the study was 60 ± 11.0 years, with 16% of the patients being women. Among all AMI patients, the intensity of chest pain in patients with isolated diagonal branch vessel disease was 2.6 units higher as compared to those with other epicardial coronary vessel diseases (p-value: <0.001; 95% CI: 1.67 - 3.46). CONCLUSION:  This preliminary study indicates severe chest pain can be a differentiating symptom in AMI patients with diagonal branch disease. It emphasizes clinicians to look for a possibility of a diagonal branch as a culprit vessel in AMI for better judgment, as it is often overlooked. future studies may be conducted at multiple centers for larger sample size and better generalizability.