CDK7 as a Potential Exploratory Biomarker for Distinguishing Acute Myocardial Infarction Subtypes via DDR Pathways: Evidence From a Bangladeshi Cohort

INTRODUCTION: Acute myocardial infarction (AMI) is a major cause of cardiovascular death, with STEMI and NSTEMI as distinct subtypes. Current diagnostic tools often lack the sensitivity and timeliness to rapidly distinguish these subtypes at early clinical presentation. The DNA damage response (DDR), activated by ischemia and oxidative stress during AMI, represents a promising pathway for identifying novel biomarkers. Despite evidence of its role in myocardial infarction, little is known about DDR gene expression in South Asian populations, particularly in Bangladesh. This study evaluated the expression of four DDR genes; ATM, CDK7, OGG1, and NBN and their potential for distinguishing between STEMI and NSTEMI. METHODS: A total of 70 AMI patients and 60 healthy controls from the Bangladeshi population were recruited. RNA was extracted from blood samples, and gene expression was quantified using qRT-PCR. Statistical analyses included Mann-Whitney U tests for group differences, linear regression analysis and Spearman's correlation analysis for gene co-expression. RESULTS: CDK7 expression was significantly higher in NSTEMI compared to STEMI patients (p < 0.05). However, ATM, OGG1, and NBN did not differ significantly between the subtypes. Co-expression analysis revealed strong positive correlations among all four genes, with the strongest between ATM and CDK7 (r = 0.76, p < 0.001). CONCLUSION: This is the first study in the Bangladeshi population to demonstrate distinct DDR gene expression patterns across AMI subtypes, with CDK7 showing subtype-specific differential expression between STEMI and NSTEMI. Although the observed discrimination was modest and requires further validation, these findings provide important exploratory insights into ischemia-associated transcriptional regulation in an underrepresented population.