MicroRNAs (miRNAs) are small, single-stranded, non-protein-coding RNAs of about 22 nucleotides. miRNA molecules have been identified that plays key roles in a broad range of physiologic and pathologic processes. Polymorphisms in the corresponding sequence space are likely to make a significant contribution to phenotypic variation.

To assess the variations of rs11614913 T → C in hsa-mir-196a2 and rs3746444 A → G in hsa-mir-499 in the complex etiology of coronary artery disease (CAD), 956 CAD patients diagnosed by coronary arterial angiography and 620 controls were enrolled. Among the patients, 785 (785/956) had complete follow-ups for 42 months. The variant genotypes CC/CT of hsa-mir-196a2 rs11614913 T → C were not associated with a significantly increased risk of CAD (adjusted OR = 1.02, 95% CI = 0.76–1.38), compared with wide genotype TT, but CC and CC/CT genotypes were associated with 34 and 35% increased risks of serious prognosis of CAD (adjusted HR = 1.34, 95% CI = 1.02–1.75 for CC; adjusted HR = 1.35, 95% CI = 1.03–1.75 for CC/CT). In the variant of hsa-mir-499 rs3746444A → G, GG was associated with the 223% increased risk of CAD (adjusted OR = 3.23, 95% CI = 1.56–6.67). Cox regression analysis showed that age, smoking status, numbers of pathological changes in coronary arteries, rs11614913 T → C, and diabetes mellitus were associated with serious prognosis of CAD.

Our findings strongly implicate the functional miRNAs polymorphisms of hsa-mir-196a2 and hsa-mir-499 genes may modulate the occurrence or prognosis in Chinese CAD.