Abstract 162: Single Nucleotide Polymorphism of the B-Type Natriuretic Peptide Helps Predict the Presence of Significant Coronary Artery Disease

Early detection and diagnosis of coronary artery disease (CAD) is crucial in reducing the morbidity and mortality. The clinical standard for detecting CAD is by angiography which is associated with rare but important clinical risks. Recent studies have shown that up to 40% of patients referred for angiography do not have significant disease. This discrepancy between referral and diagnosis may be improved by the utilization of genetic screening. A single nucleotide polymorphisms (SNP) of the B-type natriuretic peptide gene (NPPB), rs198389, was previously found to be associated with several cardiovascular diseases. Our objective was to determine whether detection of genetic variation could contribute to better selection of patients referred for angiography. We hypothesized that an SNP analysis of the NPPB gene may help differentiate patients with significant disease from those with non-significant CAD. Ninety-three patients referred for coronary angiography at the Kingston General Hospital Cardiac Catheterization Lab were consented for genetic screening. Blood samples were collected during angiography procedure. Genomic DNA was isolated from leukocytes, and screened for SNPs using a real-time PCR-based TaqMan SNP Assay. We found that more males were referred for coronary angiography than females: 69% versus 31%. Two out of ten males (20%) were found to have no or minimal CAD. In contrast, 48% of females were found to have non-significant CAD. Older age (≥ 69 years) was deemed to be a significant predictor of CAD in the total recruited population (odds ratio of 3.4), but no age difference was found between healthy and diseased females. Additionally, a mutation of the B-type natriuretic peptide gene (NPPB) was found to be a significant predictor of CAD in the younger population (< 69 years), with an odds ratio of 5.9. We found a significant difference between patterns of CAD development in males and females, suggesting that different diagnostic criteria should be used depending upon gender. Moreover, younger individuals with two copies of the major allele for the NPPB SNP were more likely to develop CAD, making this SNP a potential factor in the prediction of CAD in younger population.