Genome-wide association meta-analysis of spontaneous coronary artery dissection reveals common variants and genes related to artery integrity and tissue-mediated coagulation

Spontaneous coronary artery dissection (SCAD) is an understudied cause of acute myocardial infarction primarily affecting women. It is not known to what extent SCAD is genetically distinct from other cardiovascular diseases, including atherosclerotic coronary artery disease (CAD). Through a meta-analysis of genome-wide association studies including 1917 cases and 9292 controls of European ancestry, we identified 17 risk loci, including 12 new, with odds ratios ranging from 2.04 (95%CI 1.77-2.35) on chr21 to 1.25 (95%CI 1.16-1.35) on chr4. A locus on chr1 containing the tissue factor gene (F3), which is involved in blood coagulation cascade, appears to be specific for SCAD risk. Prioritized genes were mainly expressed in vascular smooth muscle cells and fibroblasts of arteries and are implicated predominantly in extracellular matrix biology (e.g. COL4A1/A2, HTRA1 and TIMP3). We found that several variants associated with SCAD had diametrically opposite associations with CAD suggesting that shared biological processes contribute to both diseases but through different mechanisms. We also demonstrated an inferred causal role for high blood pressure, but not other CAD risk factors, in SCAD. Our findings provide novel pathophysiological insights involving arterial integrity and tissue-mediated coagulation in SCAD and set the stage for future specific therapeutics and prevention for this disease.