NEW YORK – New research suggests that some of the same genetic factors contribute to both myocardial infarction and to spontaneous coronary artery dissection (SCAD), though the variants that increase the likelihood of having a heart attack appeared to reduce the risk of SCAD — a condition that is overrepresented in women under 50 who are atherosclerosis-free and lack obvious cardiac risk factors.
"Spontaneous coronary artery dissection is an increasingly recognized cause of myocardial infarction in young and otherwise healthy women, for which the etiology is incompletely understood," senior author Santhi Ganesh, a cardiovascular medicine, internal medicine, and human genetic researcher at the University of Michigan, and her co-authors explained in a study published in Nature Communications on Friday.
Ganesh and colleagues from the University of Michigan, University of British Columbia, and elsewhere did a genome-wide association study involving 270 individuals with SCAD and 5,263 unaffected control individuals, leading to a chromosome 1 variant with apparent ties to expression of the ADAMTSL4 gene. With a related meta-analysis that included 163 more SCAD cases and more than 3,200 controls, they uncovered still other loci linked to SCAD on chromosomes 6 and 12, along with a female-specific association involving a site in and around LINC00310 on chromosome 21.
"The findings of the current study support a complex genetic basis of SCAD and new biological leads for further mechanistic investigation of arterial pathobiology and sex-dimorphic mechanisms," the authors reported.
Based on a follow-up analysis done using a polygenic risk score for SCAD and data for hundreds more patients, the team saw signs that some of the same variants contributing to SCAD coincided with higher-than-usual risk of a vascular condition known as fibromuscular dysplasia (FMD). A related pleiotropy analysis also pointed to shared genetic contributors to SCAD and conditions such as hypertension or migraine headache.
"As a physician caring for patients with both FMD and SCAD, it is gratifying to see results from our research that are beginning to uncover the genetic architecture and risk for these diseases about which so little is known," Ganesh said in a statement.
In contrast, the results hinted that the SCAD PRS corresponded to decreased risk of atherosclerosis-related myocardial infarction and coronary artery disease in an analysis that relied on genetic and clinical data from large clinical efforts such as the UK Biobank project and the Million Veterans Program.
"It is especially intriguing that many of the same genetic markers are involved, but in different ways, in both SCAD-induced heart attack and atherosclerotic heart attack," Ganesh said in a statement.