Heart size, function linked to vascular complications in vEDS
Larger left atrium, lower left ventricle function may indicate risk
Lower heart function and larger heart size in vascular Ehlers-Danlos syndrome (vEDS) patients were linked to a higher risk of dissections (ruptures) or aneurysms (bulges) in arteries, according to a study.
“Our study sheds light on the subtle [heart muscle] abnormalities in vEDS,” the researchers wrote. “A multidisciplinary approach involving comprehensive genetic, cardiologic, and imaging assessment would be beneficial for clinical management.”
The study, “Association Between Cardiac Size, Systolic Function, and Complications in Vascular Ehlers-Danlos Syndrome,” was published in the Canadian Association of Radiologists Journal.
EDS is a group of genetic disorders affecting connective tissues, causing symptoms like joint hyper-mobility, skin that stretches easily, and fragile tissues. vEDS is usually caused by mutations in the COL3A1 gene, which instructs the making of type III collagen, a major component of blood vessel walls. Collagen dysfunction leads to weakened blood vessel walls and a higher risk of serious complications, such as dissections or aneurysms.
The heart muscle is rich in type III collagen, which plays an important role in cardiac structure and function. But research into heart involvement in vEDS is lacking, according to the scientists.
LVEF as a marker
The study involved 26 vEDS patients from a single medical center in Canada. They had MRI scans between 2015 and 2023 as part of routine check-ups of blood vessel abnormalities. Their heart function and size were compared to a control group of 26 healthy individuals. Both groups had a mean age of 38, and 50% were women.
Results showed that while the two groups had similar end-diastolic and end-systolic volumes, meaning how much blood is in the ventricles before the heart contracts and at the end of contraction, patients with vEDS had significantly lower ejection fraction (a measure of the heart’s ability to pump blood). This difference was seen despite the fact that most vEDS patients were using anti-hypertension medication, the researchers said.
Decreased heart function in vEDS, specifically in the left ventricle, was linked to a greater risk of dissections or aneurysms. A higher percentage of vEDS patients had arterial dissections and/or aneurysms when their ejection fraction in the left ventricle (LVEF) was lower than the mean value of 58% than when LVEF was higher (75% vs. 12.5%). Pneumothorax, a condition in which air leaks into the space between the lungs and chest wall and causes lung collapse, only occurred in those with lower LVEF.
“According to our data, for every 1% increase in LVEF, the odds of having any complication decreases by 29%, highlighting the importance of LVEF as a predictive marker for complications in vEDS patients,” the scientists wrote.
Overall, 53.8% of the vEDS patients had at least one arterial complication. The most frequently affected blood vessel was the common iliac artery, which transports blood from the aorta toward the pelvic region and lower extremities.
One chamber of the heart, the left atrium, was significantly larger in patients with more dissections.
Limitations noted in the study included its small sample size. “Prospective multicentre longitudinal studies with larger cohorts are necessary to confirm the findings and understand the underlying pathophysiologic [disease-related] mechanisms,” the team wrote. “Understanding the impact of the pathogenic [disease-causing] variants of COL3A1 mutations on the myocardium [heart muscle] and their clinical manifestations would also be important.”
Larger heart size and lower ventricular function are linked to vEDS-related complications, the researchers wrote, and “cardiac MRI-derived ventricular volumetry may aid in the prognostication in vEDS.”
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