NEW YORK (Reuters Health) – Patients with osteogenesis imperfecta face an increased risk of cardiovascular abnormalities, researchers from Norway report in the March American Heart Journal.

Osteogenesis imperfecta (OI), a hereditary connective tissue disorder caused by genetic defects in type I collagen synthesis, has been associated with valvular dysfunction and aortic root dilatation in a few studies of limited numbers of patients, but the actual prevalence of cardiovascular abnormalities in these patients is unknown.

“We knew that the collagen rich tissues are affected in this group of patients and knew up to the certain level that both myocardium and valves are affected, but we were surprised at the prevalence of aortic and mitral regurgitation and increased dimensions of the left ventricle,” Dr. Zoran Radunovic from Oslo University Hospital-Aker, Oslo, Norway told Reuters Health in an email.

Dr. Radunovic and colleagues gathered echocardiographic data from 99 adult OI patients registered at TRS-National Resource Centre for Rare Disorders in order to investigate cardiac abnormalities, especially those of the left ventricle and the ascending aorta. Fifty-two age- and sex-matched controls were evaluated for comparison.

Systolic and diastolic blood pressures were significantly higher and body-surface area was significantly smaller among OI patients than among controls.

Interventricular septal wall thickness, left ventricular posterior wall thickness, left ventricular mass, and left ventricular relative wall thickness were significantly larger in the OI group than in the control group.

When indexed for body-surface area, all 4 aortic diameters measured were significantly larger in the OI group than in the control group. Diameters were largest in the group with type III OI (the most severe form) compared to other types.

Mild mitral regurgitation was present in both the OI and control groups, but moderate mitral regurgitation and mild or moderate aortic regurgitation were present only among OI patients.

In a multivariate linear regression analysis, OI and systolic blood pressure were the only 2 significant predictors of left ventricular wall thickness and mass, whereas OI was the only significant predictor of all 4 aortic diameters.

“We hope that the results of our study are going to draw the physician’s attention and focus their interest not only on skeletal problems, which are well studied and known, but on the cardiovascular system as well,” Dr. Radunovic said.

“This group should be followed up more closely, and the referral threshold to a cardiologist should be lower,” Dr. Radunovic concluded. “We are missing a prospective study which could help us understand the development of the disease through the years.”

Am Heart J