Echocardiographic phenotype in osteogenesis imperfecta varies with disease severity.

BACKGROUND AND OBJECTIVES: Our purpose was to investigate cardiovascular abnormalities in children with osteogenesis imperfecta (OI).

METHODS: Two hundred children (100 OI, 100 matched volunteers) were prospectively studied. Aortic and left ventricular (LV) measurements were performed using transthoracic echocardiography. Patients were typed according to modified phenotypical Sillence classification as published in the Nosology and Classification of Genetic Skeletal disorders: 2015 Revision .

RESULTS: Patients (age 9.6±4.1 years, body surface area 1.08±0.47 m2 ) consisted of OI types: 1 (n=44), 3/4 (n=54), 4 (n=1) and 15 (n=1). The 95% CIs for Z-score of aortic annulus, sinus, sinotubular junction and ascending aorta for OI were 0.43 to 0.73, 0.56 to 0.94, 0.28 to 0.70 and 0.78 to 1.24, respectively. In type 1, sinus, sinotubular junction and ascending aorta diameters were 2.29 cm, 1.81 cm and 2.05 cm, respectively, which did not differ compared with controls. The LV dimensions were larger in type 1. In type 3/4, aortic dimensions were larger than controls at all levels: annulus (1.61 vs 1.50 cm, p<0.001), sinus (2.19 vs 2.05 cm, p=0.001), sinotubular junction (1.77 vs 1.64 cm, p<0.001) and ascending aorta (1.98 vs 1.82 cm, p<0.001), but LV dimensions were normal.

CONCLUSIONS: Cardiovascular effects are identifiable in childhood even in mild forms of OI. Aortic dilation was the predominant finding, while valvular abnormalities were infrequent. Patients with more severe skeletal pathology (types 3/4) have more significant findings. Aortic and LV dilation in type 1 vs type 3/4 appears to differ based on the biochemical mechanism of disease.