Association between cardiovascular risk factors and the diameter of the main pulmonary artery in asymptomatic population in the Appalachian region

Abstract

Pulmonary artery (PA) diameter may be altered in association with cardiovascular (CV) risk factors as noted in aorta in systemic hypertension. The flow of blood from the right ventricle to the PA and all the way to the capillary level depends on the pulmonary vascular resistance and to a lesser extent compliance and impedance of the PA, which are the fundamental conduit for maintenance of the right heart hemodynamics. Our objective is to determine the association between CV risk factors and the main pulmonary artery (MPA) diameter. The study population are asymptomatic individuals with no known diagnosis of CV diseases in central Appalachia (n=1,282). Adults aged 18 years or older were eligible for the screening if they were referred by a physician. For self-referral, only males aged ≥45 years and females aged ≥55 years were eligible. Unadjusted and adjusted linear regression analyses were performed. The mean MPA diameter was significantly higher among males compared to females (27.19±4.20 vs. 24.99±3.91 mm, P<0.0001). Participants with diabetes also had wider MPA diameter (26.79±4.56 mm) compared to those without diabetes (25.93±4.11 mm) (P=0.015). Further, hypertensive (26.42±4.15 vs. 25.71±4.21 mm, P=0.002) and obese (27.25±4.11 vs. 25.28±4.07 mm, P<0.0001) participants had significantly wider MPA diameter compared to non-hypertensive and non-obese participants, respectively. Multivariable model showed that age, sex and body mass index (BMI) were significantly associated with MPA diameter. A 1-year increase in age increased MPA diameter by 0.046 mm (P<0.0001). The diameter of MPA was wider among males by 2.16 mm compared to females (P<0.0001). Finally, with one unit increase in BMI, the MPA diameter increased by 0.16 mm (P<0.0001). MPA diameter was significantly associated with age, sex, and BMI. Further prospective studies are needed to correlate computed tomography (CT) measurement of MPA diameter with pulmonary pressure as assessed by echocardiogram to diagnose pulmonary hypertension (PH).