Extent of Right Ventricular Epicardial Vascularization in Pulmonary Arterial Hypertension

Individuals with pulmonary arterial hypertension (PAH) may have more extensive right ventricular (RV) epicardial vasculature compared with those individuals without PAH, according to a study published in Heart, Lung and Circulation.

Researchers identified 37 patients with PAH (idiopathic, n=25; associated with connective tissue disease, n=12) and 37 control participants with normal coronary arteries from a single PH center to determine whether patients with PAH have altered RV epicardial vasculature, and how it relates to RV hemodynamic stress.

Study results showed that patients with PAH had more right coronary artery branches (RCAB) compared with controls (7 vs 6; P <.001), and an increased sum of the diameters of RCABs (RCAB_sum;9.4 vs 7.3 mm; P <.001), but had comparable left coronary artery branch count (4 vs 4; P =.50). It was also identified, in a stepwise multivariable linear regression model, that RA area (β = .152; P =.002) and diastolic wall stress (β = .025; P =.02) were significant predictors of RCAB_sum (model R² = 0.65; P <.0001).

The investigators concluded that patients with PAH, compared with controls, have more extensive RV epicardial vascularization. In addition, a linear relation was identified between potential markers of advanced RV diastolic function and the extent of RV epicardial vascularization. Therefore, it is suspected that in patients with PAH, the blood flow in the epicardial arteries is increased and contributes to vasodilation.

Some limitations of the study include its cross-sectional design and its being conducted in a single pulmonary hypertension center with a low number of enrolled participants.

Reference

Magoń W, Stepnięwski J, Miszalski-Jamka T, Urbańszyk-Zawadzka M, Podolec P, Kopeć G. Right ventricular epicardial vascularization in patients with pulmonary arterial hypertension [published online September 28, 2017]. Heart Lung Circ. doi:10.1016/j.hlc.2017.08.023