Pulmonary Artery Diameter (PAD) and the Pulmonary Artery to Aorta Ratio (PAD/AAD) as Assessed by Non-contrast Cardiac CT: The Association with Left Ventricular (LV) Remodeling and the LV Function

OBJECTIVE: Dilatation of the pulmonary artery itself (PAD: pulmonary artery diameter) or in relation to the ascending aorta (PAD/AAD: pulmonary artery diameter to ascending aortic diameter ratio) has been reported to be associated with pulmonary hypertension and with a prognostic outcome of either heart failure or cardiovascular events. We herein aimed to assess the correlations between pulmonary hypertension-related parameters PAD (or PAD/AAD) and left ventricular (LV) remodeling and LV function. METHODS: This retrospective study included 193 patients (ages: 67±12 years) who underwent both coronary CT angiography (CCTA) and echocardiography. The PAD and the AAD were measured on a transaxial non-contrast CCTA image at the level of the pulmonary artery bifurcation. Left ventricular mass (LVM), relative wall thickness ratio (RWT), left ventricular ejection fraction (LVEF), left atrial volume (LAV), and early mitral inflow velocity to mitral annular early diastolic velocity ratio (E/e') were evaluated by echocardiography. The relationships between PAD (or PAD/AAD) and echocardiography parameters were assessed, and adjusted for the demographic data and cardiovascular disease (CVD) risk factors by a multivariable linear regression analysis. RESULTS: PAD (mean±SD: 2.6±0.4 cm) was positively correlated with LVM (r=0.34, p＜0.001), LAV (r=0.41, p＜0.001), and E/e' (r=0.29, p＜0.001). PAD/AAD (mean±SD: 0.76±0.12 cm) was positively correlated with LVM (r=0.12, p=0.09), LAV (r=0.24, p＜0.001), and E/e' (r=0.15, p=0.04). These correlations remained significant after adjusting for demographic data and CVD risk factors. PAD (or PAD/AAD) did not correlate with LVEF or RWT (p＞0.05). CONCLUSION: Greater PAD or PAD/AAD is significantly associated with LV remodeling and an impaired LV function.