Abstract P388: Association of Clinical Characteristics and Cardiopulmonary Risk Factors with Aortic and Pulmonary Arterial Enlargement by Magnetic Resonance

Abstract

Purpose: To determine the association of clinical characteristics and cardiopulmonary risk factors with aortic and main pulmonary artery (MPA) enlargement by cardiovascular magnetic resonance (CMR). Methods: 1794 Framingham Offspring cohort members (65±9 y, 844 M) underwent axial 2D black-blood T2-weighted thoracoabdominal CMR. MPA and ascending (ASC) and descending (DSC) thoracic aortic diameters were measured at MPA-bifurcation level, abdominal (ABD) aortic diameter at 5 mm above renal artery origins. We assessed relationship of arterial diameters to height (HT) and body surface area (BSA) using Pearson correlation and determined sex-specific 90th percentile cutpoints (p90) for ASC, DSC, ABD, and MPA in a referent group free of obesity (BMI≥30), emphysema, myocardial infarction, heart failure, and any history of hypertension (HTN) or smoking. For the overall study sample, multivariable logistic regression was used to determine the association of high (≥p90) vessel diameters with the above risk factors and age, sex and pack-years smoked. Results: 370 Offspring (157 M) met referent-group criteria. In men neither HT nor BSA correlated with aortic diameter. In women DSC, ABD and MPA correlated with HT and BSA (r=0.14 - 0.25, all p≤0.045), but BSA-indexation gave inverse correlations with HT and BSA (all p<0.0001); HT-indexation gave inverse correlations with HT (all p≤0.045). Thus we used unindexed p90 cutpoints of (M,W): ASC=34.9, 31.8mm; DTA=25.3, 22.7mm; ABD=20.0, 17.3mm; MPA=26.6, 24.2mm. Prevalence of and MV-adjusted odds ratios for high diameter are in the Table (N=1794). Obesity was globally and most strongly associated with overall vessel enlargement. ABD enlargement was associated with total pack-years, but not with positive smoking history. Conclusions: ABD enlargement was slightly more prevalent in women. In both sexes MPA and general aortic enlargement are associated with greater age and obesity, but smoking (as pack years) was associated with ABD enlargement only and HTN with the thoracic aorta only.