In this interesting prospective study, the authors evaluated the power of pulmonary artery (PA) diameter, and its ratio with aortic (Ao) diameter, on top of right ventricular size, function and septomarginal trabeculation (SMT) derived by CMR, to predict elevated mean pulmonary pressure measured by right heart catheterization (RHC) and also prognosis in a relatively large cohort of patients (
n = 111) with heart failure and preserved left ventricular ejection fraction (HFpEF) [
209]. Patients were classified into one of two groups, either with or without moderate/severe pulmonary hypertension (PH), based on whether mean pulmonary artery pressure (mPAP) was 30 mmHg or more by RHC. 64% of patients were in the moderate/severe PH group by this classification. Significant differences between groups with and without moderate/severe PH were observed with respect to PA diameter (30.9 ± 5.1 mm versus 26 ± 5.1 mm,
p < 0.001), PA:Ao ratio (0.93 ± 0.16 versus 0.78 ± 0.14,
p < 0.001), and SMT diameter (4.6 ± 1.5 mm versus 3.8 ± 1.2 mm;
p = 0.008). While PA diameter measurements and PA:Ao ratio showed reasonable inter-observer agreement, measurement of SMT diameter and area as well as RV free wall thickness failed to show reproducibility. The strongest correlation with mPAP was found for PA:Ao ratio (
r = 0.421,
p < 0.001). By ROC analysis, the best cut-off for the detection of moderate/severe PH was found for a PA:Ao ratio of 0.83 (area under curve 0.76). Over a mean follow-up of 22.0 ± 14.9 months, event-free survival was significantly worse in patients with a PA:Ao ratio ≥0.83 (log rank,
p = 0.004), although the event rates were mainly driven by hospitalisation rate. By multivariable Cox-regression analysis, PA:Ao ratio was the only independent predictor of event-free survival (
p = 0.003).