Pulmonary artery to aorta ratio for the detection of pulmonary hypertension: cardiovascular magnetic resonance and invasive hemodynamics in heart failure with preserved ejection fraction

Abstract

BackgroundPrevious work indicates that dilatation of the pulmonary artery (PA) itself or in relation to the ascending aorta (PA:Ao ratio) predicts pulmonary hypertension (PH). Whether these results also apply for heart failure with preserved ejection fraction (HFpEF) is unknown.In the present study we evaluated the diagnostic and prognostic power of PA diameter and PA:Ao ratio on top of right ventricular (RV) size, function, and septomarginal trabeculation (SMT) thickness by cardiovascular magnetic resonance (CMR) in HFpEF.Methods and Results159 consecutive HFpEF patients were prospectively enrolled. Of these, 111 underwent CMR and invasive hemodynamic evaluation.By invasive assessment 64 % of patients suffered from moderate/severe PH (mean pulmonary artery pressure (mPAP) ≥30 mmHg). 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). 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.Patients were followed for 22.0 ± 14.9 months. By Kaplan Meier analysis event-free survival was significantly worse in patients with a PA:Ao ratio ≥0.83 (log rank, p = 0.004). By multivariable Cox-regression analysis PA:Ao ratio was independently associated with event-free survival (p = 0.003).ConclusionPA:Ao ratio is an easily measureable noninvasive indicator for the presence and severity of PH in HFpEF, and it is related with outcome.

Clinical and prognostic relationships of pulmonary artery to aorta diameter ratio in patients with heart failure: a cardiac magnetic resonance imaging study

“…An enlarged main pulmonary artery (PA) and an increased pulmonary artery/aorta (PA/Ao) diameter ratio are indirect signs of pulmonary hypertension . Their clinical and predictive value has been mainly studied in patients with respiratory diseases, including chronic obstructive pulmonary disease (COPD) and pulmonary arterial hypertension . Previous studies suggest that the PA/Ao ratio, as assessed on computed tomography (CT), may be a useful measure of pulmonary hypertension, especially in patients age < 50 years .…”

The Role of Cardiovascular Magnetic Resonance Imaging in Heart Failure

“…140,141 While 2D-echocardiography has superior temporal resolution for assessment of LV filling, CMR may contribute superior assessment of LVEF, LV mass and LA volumes, in addition to correlates of pulmonary hypertension (e.g. pulmonary artery:aorta ratio 142 and RV function 143 ). The use of correlations between diastolic dysfunction and diffuse myocardial fibrosis 144 and between post-contrast T1 and outcome 145 is under investigation and CMR indices of diastolic function are not yet routinely measured.…”

Review of Journal of Cardiovascular Magnetic Resonance 2015

“…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.…”