Diameter of the Pulmonary Artery in Relation to the Ascending Aorta: Association with Cardiovascular Outcome

COPD Subtypes Are Differentially Associated With Cardiovascular Events and COPD Exacerbations

BACKGROUND

The coronary artery calcium score (CACS) and ratio of the pulmonary artery to aorta diameters (PA:A ratio) measured from chest CT scans have been established as predictors of cardiovascular events and COPD exacerbations, respectively. However, little is known about the reciprocal relationship between these predictors and outcomes. Furthermore, the prognostic implications of COPD subtypes on clinical outcomes remain insufficiently characterized.

RESEARCH QUESTION

How can these two chest CT scan-derived parameters predict subsequent cardiovascular events and COPD exacerbations in different COPD subtypes?

STUDY DESIGN AND METHODS

Using COPDGene study data, we assessed prospective cardiovascular disease (CVD) and COPD exacerbation risk in patients with COPD (Global Initiative for Chronic Obstructive Lung Disease spirometric grades 2-4), focusing on CACS and PA:A ratio at study enrollment, with logistic regression models. These outcomes were analyzed in three COPD subtypes: 1,042 patients with non-emphysema-predominant disease (NEPD) (low attenuation area at -950 Hounsfield units [LAA-950] < 5%), 1,324 patients with emphysema-predominant disease (EPD) (LAA-950 ≥ 10%), and 465 patients with intermediate emphysema disease (5% ≤ LAA-950 < 10%).

RESULTS

Our study indicated significantly higher overall risk for cardiovascular events in patients with higher CACS (≥ median; OR, 1.61; 95% CI, 1.30-2.00) and increased COPD exacerbations in those with higher PA:A ratios (≥ 1; OR, 1.80; 95% CI, 1.46-2.23). Notably, patients with NEPD showed a stronger association between these indicators and clinical events than those with EPD (with CACS/CVD, NEPD vs EPD: OR, 2.02 vs 1.41; with PA:A ratio/COPD exacerbation, NEPD vs EPD: OR, 2.50 vs 1.65); the difference in ORs between COPD subtypes was statistically significant for CACS/CVD.

INTERPRETATION

Two chest CT scan parameters, CACS and PA:A ratio, hold distinct predictive values for cardiovascular events and COPD exacerbations that are influenced by specific COPD subtypes.

TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT00608764; URL: www.

CLINICALTRIALS

gov.

Larger pulmonary artery to ascending aorta ratios are associated with decreased survival of patients undergoing pulmonary endarterectomy

Objectives

The ratio of pulmonary artery (PA) and ascending aorta (AA) diameters has recently been shown to be a useful indicator for disease severity and predictor of outcome in patients with pulmonary hypertension and heart failure. This study aimed at evaluating the applicability of this ratio for perioperative risk assessment of patients with chronic thromboembolic pulmonary hypertension undergoing pulmonary endarterectomy.

Methods

In this retrospective cohort study on 149 patients undergoing pulmonary endarterectomy between 2013 and 2020, the preoperative PA to AA ratio was analyzed on axial computed tomography. Variables of pulmonary hemodynamic status were assessed during preoperative right heart catheterization and postoperative Swan-Ganz catheter measurements. Perioperative survival was analyzed by Kaplan-Meier method and log-rank tests.

Results

Preoperative computed tomography measurements showed a median AA diameter of 31 mm (range, 19-47 mm), and a median PA diameter of 36 mm (range, 25-55 mm). The calculated median PA to AA ratio was 1.13 (range, 0.79-1.80). PA to AA ratio correlated positively with PA pressure (systolic, r = 0.352 [P < .001]; diastolic, r = 0.406 [P < .001]; mean, r = 0.318 [P < .001]) and inversely with age (r = −0.484 [P < .001]). Univariable Cox regression analysis identified PA diameter (P = .008) as a preoperative parameter predictive of survival. There was a significant difference (log-rank P = .037) in 30-day survival probability for patients with lower PA to AA ratios (<1.136; survival probability, 97.4%) compared with patients with higher ratios (>1.136; survival probability, 88.9%).

Conclusions

PA to AA ratio shows a correlation with other variables associated with pulmonary hypertension. In addition, patients with higher PA to AA ratios have lower survival probabilities after PEA. Further analysis of PA to AA ratio on the selection of chronic thromboembolic pulmonary hypertension for different treatment modalities—pulmonary endarterectomy, medical therapy, and or balloon pulmonary angioplasty—is warranted.

Association between Large Arteries Diameter and Heart Function in Subjects Free of Cardiovascular Diseases

To investigate the association between Aorta (Ao), pulmonary artery (PA) diameters and the PA/Ao ratio with right (RV) and left ventricle (LV) volumetric properties in subjects free of cardiovascular diseases. In the KORA-MRI study, 339 subjects (mean age 56.3 ± 9.1 years; 43.7% female) underwent whole-body 3T-MRI. Ao and PA were measured on DIXON sequences. Cvi42 quantified cardiac functional parameters from a SSFP sequence. The relationship between ascending (AAo), and descending aorta (DAo), as well as PA diameters, and RV and LV function were assessed using linear regression models adjusted for age, sex, and cardiovascular risk factors. AAo and DAo diameter were associated with LV end-diastolic volume (β = 4.52, p = 0.015; ß = 7.1, p ≤ 0.001), LV end-systolic volume (β = 2.37, p = 0.031; ß = 3.66, p = 0.002), while DAo associated with RV end-diastolic volume (β = 6.45, p = 0.006) and RV end-systolic volume (β = 3.9, p = 0.011). PA diameter was associated with LV end-diastolic volume (β = 4.81, p = 0.003). Interestingly, the PA/Ao ratio was only associated with RV end-diastolic and end-systolic volume (β = 4.48, p = 0.029; ß = 2.82, p = 0.037). Furthermore, we found different relationships between men and women. Ao and PA diameter were associated with LV and RV volumetric parameters in subjects free of cardiovascular diseases suggesting that ventricular volumetric performance directly relates to vascular diameter properties.

Pulmonary artery to ascending aorta ratio by echocardiography: A strong predictor for presence and severity of pulmonary hypertension

BACKGROUND

The pulmonary artery (PA) to ascending aorta diameter ratio (PA:A) has been evaluated in numerous studies analyzing cardiac magnetic resonance (CMR) and computed tomography (CT) data. Previously, no transthoracic echocardiography (TTE) cutoffs have been published. We sought to evaluate (1) the feasibility to image the pulmonary trunk in a prospective cohort, and (2) the ability of PA:A derived by TTE to predict pulmonary hypertension (PH).

METHODS

We performed a post-hoc analysis of a prospectively recruited consecutive cohort of patients referred to our tertiary center cardiology department due to suspicion for PH. Invasive hemodynamic assessment and quasi-simultaneous TTE was performed in all participants.

RESULTS

A total of 84 patients were included in the analysis, median age was 70.5 years (IQR 58-75), 46 (55%) were female. The PA was significantly wider in the PH group (28mm vs. 22.5mm, p<0.001) with a resulting median PA:A of 0.84 vs. 0.66 (p<0.001). Both PA diameter (r = 0.524 and r = 0.44, both p<0.001) and PA:A (r = 0.652 and 0.697, both p<0.001) significantly correlated with mPAP and with PVR, respectively. Area under the curve for the detection of PH was 0.853 (95%CI 0.739-0.967, p<0.001).

CONCLUSION

The PA can be visualized in almost all echocardiographic exams, especially when it is dilated. A view showing the pulmonary trunk should be included in every routine TTE. An increased PA:A should raise suspicion for PH and prompt further evaluation and follow-up examinations of these patients.

Impact of Pulmonary Artery-to-Aorta Ratio by CT on the Clinical Outcome in Heart Failure

INTRODUCTION

Previous studies have indicated that the ratio of pulmonary artery (PA) to ascending aorta (Ao) diameter as measured by computed tomography (PA/Ao) is strongly associated with pulmonary artery pressure. However, the clinical significance of PA/Ao in heart failure (HF) has not been fully characterized. We sought to investigate the prognostic impact of PA/Ao in HF.

METHODS

Based on the prospective registry of patients admitted to our institution due to acute decompensated HF (ADHF), the records of the consecutive 761 patients admitted between 2011 and 2016 were reviewed. Thoracic computed tomography data during the hospital stays were obtained from 447 patients (median 78 (70-84) years of age; male, 62.2%). The diameters of PA and Ao were measured at the level of PA bifurcation. The subjects were divided into the H group (PA/Ao ≥ 1.0) and the L group (PA/Ao < 1.0) according to the PA/Ao values. The cutoff value was derived from receiver operating curve analysis.

RESULTS

There were no significant differences in age, sex or body mass index between the H and L groups. The H group was associated with significantly larger left atrial dimension (LAD), higher tricuspid regurgitation peak gradient (TRPG) and E/e' (LAD, H, 48 (42-55) mm vs L, 45 (39-50) mm, P < 0.001; TRPG, H, 34 (26-48) mm Hg vs L, 28 (22-38) mm Hg, P < 0.001; E/e', H, 23.3 (42-55) vs L, 18.4 (13.9-25), P < 0.001). Length of hospital stay was significantly longer in the H group than in the L group (H, 19 (14-32) days vs L, 16 (12-23) days, P < 0.001). In-hospital mortality was significantly higher in the H group compared with the L group (H, 5.4% vs L, 1.2%, P = 0.02). Age, sex, LAD and TRPG were independently associated with PA/Ao. The primary endpoint, defined as the composite of all-cause death and ADHF rehospitalization during a median of 479 days after discharge, was significantly more common in the H group (P < 0.001, log-rank test). PA/Ao was independently associated with the primary endpoint, even after adjusting for the other confounding factors (P = 0.002).

CONCLUSIONS

PA/Ao is a reliable marker for the prediction of the outcome of patients with ADHF.

Impact of Systemic Volume Status on Cardiac Magnetic Resonance T1 Mapping

Diffuse myocardial fibrosis is a key pathophysiologic feature in heart failure and can be quantified by cardiac magnetic resonance (CMR) T1 mapping. However, increases in myocardial free water also prolong native T1 times and may impact fibrosis quantification. Thus far, the impact of systemic patient volume status remains unclear. In this study, native T1 time by CMR was investigated in hemodialysis (HD) patients (n = 37) and compared with healthy controls (n = 35). Volume status was quantified by bioimpedance spectroscopy and correlated with CMR T1 time. While no differences between HD patients and controls were present with regard to age (p = 0.180), height (p = 0.535), weight (p = 0.559) and left ventricular (LV) ejection fraction (p = 0.273), cardiac size was significantly larger in HD patients (LV end-diastolic volume 164 ± 53 vs. 132 ± 26 ml, p = 0.002). Fluid overloaded HD patients had significantly longer native T1 times than normovolemic HD patients and healthy controls (1,042 ± 46 vs. 1,005 ± 49 vs. 998 ± 47 ms, p = 0.030). By regression analysis, T1 time was significantly associated with fluid status (r = 0.530, p = 0.009, post-HD fluid status). Our data strongly indicate that native CMR T1 time is significantly influenced by systemic volume status. As fluid overload is common in patients with cardiovascular diseases, this finding is important and requires further study.