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

Novel Noninvasive Index Combining Echocardiography and Computed Tomography for Screening for Pulmonary Hypertension in Patients With Systemic Sclerosis

Background

In patients with systemic sclerosis (SSc), early detection of pulmonary hypertension (PH) improves survival. This study aimed to investigate whether a combination index (cPAT) of the tricuspid regurgitation jet peak gradient and the ratio of pulmonary artery (PA) diameter to aortic diameter measured by computed tomography (CT; PA ratio) can estimate the mean PA pressure (mPAP) and detect PH more accurately than conventional parameters in SSc patients.

Methods

A total of 36 SSc patients who underwent PH screening were retrospectively analyzed. All patients were screened for PH between 2013 and 2017 by echocardiography, CT, and right heart catheterization. Patients with mPAP > 20 mm Hg by right heart catheterization were diagnosed as having PH. Additionally, patients with an mPAP > 20 mm Hg, pulmonary vascular resistance > 2 Wood units, and PA wedge pressure ≤ 15 mm Hg, for whom other causes were ruled out, including group 2-5, were defined as having pulmonary atrial hypertension.

Results

Of 36 patients, 29 patients were female (81%), and the average duration of SSc was 7.5 years. The mPAP was significantly correlated with the tricuspid regurgitation jet peak gradient (r = 0.734), the PA ratio (r = 0.584), and the cPAT (r = 0.848). In receiver operating characteristic analysis to identify PH, the cPAT showed the highest area under the curve, 0.906, among the 3 parameters. Additionally, in receiver operating characteristic analysis to identify pulmonary atrial hypertension, the cPAT also showed the highest area under the curve, 0.851, among the 3 parameters.

Conclusions

The cPAT is a new index combining echocardiogram and CT results that provides the most accurate noninvasive assessment of mPAP in SSc patients. The cPAT can also help detect PH early in SSc patients, thereby allowing for earlier treatment.

Revisiting the Clinical Interpretation of CT-Measured Pulmonary Artery-to-Aorta Ratio-The Rotterdam Study

RATIONALE

The pulmonary artery (PA) diameter-to-aorta ratio (PA:A) ratio is a novel marker in cardiovascular imaging for detecting pulmonary hypertension. However, we question the effect of the varying aorta diameter on the ratio, which complicates the interpretation of the PA:A ratio.

OBJECTIVE

Investigate the variability of the PA:A ratio by examining the correlation between PA:A ratio and aorta diameter and by comparing the associations of the PA diameter, aorta diameters, and PA:A ratio.

METHODS

We included 2197 participants from the Rotterdam Study who underwent non-contrast multidetector computed tomography to measure the PA and aorta diameters. Pearson correlation coefficient was calculated between the PA:A ratio and aorta diameter. Multiple linear regression analyses were performed to compare the determinants of the individual diameters and PA:A ratio.

RESULTS

We found a statistically significant correlation between the PA:A ratio and aorta diameter (r = -0.38, p < 0.001). The PA diameter was statistically significantly associated with, height, weight, diastolic blood pressure, blood pressure medication, prevalence of atrial fibrillation, prevalence of heart failure, and prevalence of stroke (p < 0.05). Except for blood pressure medication, the PA:A ratio had similar determinants compared to the PA diameter but was also statistically significantly associated with sex, and systolic blood pressure (p < 0.05), which were statistically significantly associated with the aorta diameter (p < 0.05).

CONCLUSION

The PA:A ratio should not be interpreted without taking into account the variability of the individual components (PA and aorta diameter) according to the anthropomorphic and clinical characteristics.

The impact of pulmonary artery to ascending aorta diameter ratio progression on the prognosis of NSCLC patients treated with immune checkpoint inhibitors

Background

Immunotherapy, represented by immune checkpoint inhibitors (ICIs), is a major breakthrough in cancer treatment. Studies have reported that the use of ICIs is associated with an increase in the pulmonary artery to ascending aorta diameter (PAD/AoD) ratio. However, the impact of PAD/AoD ratio progression on the prognosis of patients is unclear.

Methods

This retrospective cohort study included patients with stage III or IV non-small cell lung cancer (NSCLC) treated with ICIs at the Wuhan Union Hospital between March 1, 2020, and September 1, 2022. The baseline and post-treatment PAD/AoD ratios of patients were evaluated through chest CT scans. The primary outcome of this study was overall survival (OS), while the secondary outcomes included progression-free survival (PFS), objective response rate (ORR) and disease control rate (DCR).

Results

The PAD/AoD ratio increased after the initiation of ICIs (from 0.75 to 0.78; P < 0.001). A total of 441 patients were divided into severe group (n=221) and non-severe group (n=220) according to the median increase of PAD/AoD ratio (1.06). Compared with the non-severe group, the severe group had a lower DCR (87.8% vs. 96.0%, P = 0.005) and ORR (87.5% vs. 96.0%, P = 0.063). Over the entire duration of follow-up (median 22.0 months), 85 (38.5%) patients in the severe group and 30 (7.3%) patients in the non-severe group died. An increased PAD/AoD ratio was associated with shorter PFS (Hazard ratio (HR): 1.48 [95% CI, 1.14 to 1.93]; P = 0.003) and OS (HR: 3.50 [95% CI, 2.30 to 5.30]; P < 0.001). Similar results were obtained across subgroups.

Conclusions

ICI treatment exacerbates an increase in the PAD/AoD ratio in patients with cancer, and greater increase in the PAD/AoD ratio was associated with a worse prognosis. PAD/AoD ratio could be a biomarker to stratify prognosis of NSCLC patients treated with ICIs.

Aortic root diameter, main pulmonary artery diameter/aortic root diameter and pericardial fat volume as predictors of occlusive coronary artery disease

The clinical relevance of aortic root diameter (ARD), main pulmonary artery diameter (MPAd), or pericardial fat volume (PFV) in the assessment of coronary artery disease (CAD) is largely unknown. We aimed to assess the relationship of PFV, ARD, MPAd, and MPAd/ARD ratio with occlusive CAD (stenosis >50%).This cross-sectional study included patients who had chest pain suggestive of CAD and underwent a 64-multislice multi-detector computed tomography angiography exam to exclude occlusive CAD presence. A total of 145 patients were enrolled in this study. The mean age was 54±10 years, and 51% were males. The mean PFV, ARD, MPAd, and MPAd/ARD ratio in all patients were 155 cm3, 29.9 mm, 23.4 mm, and 0.8, respectively. On univariate analysis, PFV [odds ratio (OR) (confidence interval, CI)=1.1 (1.01-1.3), p<0.01], ARD [OR (CI)=1.2 (1.1-1.4), p<0.01], and MPAd/ARD ratio [OR (CI)= 0.2 (0.1-0.5), p=0.02] showed significant association with occlusive CAD presence. After adjusting for cardiac risk factors, only PFV [OR (CI)=1.1 (1.02-1.3), p<0.01], but not ARD [OR (CI)=0.9(0.3-2), p=0.85] or MPAd/ARD ratio [OR (CI)=0.1(0.1-2), p=0.69], was independently associated with occlusive CAD. In conclusion, increased PFV, but not ARD or MPAd/ARD ratio, showed a significant and independent association with occlusive CAD presence in patients with chest pain suggestive of CAD.