Pulmonary Artery Enlargement Research Articles

Unusual echocardiographic views for the diagnosis of pulmonary embolism

A 42 year-old woman with history of two spontaneous abortions. She came to our institution with progressive dyspnea and palpitations of 10 month-evolution. On physical examination she had tachycardia (96 bpm) and hypertension (blood pressure: 127/91 mm Hg). On heart auscultation a murmur of tricuspid regurgitation II/IV was heard. The chest X-ray showed cardiomegaly and enlarged pulmonary artery (Fig. 1) and the electrocardiogram was in sinus rhythm with S wave in lead I, Q wave in lead III and inverted T waves in lead III, V5-V6 (Fig. 1). The diagnosis of pulmonary embolism was suspected.

Implications of the pulmonary artery to ascending aortic ratio in patients with relatively mild chronic obstructive pulmonary disease.

Identifying markers for predicting the course and outcome of chronic obstructive pulmonary disease (COPD) remains important. The relative pulmonary artery enlargement to aorta ratio (PA-A ratio), which is measured using computed tomography (CT), is a reported predictor for COPD exacerbation and mortality. However, little is known about the implications of the PA-A ratio in patients with mild COPD. We investigated the utility of the PA-A ratio as a biomarker in patients with relatively mild COPD. A total of 131 patients with mild to moderate COPD [post-bronchodilator forced expiratory volume in 1 sec (FEV1)/forced vital capacity (FVC) 61.6±6.4, mean post-bronchodilator FEV1 83%±17.8% of predicted value] were selected from a Korean COPD cohort (from 2012 until the end of 2014) and analyzed retrospectively. We determined the correlation between the PA-A ratio and clinical parameters using a linear regression model. The COPD assessment test (P=0.04), FEV1 (P=0.03), and a history of exacerbation in the last year (P=0.03) were significant factors in the univariate linear regression analysis. Post-bronchodilator FEV1 was most significantly associated with the PA-A ratio in the multivariate analysis (P=0.01). The PA-A ratio evaluated by CT imaging was independently correlated with a representative pulmonary function factor (FEV1) in patients with relatively mild COPD. The results suggest that the PA-A ratio may be an important biomarker for clinical outcome in patients with mild COPD.

Does Crimean-Congo Hemorrhagic Fever Cause a Vasculitic Reaction with Pulmonary Artery Enlargement and Acute Pulmonary Hypertension?

PurposeCrimean-Congo hemorrhagic fever (CCHF) is a viral tick-borne illness. Although its etiopathogenesis is not clearly understood, it is known to be a Nairovirus. We aimed to examine the viral effects of intense systemic inflammation and vascular damage on the pulmonary vascular beds and lung tissues.MethodsA total of 45 patients who were diagnosed with CCHF were considered for this retrospective study. In this patient group, those whose lungs had been visualized via thoracic computer tomography (CT) were entered into the study. Diameters of the pulmonary trunk, main pulmonary arteries, atria, and ventricles were measured. Study group measurements were compared with the control group, which included patients with normal thoracic CT.ResultsOverall, 90 patients were enrolled in the study, with 45 patients in the study group and 45 in the control group. In the study group, the man-to-woman balance was 3/2. The average age in the study group was 54.07 ± 17.91 years. In comparing the average diameters of pulmonary arteries in the study and control groups, the study group’s average pulmonary artery diameter was significantly larger than the control group (p < 0.001).ConclusionsThe increase in diameters of the pulmonary trunks and main pulmonary arteries due to CCHF was first shown in this current study. Moreover, due to our findings, it should be noted that with the rise in pulmonary artery diameter in CCHF, pulmonary hypertension can appear acutely, and this condition can be significantly alter clinical course and follow-up of the viral illness.

Pulmonary artery enlargement and cystic fibrosis pulmonary exacerbations: a cohort study

BackgroundAcute pulmonary exacerbations are associated with progressive lung function decline and increased mortality in cystic fibrosis (CF). The role of pulmonary vascular disease in pulmonary exacerbations is unknown. We investigated the association between pulmonary artery enlargement (PA:A>1), a marker of pulmonary vascular disease, and exacerbations.MethodsWe analyzed clinical, computed tomography (CT), and prospective exacerbation data in a derivation cohort of 74 adult CF patients, measuring the PA:A at the level of the PA bifurcation. We then replicated our findings in a validation cohort of 190 adult CF patients. Patients were separated into groups based on the presence or absence of a PA:A>1 and were followed for 1-year in the derivation cohort and 2-years in the validation cohort. The primary endpoint was developing ≥1 acute pulmonary exacerbation during follow-up. Linear and logistic regression models were used to determine associations between clinical factors, the PA:A ratio, and pulmonary exacerbations. We used Cox regression to determine time to first exacerbation in the validation cohort.FindingsWe found that PA:A>1 was present in n=37/74 (50%) of the derivation and n=89/190 (47%) of the validation cohort. In the derivation cohort, n=50/74 (68%) had ≥1 exacerbation at 1 year and n=133/190 (70%) in the validation cohort had ≥1 exacerbation after 2 years. PA:A>1 was associated with younger age in both cohorts and with elevated sweat chloride (100.5±10.9 versus 90.4±19.9mmol/L, difference between groups 10.1mmol/L [95%CI 2.5–17.7], P=0.017) in the derivation group. PA:A>1 was associated with exacerbations in the derivation (OR 3.49, 95%CI 1.18–10.3, P=0.023) and validation (OR 2.41, 95%CI 1.06–5.52, P=0.037) cohorts when adjusted for confounders. Time to first exacerbation was shorter in PA:A>1 versus PA:A<1 [HR 1.66 (95%CI 1.18–2.34), P=0.004] in unadjusted analysis, but not when adjusted for sex, BMI, prior exacerbation, positive Pseudomonas status, and FEV1/FVC [HR 1.14 (95%CI 0.80–1.62), P=0.82]).InterpretationPA enlargement is prevalent in adult CF patients and is associated with acute pulmonary exacerbation risk in two well-characterized cohorts. PA:A may be a predictive marker in CF.

Screening of Mechanical Complications of Dilated Pulmonary Artery Related to the Risk for Sudden Cardiac Death in Patients with Pulmonary Arterial Hypertension by Transthoracic Echocardiography

In patients with pulmonary arterial hypertension (PAH), the mechanical complications of pulmonary artery (PA) enlargement are related to sudden cardiac death (SCD). The aim of this study was to investigate the prevalence of PA enlargement, the correlation of main PA (MPA) diameter with other echocardiographic parameters,and the role of transthoracic echocardiography in screening for such complications. Among 298 patients who were followed for PAH, patients with PA enlargement (>40mm) by transthoracic echocardiography were consecutively enrolled in a prospective manner. The presence of left main and airway compression, PA dissection, or PA thrombus was determined with cardiac computed tomography. Forty-six patients (15.4%; mean age, 49±14years; 32.6% men) with dilated MPAs were enrolled. Mechanical complications were present in 16 patients (34.8%). Those with complications had more dilated MPAs compared with patients without (mean PA diameter, 55.6±12.2 vs 46.7±4.3mm; P=.012). Other echocardiographic parameters of the right heart, such as right ventricular systolic pressure, showed no differences (P>.05 for all). The area under the receiver operating characteristic curve for MPA diameter was 0.750 (95% CI, 0.577-0.923; P=.009), with the highest sensitivity and specificity values for the presence of complications being 85.7% and 58.6%, respectively, according to an MPA diameter of 46.5mm. Mechanical complications related to sudden cardiac death in patients with PAH with dilated PAs are common. The overall performance of transthoracic echocardiography as a screening tool for predicting such complications appears reasonable. Given the burden of sudden cardiac death, measurement of PA diameter should be routinely included over the course of follow-up, especially in patients with PAH.

Pulmonary artery size as a predictor of outcomes in idiopathic pulmonary fibrosis.

IPF patients have heightened propensity for pulmonary hypertension, which portends a worse outcome. Presence of pulmonary hypertension may be reflected in an enlarged pulmonary artery. We investigated pulmonary artery size measured on high-resolution computed tomography (HRCT) as an outcome predictor in IPF.We retrospectively reviewed all IPF patients evaluated at a tertiary-care centre between 2008 and 2013. Pulmonary artery and ascending aorta diameters were measured from chest HRCT with pulmonary artery:ascending aorta diameter (PA:A) ratio calculations. Outcome analysis defined by either death or lung transplant based on pulmonary artery size and PA:A ratio over 60 months was performed. Independent effects of different variables on overall outcomes were evaluated using the Cox proportional hazards model.98 IPF patients with available HRCT scans had a mean pulmonary artery diameter and PA:A ratio of 32.8 mm and 0.94, respectively. Patients with a PA:A ratio >1 had higher risk of death or transplant compared with a PA:A ratio ≤1 (p<0.001). A PA:A ratio >1 was also an independent predictor of outcomes in unadjusted and adjusted outcomes analyses (hazard ratio 3.99, p<0.001 and hazard ratio 3.35, p=0.002, respectively).A PA:A ratio >1 is associated with worse outcomes in patients with IPF. A ratio measurement may assist in risk stratification and prognostication of IPF patients.

Measurement of pulmonary artery to aorta ratio in computed tomography is correlated with pulmonary artery pressure in critically ill chronic obstructive pulmonary disease patients

AimChronic obstructive pulmonary disease (COPD) is one of the leading chronic diseases and a common cause of death. Identification of COPD patients at high risk for complications and mortality is of utmost importance. Computed tomography (CT) can be used to measure the ratio of the diameter of the pulmonary artery (PA) to the diameter of the aorta (A), and PA/A ratio was shown to be correlated with PA pressure (PAP). However, the prognostic value of PA size remains unclear in patients with COPD. We hypothesized that PA enlargement, as shown by a PA/A ratio greater than 1, could be associated with a higher risk of mortality in COPD patients admitted to the intensive care unit. MethodsData of patients admitted to a medical intensive care unit of a university hospital were retrospectively reviewed between January 2008 and December 2012. Patients who were identified to have a diagnosis of acute exacerbation of COPD and who had an echocardiogram and CT scan were included. Pulmonary artery to aorta ratio was calculated and patients were grouped as PA/A ≤1 and PA/A >1. Comparisons were made between the groups and between patients who died and survived. Correlation analysis, survival analysis, and logistic regression analysis were done, where appropriate. ResultsOne hundred six COPD patients were enrolled. There were 40 (37.4%) patients who had a PA/A >1. Echocardiography measured PAP was higher in the group with PA/A >1 than in those with PA/A ≤1 (62.1 ± 23.2 mm Hg vs 45.3 ± 17.9 mm Hg, P = .002). Mortality rate of patients with PA/A >1 was higher (50%) than of those patients with PA/A ≤1 (36.4%), although the difference did not reach a statistical significance (P = .17). Correlation was found between vmeasured PA diameter and PAP (r = 0.51, P = .001) as well as between the Acute Physiology and Chronic Health Evaluation II values and PAP (r = 0.25, P = .025). ConclusionThe PA/A ratio is an easily measured method that can be performed on thorax CT scans. Although, we failed to demonstrate a statistically significant association between higher PA/A and increased mortality, PA/A can be used as a surrogate marker to predict the pulmonary hypertension.

Combined ostium secundum type ASD and pulmonary arterial thromboembolism causing pulmonary artery enlargement, pulmonary hypertension and recurrent paradoxical cerebral embolism due to deep venous thrombosis

Combined ostium secundum type ASD and pulmonary arterial thromboembolism causing pulmonary artery enlargement, pulmonary hypertension and recurrent paradoxical cerebral embolism due to deep venous thrombosis

Pulmonary Artery Enlargement Is Associated With Cardiac Injury During Severe Exacerbations of COPD.

Relative pulmonary arterial enlargement, defined by a pulmonary artery to aorta (PA/A) ratio > 1 on CT scanning, predicts hospitalization for acute exacerbations ofCOPD (AECOPD). However, it is unclear how AECOPD affect the PA/A ratio. We hypothesized that the PA/A ratio would increase at the time of AECOPD and that a ratio >1would be associated with worse clinical outcomes. Patients discharged with an International Classification of Diseases, Ninth Revision, diagnosis of AECOPD from a single center over a 5-year period were identified. Patients were included who had a CT scan performed during the stable period prior to the index AECOPD episode as well as a CT scan at the time of hospitalization. A subset of patients also underwent postexacerbation CT scans. The pulmonary arterial diameter, ascending aortic diameter, and the PA/A ratio were measured on CT scans. Demographic data, comorbidities, troponin level, and hospital outcome data were analyzed. A total of 134 patients were included in the study. They had a mean age of 65 ± 10 years, 47%were male, and 69%were white; overall, patients had a mean FEV1 of 47%±19%. The PA/A ratio increased from baseline at the time of exacerbation (0.97 ± 0.15 from 0.91 ± 0.17; P< .001). Younger age and known pulmonary hypertension were independently associated with an exacerbation PA/A ratio > 1. Patients with PA/A ratio > 1 had higher troponin values. Those with a PA/A ratio > 1 and troponin levels > 0.01ng/mL had increased acute respiratory failure, ICU admission, or inpatient mortality compared with those without both factors (P= .0028). The PA/A ratio returned to baseline values following AECOPD. The PA/A ratio increased at the time of severe AECOPD and a ratio > 1 predicted cardiac injury and a more severe hospital course.

Idiopathic dilatation of pulmonary artery.

Idiopathic dilatation of pulmonary arteries (IDPA) is a rare abnormality of pulmonary arteries, the reported incidence in literature being as low as 0.007% in autopsy samples. With the improvement in diagnostic modalities, antemortem diagnosis of IDPA has been increasingly established by excluding diseases that induce pulmonary arterial enlargement. Here, we present a rare case of idiopathic dilatation of the pulmonary artery admitted with shortness of breath where IDPA was diagnosed as an incidental finding using computed tomography pulmonary angiography and cardiac catheterization.

Pulmonary Artery Abnormalities in Ex-smokers with and without Airflow Obstruction

Pulmonary vascular disease is a common complication of chronic obstructive pulmonary disease (COPD), and an important risk factor for COPD exacerbations and death. We explored the relationship between pulmonary artery volumes measured using thoracic computed tomography (CT) and lung structure-function measured using spirometry, CT and magnetic resonance imaging (MRI) in 124 ex-smokers with (n = 68) and without (n = 56) airflow obstruction, and a control group of 35 never-smokers. We observed significantly greater main (p = .01), right (p = .001) and total (p = .003) pulmonary artery volumes in ex-smokers with airflow obstruction as compared to ex-smokers without airflow obstruction. There were also significantly greater pulmonary artery volumes in both ex-smoker subgroups, compared to the never-smoker subgroup (p = .008). For all participants, there were significant correlations for pulmonary artery volumes with the ratio of the forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC), the diffusing capacity of the lung for carbon monoxide (DLCO%pred), airway count, MRI ventilation defect percent and MRI apparent diffusion coefficients. In ex-smokers, ventilation defect percent was significantly correlated with right (r = 0.27, p = .02) and total (r = 0.25, p = .03) pulmonary artery volumes. Multivariate zero-inflated Poisson regression analysis showed that FEV1%pred (p = .004), DLCO%pred (p = .03), the six minute walk distance (p = .04) and total pulmonary artery volume (p = .03) were significant predictors of acute exacerbations of COPD, while the number of previous exacerbations was not. In conclusion, pulmonary artery enlargement measured using thoracic CT was observed even in ex-smokers without airflow obstruction and was predictive of COPD exacerbations in ex-smokers with airflow obstruction.

Pulmonary artery enlargement in schistosomiasis associated pulmonary arterial hypertension

BackgroundSchistosomiasis associated pulmonary arterial hypertension (Sch-PAH) might represent the most prevalent form of PAH worldwide. In Sch-PAH, the presence of aneurismal dilation of the pulmonary artery has been described, although it is still a matter of debate whether on average the pulmonary artery is more enlarged in Sc-PAH than IPAH.MethodsWe retrospectively evaluated patients with IPAH (n = 25) and Sch-PAH (n = 22) who underwent computed tomography pulmonary angiogram and right heart catheterization.ResultsSch-PAH patients were older and presented less severe hemodynamic profiles. Main pulmonary artery diameter (MPAD) was greater in Sch-PAH than IPAH (4.5 ± 1.8 vs 3.7 ± 1.1 cm, p = 0.018). For the same level of mean pulmonary artery pressure, the MPAD in Sch-PAH was 0.89 cm larger than in IPAH (Covariance model p = 0.02).ConclusionThis study demonstrated that pulmonary artery enlargement is more pronounced in Sch-PAH than IPAH, independently of mean pulmonary artery pressure level, suggesting that this is more likely a feature of Sch-PAH.

Potential Role of CT Metrics in Chronic Obstructive Pulmonary Disease with Pulmonary Hypertension.

Recent imaging studies demonstrated the usefulness of quantitative computed tomographic (CT) analysis assessing pulmonary hypertension (PH) in patients with chronic obstructive lung disease (COPD-PH). The aim of this study was to investigate whether it would be also valuable for predicting and evaluating the effect of pulmonary vasodilators in patients with COPD-PH. We analyzed a correlation between the extent of cystic destruction (LAA%) and total cross-sectional areas of small pulmonary vessels less than 5mm(2) (%CSA <5) in many CT slices from each of four COPD-PH patients before and after the initiation of pulmonary vasodilator. To evaluate those generalized data from patients with COPD, we evaluated multiple slices from 42 patients whose PH was not clinically suspicious. We also selected five PH patients with idiopathic interstitial pneumonia (IIP-PH) and analyzed serial changes of pulmonary artery enlargement (PA:A ratio). In 42 COPD patients without PH, LAA% had a statistically significant negative correlation with %CSA <5. However, three of four COPD-PH patients manifested no such correlation. In two patients, clinical findings were dramatically improved after the initiation of pulmonary vasodilator. Notably, LAA% and %CSA <5 in those patients correlated significantly after its treatment. In COPD-PH, the PA:A ratio was significantly decreased after the initiation of pulmonary vasodilator therapy (1.25±0.13 vs. 1.13±0.11, p=0.019), but not in IIP-PH. Our study demonstrates that the use of quantitative CT analysis is a plausible and beneficial tool for predicting and evaluating the effect of pulmonary vasodilators in patients with COPD-PH.

The Relationship Among Pulmonary Function, Arterial Blood Gases, Airway Remodeling, and Pulmonary Artery Enlargement in Patients With Advanced Chronic Obstructive Pulmonary Disease

The Relationship Among Pulmonary Function, Arterial Blood Gases, Airway Remodeling, and Pulmonary Artery Enlargement in Patients With Advanced Chronic Obstructive Pulmonary Disease

Pulmonary arterial enlargement predicts cardiopulmonary complications after pulmonary resection for lung cancer: a retrospective cohort study.

BackgroundThe finding of pulmonary arterial enlargement on computed tomography has been reported to be associated with pulmonary hypertension. On the other hand, pulmonary hypertension is a known risk factor for thoracic surgery. We investigated whether pulmonary arterial enlargement predicts cardiopulmonary complications following pulmonary resection for lung cancer.MethodsWe reviewed 237 consecutive patients who underwent pulmonary resection for lung cancer. Preoperative patient characteristics (sex, age, Brinkman index, cardiopulmonary comorbidities, cardiothoracic ratio, pulmonary function, and pulmonary arterial enlargement) and surgical data (surgical procedure, pathological stage, postoperative complications, mortality, and length of postoperative hospital stay) were analyzed. In order to evaluate preoperative pulmonary arterial enlargement, we measured the diameter of the main pulmonary artery at its bifurcation and that of the ascending aorta at its widest point using chest computed tomography and calculated the ratio of the former diameter to the latter.ResultsIn all, 16 patients developed postoperative cardiopulmonary complications and 221 did not. One patient died from postoperative pneumonia. The mean age of patients who developed postoperative cardiopulmonary complications was significantly higher than that of those who did not (78 ± 5 years vs 69 ± 9 years, P = 0.0001). The pulmonary artery-to-ascending-aorta ratio was significantly higher in patients who developed postoperative complications than in those who did not (0.94 ± 0.15 vs. 0.81 ± 0.11, P = 0.03). Other preoperative patient characteristics and surgical data did not differ significantly between the groups. On multivariate analysis, pulmonary artery-to-ascending-aorta ratio (0.1-point increase; odds ratio 2.3, 95 % confidence interval 1.5–3.5; P = 0.0002) and age (1-year increase; odds ratio 1.2, 95 % confidence interval 1.1–1.3; P = 0.03) were found to be independent predictors of postoperative cardiopulmonary complications.ConclusionsA finding of pulmonary arterial enlargement on computed tomography is a potential predictor of postoperative cardiopulmonary complications after lung cancer surgery.

Correction of Double-Chambered Right Ventricle 40 Years after Pulmonary Valvuloplasty.

Background Double-chambered right ventricle is a partial separation of the right ventricle by pathological tissue. This anomaly is described in infants and children but can also be diagnosed in young adults. Case Description A 47-year-old patient presented with chest pain and exercise intolerance. Further evaluation revealed a double-chambered right ventricle. During the surgical procedure, fibrotic tissue was transected, and a pulmonary valve replacement including enlargement of the main pulmonary artery was performed. Conclusion Subpulmonary obstruction of the right ventricle can be related to double-chambered right ventricle even in adulthood. Treatment options include surgical resection with pulmonary valve replacement.

PP.22.07

Objective: The left main coronary artery compression syndrome secondary to pulmonary artery trunk dilatation is a syndrome that is associated with severe pulmonary artery hypertension. Though the syndrome is known for quite a long time, the appropriate diagnostic and treatment approaches still remain poorly defined. Recently stenting of left main coronary artery became available for these patients as a new treatment strategy, though its implementation is still debatable. The definition of indications for endovascular treatment in this group of patients is difficult. Here we present a new methodology that helps to form a stent placement indication in patients with left main coronary artery compression syndrome. Design and method: A 32-years-old female with idiopathic pulmonary hypertension came to the hospital with increased exertional dyspnea and appearance of chest pain. Via performed computed tomography left main coronary artery compression was diagnosed. We observed the extrinsic compression of left main coronary artery by enlarged pulmonary artery. Data obtained from coronary angiography confirmed 60% left main coronary artery stenosis that is hemodynamically significant. To determine indications for revascularization intravascular ultrasound of left main coronary artery was performed. Results: Computed tomography showed a marked enlargement of the main pulmonary artery trunk (4.7 cm) with compression of the ostial left main coronary artery lumen. During coronary angiography we observed significant ostial left main coronary artery 60% stenosis, otherwise coronary arteries were intact. To determine the significance of the stenosis intravascular ultrasound was performed. According to intravascular ultrasound results there were not indications for endovascular left main treatment. It revealed narrowed lumen of the left main coronary artery (lumen area 9 mm2), compared to normal middle and distal areas of the artery (lumen area 20 mm2). So, in this case in contrast with coronary angiogram intravascular ultrasound data haven’t shown hemodynamically significant compression of left main coronary artery and conservative treatment was elected. Pulmonary hypertension specific therapy (Sildenafil) was initiated.Conclusions: We suggest that after computed tomography and coronary angiography intravascular ultrasound can be an addition method in determination of indications for endovascular treatment in patients with left main compression syndrome.

CT-Definable Subtypes of Chronic Obstructive Pulmonary Disease: A Statement of the Fleischner Society.

The purpose of this statement is to describe and define the phenotypic abnormalities that can be identified on visual and quantitative evaluation of computed tomographic (CT) images in subjects with chronic obstructive pulmonary disease (COPD), with the goal of contributing to a personalized approach to the treatment of patients with COPD. Quantitative CT is useful for identifying and sequentially evaluating the extent of emphysematous lung destruction, changes in airway walls, and expiratory air trapping. However, visual assessment of CT scans remains important to describe patterns of altered lung structure in COPD. The classification system proposed and illustrated in this article provides a structured approach to visual and quantitative assessment of COPD. Emphysema is classified as centrilobular (subclassified as trace, mild, moderate, confluent, and advanced destructive emphysema), panlobular, and paraseptal (subclassified as mild or substantial). Additional important visual features include airway wall thickening, inflammatory small airways disease, tracheal abnormalities, interstitial lung abnormalities, pulmonary arterial enlargement, and bronchiectasis.

Typical signs of secundum atrial septal defect in a young female

We report the case of a 25-year-female presented with dyspnea &amp; chest pain on exertion. The ECG showed signs of right ventricular overload. The chest X-ray showed an enlargement of central pulmonary arteries, pulmonary plethora and a small aortic knuckle. Atrial septal defect (ASD) was suspected and transthoracic echocardiography (TTE) subsequently confirmed the presence of a large ostium secundum ASD. A surgical closure with an equine pericardium patch was performed. Two months after the surgical repair, the ECG and TTE showed the regression of signs of right ventricular overload.Bangladesh Journal of Medical Science Vol.14(2) 2015 p.203-205

Pulmonary artery enlargement is associated with right ventricular dysfunction and loss of blood volume in small pulmonary vessels in chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease causes significant morbidity and concomitant pulmonary vascular disease and cardiac dysfunction are associated with poor prognosis. Computed tomography-detected relative pulmonary artery (PA) enlargement defined as a PA to ascending aorta diameter ratio >1 (PA:A>1) is a marker for pulmonary hypertension and predicts chronic obstructive pulmonary disease exacerbations. However, little is known about the relationship between the PA:A ratio, pulmonary blood volume, and cardiac function. A single-center prospective cohort study of patients with chronic obstructive pulmonary disease was conducted. Clinical characteristics and computed tomography metrics, including the PA:A and pulmonary blood vessel volume, were measured. Ventricular functions, volumes, and dimensions were measured by cine cardiac MRI with 3-dimensional analysis. Linear regression examined the relationships between clinical characteristics, computed tomography and cardiac MRI metrics, and 6-minute walk distance. Twenty-four patients were evaluated and those with PA:A>1 had higher right ventricular (RV) end-diastolic and end-systolic volume indices accompanied by lower RV ejection fraction (52±7% versus 60±9%; P=0.04). The PA:A correlated inversely with total intraparenchymal pulmonary blood vessel volume and the volume of distal vessels with a cross-sectional area of <5 mm(2). Lower forced expiratory volume, PA:A>1, and hyperinflation correlated with reduced RV ejection fraction. Both PA diameter and reduced RV ejection fraction were independently associated with reduced 6-minute walk distance. The loss of blood volume in distal pulmonary vessels is associated with PA enlargement on computed tomography. Cardiac MRI detects early RV dysfunction and remodeling in nonsevere chronic obstructive pulmonary disease patients with a PA:A>1. Both RV dysfunction and PA enlargement are independently associated with reduced walk distance. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00608764.