Improving Reporting of Exercise Capacity Across Age Ranges Using Novel Workload Reference Equations

Exercise capacity (EC) is an important predictor of survival in the general population and in subjects with cardiopulmonary disease. Despite its relevance, considering the percent-predicted workload (%pWL) given by current equations may overestimate EC in older adults. Therefore, to improve the reporting of EC in clinical practice, our main objective was to develop workload reference equations (pWL) that better reflect the relation between workload and age. Using the Fitness Registry and the Importance of Exercise National Database (FRIEND), we analyzed a reference group of 6,966 apparently healthy participants and 1,060 participants with heart failure who underwent graded treadmill cardiopulmonary exercise testing. For the first group, the mean age was 44 years (18 to 79); 56.5% of participants were males and 15.4% had obesity. Peak oxygen consumption was 11.6 ± 3.0 METs in males and 8.5 ± 2.4 METs in females. After partition analysis, we first developed sex-specific pWL equations to allow comparisons to a healthy weight reference. For males, pWL (METs) = 14.1-0.9×10-3×age2 and 11.5-0.87×10-3×age2 for females. We used those equations as denominators of %pWL, and based on their distribution, we determined thresholds for EC classification, with average EC defined by the range corresponding to 85% to 115%pWL. Compared with %pWL using current equations, the new equations yielded better-calibrated %pWL across different age ranges. We also derived body mass index-adjusted pWL equations that better assessed EC in subjects with heart failure. In conclusion, the novel pWL equations have the potential to impact the report of EC in practice.

Morphometric aspects of remodeling of the arterial bed of the testicles in post- resection portal and pulmonary hypertensions

OBJECTIVE

Aim: To perform a morphometric analysis of the features of vascular remodeling of the arterial bed of the testicles in post-resection portal and pulmonary hypertension.

PATIENTS AND METHODS

Materials and Methods: The testes of 54 white rats were studied, which were divided into groups: 1st included 16 intact animals, 2nd - 20 rats with pulmonary hypertension, 3rd - 18 individuals with post-resection portal hypertension. Postresection pulmonary hypertension was modeled by right-sided pulmonectomy. Postresection portal hypertension was simulated by removing 58.1 % of the liver parenchyma.

RESULTS

Results: The outer diameter of the small-caliber arteries of the left testicle increased by 3.4% (p<0.05) in post-resection arterial pulmonary hypertension, and by 2.9% in post-resection portal hypertension. The inner diameter of the small-caliber arteries of the left testicle decreased by 7.7% (p<0.001) in pulmonary heart disease, and by 6.5% (p<0.01) in post-resection portal hypertension. The Kernogan index decreased by 23.0% (p<0.001), the Vogenvoort index increased by 1.26 times. In case of post-resection portal hypertension, the Kernogan index decreased by 19.0% (p<0.001) and the Wogenvoort's index increased by 1.19 times. The relative volume of damaged endotheliocytes in the small-caliber arteries of the left testis increased 20.6 times (p<0.001) in pulmonary heart disease, and increased 16.3 times (p<0.001) in post-resection portal hypertension.

CONCLUSION

Conclusions: Portal and pulmonary hypertension lead to pronounced remodeling of the arterial bed of the testicles, which is characterized by thickening of the arterial wall, narrowing of their lumen, significant changes in Wogenvoort and Kernogan indexes, atrophy, dystrophy, and necrobiosis of endotheliocytes.

Inflammation and comorbidities of chronic obstructive pulmonary disease: The cytokines put on a mask!

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a well-known complex multicomponent disease characterized by systemic inflammation that frequently coexists with other conditions. We investigated the relationship between some inflammatory markers and complications in COPD patients to explore the possible roles of inflammation in these comorbidities.

METHODS

This study used cross-sectional and case-control methods. We included 336 hospitalized COPD patients, 64 healthy controls, and 42 major depression patients and evaluated all participants using the Hamilton Rating Scale. C-reactive protein (CRP), red blood cell distribution width (RDW), neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), monocyte/lymphocyte ratio (MLR), interleukin-1β (IL-1β) and interleukin-6 (IL-6) were collected and measured in the study population. Statistical methods were used to analyze the association of inflammatory markers with COPD comorbidities.

RESULTS

Cor pulmonale and psychological comorbidities (depression and anxiety) were more common in this study on COPD patients. We found that MLR (OR = 2.054, 95 % CI 1.129-3.735, p = 0.018) and RDW (OR = 1.367, 95 % CI 1.178-1.586, p = 0.000) were related to COPD patients complicated with cor pulmonale, while IL-6 (OR = 1.026, 95 % CI 1.001-1.053, p = 0.045) and RDW (OR = 1.280, 95 % CI 1.055-1.552, p = 0.012) were related to depression symptoms.

CONCLUSION

MLR, RDW and IL-6 were closely related to cor pulmonale and depression in COPD patients. IL-1 β and IL-6 are closely related to depression in humans.

Diagnostic, prognostic and clinical value of left ventricular radial strain to identify paradoxical septal motion in ventilated patients with the acute respiratory distress syndrome: an observational prospective multicenter study

BACKGROUND

Acute cor pulmonale (ACP) is prognostic in patients with acute respiratory distress syndrome (ARDS). Identification of paradoxical septal motion (PSM) using two-dimensional echocardiography is highly subjective. We sought to describe feature-engineered metrics derived from LV radial strain changes related to PSM in ARDS patients with ACP of various severity and to illustrate potential diagnostic and prognostic yield.

METHODS

This prospective bicentric study included patients under protective ventilation for ARDS related to COVID-19 who were assessed using transesophageal echocardiography (TEE). Transgastric short-axis view at mid-papillary level was used to visually grade septal motion, using two-dimensional imaging, solely and combined with LV radial strain: normal (grade 0), transient end-systolic septal flattening (grade 1), prolonged end-systolic septal flattening or reversed septal curvature (grade 2). Inter-observer variability was calculated. Feature engineering was performed to calculate the time-to-peak and area under the strain curve in 6 LV segments. In the subset of patients with serial TEE examinations, a multivariate Cox model analysis accounting for new-onset of PSM as a time-dependent variable was used to identify parameters associated with ICU mortality.

RESULTS

Overall, 310 TEE examinations performed in 182 patients were analyzed (age: 67 [60-72] years; men: 66%; SAPSII: 35 [29-40]). Two-dimensional assessment identified a grade 1 and grade 2 PSM in 100 (32%) and 48 (15%) examinations, respectively. Inter-rater reliability was weak using two-dimensional imaging alone (kappa = 0.49; 95% CI 0.40-0.58; p < 0.001) and increased with associated LV radial strain (kappa = 0.84, 95% CI 0.79-0.90, p < 0.001). The time-to-peak of mid-septal and mid-lateral segments occurred significantly later in systole and increased with the grade of PSM. Similarly, the area under the strain curve of these segments increased significantly with the grade of PSM, compared with mid-anterior or mid-inferior segments. Severe acute cor pulmonale with a grade 2 PSM was significantly associated with mortality. Requalification in an upper PSM grade using LV radial strain allowed to better identify patients at risk of death (HR: 6.27 [95% CI 2.28-17.2] vs. 2.80 [95% CI 1.11-7.09]).

CONCLUSIONS

In objectively depicting PSM and quantitatively assessing its severity, TEE LV radial strain appears as a valuable adjunct to conventional two-dimensional imaging.

Obesity-related Changes in Diffusing Capacity and Transfer Coefficient of the Lung for Carbon Monoxide and Resulting Patterns of Abnormality across Reference Equations

Rationale: In 2017, an American Thoracic Society/European Respiratory Society Task Force report recommended further research on the effects that body mass index (BMI) has on diffusing capacity of the lung for carbon monoxide (DlCO), the transfer coefficient (Kco), and the alveolar volume (VA). Objectives: Our goals were to 1) quantify the magnitude and direction of change to measured and predicted DlCO values as BMI increases in patients free of cardiopulmonary disease and 2) identify how BMI and obesity-related changes differ by reference set. Methods: Using data from a prospective cohort study of service members free of cardiopulmonary disease, we modeled the effect that BMI has on measured values of DlCO, Kco, and VA, after adjusting for age, sex, hemoglobin (Hgb), and height. We then referenced DlCO, Kco, and VA to normal values using four different reference equations. Results: There were 380 patients with data available for analysis, and 130 had a BMI ⩾ 30 kg/m2 (87.7% class I obesity). After controlling for age, sex, Hgb, and height, increased BMI was significantly associated with Kco (β = 0.09, P < 0.01) and VA (β = -0.15, P < 0.01) but not DlCO. After adjustment for Hgb, for every 5-kg/m2 increase in BMI, the mean increase in percent predicted (PPD) values ranged from 4.2% to 6.5% and from 5.0% to 7.5% for DlCO and Kco, respectively; and the mean decrease in VA PPD was 3.2-4.0%. In the presence of obesity (BMI ⩾ 30 kg/m2), the prevalence of DlCO and Kco abnormalities dropped by 4.1-12.1% and 0.4-16.3%, respectively, across equations, whereas VA abnormalities increased from 7.7% to 9.9%. Eliminating 163 patients with abnormal trans-thoracic echocardiogram (TEE), high-resolution computed tomographic (HRCT) scan, or Hgb altered the magnitude of relationships, but significance was preserved. Conclusions: In an otherwise healthy population with predominantly class I obesity and normal TTE, HRCT scan, and Hgb, we found that Kco and VA were more affected by BMI than DlCO. Increases in PPD values varied across equations and were modest but significant and could change clinical decision making by reducing sensitivity for detecting gas-exchange abnormalities. BMI and obesity had the smallest effect on Global Lung Function Initiative PPD values.

HIV status and survival of patients with pulmonary hypertension due to left heart disease: the Pan African Pulmonary Hypertension Cohort

In sub-Saharan Africa, little is known about pulmonary hypertension in left heart disease (PH-LHD). We used multivariate logistic and cox-hazard proportional regression models to examine factors associated with increased right ventricular systolic pressure (RVSP) and the effect of real-world HIV status scenarios on 6-month survival rate in the Pan African Pulmonary Hypertension Cohort (PAPUCO) study, a prospective cohort from four African countries. Exposure to biomass fuel smoke (aOR, 95%CI 3.07, 1.02-9.28), moderate to severe NYHA/FC III/IV (aOR, 95%CI 4.18, 1.01-17.38), and unknown HIV status (aOR, 95%CI 2.73, 0.96-7.73) predicted moderate to severe RVSP at the time of presentation. Six months later, HIV infection, moderate-to-severe NYHA/FC, and alcohol consumption were associated with decreased survival probabilities. Upon adjusting for HIV infection, it was observed that an incremental rise in RVSP (1 mmHg) and inter-ventricular septal thickness (1 mm) resulted in an 8% (aHR, 95%CI 1.08, 1.02-1.13) and 20% (aHR, 95%CI 1.2, 1.00-1.43) increase in the probability of mortality due to PH-LHD. In contrast, the risk of death from PH-LHD was reduced by 23% for each additional unit of BMI. (aHR, 95%CI 0.77, 0.59-1.00). In conclusion, the present study offers insights into the determinants that are notably linked to unfavorable survival outcomes in patients with pulmonary hypertension due to left heart disease. Certain factors identified in this study are readily evaluable and amenable to modification, even in settings with limited resources.

Analysis of Inducing Factors of Chronic Pulmonary Heart Disease Caused by Chronic Obstructive Pulmonary Disease at High Altitude through Epidemiological Investigation under Intelligent Medicine and Big Data

This study explores the risk factors of chronic pulmonary heart disease (CPHD) induced by plateau chronic obstructive pulmonary disease (COPD) based on intelligent medical treatment and big data of electrocardiogram (ECG) signal. Based on GPU, a wavelet algorithm is introduced to extract features of ECG signal, and it was combined with generalized regression neural network (GRNN) to improve classification accuracy. From June 2018 to December 2020, 10,185 patients diagnosed with COPD in the plateau area by pulmonary function testing, ECG, and chest X-ray at X Hospital are taken as the research objects to evaluate the distribution of CPHD incidence at different ages and altitudes. The running time of GTX780Ti is about 15 times shorter than that of CPU. The accuracy of N detection based on the GPU-accelerated neural network model reached 98.06%. Accuracy (Acc), sensitivity (Se), specificity (Sp), and positive rate (PR) of V were 99.03%, 89.17%, 98.92%, and 93.18%, respectively. The Acc, Se, Sp, and PR of S were 99.54%, 86.22%, 99.74%, and 92.56%, respectively. The GRNN classification accuracy was up to 98%. 19% of COPD patients were diagnosed with CPHD, including 1,409 males (72.82%) and 526 females (36.24%). The highest prevalence of CPHD was 64.60% when the altitude was 1,900-2,499 m, and the prevalence was only 2.43% when the altitude was ≥3,500 m. The highest prevalence of CPHD was 63.77% at the age of 61-70 years, and the lowest prevalence at the age of 15∼20 years was only 0.26%. Therefore, the GPU-based neural network model improved the classification accuracy of ECG signals. Age and altitude were risk factors for CPHD induced by high-altitude COPD, which provided a reference for the prevention, diagnosis, and treatment of CPHD in high-altitude areas.

[Pulmonary tumor embolism]

Pulmonary tumor embolism is characterized by the occlusion of pulmonary vessels by tumor clots, which can be found in the proximal arteries (macro-embolism) or the small vessels (micro-embolism). The clinical presentation is mainly a progressive dyspnea associated with pulmonary hypertension and subacute cor pulmonale. The diagnosis is difficult, mostly made post-mortem. It is rarely obtained through a combination of multiple diagnostic tests (chest CT, ventilation-perfusion scanning, pulmonary artery cytology, biopsy). Treatment is based on the one of the underlying cancer. The prognosis is poor, and patients usually die within weeks to months. It is a rare cause of pulmonary hypertension that must be considered even without a prior oncological diagnosis.

Characteristics of length of stay and cardiovascular pharmacotherapy advice among chronic obstructive pulmonary disease patients

Chronic obstructive pulmonary disease (COPD) increases the global disease burden due to its diverse adverse health effects on the respiratory and cardiovascular systems. This study aimed to elucidate the potential indicators of length of stay (LOS) and pharmacotherapy advice among COPD patients. Thereafter, hospitalized COPD patients with clinical records and respiratory and cardiovascular pharmacotherapy advice were retrospectively collected from a tertiary hospital between April 2017 and September 2020, and the determinants of LOS and cardiovascular pharmacotherapy advice were explored using regression analyses. Overall, 475 patients with COPD were recruited and stratified according to exacerbation and presence of Cor pulmonale (CP). The extended LOS, increased B-type natriuretic peptides (BNP), and a higher percentage of cardiovascular pharmacotherapy advice were observed in COPD with CP regardless of exacerbation, although the percentage of respiratory prescriptions was comparable. The presence of CP indicated a longer LOS (B = 1.850, p < 0.001) for COPD regardless of exacerbation. Meanwhile, elevated BNP levels indicated cardiovascular pharmacotherapy advise for both COPD in exacerbation (OR = 1.003, p = 0.012) and absence of exacerbation (OR = 1.006, p = 0.015). Moreover, advice for trimetazidine use for COPD in exacerbation (OR = 1.005, p = 0.002) has been suggested. Therefore, CP appears to be an important comorbidity resulting in extended LOS for COPD, which is likely to be advised with cardiovascular pharmacotherapy, which might be guided through BNP monitoring.

Expression of CCL-18 and CX3CL1 in Serum, and Their Potential Roles as Two Diagnostic and Prognostic Markers in Chronic Obstructive Pulmonary Disease and Chronic cor Pulmonale (COPD&CCP): a Pilot Study

BACKGROUND

CC chemokine ligand-18 (CCL-18) and CX3 chemokine ligand 1 (CX3CL1) are key factors of vascular and tissue injury in chronic respiratory diseases. Here, we investigated the value of CCL-18 and CX3CL1 in diagnosis and prognosis of patients with chronic obstructive pulmonary disease and chronic cor pulmonale (COPD&CCP).

METHODS

First, we investigated the expression profile of CCL-18 and CX3CL1 in serum of COPD&CCP patients. Then the relationship of the level of CCL-18 and CX3CL1 with clinicopathological characteristics was analyzed. Subsequently, we evaluated the diagnostic accuracy of CCL-18 and CX3CL1 to discriminate COPD&CCP. The prognostic value and therapy outcome were also evaluated.

RESULTS

Compared to healthy subjects, the level of CCL-18 (8.01 ± 2.01 ng/mL) and CX3CL1 (2,096.11 ± 306.09 ng/mL) was significantly increased in COPD&CCP patients (p < 0.05). The upregulation of CCL-18 and CX3CL1 was significantly correlated with clinicopathological characteristics including CRP, IL-6, FIB, NT-proBNP, FEV1, FEV1/FVC, PASP, LVEF, and T wave anomaly. The combination of CCL-18 and CX3CL1 showed high precision for discriminating COPD&CCP with high AUC values (0.828), sensitivity (66.1%), and specificity (92.5%). Furthermore, CCL-18 and CX3CL1 acted as independent factors which lead to poor clinical benefits and indicated poor prognosis of COPD&CCP patients.

CONCLUSIONS

Taken together, our results indicated that CCL-18 and CX3CL1 could act as suitable biomarkers in prognosis and prognostic evaluation of COPD&CCP.

[MORPHOMETRIC ASSESSMENT OF PECULIARITIES OF BLOOD VESSELS OF THE TESTIS IN EXPERIMENTAL ANIMALS AT ARTERIAL HYPERTENSION IN A LITTLE CIRCLE OF CIRCULATION]

Aim of the research - to study the features of the structural reconstruction of blood vessels of the testes of experimental animals at arterial hypertension in the pulmonary circulation using a complex of morphological methods. Experiments were carried out on 78 laboratory sexually mature white male rats, which were divided into 3 groups. The 1 group included 15 intact practically healthy animals, 2 - 48 rats with hypertension in the pulmonary circulation and compensated cor pulmonale, 15 animals with pulmonary hypertension, which developed decompensation of cor pulmonale, constituted the 3 group. Arterial hypertension in the pulmonary circulation was simulated by performing a right-sided pulmonectomy. Three months after the beginning of the experiment, the rats were euthanized by bloodletting under thiopental anesthesia. Histological micropreparations were made from the testes, on which the morphometry of arteries, veins, and microvessels was performed. Quantitative indicators were processed statistically. It was revealed that postresection hypertension in the pulmonary circulation leads to structural reconstruction of arteries, microvessels, and the venous bed of the left and right testes. At the same time, the degree of remodeling of the studied vessels dominates in the microhemocirculatory bed of the left testis at decompensation of the cor pulmonale. Structural reconstruction of the vessels of the microhemocirculatory bed of the testes in case of insufficiency of the cor pulmonary is characterized by a pronounced narrowing of the arterioles, precapillary arterioles), exchange (hemocapillaries) links of the microhemocirculatory bed and the expansion of postcapillary venules and venules, venous plethora, hypoxia, impaired trophism and metabolism, dystrophy, necrobiosis of cells, tissues, infiltration and sclerosis.

Application of Gastroscopy Based on Nano Carbon in the Remedy of Chronic Pulmonary Heart Disease Caused by Helicobacter Pylori

Chronic pulmonary heart disease is a common respiratory disease. Helicobacter pylori infection can lead to the occurrence of chronic pulmonary heart disease. However, most drugs for chronic pulmonary heart disease caused by helicobacter pylori are lack of tissue specificity. At the same time, due to the blocked blood circulation in the ischemic area, the distribution of drugs in the ischemic area is often not ideal. The gastroscope technology of nano carbon can make the drug release in the focus as much as possible, and can achieve the goal of targeted treatment. This paper mainly studies the application of the gastroscope technology based on nano carbon in the remedy of chronic pulmonary heart disease caused by helicobacter pylori. After 8 weeks of treatment, the indexes of right heart function in the two groups: TAPSE and RVMPI were better than before treatment, and the improvement degree in the remedy group was more obvious than that in the control group (P < 0.05). The improvement degree of E/A and PASP was not statistically significant, the difference between the two groups was not significant (P > 0.05). In addition, the gastroscope of nano carbon can also reduce UA and TG in blood. The overall response rate was 93.75% in the remedy group, which was higher than that in the control group (P < 0.05).

[Study on tissue Doppler imaging in diagnosis of right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease]

OBJECTIVE

To investigate the value of tissue Doppler imaging (TDI) in the diagnosis of right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease.

METHODS

A total of 50 cases of silicosis complicated by chronic pulmonary heart disease in our hospital underwent conventional electrocardiography (ECG) and TDI. The detection rates for right ventricular hypertrophy by two methods were compared.

RESULTS

Of 50 cases of silicosis complicated by chronic pulmonary heart disease, 19 were diagnosed with right ventricular hypertrophy by ECG, with a detection rate of 38.0%; 29 were diagnosed with right ventricular hypertrophy by TDI, with a detection rate off 58.0%. Statistical analysis suggested that TDI leads to a significantly higher detection rate for right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease (χ² = 4.006, P = 0.036).

CONCLUSION

Both TDI and ECG can be used for detecting right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease, but the detection rate is higher when TDI is employed. In addition, ECG cannot directly reflect the increase in pulmonary artery pressure. Therefore, TDI is more suitable for the diagnosis of right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease and provides a strong diagnostic basis for the clinical treatment of silicosis complicated by pulmonary heart disease.

Acute cor pulmonale due to lymphocytic interstitial pneumonia in a child with AIDS

BACKGROUND

Acute cor pulmonale is a clinical syndrome with signs of right-sided heart failure resulting from sudden increase of pulmonary vascular resistance.

CASE PRESENTATION

A five-year-old male, infected by human immunodeficiency virus (HIV), was admitted at the division of infectious diseases of this hospital with cough, tachydyspnea, fever, and breathing difficulty. Computed tomography scan showed ground-glass opacities, cystic lesions, and bronchiectasis. The patient had nasal flaring, intercostal and subcostal retractions, and keeled chest. Abdomen was depressible; liver was 3 cm from the right-costal border, while spleen was 6 cm from the left-costal border. Echocardiogram examinations showed signs of acute cor pulmonale characterized by pulmonary hypertension and increased right-heart chamber dimensions. DIAGNOSTICS OUTCOME: Acquired immunodeficiency syndrome (AIDS)-B3, lymphocytic interstitial pneumonia (LIP), and acute cor pulmonale. Regressions of pulmonary hypertension and of right-heart chamber were observed after 30 days of highly active antiretroviral therapy (HAART) and chloroquine therapy.

CONCLUSION

AIDS should be considered in children with recurrent pneumonia that is mostly associated with LIP rather than cystic fibrosis.

High plasma brain natriuretic peptide levels in stable COPD without pulmonary hypertension or cor pulmonale

BACKGROUND

Early diagnosis of chronic obstructive pulmonary disease (COPD) with latent pulmonary hypertension (PH) and cor pulmonale is important because the prognosis of this condition is poor.

OBJECTIVE

To investigate the utility of brain natriuretic peptide (BNP) for prognostication of COPD, plasma BNP was measured in patients with COPD without symptoms or physical findings of PH or cor pulmonale.

METHODS

Plasma BNP was measured in 60 patients with COPD, 10 asthmatics, and 30 healthy subjects. Echocardiography, arterial blood gas analysis, and spirometry were also performed. Mortality and exacerbation were compared between COPD patients with high and low plasma BNP levels over a 3-year follow-up period.

RESULTS

Plasma BNP (mean +/- SEM, pg/mL) in COPD patients (41.0+/-6.6) was significantly higher than in normal subjects (14.8+/-2.7) and asthmatics (17.4+/-4.5) (p<0.0001 and p<0.05, respectively). No significant correlations were observed between plasma BNP level and pulmonary function or hypoxia. There was, however, a significant correlation between plasma BNP level and % ejection fraction (r=-0.41, p=0.0197) and pulmonary artery systolic pressure (r=0.5, p=0.004). The period until initial COPD exacerbation in subjects with a high plasma BNP level was significantly shorter (p<0.05). Plasma BNP level during exacerbations (79.9+/-16.2) was also significantly higher than during stable disease (41.2+/-8.7) (p=0.004).

CONCLUSION

We suggest that plasma BNP is a non-invasive biomarker that can be used as a screening parameter for latent PH and left ventricular dysfunction, and also as a predictor of exacerbation in stable COPD.

The inhibition of pulmonary vessel remodeling by carbon monoxide system in rats with chronic pulmonary heart disease

OBJECTIVE

To study the effect of carbon monoxide on pulmonary vessel remodeling of chronic pulmonary heart disease.

METHODS

Thirty-six sprague-dawley rats were randomly divided into three groups: control group, and hypoxic hypercapnic group, and hypoxic hypercapnia + hemin group. Blood CO concentration (COHb%), activity of HO-1 in blood serum and lung homogenate, pulmonary arteriole micromorphometric index, HO-1 and HO-1 mRNA were measured.

RESULTS

(1) mPAP and RV/(LV + S) were (20.1 +/- 0.8) mm Hg and (35.5 +/- 1.7)% in hypoxic hypercapnic group, they were significantly higher than those of control group's (15.3 +/- 1.4) mm Hg, (26.7 +/- 1.7)%, and those of hypoxic hypercapnia + hemin (activator of HO-1) group's (16.5 +/- 3.7) mm Hg, (30.2 +/- 1.6)% (P < 0.01). (2) Pulmonary arteriole micromorphometric index in rats of hypoxic hypercapnic group were significantly higher than those of control group and hypoxic hypercapnia + hemin group (P < 0.01). (3) Blood CO concentration, activity of HO-1 in blood serum and lung homogenate, content of HO-1 and HO-1 mRNA in pulmonary arterioles in rats of hypoxic hypercapnic group were (2.1 +/- 0.9)%, (73 +/- 18) nmol.L(-1).h(-1), (1 751 +/- 311) pmol.mg(-1).h(-1), 0.191 +/- 0.012 and 0.301 +/- 0.017, were significantly higher than those of control group: (0.5 +/- 0.3)%, (25 +/- 8) nmol.L(-1).h(-1), (385 +/- 46) pmol.mg(-1).h(-1), 0.059 +/- 0.005, 0.131 +/- 0.011, but were significantly lower than those of hypoxic hypercapnia + hemin group: (4.9 +/- 2.1)%, (132 +/- 39) nmol.L(-1).h(-1), (2 849 +/- 426) pmol.mg(-1).h(-1), 0.272 +/- 0.013, 0.339 +/- 0.020 (P < 0.01). (4) Correlation analysis revealed that the relationship between carbon monoxide system and pulmonary arteriole micromorphometric index was significantly negative (P < 0.01).

CONCLUSION

Up-regulation of endogenous carbon monoxide system can inhibit pulmonary vessel remodeling in rats with chronic pulmonary heart disease induced by hypoxia and hypercapnia.