Qing Zhao

Long-term effects of continuous positive airway pressure on blood pressure and prognosis in hypertensive patients with coronary heart disease and obstructive sleep apnea: a randomized controlled trial.

BACKGROUND Obstructive sleep apnea (OSA) can result in hypertension and significantly increase cardiovascular morbidity and mortality. There are few reports on the long-term effects of continuous positive airway pressure (CPAP) on blood pressure in patients with uncontrolled hypertension with coronary heart disease (CHD) and OSA. METHODS We conducted a prospective, long-term follow-up study in 83 patients with uncontrolled hypertension, CHD, and OSA randomized to control or CPAP groups. Daytime systolic blood pressure (SBP), diastolic blood pressure (DBP), and severe cardiovascular and cerebrovascular events (SCCEs) were recorded at baseline and follow-up. RESULTS Seventy-three patients completed the study with a median follow-up of 36 (interquartile range = 24-54) months. The 2 groups had similar characteristics at baseline. CPAP was used for 4.5±1.1 hour/night. SBP in the CPAP group was significantly reduced at follow-up (143±7 mm Hg vs. 139±7 mm Hg, P = 0.04), and SBP decreased by 8mm Hg (95% confidence interval = 1.4-9.9; P = 0.01). Hypertension control was improved (CPAP, 69.4% for CPAP users vs. 43.2% for control subjects; P = 0.02); however, DBP did not reach statistical difference between the groups (81±10 mm Hg vs. 79±8 mm Hg; P = 0.49). In the CPAP group, the Epworth Sleepiness Scale was markedly reduced (7.0±3.4 vs. 3.7±2.3; P < 0.001). There was 1 SCCE in the CPAP group (heart failure), and 5 SCCEs in the control group (acute myocardial infarction: 2 (with 1 death); stroke: 3), but there was no significant difference identified. CONCLUSIONS Long-term CPAP application in uncontrolled hypertension with CHD and OSA significantly reduced daytime SBP, improved hypertension control and daytime sleepiness, and decreased the trend in SCCEs compared with control subjects. CLINICAL TRIAL REGISTRATION NUMBER ClinicalTrials.gov NCT02059993.

Differences in Exercise Capacity in Patients with Chronic Left Heart Failure and Chronic Right Heart Failure

BACKGROUND Exercise impairment is common in chronic left heart failure and pulmonary arterial hypertension (PAH). Exercise impairment degree is a strong predictor of clinical outcome. Our purpose was to evaluate differences in exercise capacity using cardiopulmonary exercise testing (CPX) in patients with chronic left and right heart failure, and determine which factors were related to exercise impairment. METHODS 102 patients with class II/III New York Heart Association were involved in the study (41 with chronic left heart failure, 61 with chronic right heart failure secondary to PAH). All patients underwent CPX to evaluate exercise capacity. RESULTS Patients with right heart failure had significantly lower peak oxygen uptake (VO2), peak VO2/kg ratio, peak oxygen uptake/heart rate (VO2/HR) ratio and increases in oxygen uptake/increase in work rate (ΔVO2/ΔWR) slope, and had higher minute ventilation/CO2 production ratio and peak dead space volume/tidal volume during exercise. In patients with left heart failure, peak VO2/HR ratio was positively correlated with ΔVO2/ΔWR slope. However, VO2 and VO2/HR ratio were positively correlated with ΔVO2/ΔWR slope in patients with right heart failure. CONCLUSIONS Compared with left heart failure, patients with right heart failure showed worse exercise capacity resulting from worse pulmonary and cardiovascular adaptation to exercise.

Association of elevated NTproBNP with recurrent thromboembolic events after acute pulmonary embolism

INTRODUCTION N-Terminal Pro-Brain Natriuretic Peptide (NTproBNP) is a predictor of adverse short-term clinical outcomes in patients with acute pulmonary embolism (APE), but its long-term prognostic value remains largely undefined. The aim of this study was to assess the value of plasma NTproBNP with regard to recurrent venous thromboembolism (VTE). MATERIALS AND METHODS NTproBNP levels were measured in 224 consecutive patients with the first episode of acute pulmonary embolism occurring from January 2005 through October 2010. Patients were categorized into two groups by NTproBNP reference range. Follow-ups were performed at 3, 6, and 12months and yearly thereafter. The primary end point was symptomatic, recurrent fatal or nonfatal VTE. RESULTS NTproBNP was elevated in 158 (70.5%) patients and not elevated in 66 (29.5%) patients. After a mean follow-up period of 31.0±19.4months, patients with elevated NTproBNP showed an increased risk of recurrent VTE (20 patients, 12.7%) compared to those without elevated NTproBNP (only 1 patient, 1.5%) (P=0.009). Of the 7 deaths related to pulmonary embolism, 6 occurred in patients with elevated NTproBNP compared to patients with normal NTproBNP (1 of 7 deaths). In a multivariate analysis stratified by oral anticoagulant treatment duration, elevated NTproBNP was an independent predictor of recurrent VTE (hazard ratio, 9.32; P=0.02). CONCLUSIONS Elevated NTproBNP is associated with recurrent VTE in acute pulmonary embolism patients.

Predictors of Blood Pressure Fall With Continuous Positive Airway Pressure Treatment in Hypertension With Coronary Artery Disease and Obstructive Sleep Apnea

BACKGROUND The present study aimed to investigate the predictors of changes in blood pressure (BP) with continuous positive airway pressure (CPAP) treatment in hypertensive patients with coronary heart disease (CHD) and obstructive sleep apnea (OSA). METHODS Seventy-one hypertensive patients with CHD and OSA were enrolled in this study. Daytime systolic BP (SBP), diastolic BP (DBP), Epworth Sleepiness Scale (ESS), and anthropometric characteristics were assessed at baseline and follow-up. RESULTS Sixty-six patients completed the study. The median follow-up period was 36 months (interquartile range, 24-60 months). The mean duration of CPAP application was 4.3 ± 1.2 hours per night. From baseline to follow-up, SBP and DBP were reduced by 5.6 mm Hg (95% confidence interval [CI], 3.0-8.1) and 3.0 mm Hg (95% CI, 0.8-5.3), respectively. Daytime somnolence was significantly improved (ESS, from 9.5 ± 3.4 at baseline to 3.6 ± 2.0 at follow-up; P < 0.001); the mean improvement in ESS was 6.0 (95% CI, 5.1-6.9). Correlation analysis of the fall in mean BP (MBP) showed that baseline MBP, change in ESS, heart rate, and CPAP compliance showed a positive correlation, whereas the baseline body mass index (BMI) and ESS had an inverse relationship. Stepwise multiple linear regression analysis, however, indicated that only baseline BMI, baseline MBP, and CPAP compliance were independently correlated with the fall in MBP. CONCLUSIONS Long-term CPAP treatment reduces BP in hypertensive patients with CHD and moderate/severe OSA; baseline BMI, baseline MBP, and CPAP compliance are independent predictors of the decrease in BP with CPAP treatment in these patients.

Pulmonary function differences in patients with chronic right heart failure secondary to pulmonary arterial hypertension and chronic left heart failure.

Background Pulmonary abnormalities are found in both chronic heart failure (CHF) and pulmonary arterial hypertension (PAH). The differences of pulmonary function in chronic left heart failure and chronic right heart failure are not fully understood. Material/Methods We evaluated 120 patients with stable CHF (60 with chronic left heart failure and 60 with chronic right heart failure). All patients had pulmonary function testing, including pulmonary function testing at rest and incremental cardiopulmonary exercise testing (CPX). Results Patients with right heart failure had a significantly lower end-tidal partial pressure of CO2 (PetCO2), higher end-tidal partial pressure of O2 (PetO2) and minute ventilation/CO2 production (VE/VCO2) at rest. Patients with right heart failure had a lower peak PetCO2, and a higher peak dead space volume/tidal volume (VD/VT) ratio, peak PetO2, peak VE/VCO2, and VE/VCO2 slope during exercise. Patients with right heart failure had more changes in ΔPetCO2 and ΔVE/VCO2, from rest to exercise. Conclusions Patients with right heart failure had worse pulmonary function at rest and exercise, which was due to severe ventilation/perfusion (V/Q) mismatching, severe ventilation inefficiency, and gas exchange abnormality.

Obstructive sleep apnea in patients with chronic thromboembolic pulmonary hypertension

Background Due to its effects, like an exaggerated negative intrathoracic pressure, sympathetic activation, systemic inflammation, oxidative stress, and endothelial dysfunction, obstructive sleep apnea (OSA) has been involved as a cause in multiple cardiovascular diseases. These diseases include coronary artery disease, hypertension, heart failure, and pulmonary hypertension (PH). Furthermore, OSA often coexists with chronic thromboembolic pulmonary hypertension (CTEPH) in clinical practice. However, few studies focus on OSA and its relationship with CTEPH. This study aims to determine whether OSA has an influence on the clinic status of patients with CTEPH, and to identify what possible factors are associated with OSA in CTEPH. Methods Patients who were newly diagnosed with CTEPH and received overnight polysomnography (PSG) monitoring from September 2015 to December 2017 were enrolled. OSA was defined as apnea-hypopnea index (AHI) of ≥5/h and the obstructive events at ≥50%. Baseline clinical characteristics and parameters were collected and compared between CTEPH patients with and without OSA. In addition, logistic regression analysis was performed to identify possible factors associated with OSA in CTEPH. Results Fifty-seven patients with CTEPH were eventually enrolled. Among them, 32 patients were diagnosed with OSA by PSG. CTEPH patients with OSA showed an older age, a higher body mass index (BMI), a higher hemoglobin level, a lower oxygen saturation and a worse World Health Organization functional class (WHO FC) (all P<0.05) when compared to CTEPH patients without OSA. In addition, sleep data including AHI, oxygen desaturation index and minimum oxygen saturation were also statistically different between two groups (all P<0.05). Adjusted for age, sex and BMI, hemoglobin [odd ratio (OR) =1.057, 95% confidence interval (CI): 1.001-1.117, P=0.046], oxygen saturation (OR =0.718, 95% CI: 0.554-0.929, P=0.012), N-terminal pro-brain natriuretic peptide (OR =1.001, 95% CI: 1.000-1.002, P=0.016), mean right atrium pressure (OR =1.284, 95% CI: 1.030-1.600, P=0.026), mean pulmonary arterial pressure (mPAP) (OR =1.087, 95% CI: 1.001-1.180, P=0.048), cardiac index (CI) (OR =0.058, 95% CI: 0.008-0.433, P=0.037), pulmonary vascular resistance (OR =1.004, 95% CI: 1.001-1.007, P=0.014) and WHO FC III-IV (OR =18.550, 95% CI: 2.363-144.128, P=0.005) were associated with OSA in CTEPH. Multivariate logistic regression analysis demonstrated CI (OR =0.051, 95% CI: 0.003-0.868, P=0.040) was independently associated with OSA in CTEPH in addition to age, sex and BMI. Conclusions OSA may aggravate the clinical status of CTEPH patients to some degree. In turn, a worse hemodynamics, oxygenation state and cardiac function are associated with OSA in CTEPH after being adjusted for age, sex and BMI. Among them, CI is the most important parameter in indicating the coexistence of OSA and CTEPH.

Prevalence of iron deficiency in different subtypes of pulmonary hypertension

Objectives: Iron deficiency (ID) prevalence in Chinese patients suffering from pulmonary hypertension (PH) is unclear so far. This study aimed to investigate ID prevalence in different subtypes of PH and its relevant factors. Methods: Hospitalized patients diagnosed with PH from September 2015 to March 2017 were retrospectively enrolled. Patients were grouped based on etiology. Logistic regression analysis was performed to determine factors associated with ID. Results: ID was found in 38.25% of 251 PH patients; with the highest prevalence in connective tissue disease associated pulmonary arterial hypertension (CTD‐PAH). Univariate logistic regression analysis showed that female sex, age, CTD‐PAH diagnosis and high sensitive C reactive protein (hs‐CRP) were associated with ID. After adjusting for age, sex and hs‐CRP, the diagnosis of CTD‐PAH was still associated with ID (OR = 3.01, 95%CI 1.02–8.90, P < 0.05). Conclusions: ID is common in PH in China. CTD‐PAH is independently associated with ID, after adjustment for age, sex, and hs‐CRP.