Prevalence and predictors associated with severe pulmonary hypertension in COPD

Background

Pulmonary hypertension (PH) is one of the most common complications of COPD (chronic obstructive pulmonary disease), but its severe form is uncommon. Various factors play an important role in the occurrence and severity of pulmonary hypertension in patients.

The lowest VE/VCO2 ratio best identifies chronic thromboembolic pulmonary hypertension

Introduction

The natural history of acute pulmonary embolism (PE) under treatment is about a gradual resolution of the thrombi, and uncommonly, the development of chronic thromboembolic pulmonary hypertension (CTEPH). We hypothesized that ventilatory efficiency parameters during cardiopulmonary exercise testing (CPET) may be able to monitor the process and predict CTEPH.

Methods

15 patients rehabilitated from acute PE (total resolution of thrombi), 44 patients with chronic PE (with residual thrombi), 66 patients with CTEPH, and 36 sedentary healthy controls performed incremental CPET.

Results

The lowest VE/VCO₂ was higher in CTEPH patients than that in chronic PE and rehabilitated patients (43.4 L/min vs 29.9 L/min vs 27.1 L/min, p < 0.005). The VE/VCO₂ slope (48.4 L/min/L/min vs 29.9 L/min/L/min vs 28.0 L/min/L/min, p < 0.005) and oxygen uptake efficiency plateau (OUEP) (37.1 L/min vs 27.0 L/min vs 25.2 L/min, p < 0.005) had the similar changes. In logistic regression analysis, the lowest VE/VCO₂ ≥ 34.35 L/min was the best predictor of CTEPH (OR 159.0, 95% CI 36.0-702.3, p < 0.001). The lowest VE/VCO₂ was higher in chronic PE patients compared with the controls (29.9 L/min vs 26.5 L/min, p < 0.05), but there was no difference between the rehabilitated patients and the controls. In multiple linear regression analysis, the percentage of vascular obstruction by ventilation-perfusion lung scanning (PVO) was the most significant independent predictor for indices of ventilatory efficiency in chronic PE and rehabilitated patients.

Conclusions

CTEPH is associated with weakened ventilatory efficiency. The lowest VE/VCO2 ratio has the best capability to predict CTEPH. Ventilatory inefficiency improves along with recovery of acute PE.     

Predictors and Outcomes of Renal Replacement Therapy After Left Ventricular Assist Device Implantation

ObjectiveTo examine the frequency and outcomes of patients requiring renal replacement therapy (RRT) early after left ventricular assist device (LVAD) implantation.Patients and MethodsWe examined use of in-hospital RRT and outcomes in consecutive adults who underwent continuous-flow LVAD implantation from February 15, 2007, through August 8, 2017. Logistic regression was used to examine predictors of RRT. The associations of RRT with outcomes were examined using Cox proportional hazards regression.ResultsOf 354 patients who underwent LVAD implantation, 54 (15%) required in-hospital RRT. Patients receiving RRT had higher preoperative Charlson Comorbidity Index values (median, 5 vs 4; P=.03), Model for End-Stage Liver Disease scores (mean, 19.0 vs 14.5; P<.001), right atrial pressure (mean, 19.1 vs 13.4 mm Hg; P<.001), and estimated 24-hour urine protein levels (median, 357 vs 174 mg; P<.001) and lower preoperative estimated glomerular filtration rate (eGFR) (median, 43 vs 57 mL/min; P<.001) and measured GFR using ¹²⁵I-iothalamate clearance (median, 33 vs 51 mL/min; P=.001) than those who did not require RRT. Approximately 40% of patients with eGFR less than 45 mL/min/1.73 m² and 24-hour urine protein level greater than 400 mg required RRT vs 6% with eGFR greater than45 mL/min/1.73 m² and without significant proteinuria. Lower preoperative eGFR, higher estimated 24-hour urine protein level, higher right atrial pressure, and longer cardiopulmonary bypass time were independent predictors of RRT after LVAD implantation. Of patients requiring in-hospital RRT, 18 (33%) had renal recovery, 18 (33%) required outpatient hemodialysis, and 18 (33%) died before hospital discharge. After median (Q1, Q3) follow-up of 24.3 (8.9, 49.6) months, RRT was associated with increased risk of death (adjusted hazard ratio [HR], 2.86; 95% CI, 1.90-4.33; P<.001) and gastrointestinal bleeding (adjusted HR, 4.47; 95% CI, 2.57-7.75; P<.001).ConclusionIn-hospital RRT is associated with poor prognosis after LVAD. A detailed preoperative assessment of renal function before LVAD may be helpful in risk stratification and patient selection.     

End-tidal PCO2 abnormality and exercise limitation in patients with primary pulmonary hypertension

OBJECTIVES: Primary pulmonary hypertension (PPH) is a pulmonary vasculopathy resulting in exercise intolerance, usually due to dyspnea. We hypothesized that ventilation is increased during exercise in PPH relative to normal because the ventilated lung is underperfused, cardiac output increase is restricted, and arterial hypoxemia may develop. Our aim was to determine the size of the reduction in end-tidal Pco(2) (Petco(2)) as a reflection of the abnormality in ventilatory efficiency and ventilatory drive in PPH patients. METHODS: We performed cardiopulmonary exercise testing (CPET) in 52 PPH patients. All had hemodynamic measurements to confirm the diagnosis of PPH. A subgroup of 29 patients who underwent right-heart catheterization within 50 days of CPET were studied to compare their CPET responses to resting hemodynamics. Nine healthy volunteers matched for age and gender served as CPET control subjects. RESULTS: In PPH patients, the percentage of predicted peak oxygen uptake (Vo(2)) correlated significantly with mean pulmonary artery pressure (mPAP) [r = - 0.59, p = 0.0007, n = 29]. Petco(2) values at rest, anaerobic threshold (AT), and peak Vo(2) were proportionately reduced as percentage of predicted peak Vo(2) decreased (r = 0.66 to 0.72, p < 0.0001, n = 52). Petco(2) values at rest, AT, and peak Vo(2) were also reduced as mPAP increased (r = - 0.51 to - 0.53, p < 0.005, n = 29). In contrast to normal subjects in whom Petco(2) increased from rest to AT, Petco(2) decreased in PPH patients, except for two patients with mild PPH in whom there was no change. Also, Petco(2) increased rather than decreased further at the start of recovery, in contrast to normal. Although usually normal at rest, oxyhemoglobin saturation decreased during exercise in most PPH patients. CONCLUSIONS: In patients with PPH, Petco(2) at rest and exercise is significantly reduced in proportion to physiologic disease severity. The range of values is unusually low. Furthermore, the directional changes of Petco(2) during exercise and early recovery are in the opposite direction of normal.     

Pulmonary Artery Denervation Significantly Increases 6-Min Walk Distance for Patients With Combined Pre- and Post-Capillary Pulmonary Hypertension Associated With Left Heart Failure: The PADN-5 Study

Objectives

The authors sought to assess the benefits of pulmonary artery denervation (PADN) among combined pre- and post-capillary pulmonary hypertension (CpcPH) patients in a prospective, randomized, sham-controlled trial.

应用超声心动图观察螺内酯对血吸虫性肺动脉高压的疗效

目的探讨螺内酯对血吸虫性肺动脉高压的影响。方法 62例血吸虫病所致肺动脉高压病人随机分为实验组(螺内酯组)和对照组,每组31例。观察两组患者治疗前后的肺动脉平均压、肺动脉直径、心功能和6 min步行试验的变化。结果治疗前后肺动脉平均压、肺动脉直径、心功能和6 min步行试验结果比较,螺内酯组差异有显著性(P<0.05),而对照组差异无显著性(P>0.05)。结论螺内酯能降低血吸虫性肺动脉高压病人的肺动脉压,并能改善肺功能。