Risk prediction in pulmonary hypertension due to chronic heart failure: incremental prognostic value of pulmonary hemodynamics

Background

There is no generally accepted comprehensive risk prediction model cooperating risk factors associated with heart failure and pulmonary hemodynamics for patients with pulmonary hypertension due to left heart disease (PH-LHD). We aimed to explore outcome correlates and evaluate incremental prognostic value of pulmonary hemodynamics for risk prediction in PH-LHD.

Methods

Consecutive patients with chronic heart failure undergoing right heart catheterization were prospectively enrolled. The primary endpoint was all-cause mortality. Individual variable selection was performed by machine learning methods. Cox proportional hazards models were conducted to identify the association between variables and mortality. Incremental value of hemodynamics was evaluated based on the Seattle heart failure model (SHFM) and Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) scores.

Results

A total of 276 PH-LHD patients were enrolled, with a median follow-up time of 34.7 months. By L1-penalized regression model and random forest approach, diastolic pressure gradient (DPG) and mixed venous oxygen saturation (SvO₂) were the hemodynamic predictors most strongly associated with mortality (coefficient: 0.0255 and -0.0176, respectively), with consistent significance after adjusted for SHFM [DPG: HR 1.067, 95% CI 1.024–1.113, P = 0.022; SvO₂: HR 0.969, 95% CI 0.953–0.985, P = 0.002] or MAGGIC (DPG: HR 1.069, 95% CI 1.026–1.114, P = 0.011; SvO₂: HR 0.970, 95% CI 0.954–0.986, P = 0.004) scores. The inclusion of DPG and SvO₂ improved risk prediction compared with using SHFM [net classification improvement (NRI): 0.468 (0.161–0.752); integrated discriminatory index (IDI): 0.092 (0.035–0.171); likelihood ratio test: P < 0.001] or MAGGIC [NRI: 0.298 (0.106–0.615); IDI: 0.084 (0.033–0.151); likelihood ratio: P < 0.001] scores alone.

Conclusion

In PH-LHD, pulmonary hemodynamics can provide incremental prognostic value for risk prediction.

Clinical trial registration: NCT02164526 at https://clinicaltrials.gov.

Echocardiographic Assessment of Right Ventricular Afterload in Preterm Infants: Maturational Patterns of Pulmonary Artery Acceleration Time Over the First Year of Age and Implications for Pulmonary Hypertension

BACKGROUND

Assessment of pulmonary hemodynamics is critical in the diagnosis and management of cardiopulmonary disease of premature infants, but reliable noninvasive indices of pulmonary hemodynamics in preterm infants are lacking. Because pulmonary artery acceleration time (PAAT) is a validated noninvasive method to assess right ventricular (RV) afterload in infants and children, the aim of this study was to investigate the maturational changes of PAAT measures in preterm infants over the first year of age and to discern the impact of typical cardiopulmonary abnormalities on these measures.

METHODS

In a prospective multicenter study of 239 preterm infants (<29 weeks at birth), PAAT was assessed at days 1, 2, and 5 to 7, at 32 and 36 weeks' postmenstrual age, and at 1-year corrected age. To account for heart rate variability, PAAT was adjusted for RV ejection time. Premature infants who developed bronchopulmonary dysplasia or had echocardiographic findings of pulmonary hypertension were analyzed separately. Intra- and interobserver reproducibility analysis was performed.

RESULTS

PAAT was feasible in 95% of the image acquisitions, and there was high intra- and interobserver agreement (intraclass correlation coefficients > 0.9 and coefficients of variation < 6%). In uncomplicated preterm infants (n = 103 [48%]) PAAT and PAAT adjusted for RV ejection time increased longitudinally from birth to 1-year corrected age (P < .001) and were linearly associated with gestational age at birth (r = 0.81 and r = 0.82, P < .001) and increasing postnatal weight and postnatal age (r > 0.81, P < .001). PAAT measures were significantly reduced (P < .001) in infants with bronchopulmonary dysplasia and/or pulmonary hypertension (n = 119 [51%]) beyond 1 week of age.

CONCLUSIONS

PAAT measures increase in preterm infants from birth to 1-year corrected age, reflective of the physiologic postnatal drop in RV afterload. Bronchopulmonary dysplasia and pulmonary hypertension have a negative impact on PAAT measures. By demonstrating excellent reliability and establishing reference patterns of PAAT in preterm infants, this study suggests that PAAT and PAAT adjusted for RV ejection time can be used as complementary parameters to assess physiologic and pathologic changes in pulmonary hemodynamics in neonates.

Selexipag for Chronic Thromboembolic Pulmonary Hypertension in Japanese Patients - A Double-Blind, Randomized, Placebo-Controlled, Multicenter Phase II Study

BACKGROUND

Selexipag is an oral prostacyclin receptor (IP receptor) agonist with a non-prostanoid structure. This study examined its efficacy and safety in Japanese patients with non-operated or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH).Methods and Results:This Phase II study was a randomized, double-blind, placebo-controlled parallel-group comparison. The primary endpoint was a change in pulmonary vascular resistance (PVR) from baseline to week 17. The main analysis involved a per-protocol set group of 28 subjects. The change in PVR (mean±SD) after 17 weeks of treatment in the selexipag group was -104±191 dyn·s/cm⁵, whereas that in the placebo group was 26±180 dyn·s/cm⁵. Thus, the treatment effect after 17 weeks of selexipag treatment was calculated as -130±189 dyn·s/cm⁵(P=0.1553). Although the primary endpoint was not met, for the group not concomitantly using a pulmonary vasodilator the PVR in the selexipag group was significantly decreased compared with placebo group (P=0.0364). The selexipag group also showed improvement in total pulmonary resistance and cardiac index.

CONCLUSIONS

Selexipag treatment improved pulmonary hemodynamics in Japanese patients with CTEPH, but PVR did not show a significant difference between the selexipag and placebo groups. (Trial registration: JAPIC Clinical Trials Information [JapicCTI-111667]).

Exercise Hemodynamics in the Prognosis of Patients with Pulmonary Arterial Hypertension

BACKGROUND

Assessment of prognosis is of major importance when deciding on a therapeutic strategy in patients with pulmonary arterial hypertension (PAH).

OBJECTIVES

The aim of this study was to investigate the prognostic value of pulmonary hemodynamics during exercise and changes during treatment in patients with PAH.

METHODS

Consecutive incident patients (n = 49) with PAH undergoing right heart catheterization at rest and during a constant workload cycle exercise in supine position were included. Predictors of survival were identified at baseline using Cox proportional hazard regression models in a univariate analysis unadjusted and adjusted for age and gender.

RESULTS

During a median follow-up period of 42 months, 13 (27%) of the 49 patients studied died. Two predictors of death were found: rest-to-exercise changes in heart rate and systolic pulmonary artery pressure. Adjusted hazard ratios were 0.92 (95% CI 0.86-0.99) and 0.93 (95% CI 0.88-0.99), respectively. These 2 variables were correlated with each other (r = 0.55, p < 0.001).

CONCLUSIONS

Rest-to-exercise changes in heart rate and systolic pulmonary artery pressure measured at diagnosis are predictors of survival in patients with PAH. These measurements taken from an exercise test reflect right ventricular function.

Riociguat Improves Pulmonary Hemodynamics in Patients with Inoperable Chronic Thromboembolic Pulmonary Hypertension

Background

Few studies have investigated the effects of riociguat on pulmonary hemodynamics in Asian patients with chronic thromboembolic pulmonary hypertension (CTEPH). In this study, we evaluated the effects of riociguat on pulmonary hemodynamics in inoperable CTEPH patients.

Methods

We retrospectively collected the clinical data of 11 inoperable CTEPH patients. Pulmonary hemodynamic parameters of right heart catheterization, echocardiography, 6-minute walk distance and World Health Organization (WHO) functional class were assessed at baseline and after riociguat treatment.

Results

The median duration of riociguat treatment was 12 months, and all 11 patients tolerated riociguat 7.5 mg/day well after titration. With regards to pulmonary hemodynamic data, both mean pulmonary artery pressure and pulmonary vascular resistance significantly decreased from 41 ± 8 mmHg to 38 ± 9 mmHg (p = 0.045) and 787 ± 417 dyn·s·cm^-5 to 478 ± 267 dyn·s·cm^-5 (p = 0.007), respectively. With regards to clinical symptoms, WHO functional class significantly improved in nine of the 11 patients, and there was no change in the other two patients (p = 0.004). In addition, the median level of N-terminal pro-brain natriuretic peptide also significantly decreased from 281 (117-5943) pg/ml to 226 (48-1276) pg/ml (p = 0.021).

Conclusions

Riociguat treatment improved both clinical symptoms and pulmonary hemodynamics in the inoperative CTEPH patients in this study.

Pulmonary hemodynamic effects and pulmonary arterial compliance during hypovolemic shock and reinfusion with human relaxin-2 (serelaxin) treatment in a sheep model

BACKGROUND

Previous studies on the recombinant form of human relaxin-2 (serelaxin) have shown a decrease of pulmonary hemodynamics after serelaxin injection. Currently, the effect of serelaxin treatment during hypovolemia in a large animal model remains mostly unknown.

METHODS

12 sheep were randomly assigned to a sham or serelaxin (30μg/kg serelaxin) group and underwent right heart catheterization. 50% of the estimated total blood volume were removed to induce hypovolemia, and subsequently retransfused 20 min later (reinfusion). Blood gases, heart rate, peripheral and pulmonary arterial oxygen saturation, systolic, diastolic and mean values of both pulmonary artery pressure (PAP) and pulmonary capillary wedge pressure (PCW) were measured. Cardiac output (CO), pulmonary vascular resistance (PVR), pulmonary arterial compliance (PAcompl) and systemic vascular resistance (SVR) were calculated.

RESULTS

Hypovolemia and shock led to a similar decrease of PAP and PCW in both groups (p≤0.001). CO, SV and PAcompl decreased only in the control group (p≤0.05) and remained higher in the serelaxin-treated group. The results of this study suggest that serelaxin treatment did not negatively influence hemodynamic parameters during hypovolemic shock.

CONCLUSION

The main conclusion of this study is that cardiopulmonary adaption mechanisms are not critically altered by serelaxin administration during severe hypovolemia and retransfusion.

Sex differences in hemodynamic responses and long-term survival to optimal medical therapy in patients with pulmonary arterial hypertension

It is widely known that the incidence of pulmonary arterial hypertension (PAH) is higher in female, whereas prognosis is poorer in male patients. However, sex differences in hemodynamic response to and long-term prognosis with PAH-targeted treatment in the modern era remain to be fully elucidated. We examined the long-term prognosis of 129 consecutive PAH patients (34 males and 95 females) diagnosed in our hospital from April 1999 to October 2014, and assessed hemodynamic changes in response to PAH-targeted therapy. Female patients had better 5-year survival compared with male patients (74.0 vs. 53.4%, P = 0.003); however, higher age quartiles in females were associated with poor outcome. Follow-up examination after medical treatment showed significant decreases in mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), and pulmonary arterial capacitance (PAC) in both sexes (both P < 0.05), whereas only females had a significant improvement in right ventricular end-diastolic pressure (RVEDP), right atrial pressure (RAP), cardiac index, and mixed venous oxygen saturation (SvO₂) (all P < 0.05). Baseline age significantly correlated with the hemodynamic changes only in female patients; particularly, there were significant sex interactions in RVEDP and RAP (both P < 0.10). The multivariable analysis showed that SvO₂ at baseline and mPAP and SvO₂ at follow-up were significant prognostic factors in males, whereas the changes in mPAP, PVR, and PAC and use of endothelin-receptor antagonist in females. These results indicate that female PAH patients have better long-term prognosis than males, for which better improvements of right ventricular functions and hemodynamics may be involved.

Lung Tissue Volume is Elevated in Obesity and Reduced by Bariatric Surgery

BACKGROUND

Bariatric surgery (BS) in severely obese subjects causes a significant reduction of body weight with lung function improvement. We have shown that abnormalities in pulmonary gas exchange in morbidly obese subjects are substantially improved with BS. These abnormalities were thought to be related to reduced lung volumes as well as to abnormal endothelial function induced by low-grade chronic inflammation linked to perivascular adipose tissue (PVAT). In this study, we used computed tomography (CT) to assess whether BS also caused measurable structural changes in the lung tissue volume (Vtiss) and cross-sectional vessel analysis, hypothesizing that these measures could be related to the previously reported lung functional changes.

METHODS

This is a post hoc analysis of a previous reported prospective study. Pulmonary vessels and lung volumes, including Vtiss, were quantified in thoracic CT scans. We compared findings in 12 obese women before and after BS and in 8 healthy lean women.

RESULTS

Vtiss was significantly elevated in obese subjects before BS compared to control subjects and systematically reduced after BS (by 8 %); other CT lung volumes or vascular areas were not affected in a consistent manner. No relationship was observed between BS-induced individual changes in Vtiss and pulmonary vessel area.

CONCLUSIONS

Vtiss is elevated in morbidly obese subjects, compared to lean individuals of similar body height, and is systematically reduced by BS. These effects do not appear related to vascular changes but may be caused by elevated extravascular lung water, due to low-grade inflammation, and/or hypertrophic PVAT in severe obesity.

Phosphodiesterase-5 Inhibitors Improve Clinical Outcomes, Exercise Capacity and Pulmonary Hemodynamics in Patients With Heart Failure With Reduced Left Ventricular Ejection Fraction: A Meta-Analysis

BACKGROUND

Several studies have compared the use of phosphodiesterase-5 (PDE5) inhibitors sildenafil or udenafil with the placebo in patients suffering from pulmonary hypertension (PH) due to left chronic heart failure (CHF), corresponding to group 2 (PH due to left heart disease) of the PH classification (according to 2015 ESC/ERS guidelines for the diagnosis and treatment of PH). The results of the use of PDE5 inhibitors in the PH due to left heart disease were inconsistent and heterogeneous. Therefore, we carried out a meta-analysis to assess the effect of PDE5 inhibitors in this clinical setting, i.e., patients with left CHF.

METHODS

A systematic search was conducted using the PubMed and Embase electronic archives. Studies had to be prospective randomized controlled trials (RCTs). In each of the RCTs admitted to meta-analysis, a comparison was made between a group of CHF patients taking a PDE5 inhibitor and a second group assigned a placebo. Studies were incorporated in the meta-analysis provided that they had sufficient information about two or more of the following clinical, ergospirometric or hemodynamic outcomes: the composite of all-cause death and hospitalization, adverse events, peak VO₂, 6-min walking distance (6MWD), left ventricular ejection fraction (LVEF), E/e' ratio, mean pulmonary arterial pressure (mPAP), pulmonary arterial systolic pressure (PASP), and pulmonary vascular resistance (PVR).

RESULTS

Fourteen studies enrolling a total of 928 patients were incorporated in the meta-analysis. Among them,13 were RCTs and one was a subgroup analysis. Among patients with CHF with reduced left ventricular ejection fraction (HFREF, n = 555), a significant benefit was conferred by PDE5 inhibitors against the risk of the composite endpoint of death and hospitalizations (odds ratio (OR): 0.28; 95% confidence interval (CI): 0.10 - 0.74; P = 0.03). Furthermore, among HFREF patients, PDE5 inhibitors were associated with a significant improvement in peak VO₂ (difference in means (MD): 3.76 mL/min/kg; 95% CI: 3.27 - 4.25) as well as in 6MWD (MD: 22.7 m; 95% CI: 8.19 - 37.21) and LVEF (MD: 4.30%; 95% CI: 2.18% to 6.42%). For patients with HFREF, PDE5 inhibitors caused a non-significant reduction in mPAP, while PASP was significantly reduced (MD: -11.52 mm Hg; 95% CI: -15.56 to -7.49; P < 0.001). By contrast, in the RCTs of patients with CHF with preserved left ventricular ejection fraction (HFpEF, n = 373), no benefit ensued from PDE5 inhibitor use regarding all of the investigated clinical, ergospirometric or hemodynamic endpoints.

CONCLUSIONS

PDE5 inhibitors improved clinical outcomes, exercise capacity and pulmonary hemodynamics in patients with HFREF, but not in HFpEF. However, considering the relatively small size of the HFpEF subset enrolled so far in the RCTs that explored the PDE5 inhibitor effects, further research in this field is undoubtedly warranted.

Serial Changes in Pulmonary Hemodynamics During Pregnancy: A Non-Invasive Study Using Doppler Echocardiography

Background

This study aimed to describe the pulmonary hemodynamic changes during the course of pregnancy and to observe any significant effects on symptomatology and outcome of pregnancy due to these changes.

Methods

A total of 75 patients were recruited for the study, 60 pregnant women from first trimester to third trimester and 6 weeks of puerperium for the study group and 15 non-pregnant patients. All the subjects were interrogated about their complaints like excessive cough, exertional dyspnea, palpitations, orthopnea, syncope, exertional chest pain and lower extremity edema along with their duration. Baseline investigations, echocardiography (ECG) and Doppler echo were done.

Results

The commonest symptoms were palpitations (40%), exertional dyspnea (35%) and lower extremity edema (47%). Palpitations and dyspnea were also present in control group. Right axis deviation was the next most common abnormality in study group (12.3% patients). Pulmonary blood flow was decreased by more than 50% of predelivery value at the end of puerperium. Fall in pulmonary vascular resistance returned to base line values. Increased pulmonary artery pressure was seen during the pregnancy, which was not statistically significant.

Conclusion

During pregnancy, though the pulmonary blood flow increases significantly, the pulmonary artery pressure remains unchanged due to substantial fall in pulmonary vascular resistance in early gestation.

Intermittent positive pressure ventilation increases diastolic pulmonary arterial pressure in advanced COPD

OBJECTIVES

To measure the impact of intermittent positive pressure ventilation (IPPV) on diastolic pulmonary arterial pressure (dPAP) and pulmonary pulse pressure in patients with advanced COPD.

BACKGROUND

The physiological effects of raised intrathoracic pressures upon the pulmonary circulation have not been fully established.

METHODS

22 subjects with severe COPD receiving IPPV were prospectively assessed with pulmonary and radial arterial catheterization. Changes in dPAP were assessed from end-expiration to early inspiration during low and high tidal volume ventilation.

RESULTS

Inspiration during low tidal volume IPPV increased the median [IQR] dPAP by 3.9 [2.5-4.8] mm Hg (P < 0.001). During high tidal volume, similar changes were observed. The IPPV-associated change in dPAP was correlated with baseline measures of PaO2 (rho = 0.65, P = 0.005), pH (rho = 0.64, P = 0.006) and right atrial pressure (rho = -0.53, P = 0.011).

CONCLUSIONS

In severe COPD, IPPV increases dPAP and reduces pulmonary pulse pressure during inspiration.