Bosentan in mild pulmonary hypertension

The incremental shuttle walk test predicts mortality in non-group 1 pulmonary hypertension: results from the ASPIRE Registry

Pulmonary hypertension (PH) is classified into five groups based on disease etiology but there is only limited information on the prognostic value of exercise testing in non-group 1 PH. In group 1 PH, the incremental shuttle walking test (ISWT) distance has been shown to correlate with pulmonary hemodynamics and predict survival without a ceiling effect. This study assessed the ISWT in non-group 1 PH. Data were retrieved from the ASPIRE Registry (Assessing the Spectrum of Pulmonary hypertension Identified at a REferral centre) for consecutive patients diagnosed with PH. Patients were required to have been systematically assessed as group 2-5 PH and to have a baseline ISWT within three months of cardiac catheterization. Patients were stratified according to incremental shuttle walk test distance (ISWD) and ISWT distance percent predicted (ISWD%pred). A total of 479 patients with non-group 1 PH were identified. ISWD and ISWD%pred correlated significantly with symptoms and hemodynamic severity. ISWD and ISWD%pred predicted survival with no ceiling effect. The test was prognostic in groups 2, 3, and 4. ISWD and ISWD%pred and change in ISWD and ISWD%pred at one year were all significant predictors of outcome. In patients with non-group 1 PH the ISWT is a simple non-invasive test that is easy to perform, is predictive of survival at baseline and follow-up, reflects change, and can be used in the assessment of PH of any etiology.

Incremental Shuttle Walking Test Distance Is Reduced in Patients With Pulmonary Hypertension in World Health Organisation Functional Class I

Background: There is increasing interest in screening for and diagnosing pulmonary hypertension earlier in the course of disease. However, there is limited data on cardiopulmonary abnormalities in patients with pulmonary hypertension newly diagnosed in World Health Organization Function Class (WHO FC) I. Methods: Data were retrieved from the ASPIRE registry (Assessing the Spectrum of Pulmonary hypertension Identified at a REferral center) for consecutive treatment naïve patients diagnosed with pulmonary hypertension by cardiac catheterization between 2001 and 2010 who underwent incremental shuttle walk exercise testing. Results: Eight hundred and ninety-five patients were diagnosed with Group 1-5 pulmonary hypertension. Despite the absence of symptoms, patients in WHO FC I (n = 9) had a significant reduction in exercise capacity (Incremental shuttle walk distance percent predicted (ISWD%pred) 65 ± 13%, Z score -1.77 ± 1.05), and modest pulmonary hypertension with a median (interquartile range) pulmonary artery pressure 31(20) mmHg and pulmonary vascular resistance 2.1(8.2) Wood Units, despite a normal diffusion of carbon monoxide adjusted for age and sex (DLco)%pred 99 ± 40%. Compared to patients in WHO FC I, patients in WHO FC II (n = 162) had a lower ISWD%pred 43 ± 22 and lower DLco%pred 65 ± 21%. Conclusion: Our results demonstrate that patients with newly diagnosed pulmonary hypertension with no or minimal symptomatic limitation have a significant reduction of exercise capacity.

Incremental shuttle walk test distance and autonomic dysfunction predict survival in pulmonary arterial hypertension

BACKGROUND

To ensure effective monitoring of pulmonary arterial hypertension (PAH), a simple, reliable assessment of exercise capacity applicable over a range of disease severity is needed. The aim of this study was to assess the ability of the incremental shuttle walk test (ISWT) to correlate with disease severity, measure sensitivity to change, and predict survival in PAH.

METHODS

We enrolled 418 treatment-naïve patients with PAH with baseline ISWT within 3 months of cardiac catheterization. Clinical validity and prognostic value of ISWT distance were assessed at baseline and 1 year.

RESULTS

ISWT distance was found to correlate at baseline with World Health Organization functional class, Borg score, and hemodynamics without a ceiling effect (all p < 0.001). Walking distance at baseline and after treatment predicted survival; the area under the receiver operating characteristic curve for ability of ISWT distance to predict mortality was 0.655 (95% confidence interval 0.553-0.757; p = 0.004) at baseline and 0.737 (95% confidence interval 0.643-0.827; p < 0.001) at 1 year after initiation of treatment. Change in ISWT distance also predicted survival (p = 0.04). Heart rate (HR) and systolic blood pressure (SBP) parameters reflecting autonomic response to exercise (highest HR, change in HR, HR recovery at 1 minute >18 beats/min, highest SBP, change in SBP, and 3-minute SBP ratio) were significant predictors of survival (all p < 0.05).

CONCLUSIONS

In patients with PAH, the ISWT is simple to perform, allows assessment of maximal exercise capacity, is sensitive to treatment effect, predicts outcome, and has no ceiling effect. Also, measures of autonomic function made post-exercise predict survival in PAH.

Bosentan treatment is associated with improvement of right ventricular function and remodeling in chronic thromboembolic pulmonary hypertension

BACKGROUND

Medical pretreatment before pulmonary endarterectomy (PEA) can optimize right ventricular (RV) function and may improve postoperative outcome in high-risk patients. Using cardiac magnetic resonance imaging (cMRI), we determined whether the dual endothelin-1 antagonist bosentan improves RV function and remodeling in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who waited for PEA.

HYPOTHESIS

We hypothesized that medical therapy prior to PEA will be associated with improvements in RV remodeling and function.

METHODS

In this pilot study, 15 operable CTEPH patients were randomly assigned to either bosentan (n = 8) or no bosentan (n = 7, control) for 16 weeks, next to "best standard of care." Both before and after treatment, RV stroke volume index (RVSVI), RV ejection fraction (RVEF), RV mass, RV isovolumic relaxation time (rIVRT), leftward ventricular septal bowing (LVSB), and left ventricular ejection fraction (LVEF) were determined using cMRI.

RESULTS

After 16 weeks, the change (Δ) from baseline (median [range]) in the studied cMRI parameters differed significantly between the bosentan group and the controls: Δ RVSVI: 6 [-4-11] vs 1 [-6-3] mL/m(-2) ; Δ RVEF: 8 [-10-15] vs -4 [-7-5]%; Δ RV mass: -3 [-6--2] vs 2 [-1-3] g/m(-2) ; Δ rIVRT: -30 [-130-20] vs 10 [-30-30] msec; Δ LVSB: 0.03 [-0.03-0.13] vs -0.03[-0.08-0.04] cm(-1) ; and Δ LVEF: 8 [-5-17] vs -2 [-14-2]% (all P < 0.05). The change from baseline in mean pulmonary artery pressure (-11 [-17-11] vs 5 [-6-21] mm Hg, P < 0.05) and 6-minute walk distance (20 [3-88] vs -4 [-40-40] m, P < 0.05) also differed significantly.

CONCLUSIONS

In CTEPH, compared with control, treatment with bosentan for 16 weeks was associated with a significant improvement in cMRI parameters of RV function and remodelling.

Improved Survival Among Patients With Eisenmenger Syndrome Receiving Advanced Therapy for Pulmonary Arterial Hypertension

Background— Advanced therapy (AT) for pulmonary arterial hypertension in the context of congenital heart disease (Eisenmenger syndrome) improves pulmonary hemodynamics, functional class, and the 6-minute walk test. We examined the potential effect of AT on survival in this population.

Methods and Results— Data on all Eisenmenger patients attending our center over the past decade were collected. Survival rates were compared between patients on and off AT with the use of a modified version of the Cox model, which treats AT as a time-varying covariate. Baseline differences were adjusted for the use of propensity scores. A total of 229 patients (aged 34.5±12.6 years; 35.4% male) were included. The majority had complex anatomy, and 53.7% were in New York Heart Association class ≥III at baseline assessment. Mean resting saturations were 84.3%. Sixty-eight patients (29.7%) either were on AT or had AT initiated during follow-up. During a median follow-up of 4.0 years, 52 patients died, only 2 of them while on AT. Patients on AT were at a significantly lower risk of death, both unadjusted and after adjustment for baseline clinical differences by propensity score regression adjustment ( C statistic=0.80; hazard ratio, 0.16; 95% confidence interval, 0.04 to 0.71; P =0.015) and propensity score matching (hazard ratio, 0.10; 95% confidence interval, 0.01 to 0.78; P =0.028).

Conclusions— AT for pulmonary arterial hypertension in a contemporary cohort of adults with Eisenmenger syndrome was associated with a lower risk of death. Survival benefits should be considered together with improved hemodynamics and functional class when decisions are made about AT in this population.