Factors Associated With Potentially Inappropriate Phosphodiesterase-5 Inhibitor Use for Pulmonary Hypertension in the United States, 2006 to 2015

Cluster analysis identifies novel real-world lung disease-pulmonary hypertension subphenotypes: implications for treatment response

Background

Clinical trials repurposing pulmonary arterial hypertension (PAH) therapies to patients with lung disease- or hypoxia-pulmonary hypertension (PH) (classified as World Health Organization Group 3 PH) have failed to show a consistent benefit. However, Group 3 PH clinical heterogeneity suggests robust phenotyping may inform detection of treatment-responsive subgroups. We hypothesised that cluster analysis would identify subphenotypes with differential responses to oral PAH therapy.

Methods

Two k-means analyses were performed on a national cohort of US veterans with Group 3 PH; an inclusive model (I) of all treated patients (n=196) and a haemodynamic model (H) limited to patients with right heart catheterisations (n=112). The primary outcome was organ failure or all-cause mortality by cluster. An exploratory analysis evaluated within-cluster treatment effects.

Results

Three distinct clusters of Group 3 PH patients were identified. In the inclusive model (C1I n=43, 21.9%; C2I n=102, 52.0%; C3I n=51, 26.0%), lung disease and spirometry drove cluster assignment. By contrast, in the haemodynamic model (C1H n=44, 39.3%; C2H n=43, 38.4%; C3H n=25, 22.3%), right heart catheterisation data surpassed the importance of lung disease and spirometry. In the haemodynamic model, compared to C3H, C1H experienced the greatest hazard for respiratory failure or death (HR 6.1, 95% CI 3.2-11.8). In an exploratory analysis, cluster determined treatment response (p=0.006). Conclusions regarding within-cluster treatment responses were limited by significant differences between select variables in the treated and untreated groups.

Conclusions

Cluster analysis identifies novel real-world subphenotypes of Group 3 PH patients with distinct clinical trajectories. Future studies may consider this methodological approach to identify subgroups of heterogeneous patients that may be responsive to existing pulmonary vasodilatory therapies.

Organization of pulmonary hypertension care in non-expert care settings: Lessons learned from a multi-site study

OBJECTIVE

To examine how select Veterans Health Administration (VA) sites organized care for patients with pulmonary hypertension (PH), with a focus on describing existing practices and identifying unmet needs within the sites.

DATA SOURCES AND STUDY SETTING

Semi-structured interviews across seven diverse VA sites.

STUDY DESIGN

Qualitative multiple-site study.

DATA COLLECTION/EXTRACTION METHODS

We interviewed 54 key informants including pulmonologists, cardiologists, primary care providers, advanced care practitioners, pharmacists, and clinical leaders to assess the structures and processes of PH care delivery. We analyzed transcripts using directed content analysis and constructed site profiles for each site, comparing profiles to existing guidelines for PH expert centers.

PRINCIPAL FINDINGS

Sites varied considerably in how they organized PH care, with wide variation in the availability of structures and processes recommended for expert centers, including availability of PH expertise and PH-specific resources, multidisciplinary approach to care, establishment of clear referral pathways, and presence of PH education. Further, participants identified three areas of unmet need not directly addressed within current guidelines, including better integration of pharmacists into multidisciplinary teams, early and routine involvement of palliative care, and improved care coordination efforts.

CONCLUSIONS

The rising prevalence of PH and evolution of treatments for common PH subgroups underscore the need to standardize PH care delivery in non-expert care settings to improve care quality and patient outcomes. The insight gained from this study may inform the development of guidance appropriate for care settings outside of expert centers.

Socioeconomically disadvantaged veterans experience treatment delays for pulmonary arterial hypertension

Prompt initiation of therapy after pulmonary arterial hypertension (PAH) diagnosis is critical to improve outcomes; yet delays in PAH treatment are common. Prior research demonstrates that individuals with PAH belonging to socially disadvantaged groups experience worse clinical outcomes. Whether these poor outcomes are mediated by delays in care or other factors is incompletely understood. We sought to examine the association between race/ethnicity and socioeconomic status and time-to-PAH treatment. We conducted a retrospective cohort study of Veterans diagnosed with incident PAH between 2006 and 2019 and treated with PAH therapy. Our outcome was time-to-PAH treatment. Our primary exposures were race/ethnicity, annual household income, health insurance status, education, and housing insecurity. We calculated time-to-treatment using multivariable mixed-effects Cox proportional hazard models. Of 1827 Veterans with PAH, 27% were Black, 4% were Hispanic, 22.1% had an income < $20,000, 53.3% lacked non-VA insurance, 25.5% had Collapse

Key Words

• pulmonary arterial hypertension
• racial, ethnic, or social disparities in lung disease and treatment
• research design/program evaluation/statistical models

Collapse

MESH Headings Collapse

Grants

• R21 HL145420 NHLBI NIH HHS
• F32 HL149236 NHLBI NIH HHS
• T32 HL007035 NHLBI NIH HHS
• R01 HL139613 NHLBI NIH HHS
• UG3 HL143192 NHLBI NIH HHS
• UL1 TR001430 NCATS NIH HHS
• U54 HL119145 NHLBI NIH HHS
• R01 HL155096 NHLBI NIH HHS
• NCATS
• NIH

Collapse

Affiliation(s)

Kari R. Gillmeyer The Pulmonary CenterBoston University School of MedicineBostonMassachusettsUSA Center for Healthcare Organization & Implementation ResearchVA Bedford Healthcare System and VA Boston Healthcare SystemBedford and BostonMassachusettsUSA
Seppo T. Rinne The Pulmonary CenterBoston University School of MedicineBostonMassachusettsUSA Center for Healthcare Organization & Implementation ResearchVA Bedford Healthcare System and VA Boston Healthcare SystemBedford and BostonMassachusettsUSA
Shirley X. Qian Center for Healthcare Organization & Implementation ResearchVA Bedford Healthcare System and VA Boston Healthcare SystemBedford and BostonMassachusettsUSA VA Boston Healthcare SystemBostonMassachusettsUSA
Bradley A. Maron Department of CardiologyVA Boston Healthcare SystemBostonMassachusettsUSA Division of Cardiovascular MedicineBrigham and Women's HospitalBostonMassachusettsUSA
Shelsey W. Johnson The Pulmonary CenterBoston University School of MedicineBostonMassachusettsUSA Center for Healthcare Organization & Implementation ResearchVA Bedford Healthcare System and VA Boston Healthcare SystemBedford and BostonMassachusettsUSA
Elizabeth S. Klings The Pulmonary CenterBoston University School of MedicineBostonMassachusettsUSA
Renda S. Wiener The Pulmonary CenterBoston University School of MedicineBostonMassachusettsUSA Center for Healthcare Organization & Implementation ResearchVA Bedford Healthcare System and VA Boston Healthcare SystemBedford and BostonMassachusettsUSA

Collapse

Tadalafil for veterans with chronic obstructive pulmonary disease-pulmonary hypertension: A multicenter, placebo-controlled randomized trial

Treating Veterans with chronic obstructive pulmonary disease complicated by pulmonary hypertension (COPD-PH) using phosphodiesterase type-5 inhibitor pharmacotherapy is common, but efficacy data are lacking. To address this further, patients with COPD-PH from five Department of Veterans Affairs hospitals were randomized (1∶1) to receive placebo or oral tadalafil (40 mg/day) for 12 months. The primary endpoint was changed from baseline in 6-min walk distance at 12 months. Secondary endpoints included change from baseline in pulmonary vascular resistance, mean pulmonary artery pressure, and symptom burden by the University of California San Diego shortness of breath questionnaire scale at 6 months. A total of 42 subjects (all male; 68 ± 7.6 years old) were randomized to placebo (N = 14) or tadalafil (N = 28). The group imbalance was related to under-enrollment. Compared to placebo, no significant difference was observed in the tadalafil group for change from the primary endpoint or change in mean pulmonary artery pressure or pulmonary vascular resistance from baseline at 6 months. A clinically meaningful improvement was observed in the secondary endpoint of shortness of breath questionnaire score in the tadalafil versus placebo group at 6 months. There was no significant difference in major adverse events between treatment groups, and tadalafil was well tolerated overall. For Veterans with COPD-PH enrolled in this study, once-daily treatment with tadalafil did not improve 6-min walk distance or cardiopulmonary hemodynamics although a decrease in shortness of breath was observed. Under-enrollment and imbalanced randomization confound interpreting conclusions from this clinical trial and limit the generalization of our findings.

Outcomes of pulmonary vasodilator use in Veterans with pulmonary hypertension associated with left heart disease and lung disease

Randomized trials of pulmonary vasodilators in pulmonary hypertension due to left heart disease (Group 2) and lung disease (Group 3) have demonstrated potential for harm. Yet these therapies are commonly used in practice. Little is known of the effects of treatment outside of clinical trials. We aimed to establish outcomes of vasodilator treatment for Groups 2/3 pulmonary hypertension in real-world practice. We conducted a retrospective cohort study of 132,552 Medicare-eligible Veterans with incident Groups 2/3 pulmonary hypertension between 2006 and 2016, and a secondary nested case-control study. Our primary outcome was a composite of death by any cause or selected acute organ failures. In our cohort analysis, we calculated adjusted risks of time to our outcome using Cox proportional hazards models with facility-specific random effects. In our case-control analysis, we used logistic mixed-effects models to estimate the effect of any past, recent, and cumulative exposure on our outcome. From our cohort study, 3249 (2.5%) Veterans were exposed to pulmonary vasodilators. Exposure to vasodilators was associated with increased risk of our primary outcome, in both Group 3 (HR: 1.58 (95% CI: 1.37-1.82)) and Group 2 (HR: 1.26 (95% CI: 1.12-1.41)) pulmonary hypertension patients. The case-control study determined odds of our outcome increased by 11% per year of exposure (OR: 1.11 (95% CI: 1.07-1.16)). Treating Groups 2/3 pulmonary hypertension with vasodilators in clinical practice is associated with increased risk of harm. This extension of trial findings to a real-world setting offers further evidence to limit use of vasodilators in Groups 2/3 pulmonary hypertension outside of clinical trials.