Differences in health policies for drug availability in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension across Latin America

Pathway to care, treatment and disease burden of pulmonary arterial hypertension: a real-world survey of physicians and patients in Latin America

OBJECTIVES

To investigate clinical characteristics, symptom profile, testing practices, treatment patterns and quality of life (QoL) among patients with pulmonary arterial hypertension (PAH) in Latin America.

DESIGN

Data from the Adelphi Real World PAH Disease Specific Programme, a cross-sectional survey with retrospective data collection.

SETTING

University/teaching hospital, regional centres, private practices and government institutions in Argentina, Brazil, Colombia and Mexico.

PARTICIPANTS

246 physicians provided data for 958 patients, of which 533 patients also self-reported data.

RESULTS

Mean (SD) patient age was 53.7 (17) years, 70% of patients were female and 79% were WHO functional class (WHO FC) I-II. Overall, 76% had undergone a right heart catheterisation, ranging from 92% in Argentina to 64% in Brazil (p<0.0001). Only 28% underwent a simplified risk assessment strategy in the past 12 months, ranging from 46% in Argentina to 16% in Brazil. Fatigue and dyspnoea on exertion were reported most commonly by physicians (37% and 53%) and patients (68% and 67%). Patient-physician agreement on symptom reporting was minimal-to-weak (kappa, 0.21-0.42). PAH-specific combination therapy varied across countries (21% Mexico, 30% Brazil, 70% Colombia and 79% Argentina, p<0.0001)). Overall, 73% of patients received a phosphodiesterase type 5 inhibitor; 52% an endothelin receptor antagonist, 15% a prostacyclin pathway agent and 11% a soluble guanylate cyclase stimulator. The mean (SD) EQ-5D (generic instrument to define quality of life)utility ranged from 0.66 (0.20) to 0.70 (0.20) across countries and the mean (SD) EQ-5D Visual Analogue Scale (VAS) was 67.0 (18.10). Lower VAS and utility scores were reported among patients with higher WHO FC (p<0.05).

CONCLUSIONS

Patients reported a high burden of PAH in terms of symptoms and QoL, particularly within higher WHO FC. Low usage of risk assessment strategies and PAH-specific combination therapy was seen in Brazil and Mexico. Further research could identify barriers to prescribing optimal treatment.

Evolution and optimization of clinical trial endpoints and design in pulmonary arterial hypertension

Selection of endpoints for clinical trials in pulmonary arterial hypertension (PAH) is challenging because of the small numbers of patients and the changing expectations of patients, clinicians, and regulators in this evolving therapy area. The most commonly used primary endpoint in PAH trials has been 6-min walk distance (6MWD), leading to the approval of several targeted therapies. However, single surrogate endpoints such as 6MWD or hemodynamic parameters may not correlate with clinical outcomes. Composite endpoints of clinical worsening have been developed to reflect patients' overall condition more accurately, although there is no standard definition of worsening. Recently there has been a shift to composite endpoints assessing clinical improvement, and risk scores developed from registry data are increasingly being used. Biomarkers are another area of interest, although brain natriuretic peptide and its N-terminal prohormone are the only markers used for risk assessment or as endpoints in PAH. A range of other genetic, metabolic, and immunologic markers is currently under investigation, along with conventional and novel imaging modalities. Patient-reported outcomes are an increasingly important part of evaluating new therapies, and several PAH-specific tools are now available. In the future, alternative statistical techniques and trial designs, such as patient enrichment strategies, will play a role in evaluating PAH-targeted therapies. In addition, modern sequencing techniques, imaging analyses, and high-dimensional statistical modeling/machine learning may reveal novel markers that can play a role in the diagnosis and monitoring of PAH.