May 2025, Cardiology Research and Practice, a peer-reviewed journal published by Wiley, has released the article titled:“A Real‐World Study on Pulmonary Arterial Hypertension in Bulgaria: A Single-Center Retrospective Study From 2012 to 2022.”

This important Real-World Evidence (RWE) study was authored by leading Bulgarian cardiologists, real-world data analysts from Sqilline Health, and experts from the pharmaceutical industry. The research provides the first long-term overview of pulmonary arterial hypertension (PAH) treatment and survival outcomes in Bulgaria based on real clinical practice.

Powered by Danny Platform, the retrospective analysis transformed 10 years of hospital records into structured, research-ready data. The study uncovered critical insights into treatment adherence, disease staging, and therapeutic strategies – revealing significant opportunities to optimize care pathways for PAH patients in Bulgaria.

Introduction

Pulmonary arterial hypertension (PAH) is a progressive, life-threatening condition with limited curative options. Despite clear ESC/ERS guidelines advocating combination therapy in WHO-FC III or IV patients, real-world care often relies on monotherapy. This study analyzes 194 patients with PAH treated at St. Anna University Hospital in Sofia between 2012 and 2022, providing insight into treatment patterns, disease severity at diagnosis, and survival outcomes under routine clinical conditions.

Objectives

  • To evaluate real-world characteristics, treatment decisions, and survival outcomes in PAH patients in Bulgaria over a 10-year period.
  • To examine treatment adherence, initial therapy types, and how real-world data compare with guideline recommendations.

Challenges

  • Late Diagnosis: Over 90% of patients were diagnosed at WHO Functional Class III—advanced disease stage.
  • Limited Uptake of Combination Therapy: Only 18.5% began with dual therapy; no patients started with triple therapy.
  • Follow-Up Gaps: 31% of patients were lost to follow-up, which affected treatment continuity and outcome monitoring.

Solution

Danny Platform enabled:

  • Structuring of 10 years of unstructured hospital data into research-ready datasets.
  • In-depth survival and treatment adherence analysis.
  • Extraction of comorbidity patterns and risk stratification from real-world hospital records.

Results

Patient Cohort:

  • 194 PAH patients were included in the analysis (69.5% female; mean age: 52 years).
  • Majority presented with Functional Class III symptoms (92.1%).

Treatment Patterns:

  • 5% of patients received monotherapy at initiation.
  • 5% began with dual therapy; 0% with triple therapy.
  • Most common therapy: Endothelin Receptor Antagonists (ERA), followed by PDE-5 inhibitors.

Treatment Adherence & Survival:

  • Adherence had a direct impact on outcomes:
    • Compliant patients: median overall survival = 9 months
    • Non-compliant patients: median OS = 8 months
  • Patients lost to follow-up had no access to continued reimbursement or treatment.

Comorbidities:

  • 7% had ≥1 comorbidity: hypertension, valvular heart disease, and atrial fibrillation were most common.

Benefits

  • Critical Real-World Insight: First long-term national analysis of PAH care, highlighting the gap between guidelines and real-world practice.
  • Guidance for Health Policy: Results support the urgent need for early screening, structured follow-up, and better access to combination therapy.
  • Danny Platform’s Role: Enabled processing of real-world clinical data over a decade, facilitating evidence-based improvements in cardiology care.

Authors and Affiliations

Vasil Velchev, Arman Postadzhiyan, Sarkis Kalustian, Simona Markova, Mihaela Manolova,
Cardiology Clinic, UMBAL “Saint Anna” – Sofia, Sofia, Bulgaria

Damyan Boychev, Daniel Penchev, Martina Nacheva
Data Science, Sqilline Health, Sofia, Bulgaria

Elina Petrova
Market Access, MSD Bulgaria, Sofia, Bulgaria

👉 Click here to read the full publication in Cardiology Research and Practice