New Severity Score Offers Clinical Roadmap for Managing PH-ILD

In a move that could reshape treatment decisions for a high-risk patient population, researchers have introduced a novel scoring tool designed to assess disease severity in patients with pulmonary hypertension associated with interstitial lung disease (PH-ILD). The PH-ILD Severity score, developed through retrospective analysis of 57 patients at a single academic center, aims to fill a long-standing gap in therapeutic guidance where both clinical uncertainty and disease complexity converge.

These patients often present with overlapping symptoms and disease processes that obscure timely diagnosis, and once identified, treatment strategies remain limited. Although inhaled prostacyclin therapy has been approved for this group, a subset of patients progress to right ventricular failure—a stage for which no clear therapeutic algorithm exists. The new severity score could provide a decision-making framework for determining when to escalate care, initiate parenteral therapies, or refer patients for lung transplantation evaluation.

The tool integrates four parameters: World Health Organization functional class (WHO FC), cardiac index (CI), pulmonary vascular resistance (PVR), and tricuspid annular plane systolic excursion (TAPSE). Each factor contributes one point, yielding a total score ranging from 0 to 4. A score of 3 or higher signifies high risk and was associated with significantly greater rates of clinical worsening, defined as hospitalization for cardiopulmonary issues, a sustained decline in 6-minute walk distance, all-cause mortality, or lung transplantation.

Statistically, the model proved robust. A score ≥3 yielded an area under the receiver operating characteristic curve (AUC) of 0.831 (p < 0.001), indicating strong predictive power for adverse clinical outcomes.

Each variable was chosen for its established association with disease progression and mortality in pulmonary hypertension more broadly. WHO FC captures symptom burden and functional limitation, long recognized as a proxy for disease severity. CI and PVR are hemodynamic measures that reflect the burden on the heart and pulmonary vasculature, respectively, while TAPSE offers an echocardiographic window into right ventricular performance. Notably, a TAPSE under 1.6 cm and CI under 2.0 L/min were both strong indicators of deteriorating cardiac function and carried significant weight in patient stratification.

Patient outcomes varied dramatically depending on their risk categorization. Among the high-risk group, 97% experienced clinical worsening over one year, compared to just 39% in the low-risk group. Moreover, over half of high-risk patients required advanced parenteral prostacyclin therapy, suggesting that the severity score not only reflects current status but may also help anticipate future therapeutic needs.

The implications are significant for a field that has lacked a structured approach. Current treatment paradigms in PH-ILD often borrow from management strategies for pulmonary arterial hypertension (PAH), despite key differences in pathophysiology and therapeutic response. While PAH has long benefited from validated risk stratification tools like REVEAL and ESC/ERS guidelines, PH-ILD remains underserved. This study bridges that gap by adapting those proven metrics into a new framework that is specific to the nuances of PH-ILD.

Importantly, the score is not intended to delay care or replace clinical judgment, but rather to guide earlier and more tailored interventions. For example, a patient with a score of 3 or higher might be promptly evaluated for parenteral therapy or listed for lung transplant—decisions that could otherwise be deferred until after irreversible cardiac decline.

Given the high morbidity and mortality associated with PH-ILD, the development of this tool represents a potentially transformative advance. It empowers clinicians with a practical, evidence-based framework to stratify patients by risk, tailor therapy, and make time-sensitive decisions that could alter the course of the disease.