Apparent Nonadherence to Risk-Guided Therapy in pulmonary hypertension: The Role of Clinical Complexity in Real-World Practice.

Introduction Current guidelines recommend risk-guided treatment escalation in pulmonary arterial hypertension (PAH) and selected chronic thromboembolic pulmonary hypertension (CTEPH). However, the extent to which these recommendations are implemented in routine practice and the reasons for non-adherence remain unclear. Methods We conducted a single-center, retrospective cohort study including consecutive patients with PAH (WHO group 1) and/or inoperable CTEPH (WHO group 4), including combined pulmonary hypertension, treated between September 2022 and September 2023. Risk stratification was performed using the three-strata model at baseline and the four-strata model at follow-up, in combination echocardiographic assessment. An indication for escalation of PH-specific therapy was defined as an intermediate-high or high risk score. Non-adherence was defined as absence of therapy escalation despite this increased risk score. Results A total of 119 patients were included, (median age 67 years IQR 54–75, 66% female; 80% PAH, 20% CTEPH). Combined PH was present in 43%. Non-adherence was identified in 32 patients (27%).. In nine patients, non-escalation was considered appropriate, owing to medication intolerance (n=5), patient preference (n=3), or ongoing dose titration (n=1). Potentially inappropriate non-escalation occurred in 12 patients and was mainly related to comorbidities affecting risk assessment (n=10) or undocumented physician decision-making (n=2). Non-adherence was more frequent among older patients and those with combined pulmonary hypertension. Conclusion Although risk scores often indicated treatment escalation, real-world decision-making was frequently guided by clinical complexity. In many cases, apparent non-adherence reflected appropriate individualized care, as comorbidities and limited guidance for CTEPH reduced the applicability of guideline-based strategies.