Introduction: Pulmonary Arterial Hypertension (PAH) is a chronic multifactorial hemodynamic disorder that imposes a serious impact on the patient and his environment as well as the national health system. In Colombia, specific drug therapy (oral, inhaled or parenteral) offers 14 specific PAH drugs which represent 84 possible drug combinations for three therapeutic pathways (i.e., endothelin, nitric oxide and prostacyclin). There is currently a multidisciplinary and multicenter initiative that consolidates the information of patients with hemodynamically confirmed diagnosis of PH (with emphasis on Groups 1 and 4) called the Colombian Network of Pulmonary Hypertension (HAPred.co) which allowed the analysis of the response to specific treatments in 503 patients in our country.
Aim: To evaluate the potential changes of pulmonary artery pressure and other hemodynamic or functional changes related to chronic treatment with specific drugs for PAH in incident patients of the disease (groups 1 and 4) in the Colombia.
Materials and Methods: The onset of treatment and its duration were analyzed as independent variables, and while pulmonary artery pressures (systolic, diastolic and mean PAP) were included as dependent variables. Models of linear and non-linear correlation were analyzed regarding the change both in terms of absolute values and in percentage of change (post-pre / pre,%) between the invasive hemodynamic study (diagnosis-referent) and the last available catheterization in the tracking (final).
Results: The analysis was performed in 503 adult patients (50±17 years, 74% women), with diagnosis of PH group 1 or 4. The relative change with treatment showed a wide range: PAPs decreased -9±26%, PAPd=-18±42% and PAPm=-5±31%. This dispersion was justified by the existence of three groups of patients: some without change in pulmonary pressures (ie, non-responders), others with worsening of pressure (also non-responders), and others (50% of the total) showing an improvement (decrease of 10% or more of the initial value) of the mPAP (figures 1, 2 and 3). A linear function of correlation with the treatment time was not evident (p=ns, r2≤0,1). Adjustment according to age showed no correlation with improvements. Conclusions: In patients with PAH in the Colombian Andean region, the response to specific approved drugs is not homogeneous in magnitude or sense in all patients. Responder patients (approximately 50%) and other non-responders are identified in terms of pulmonary artery pressure regardless of the time receiving treatments. This evidence highlights the need to objectively (invasively) evaluate pulmonary hemodynamics to identify patients who will require staging strategies or treatment combinations, including lung transplantation.
Supported, in part, by Grant BAYER HAPred.co 2019.