A team of researchers sought to answer the question, “Does right ventricular adaptation predict therapeutic response over time in patients with pulmonary arterial hypertension (PAH)?”
They designed a study that discovered that right ventricle (RV)-pulmonary artery (PA) coupling could not discriminate irreversible RV failure upon presentation but tended to show improvement in diastolic function with diastolic elastance (Eed) during subsequent follow-ups. This was according to a study published in the Chest Journal.
They also discovered that early changes in the Eed and baseline right ventricular ejection fraction (RVEJ) were among the best predictors for treatment response.
Current studies show that most physicians assess risk based on a number of different parameters. Patients are then usually classified as “low risk,” “intermediate risk,” or “high risk.” The research team found this multiparametric risk system to be too blunt of a tool for a proper risk assessment to be made.
“However, this strategy is imperfect as most patients remain in intermediate or high risk after initial treatment with low risk being the goal,” they wrote. They proposed using metrics of right ventricular adaptation as a more refined metric to gauge disease patient risk.
The researchers hence recruited 52 incident treatment naïve patients. The patients had advanced PAH and were treated by catheterization and cardiac imaging longitudinally at baseline, and had 2 subsequent follow-ups: follow-up 1 (approximately 3 months) and follow-up 2 (approximately 18 months).
Read more about PAH etiology
All of the patients were put on goal-directed therapy with parenteral treprostinil and/or combination therapy. Treatment escalation was included if functional class I-II was not achieved. At follow-up 1, therapeutic responders were evaluated as nonresponders (died) or responders. At follow-up 2, therapeutic responders were evaluated either as super-responders (low risk) or partial-responders (high/intermediate risk).
“Multiparametric risk was calculated based on a simplified [European Respiratory Society/European Society of Cardiology (ERS/ESC)] guideline score. RV adaptation was evaluated with the single-beat coupling ratio (Ees/Ea) and diastolic function with [Eed],” the researchers wrote.
Nine patients were nonresponders. PAH-directed therapy improved ERS low risk from 1 at baseline to 23 (2% to 55%) at follow-up 2. Ees/Ea at presentation was nonsignificantly higher in responders versus nonresponders. However, Ees/Ea at presentation was unable to predict super-responder status at follow-up 2. Instead, the baseline RVEF and changes in Eed successfully predicted super-responder status at follow-up 2.
Vanderpool RR, Hunter KS, Insel M, et al. The right ventricular-pulmonary arterial coupling and diastolic function response to therapy in pulmonary arterial hypertension. Chest. 2021;S0012-3692(21):04086-1. doi:10.1016/j.chest.2021.09.040