A new study has found that despite a sustained response to calcium channel blockers (CCBs), patients with idiopathic pulmonary arterial hypertension (PAH) can lose their response and require further targeted therapies.
The study, published in the Journal Brasileiro de Pneumologia, highlights the need for continual, multidimensional re-evaluation in these patients even when they respond well to CCB treatment.
“In a prospective study published in 1992, Rich et al. showed for the first time that idiopathic PAH patients presenting with an acute response to vasodilators could benefit from treatment with CCBs,” the authors wrote. “The objective of the present study was to evaluate a sustained clinical response to CCBs in patients with idiopathic PAH.”
The research team assessed retrospective data on 26 patients with PAH and who were responders to acute vasodilator challenge at a single PAH referral center between January 2003 and December 2018. Baseline functional and hemodynamic parameters were collected and all patients underwent right heart catheterization and vasodilator challenge before starting therapy with CCBs.
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Four of the patients had a short-term response to CCBs and 22 met the criteria for at least a 1-year response to CCBs. However, only 11 maintained their stability for longer than 1 year without any additional PAH treatment, and they were considered true responders to CCB therapy.
Furthermore, after initial CCB treatment, 82% of those who lost their response to CCBs were considered not to have a low mortality risk, and targeted PAH therapies were initiated. Nearly half of those who did respond for 1 year worsened and required further targeted therapy after 4 years of follow-up.
The authors conclude that 1 year of response to CCBs might not predict long-term favorable outcomes in patients with PAH, and they recommend ongoing, multidimensional reassessment in these patients with the aim of providing targeted PAH therapies as soon as required.
Piloto B, Fernandes CJCS, Jardim C, et al. Loss of response to calcium channel blockers after long-term follow-up treatment in patients with idiopathic pulmonary arterial hypertension. J Bras Pneumol. Published online May 1, 2023. doi:10.36416/1806-3756/e20220337