The Long-term Response to Treatment with Calcium Channel Blockers in Patients with Idiopathic Pulmonary Arterial Hypertension

Background: Long-term outcomes in patients with idiopathic pulmonary arterial hypertension (IPAH) treated with calcium channel blockers (CCBs) are not well documented. Therefore, this study aimed to determine the long-term response to treatment with CCBs in patients with IPAH. Methods: This retrospective cohort study was performed on 81 patients with IPAH admitted to our center. Vasoreactivity testing with adenosine was performed in all patients. Twenty-five patients showed a positive response to vasoreactivity testing and were included in the analysis. Results: Of 24 patients, 20 (83.3%) were female, and the mean age of the patients was 45.90±10.42 years. Fifteen patients improved after 1 year on CCB therapy (the long-term CCB responders group), and 9 showed no improvement (the CCB failure group). The CCB responders group had a greater proportion of patients in New York Heart Association (NYHA) functional class I or II (93.3%), a longer distance walked, and less severe hemodynamic parameters. At the 1-year evaluation, the long-term CCB responders had more improvements in the mean 6-minute walk test result (437.43±125.32 vs 268.17±130.06; P=0.040), the mixed venous oxygen saturation level (71.84±9.87 vs 59.03±9.95; P=0.041), and the cardiac index (4.76±1.12 vs 3.15±0.90; P=0.012). Additionally, mPAP was lower in the long-term CCB responders group (47.35±12.70 vs 67.23±14.08; P=0.034). Finally, all the CCB responders were in NYHA functional class I or II (P=0.001). Conclusion: Our study illustrated that long-term treatment with oral CCBs was effective in 60% of acute responders and 18.5% of the entire study population.