Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 18 1 2023 01 30 62 67 EN Azam Kiani Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Razieh Omidvar Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Nasim Naderi Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Sepideh Taghavi Heart Valve Disease Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Marzieh Mirtajaddini Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. 2022 11 13 2023 03 15 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. Twenty-five patients showed a positive response 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 the 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 showed 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 the 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. https://rhythm.tums.ac.ir/index.php/jthc/article/view/1756 https://rhythm.tums.ac.ir/index.php/jthc/article/download/1756/1053