The Effects of Iron Replacement on Functional Capacity in Patients with Group 1 and Group 4 Pulmonary Hypertension

Abstract

Objective: Abnormal iron handling complicates pulmonary hypertension (PH), causes functional limitation and poor outcomes. Although preliminary results in group 1 PH patients support the use of iron replacement, whether this applies to other PH subgroups is not known.

Methods: A total of 58 patients with an established diagnosis of group 1 or 4 PH, who had a serum ferritin of <100 ng/mL or 100 to 300 ng/mL in combination with a transferrin saturation (TSAT) <20% and received 500 to 1000 mg of ferric carboxymaltose (FCM) were included in the study. The change in ferritin levels and TSAT were calculated at 12- and 24-weeks follow-up. A six-minute walk test (6MWT) is undertaken at the first, 12-week and 24-week follow-up visits.

Results: In group 1 PH patients, ferritin levels increased from 14 ng/mL-1 to 133 and 90 ng/mL-1 at 12- and 24-weeks, respectively ( P < .001 for both). In group 4 PH patients, ferritin levels increased from 22.1 ng/mL-1 to 145 and 88.9 ng/mL-1 at 12- and 24-weeks, respectively ( P < .001 for both). 6MWT distances were 356, 412, and 350 m in group 1 PH patients and 260, 315 and 290 m in group 4 PH patients. Although the difference between baseline and 12-week 6MWT was significant in both groups ( P < .001 for both), this difference was lost at 24-week.

Conclusion: Our study indicates that there is no difference in response to iron replacement in patients with group 1 and group 4 PH patients, in terms of treatment success and functional status.