Short-Term Impact of Iron Deficiency in Different Subsets of Patients with Precapillary Pulmonary Hypertension from an Eastern European Pulmonary Hypertension Referral Center

Abstract

Background

Over the last few decades, interest in the role of iron status in pulmonary hypertension (PH) has grown considerably due to its potential impact on symptoms, exercise capacity (as assessed by the 6-minute walk distance [6MWD]), prognosis, and mortality. The aim of the present study was to identify iron deficiency (ID) prevalence in specific precapillary PH subgroups of Romanian patients and its short-term impact on 6MWD.

Patients and Methods

Complete datasets from 25 precapillary PH adults were examined and included in the analysis. Data were collected at baseline and after continuous follow-up of an average of 13.5 months. Enrolled patients were assigned to group 1 (pulmonary arterial hypertension) or subgroup 4.1 (chronic thromboembolic pulmonary hypertension), and individualized targeted therapy was prescribed. General characteristics, World Health Organization functional class, 6MWD, pulse oximetry, laboratory parameters, and echocardiographic and hemodynamic parameters were recorded. Ferritin values and transferrin saturation were used to assess ID.

Results

At baseline, 16 out of 25 patients were iron deficient. The univariate linear regression analysis did not show a statistically significant impact of ID on 6MWD (p=0.428). In multivariate regression analysis, possible predictors of 6MWD, including ID, were not statistically significant at baseline or after an average of 13.5 months follow-up (p=0.438, 0.361, respectively) and ID indicates a negative impact on 6MWD independent of applied corrections.

Conclusion

The results of this study demonstrate that 1.4.1 subgroup PAH patients have an increased prevalence of ID compared with other etiologies. ID has a negative impact on the functional status (assessed by 6MWD), in specific groups and subgroups of patients with precapillary PH, albeit not independently nor significant to other known predictors such as age, gender, oxygen saturation, and hemoglobin value. These data can be integrated with global research and are consistent with phenotypes of patients diagnosed with PH of different etiologies.

Keywords:

• pulmonary arterial hypertension
• chronic thromboembolic pulmonary hypertension
• ferritin
• iron replenishment
• six-minute walk distance

Data Sharing Statement

All data accompanying the present study are available from the corresponding author upon reasonable request.

Acknowledgments

We thank all patients and collaborators who were involved in this study. Special thanks to Professor Irene Marthe Lang from Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Professor Adam Torbicki, and Professor Marcin Kurzyna from Department of Pulmonary Circulation, Thromboembolic Diseases and Cardiology, Centre of Postgraduate Medical Education, European Health Centre, Otwock, Poland for their invaluable encouragement, education and training of the PH team from Targu Mures, Romania, and their support of the first BPA’s in Romania.

Author Contributions

All authors made substantial contributions to the conception and design of the study, and participated in acquisition or analysis and interpretation of data, took part in drafting or critically revising the article to optimize it for important intellectual content, agreed to submit to the current journal, gave final approval for this version to be published, and agree to be accountable for all aspects of the work.

Disclosure

The authors declare that they have no conflicts of interest related to this study.

Additional information

Funding

This work was partially supported by the “George Emil Palade” University of Medicine, Pharmacy, Science and Technology of Targu Mures, Romania, Research Grant number 615/13/17.01.2019.