COVID-19's impact on heart and lung transplantation: Citation-based analysis of research output.

Background: Since being declared as a pandemic on March 11, 2020, coronavirus disease 2019 (COVID-19) has profoundly influenced heart and lung transplant programs, impacting donor availability, patient management, and healthcare resources. This study offers a citation-based review of the research output on this subject, seeking to understand how the transplant community has responded to these challenges. Through a review of literature from the beginning of the pandemic to early 2023, we evaluate the shifts in academic emphasis and the emerging trends in heart and lung transplantation during the COVID-19 period.

Aim: To assess the impact of COVID-19 on heart and lung transplantation research, highlighting key themes, contributions, and trends in the literature during the pandemic.

Methods: We conducted an extensive search of the Web of Science database on February 9, 2023. We employed the terms "transplant" and "transplantation", as well as organ-specific terms like "heart", "cardiac", and "lung", combined with COVID-19-related terms such as "COVID-19", "coronavirus", and "SARS-CoV-2". The search encompassed publications from March 11, 2020 to February 9, 2023. Data on authors, journals, countries, institutions, and publication types (articles, reviews, conference papers, letters, notes, editorials, brief surveys, book chapters, and errata) were analyzed. The data was visualized and processed with VOSviewer 1.6.18 and Excel.

Results: We included 847 research items. There were 392 articles (46.3%) and 88 reviews (10.3%). The studies included were referenced 7757 times, with an average of 9.17 citations per article. The majority of the publications (n = 317) were conducted by institutes from the United States with highest citations (n = 4948) on this subject, followed by Germany, Italy, and France. The majority of papers (n = 101) were published in the Journal of Heart and Lung Transplantation.

Conclusion: To the fullest extent of our knowledge, this is the first bibliometric study of COVID-19's impact on heart and lung transplantation to offer a visual analysis of the literature in order to predict future frontiers and provide an overview of current research hotspots.