Invited Editorial The Relative Citation Ratio: Measuring Impact of Publications From an International Conference With a New NIH Metric The objective of this editorial is to quantify the impact of publications that resulted from the Inter- national Conference on Pediatric Mechanical Cir- culatory Support Systems and Cardiopulmonary Perfusion using The Relative Citation Ratio, a new metric developed by National Institutes of Health (NIH) colleagues from the Office of Portfolio Analysis (1). Since the First International Conference on Pedi- atric Mechanical Circulatory Support Systems and Cardiopulmonary Perfusion was held at the Hotel Hershey, Hershey, PA, USA in 2005, over 460 peer- reviewed publications have been generated from this unique event in the past 13 years. A vast majority of these peer-reviewed publications were printed in Artificial Organs (over 216 publications since 2009) and ASAIO Journal (211 publications between 2005 and 2009). In addition, 13 peer-reviewed articles were published in the World Journal for Pediatric and Congenital Heart Surgery in 2012, and over 20 articles were printed several other multidisciplinary journals, including the Journal of Thoracic and Car- diovascular Surgery, Pediatric Research, Perfusion, Microfluidics and Nanofluidics, and Lab on a Chip. During the past 12 years (excluding welcome letters, editorials, and manuscripts generated from the 13th event, currently pending for April 2018 issue of Arti- ficial Organs), an average of 34 peer-reviewed articles were published annually. Dr. Michael Lauer, NIH’s Deputy Director for Extramural Research stated, “The goal of the Rela- tive Citation Ratio is to quantify the impact and influence of a research article both within the context of its research field and benchmarked against publications resulting from NIH R01 awards” (https://nexus.od.nih.gov/all/2016/09/08/nih- rcr/). To calculate the RCR, NIH colleagues have developed a novel public database (https://icite.od. nih.gov), using PubMed and Scientific Publication Information Retrieval & Evaluation System (SPIRES). NIH-funded articles (over 1.4 million using the SPIRES between 1995 and 2014) and non- NIH funded articles (11 922 575 articles) from the PubMed database in the same time duration are the benchmark for RCR. NIH scientists suggested that any paper with an RCR score of 1.0 has an RCR higher than 50% of all NIH-funded papers (https:// icite.od.nih.gov). All of the details regarding the cal- culations of RCR can be found in the PLoS Biology article (1). The iCite database is updated monthly. Currently, the iCite database contains 16 434 305 articles pub- lished between 1995 and 2017 (last update on Aug. 29, 2017). The Relative Citation Ratios are available for articles published between 1995 and 2016 (Fig. 1). Based on RCR and percentiles for NIH-funded publi- cations, two additional tables, one solely for NIH- funded publications and the second for all publica- tions in the PubMed database, were also generated. Our goal was to calculate the impact of articles pub- lished from our international conference during the past 12 years and compare the RCR of these publica- tions with other publications in this underserved field. We used the following step-by-step approach to calculate the RCRs and NIH percentiles for con- ference publications: Step 1: Identify PMID numbers for all past publications resulted from our event using PubMed database and International Society for Pediatric Mechanical Cardiopulmonary Support website (https://www.ispmcs.org) Presented in part at the 13th International Conference on Pediatric Mechanical Circulatory Support Systems and Pediatric Cardiopulmonary Perfusion held September 28–30, 2017 in Rome, Italy. doi:10.1111/aor.13079 Artificial Organs 2017, 41(12):1085–1091 Copyright V C 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.