Research on Congenital Heart Defects: A Bibliometric Assessment of India’s Publications during 2000-19

Copyright © 2020 Phcog.Net. This is an openaccess article distributed under the terms of the Creative Commons Attribution 4.0 International license. Cite this article : Gupta BM, Ahmed KKM. Research on Congenital Heart Defects: A Bibliometric Assessment of India’s Publications during 2000-19. Int J Med Public Health. 2020;10(4):217-25. ABSTRACT The paper presents a quantitative and qualitative dimensions of congenital heart defect (CHD) research output in India, based on publications data (1335) indexed in Scopus database during 2000-19. CHD research registered 10.0% growth, averaged 7.07 citations per paper, contributed 3.04% share to the global output and constitute 13.48% share of India’s research as international collaborative. CHD research is skewed as top 10 countries account for 83.23% of global output. India ranks as the 10th most productive country in the world. The distribution of CHD research by type of research reveal that Tetralogy of Fallout accounted for the highest share (34.31% share), followed by Aortic Stenosis (30.41%), Atrial Septal Defects (28.16%), Ventricular Septal Defects (26.22%), etc. AIIMS New Delhi, Amrita Institute of Medical Sciences, Coimbatore and PGIMER Chandigarh lead the country as the most productive organizations (with 222, 73 and 64 papers). Besides, Amrita Institute of Medical Sciences, Coimbatore (33.88 and 4.79), SCTIMST Trivandrum (30.73 and 4.35) and Institute of Medical Sciences, BHU, Varanasi (17.20 and 2.43) lead the country as the most impactful organizations in terms of citation per paper and relative citation index. B. Airan, A. Saxena and S. Talwar have been the most productive authors (with 63, 63 and 59 papers) and P. Khairy (16.31 and 2.31), B. Vaidyanathan (14.3 and 2.03) and R.K. Kumar (10.53 and 1.49) have been the most impactful authors. Indian Heart Journal, Annals of Pediatric Cardiology (84 papers) and Annals of Cardiac Anaesian (53 papers) topped the list of most productive journals (with 110, 84 and 53 papers). International Journal of Cardiology (18.62), Catheterization and Cardiovascular Interventions (16.64) and Journal of Cardiothoracic and Vascular Anesthesia (11.65) leads in ranking in terms of citation per paper.


INTRODUCTION
Congenital heart disease (or defecs) (CHD) is defined as a gross structural abnormality of the heart or intrathoracic great vessels that causes significant functional impairment. 1 It simply means that it is a type of birth defect which can involve the walls of the heart, the valves of the heart and the arteries and veins (the large blood vessels) that lead to and from the heart. 2 The etiology of congenital heart diseases is still elusive. The developmental process of the heart is a tightly regulated process that requires intricate interplay between cardiac transcription factors, several cardiac-specific genes and signaling pathways, which are responsible for early cardiac morphogenesis. Both genetic and environmental factors play essential roles during cardiac development. Gene mutations and some teratogens can interfere with normal development (embryogenesis) of the heart leading to congenital heart defects. 3 Studies have also implicated non-hereditary risk factors such as rubella infection, teratogens, maternal age, diabetes mellitus, abnormal hemodynamics use of certain medications or drugs such as alcohol or tobacco, parents being closely related or poor nutritional status or obesity in the mother, besides having a parent with a congenital heart defect is also a risk factor in causing CHDs. 3,4 The most common CHD including left-to-right shunts (atrial septal defect, ventricular septal defect, atrioventricular septal defect, patent ductus arteriosus and others), obstructive lesions (pulmonary stenosis, aortic stenosis and coarctation of aorta) and cyanotic CHD (tetralogy of Fallot, transposition of great arteries, univentricular hearts, total anomalous pulmonary venous connection, Ebstein's anomaly and others). 5 Congenital heart defects are classified clinically, as cyanotic and acyanotic. Bluish discoloration of mucous membrane clinically characterizes cyanotic heart defects due to an increased level of deoxygenated hemoglobin. Therefore, cyanotic congenital heart defects are regarded as the most severe forms of CHDs. 3 Clinical presentations and severity of CHDs depend on their types or sub-types. However, most children with CHDs present with failure to thrive, cough, repeated chest infections, difficulty in breathing, exercise intolerance and bluish discoloration of mucous membranes (cyanosis). Congenital heart defects are associated with serious complications such as cognitive impairment and often affect families and individuals both emotionally and financially. 3,4 Diagnostic and treatment capabilities for congenital heart disease have dramatically improved over the past. Many studies show substantial improvement in survival in developed regions of the world, but the same success rates are not yet seen in developing regions. Despite some improvements in the past two decades, neonates in low-income and middle-income countries (LMICs) with severe forms of congenital heart disease and without access to surgical treatment are more likely to die before their fifth birthday than are those in high income countries. Additional premature mortality might occur secondary to cardiac and pulmonary complications. The congenital heart defects (CHDs) are the most frequent congenital anomalies and affect a large number of newborns accounting for a high proportion of infant mortality worldwide. There are regional differences in the prevalence and distribution pattern of CHDs. Globally, twentyeight percentage of all major congenital anomalies consist of heart defects and along with neural tube defects they account for two-thirds of all congenital malformations. 1 The birth prevalence of CHD is reported to be 8-12/1000 live births. Considering a rate of 9/1000, about 1.35 million babies are born with CHD each year globally. 6 Considering a birth prevalence as 9/1000, the estimated number of children born with CHD every year in India approximates 240,000, posing a tremendous challenge for the families, society and health care system. About one-fifth of these suffer from critical heart disease requiring early intervention. The currently available care for these children is grossly inadequate. There are over 60 centers that cater to children with congenital heart disease; majority are in southern states of India. Most of babies born with congenital heart disease in most populous states of India, such as Uttar Pradesh and Bihar, do not receive the care they deserve. Improving care of children with congenital heart disease is an uphill task, but needs to be addressed. 6 A number of guidelines are available for the management of congenital heart diseases (CHD) from infancy to adult life. However, these guidelines are for patients living in high-income countries. Separate guidelines, applicable to Indian children, are required when recommending an intervention for CHD, as often these patients present late in the course of the disease and may have coexisting morbidities and malnutrition. Guidelines emerged following expert deliberations at the National Consensus Meeting on Management of Congenital Heart Diseases in India, held on August 10 and 11, 2018, at the All India Institute of Medical Sciences. These evidence-based guidelines aims at (i) indications and optimal timing of intervention in common CHD; (ii) follow-up protocols for patients who have undergone cardiac surgery/catheter interventions for CHD; and (iii) indications for use of pacemakers in children. Evidence-based recommendations are provided for indications and timing of intervention in common CHD. In addition, protocols for follow-up of postsurgical patients are also described, disease wise. Guidelines are also given on indications for implantation of permanent pacemakers in children. 5

Literature Review
Bibliometric/scientometric studies related to analysis of "Contenital Heart Disease/defects" covering publications and patents, are only few. Amongst the existing studies, Farhat,, Abdul-Sater, Obeid, Arabi Diab, Masri, Al Hales, Nemer and Bitar 7 made a bibliometric assessment and compared the contribution of the Arab countries (530 articles) with that of the United States (12936 articles) and Europe (12260 articles), in contenital heart disease using MEDLINE, PubMed and Scopus databases. Basic research relating to genetics and animal models of CHD is emerging sparsely in the Arab world, with few articles published in high-impact-factor journals. The Arab world research output in the field of CHD per capita is substantially low, estimated to be 29 times less than in developed countries. Despite the minimal increase in published research articles, most of the research relating to CHD continues to be far from innovative. Regional collaborations with international linkage are starting to evolve. The research facilities in the Arab countries need to increase substantially in research and infrastructure funding to keep up with the pace of research in developing countries. Hsieh, Chiu, Lee et al. 8 made a bibliometric analysis of Patent Ductus Arteriosus (PDA) treatment research, including intravenous injection of indomethacin and surgery using Science Citation Index (SCI) during 1991-2002. The publication pattern concerning authorship, collaboration, original countries, citation frequency, document type, language of publication, distribution of journals, page count and the most frequently cited papers were performed. The results indicated that either treatment was not the recent emphasis of PDA research. van Doren, Brida, Gatzoulis et al. 9 examine quantum and factors associated with female representation in 35118 global CHD publications during 2006-15. It observed that 25.0% of all authors were female and women constituted for 30.2% and 20.8% of all first and senior authorship positions with great geographic heterogeneity. Significant predictors of female first authorship on logistic regression analysis were country gross domestic product, human development index, gender inequality index and a female senior author (p<0.0001 for all). Conclusions While modest improvement in female authorship over time was noted, women remain underrepresented in contemporary academic CHD In view of non-availablity of any bibliometric study on congenital heart defects publications at national level and India being contributing to largest share of newborns and infants in global mortality, we decided to carry out the present study. The study aims to examine the qualitative and qualitative aspects of India's overall research output in the area of congenital heart defects as indexed in Scopus database during 2000-19.
In particular, the study focuses and analyses: global research output in terms of publications growth and global share of top 10 most productive countries, congenital heart defects (CHD) research in India in terms of publications growth, its distribution by document and source types, broad subject areas and type of congenital heart defects, CHD research in India in terms of citation impact and describe bibliographic features of highly-cited papers and top 20 most productive organizations and authors and top 20 journals for research communications.

MATERIALS AND METHODS
In order to undertake a study of India's contribution in the congenital heart defects research, data on publications was sourced from the Scopus database (http://www.scopus.com) covering 20-year period 2000-19. A set of keywords such as "congenital heart anomaly" or "congenital heart defect" or "congenital heart disease" or "congenital heart malformation" or "hypoplastic heart syndrome" or "Obstructive heart defects" or "Septal heart defects" or "Cyanotic heart defects" were used in "Keyword tag" as well as in "Article Title tag" (joined by Bolean operator "OR") simultaneously and restricted the output to period "2000-19" to get global publication data (consisting of 43888 records). The above described search strategy was refined by country of publication (including India) to get publication output data on top 10 countries. India's publication output comprised of 1335 records. The search strategy for obtaining India's output was further refined to get statistics on India's output by subject, collaborating country, organization, author and journal. Citations to publications were counted from date of their publication till 9 May 2020. Separate search strategies were formulated to get data on various types of congenital heart defects. A complete counting method, wherein every contributing author or organization covered in multiple authorship papers was fully counted and used. (KEY("congenital heart anomaly" or "congenital heart defect" or "congenital heart disease" or "congenital heart malformation" or "hypoplastic heart syndrome" or "Obstructive heart defects" or "Septal heart defects" or "Cyanotic heart defects") OR TITLE ("congenital heart anomaly" or "congenital heart defect" or "congenital heart disease" or "congenital heart malformation" or "hypoplastic heart syndrome" or "Obstructive heart defects" or "Septal heart defects" or "Cyanotic heart defects")) AND PUBYEAR > 1999 AND PUBYEAR < 2020 AND (LIMIT-TO ( AFFILCOUNTRY, "India"))

Publication Growth
The global and Indian research output in field of "Congenital Heart Defects" (CHD) in 20 years was 43888 and 1335 publications during 2000-19, an average of 2194.4 and 66.75 publications per year. India registered 10.0% growth compared to 6.64% by the world. India's absolute growth between 2000-09 and 2010-19 was 147.66% compared to 79.40% by the world. India contributed 3.04% share to global output in 20 years; its 10-year global publications share surged from 2.44% (2000-09) to 3.37% (2010-19). In the field of CHD research, India's citation impact on a 20-year window averaged to 7.07 citations per paper (CPP) and its 10-year citation impact dropped from 9.17 CPP to 6.22 CPP during 2000-09 to 2010-19. Only 55 out 1335 India's publications are observed to be funded by national and international funding agencies. These 55 funded papers received 3680 citations, averaging 66.91 citations per paper (Table 1). Of the total publications, 75.13% appeared as articles, 9.44% as reviews, 6.74% as letters, 3.52% as notes, 2.47% as conference papers, 0.67% as short surveys and 1.87% as editorials and 0.67% as book chapters. Bulk of the global research output (83.23%) in the field was contributed by top 10 most productive countries alone, which increased from 78.10% to 86.08% during 2000-09 to 2010-19. USA is in the leadership position in the world ranking, accounting for 35.78% global publications share and other 9 countries has been in single digit ranging between 3.04% and 8.43%. India ranked at 10 th position, with global share of 3.04%. The global publication share increased in China, USA, India, Canada and Netherlands (from 0.48% to 5.52%), as against decrease in Italy, France,

India's International Collaboration
The share of international collaborative papers (180) (Table 3).

Subject-Wise Distribution of India's Research Output
Medicine research in India intersected with 3 disciplines (as identified in Scopus database classification). Of these, medicine has been the most favored subject areas in CHD research pursuits (with 92.88% publications share), followed by biochemistry, genetics and molecular biology (7.79%) and pharmacology, toxicology and pharmaceutics (2.47%). Research activity index in all subjects of increased in biochemistry, genetics and molecular biology (from 27.47 to 129.58) and pharmacology, toxicology and pharmaceutics (from 42.14 to 123.36), as against decrease in medicine (from 105.14 to 97.93) between 2000-09 and 2010-19. Medicine recorded the highest citation impact per paper of 9.09 and pharmacology, toxicology and pharmaceutics the least (7.55) during 2000-19 (Table 4).

Distribution of Publications by Type Heart Defects
In all, CHD are classified under two types: Hydroplasia and Obstructive defects. The obstructive defects are further classified as ventrivular outflow tract obstruction, septual defects and cyanotic defects. The above two type of defects are further classified under 15 subcategories as shown in Table 5

Institutional Collaboration among Top 15 Most Productive Organizations
Amongst top 15 most productive organizations, PGIMER-Chandigarh leads in collaboration linkages (38), followed by AIIMS -New Delhi (33 linkges), AIMS -Coimbatore and SCTIMST-Trivandrum (23 linkages each), etc. The collaboration between KEMH -Pune and SGSMC -Mumbai was the strongest with 10 linkages, followed by PGIMER-Chandigarh and SPGIMER-Lucknow (6 linkages), AIMS -Coimbatore and SCTIMST -Trivandrum (6 linkages), etc. (Table 7).           Table 9).  Conclude that pediatric cardiac care in India is still in its infancy. We have no data on congenital heart disease (CHD) prevalence at birth or on proportional mortality from CHD. The resources are not only limited but also are at times improperly utilized. There are very few specialized pediatric cardiology training programs, those that are, are concentrated in certain regions of India and are often imparted through combined adult and pediatric programs. The existing number of trained personnel for pediatric cardiology and pediatric cardiac surgery is inadequate. Above all there is no national policy for pediatric heart care. Increasing awareness of the problem amongst the pediatricians through CMEs, seminars, symposia is likely to be most helpful in early diagnosis and timely referral of cases. Training programs exclusively dedicated to pediatric cardiology and pediatric cardiac surgery need to be established in centres with good standards of pediatric cardiac care. 6