Research on heart failure in Colombia 1980-2015 : a systematic review

Results: 2 684 articles were identified, of which 35 met the inclusion criteria. 30 (85.7%) were published since 2009, 30 (85.7%) were conducted in Bogotá and Medellín, 11 (31.4%) had n>200, 19 (54.2%) were descriptive and 5 (14.2%) quasi-experimental. Moreover, 9 (25.7%) described general populations, 9 (25.7%) addressed the issue of self-care, 3 (8.8%) cardiac rehabilitation, 3 (8.8%) perception of the disease and 3 (8.8%) prognostic factors.


Introduction
Recently, Colombia has presented demographic and epidemiological changes in the population that have determined certain variations in the health profile of its inhabitants.Between 1985 and 2003, a two-fold increase in the number of >60-year-old people and in life expectancy was observed.These changes resulted in a "transitional" epidemiological phase, which led chronic non-communicable diseases to become predominant.For this and other reasons, circulatory system diseases were the leading cause of death by "large groups" in the country between 1997 and 2010, with 28-30% of total deaths.(1) Of these, almost half originated from ischemic heart disease, which is also related to the high prevalence of cardiovascular risk factors such as hypertension, diabetes, smoking, sedentary lifestyle and overweight.(2) Ischemic heart disease, together with hypertensive heart disease, affects cardiac and vascular function, triggering the condition known as heart failure, a chronic disease that progressively deteriorates the health state of the person.Data obtained in the USA indicated that, between 2011 and 2014, the prevalence of heart failure in people aged ≥20 years was 2.5%, which is equivalent to 6.5 billion people affected.This figure is expected to increase by 46% between 2012 and 2030 (3), a situation that requires the use of a high amount of economic resources for the health system.(4) A study conducted in Colombia estimated that the average monthly cost of outpatient treatment in 2010 was COP 304 318 (about USD 160), while the average cost of hospitalization was COP 6 427 887 (about USD 3 387).(5) With this in mind, scientific knowledge on heart failure is fundamental to offer a comprehensive clinical approach and to generate innovation processes around the topic.(6) In Colombia, the current status of research and publication about heart failure is unknown, since knowledge may be limited and publications referring to the topics are scarce.(7) Two national consensuses on acute and chronic heart failure have few citations in the bibliographical references of Colombian works.(7,8) As a result, few published studies or publications may not be adequately known due to various circumstances.
For this reason, the objective of this work is to conduct a systematic review of the literature to identify the publications of studies conducted in our country that address the issue of heart failure, expose their methodological characteristics and the most relevant results, and analyze the data provided by the studies.

Materials and methods
A systematic review of the medical literature published in Colombia on heart failure between 1980 and 2015 was carried out.The following search mechanism was used to identify the articles: Search in domestic scientific journals: A search was made in Colombian health journals acknowledged by the Sistema Nacional de Indexación y Homologación de Revistas Especializadas de CT+I (National Indexing and Homologation System for Journals Specialized in STI) of Colciencias (National Bibliographic Index-Publindex I-2013 update) that deal with topics related to clinical medicine.(9) The search in this index was filtered using the socalled Great Knowledge Area: Medical and Health Sciences.With this information, a complete list of the journals used to search for the articles was obtained.In addition, the health journals of the universities that had medical faculties in 2014 were searched in their web pages.Journals where publication of original articles of heart failure was considered unlikely were excluded.
Journals were searched individually, in their respective website, identifying the issues published between January 1980 and December 2015.The table of contents of said issues was analyzed, and articles related to heart failure were verified.Inclusion and exclusion criteria were applied to the articles initially identified.
In case that the online version of the issues was not found in its entirety, a manual search was carried out in different libraries and national newspaper archives.
Digital search in databases: A digital search was carried out in the Embase, PubMed and Lilacs databases and in the Cochrane Library, using the search structure described in Annex 1. Manual search of bibliographic references: A manual search was made of the references of all the articles identified in the three previous searches, applying inclusion and exclusion criteria.

Review of CvLac resumes of the main authors:
A search of the resumes of the main authors of the identified articles was made on CvLac to verify the existence of additional articles.Inclusion and exclusion criteria of articles: Original research on patients >18 years of age, diagnosed with acute or chronic heart failure, outpatient or inpatient in Colombia, published in full text, with an observational intervention design or clinical simulation model were included.Case reports, subject reviews, management guidelines and articles published only in summary version were excluded from the analysis.
A data collection tool was designed to carry out the bibliographic documentation, which included the affiliation data of the journal, the type of article described along with the year, issue, number and title of the document.Information on the methodological characteristics of the study, the results and the conclusions of the selected articles was also obtained.The study was approved by the Human Research Ethics Committee of the Hospital of San José of Bogotá and the Fundación Universitaria de Ciencias de la Salud.

Search result
Search in domestic scientific journals: A search of journals was carried out on February 23, 2014 in the National Bibliographic Index-Publindex I-2013 update of the official web page of Colciencias.73 records were obtained (58 in clinical medicine, 25 in health sciences, 14 in other medical sciences and 3 in basic medicine).Of the total journals identified, 58 were selected to conduct the review.The journal identification process is described in Annex 1. Table 1 shows general information of these journals.
Of 58 journals, 26 were published in full text in an online version.For the remaining 32, it was necessary to complement the search in university and national libraries.It was also necessary to contact editors and administrative staff of some journals to obtain missing issues.
All the issues of 56 journals were reviewed in their entirety.After reviewing all the articles in these issues, 87 studies were found that dealth with heart failure as a central topic, of which 31 met inclusion criteria (Figure 1).Digital search in databases: This search allowed to identify 2 597 records, of which 16 met the inclusion criteria.Of these, 12 had already been identified in the manual search (Figure 1).Annex 2 describes the digital search strategy.No additional articles were found after searching references and CvLac resumes.

Analysis of identified studies
Of 35 studies published (5,, the largest number (25.7%) was found in the Revista Colombiana de Cardiología with 9, followed by Acta Médica Colombiana with 7 (20%) (Figure 2).The cities with the highest number of publications on heart failure were Bogotá and Medellín, with 15 studies each (42.8%) (Figure 3), and the largest number of publications (85.7%) was observed in 2009 (Figure 4).Regarding methodological aspects, 19 (54.2%) studies were descriptive and 5 (14.2%) quasi-experimental.In 13 (37.1%), the sample size was <50, 11 (31.4%) had >200 patients and 9 (25.7%)described general populations (Tables 2-4).On the other hand, 9 studies (25.7%) addressed self-care, 3 (8.8%)evaluated prognostic factors and aspects of cardiac rehabilitation, while 2 evaluated issues related to disease perception, nutritional aspects and therapeutic interventions.No studies related to prevention or treatment for stages I to III, according to the classification of the New York Heart Association (NYHA), were found (Tables 2-4).Table 2. Observational studies that described populations or established causal relationships with various endpoints in outpatient and inpatient settings.

General characteristics Main results
Arredondo-Holguín (37 One of the most relevant results was related to in-hospital mortality, with a rate of 3.8-28.6%(10)(11)(12)(13)16,17,19,32); one study reported a rate of 13.8% of mortality at one month of and 45.2% at one year.(12) Furthermore, three studies reported data on median hospital stay, which was between 6-10 days (13,17,19); other three studies reported hospital re-admissions rates of 24.5%, 40.8% and 84.3% at one year (13,21,19), and another reported 23.8% re-admission rates at two months.(32) Some studies evaluated specific comorbidities, documenting a high presence of abnormalities in nutritional parameters (10), cardio-renal anemia (15), kidney failure (22), affective disorders (23) and musculoskeletal pathologies.( 27) With reference to interventions, two studies showed the beneficial effects of cardiac rehabilitation plans on patients (30,31), while four others showed an improvement in adherence to management or selfcare by patients when performing interventions or educational plans led by nursing.(29,(33)(34)(35) An important percentage of works were developed by nursing professionals; 9 (25.7%)corresponded to self-care behavior interventions and adherence to medical treatment for heart failure in quasi-experimental studies in patients.

Discussion
The main motivation to carry out this research was the need to identify domestic studies on heart failure within the framework of the discussions generated based on academic work developed by our institution around this issue.Initial observations of references of domestic guidelines, texts or review articles showed few citations of original studies; therefore, establishing the actual amount of this type of publications and the topics treated was considered important.
The results of this research show that, in fact, there are few studies published based on the observation period, although the number of publications has increased recently.Likewise, almost all designs were observational and only one was a randomized clinical trial.It is important to highlight the lack of the latter design, which offers important results from the point of view of "evidence-based medicine" when evaluating medical interventions.
In Colombia, several investigations have been carried out with the objective of evaluating scientific production in the health area.Jaramillo-Salazar et al. (44) evaluated clinical research in the country based on the scientific production recorded in the Thomson-ISI database between 1975 and 2005, while Alvis-Guzmán & De la Hoz (45) analyzed the publications in Medline and LILACS databases in the period between 1993 and 2003.In both studies, there is a significant and progressive increase in the number of publications after the 1990s.
In this study, an increasing number of publications in the last five years was observed.It is important to note that, in the aforementioned research, the number of publications in basic sciences increased more than in clinical areas and, among them, tropical medicine, neurosciences and infectious diseases were the most common.(45) Therefore, the reduced amount of publications on heart failure in the 1990s is related to a lowest amount of publications in the area of clinical medicine in general.
Most of the works were published in Bogotá and Medellín.This is consistent with other reports in health sciences in general, although cities such as Cali provide a significant number of publications in other areas of biomedical research.(45)(46)(47) Among journals evaluated, the Revista Colombiana de Cardiología journal had the highest number of publications, followed by Acta Médica Colombiana, which is an expected result.However, a significant number of articles were found in journals edited by universities.At this point, it is worth noting that, several of these journals are indexed in Latin American databases such as LILACS or Redalyc, and even some in international databases, but not all of them are, which makes it difficult to access their articles.This was one of the reasons why the digital search did not identify the total number of articles published, leaving manual search as the only option to identify them.This reinforces the importance of quality improvement processes in the journals, highlighted by various editors, to allow them to access international databases and achieve better scientific positioning.(48)(49)(50)(51) Research carried out by nursing professionals deserves special attention, since they contributed a good number of publications focused on self-care and some used qualitative methodology.This allowed obtaining valuable results that must be taken into account when comprehensively approaching the patient.The investigated issues are, in addition to the ones mentioned above, general description studies in inpatient and outpatient populations with heart failure, including studies on prevalence of specific comorbidities such as malnutrition and kidney failure.Although they are few, they offer relevant data on intra-hospital mortality, prevalence of comorbidities and treatment of this disease.
When reviewing Latin American literature, reviews on heart failure that cite studies that address epidemiological, diagnostic and therapeutic aspects were found, especially in Brazil, Chile, Argentina and Mexico.(52)(53)(54) Argentina and Chile have national records (55,56) important to evaluate the behavior of the disease in the "real world".(57) Currently, Colombia does not have information on published records of heart failure.With some frequency, the country's institutions have been part of international studies that have evaluated multiple cardiovascular issues (58)(59)(60)(61)(62); however, specific data on the Colombian population are not always widely disseminated since there are no specific publications, which would represent a valuable contribution to the knowledge of our patients.The I PREFER record is one of the cases with this kind of publications.(33,63) It has been established that research should fulfill two important functions.On the one hand, it should make an academic impact, which implies that research should be made public and discussed by the academic community involved and that it should be published in scientific journals, a fundamental part of the process.(64) The objective is to transcend the context of undergraduate and postgraduate programs and conference summaries.In the same way, once published, it should be identified and read by the actors of the community in question.Improving the visibility of published articles and generating an academic discussion around them is a challenge for all people involved in research and teaching processes in health.In this regard, citing more frequently and using domestic investigations as part of discussions of research articles is one of the tasks that should be given more attention.(48) On the other hand, research should fulfill a social function that occurs when scientific knowledge achieves a benefit for society in general.Therefore, domestic scientific production should be considered when creating social impact policies in a given area.(6,65) In this regard, several studies have been conducted that raise the importance of using the results of research in decision making.
Mosquera et al. (66) established that the results of domestic studies did not guide public health decision-making in a departmental health ministry of Colombia and stated that one of the main barriers is the lack of policies and structure for the management of the investigative process.On the other hand, Gómez et al. (67) concluded that the potential influence of research on policy decisions depends on multiple factors, some of which may be "governable" by researchers, and stressed the importance of promoting greater contact with decision makers.
The Colombian population has different biological and social realities with respect to cardiovascular risk (68,69), as shown by studies carried out in Latin America; in consequence, it is essential to generate domestic knowledge.While it is true that participation in international research networks is important for strengthening the different scientific groups of the country, strengthening our own work agenda is no less important to enlighten and help provide solutions to our problems.(70,71) From the academy, validation and local legitimization mechanisms of knowledge application processes that serve to consolidate the scientific tradition of the nation should be sought, without giving so much priority to the "centers of knowledge" that are often seen as models for local scientific activities.(72,73) The idea that "the interpretation of our reality with alien schemes only contributes to making us increasingly unknown, increasingly less free and increasingly lonely" remains valid.(74) One of the limitations of this review is that it included articles published since 1980, which did not allow identifying articles published prior to this date.However, few Colombian journals began publishing earlier.The review was limited to published studies and did not include results of abstracts or thesis, considered as products of research processes.Abstracts were excluded taking into account that many times they do not provide the data necessary to carry out a complete analysis of the research, while theses were discarded mainly because a systematic way for searching was not identified and, at the moment of carrying out the research, not all universities had a standardized form of thesis file.This undoubtedly generates a potential publication bias, inherent to the research itself.The main strength of this study was that a manual review was carried out which allowed to identify articles that were not found with a digital search.

Conclusion
The amount of original investigations published on heart failure is scarce; most of them were conducted recently, almost all in domestic journals.Descriptive design was the most common form, and the most frequently addressed subjects were self-care and population descriptions.Source: Own elaboration based on the data obtained in the study.

Figure 2 .
Figure 2. Number of articles per journal.Source: Own elaboration based on the data obtained in the study.

Figure 3 .
Figure 3. Number of articles per city.Source: Own elaboration based on the data obtained in the study.

Figure 4 .
Figure 4. Number of articles per year of publication.Source: Own elaboration based on the data obtained in the study.

Table 1 .
Description of selected journals.

Table 3 .
Studies related to interventions or costs.

Table 4 .
Observational studies that assessed self-care or patient perception.
HF: Heart Failure; NYHA: New York Heart Association; FC: Functional Classification; EF: Ejection fraction; NT-ProBNP: N-terminal prohormone of brain natriuretic peptide; VO 2 : Volume of oxygen; MET: Metabolic equivalent of task; COP: Colombian pesos, HS: Hospital stay; RCT: Randomized clinical trial; NNT: Number needed to treat; AH: Arterial hypertension.Source: Own elaboration based on the data obtained in the study.

Table A1 .
Journals of the national bibliographic index-IBN Publindex I 2013 update included for review.
Source: Own elaboration based on the data obtained in the study.

Table A2 .
Journals identified when searching for medical faculties not included in the Publindex list.Source: Own elaboration based on the data obtained in the study.

Table A3 .
Excluded journals.Source: Own elaboration based on the data obtained in the study.