Continuity of Nursing Care in Patients with Coronary Artery Disease: A Systematic Review

Coronary artery disease is the leading cause of death worldwide and patient continuity of care is essential. Health professionals can help in the transition stage by providing resources to achieve pharmacological treatment adherence, as well as social and emotional support. The objective was to analyse the effects of nursing interventions based on continuity of care in patients with coronary artery disease after hospital discharge. A systematic review of randomised controlled trials and quasi-experimental studies was carried out. Cochrane, CINAHL, Health & medical collection, Medline, and Scopus databases were consulted in January 2022. PRISMA guidelines were followed with no time limits. In total, 16 articles were included with a total of 2950 patients. Nurse-led continuity of care programs improved the monitoring and control of the disease. Positive effects were found in the quality of life of patients, and in mental health, self-efficacy, and self-care capacity dimensions. Clinical parameters such as blood pressure and lipid levels decreased. The continuity of care provided by nurses had a positive influence on the quality of life of patients with coronary artery disease. Nurse-led care focused on the needs and resources, including continuity of care, plays a key role.


Introduction
Coronary artery disease is the leading cause of death worldwide, being responsible for 27% of all deaths in Europe [1]. The main treatment objective is focused on related cardiovascular risk factors, such as high blood pressure, smoking, diabetes mellitus, or dyslipidemia [2]. In recent years, thanks to new methods of treatment such as surgical or percutaneous revascularisation, together with pharmacological treatment, the incidence of complications and mortality have been reduced [3]. However, although patients can experience a positive recovery after surgery, discharge can be challenging [4]. Patients should be prepared to cope with the recovery and follow-up, and their quality of life can decline, not only in terms of physical health but also in mental health, raising anxietydepressive states by up to 25% [5][6][7].
Hospital discharge is a critical time as patients require a lifestyle adjustment, incorporating new medications, social and emotional support [8]. These patients are particularly

Design and Search Methods
The expected outcome of this review was to analyse lifestyle changes and improvement in clinical parameters after nursing interventions based on continuity of care in patients with coronary artery disease. A systematic review of the literature was carried out following the PRISMA recommendations (Preferred Reporting Items for Systematic Reviews and Metaanalyses)(See Supplementary Material S1) [25]. The study was registered in the PROSPERO database (International Prospective Register of Systematic Reviews), ID 306445.
We searched the Cochrane Library, CINAHL (EBSCO), Health & medical collection (ProQuest, Ann Arbor, MI, USA), Medline (PubMed, Bethesda, MD, USA), and Scopus (Elsevier, Amsterdam, The Netherlands) up to January 2022. Using the MeSH terms, the search strategy was "(myocardial infarction OR angina OR coronary artery disease) AND continuity of patient care AND patient discharge AND nursing care".
The PICO (population, intervention, comparison, outcomes) strategy was used. The population was patients with coronary artery disease (angina or myocardial infarction); the intervention, the different educational programs of continuity of care led by nurses; a comparison of traditional programs or other types of interventions was conducted; and the outcomes, the improvement of the clinical parameters and the quality of life of the patients.

Selection Criteria
The inclusion criteria were: (1) randomised controlled trials or quasi-experimental studies, (2) English or Spanish language, (3) no restriction on year of publication, (4) hospital and community setting, (5) coronary artery disease (angina or myocardial infarction), and (6) nurse-led continuity of care programs after hospital discharge. Continuity of care interventions included were defined as those provided by nurses, including management, informational or relational counselling and focused on coordination and the relationship between nurses and patients across time and settings [26].
The exclusion criteria were: (1) qualitative studies, (2) studies with mixed samples of patients with other pathologies (without any data for coronary artery disease), (3) studies that analysed non-coronary circulatory problems, and (4) studies not related to continuity of care.
In the article selection process, first, two of the authors (G.P.-S. and N.S.-M) independently reviewed the titles and abstracts of the articles found. Then, the full text was read. A third author (J.L.G.-U) was consulted in case of disagreement (see Figure 1). pital and community setting, (5) coronary artery disease (angina or myocardial and (6) nurse-led continuity of care programs after hospital discharge. Continu interventions included were defined as those provided by nurses, including ma informational or relational counselling and focused on coordination and the re between nurses and patients across time and settings [26].
The exclusion criteria were: (1) qualitative studies, (2) studies with mixed patients with other pathologies (without any data for coronary artery disease), that analysed non-coronary circulatory problems, and (4) studies not related to of care.
In the article selection process, first, two of the authors (G.P.-S. and N.S pendently reviewed the titles and abstracts of the articles found. Then, the fu read. A third author (J.L.G.-U) was consulted in case of disagreement (see Figu

Quality Appraisal and Risk of Bias
The quality of the included studies was evaluated following the levels o and grades of recommendation stipulated by the OCEBM (Centre for Evide Medicine) [27] (see Table 1). Risk of bias was assessed using the Cochrane Co Risk of Bias tool [28].

Quality Appraisal and Risk of Bias
The quality of the included studies was evaluated following the levels of evidence and grades of recommendation stipulated by the OCEBM (Centre for Evidence-Based Medicine) [27] (see Table 1). Risk of bias was assessed using the Cochrane Collaboration Risk of Bias tool [28].
The risk of bias and the quality of each study was assessed by the authors who compiled the characteristic data in a table and were subsequently verified by two other authors (J L.R.-B and L.A.-G).       Motivational telephone consultation to support adherence to medical therapy, follow-up activities, emotional well-being, and healthy lifestyle (1 month)

Data Abstraction and Synthesis
Two authors (N.S.-M and M.J.M.-J.) used a coding sheet to extract the data from each selected study (see Table 1). A third author verified the data in case of disagreement (J.L.G.-U).
The following variables were obtained from each of the articles: (1) author, year of publication, and country of study; (2) type of study; (3) sample; (4) objective; (5) type of intervention; (6) measuring instrument; and (7) main results. Among the most relevant "interventions" described in Table 1, we have the following: individual or group health education through interviews, regular meetings, telephone follow-up and home visits.

Results
The database search comprised a total of 520 articles. A total of 16 articles met the inclusion criteria. The first article was published in 2006 and the last in 2019. The search and selection process is described in Figure 1.

Risk of Bias Assessment
The risk of bias for each study was assessed for all domains, as described in the Cochrane Handbook [28]. No article was excluded, all studies reached a quality level and low risk of bias according to assessment tools (see Figure 2). thors (J L.R.-B and L.A.-G).

Data Abstraction and Synthesis
Two authors (N.S.-M and M.J.M.-J.) used a coding sheet to extract the data from each selected study (see Table 1). A third author verified the data in case of disagreement (J.L.G.-U).
The following variables were obtained from each of the articles: (1) author, year of publication, and country of study; (2) type of study; (3) sample; (4) objective; (5) type of intervention; (6) measuring instrument; and (7) main results. Among the most relevant "interventions" described in Table 1, we have the following: individual or group health education through interviews, regular meetings, telephone follow-up and home visits.

Results
The database search comprised a total of 520 articles. A total of 16 articles met the inclusion criteria. The first article was published in 2006 and the last in 2019. The search and selection process is described in Figure 1.

Risk of Bias Assessment
The risk of bias for each study was assessed for all domains, as described in the Cochrane Handbook [28]. No article was excluded, all studies reached a quality level and low risk of bias according to assessment tools (see Figure 2).

Effects on Self-Care Capacity, Disease Knowledge, and Self-Efficacy
Several studies showed that an educational intervention, based on Orem's theory of self-care [30], with a follow-up telenursing program [29,44] or in time-structured home

Effects on Self-Care Capacity, Disease Knowledge, and Self-Efficacy
Several studies showed that an educational intervention, based on Orem's theory of self-care [30], with a follow-up telenursing program [29,44] or in time-structured home visits [32], improved self-care capacity in patients with coronary artery disease. In addition, after the intervention, improvements were found in the ability to perform basic activities of daily life, together with higher levels of motivation towards self-care [30,42].
Regarding knowledge about the disease, a significantly positive improvement was found in the intervention group 12 months after hospital discharge [39]. The dimension of understanding and personal control [30,33], attitudes and beliefs regarding the disease increased throughout the follow-up [39].
The continuity of care program led by nurses showed a greater self-efficacy in health promotion habits, greater satisfaction with treatment and nursing care, and better quality of life [30,32,36,42].

Effects on Change of Habits and Prevention of Risk Factors
Following the intervention, adherence to healthy lifestyles improved. Patients who received continuity of nursing care, through an educational-cognitive program with emotional support, evaluation, orientation, control and surveillance [30,31,33,36,40,42], or through tele-nursing follow-up [29], showed a positive effect in the adherence to pharmacological treatment [29,33,37,[40][41][42]. However, several authors showed that nursing interventions did not improve adherence to treatment [33,34] or do not provide information regarding this [40].
Regarding physical activity, benefits were also found in aftercare programs with an increase from 14% to 86% [40] of the subjects who conducted physical activity. In relation to the improvement of physical performance, no significant differences were found [36], although some authors found an improvement in muscle strength and functional status [42].
Additionally, significant improvements were found related to nutritional habits, with a decrease in the risk of malnutrition in patients after discharge [29,31,36,37,40]. In overweight or obese patients, the body mass index was significantly reduced [40,44]. Finally, tobacco consumption was also reduced by 47% [40].

Effects on Mental Health and Social Relationships
Following nurse-led continuity of care, a reduction in stress and anxiety was found [34,41]. It also improved psychological and spiritual well-being [30,33,35,36,38], as well as interpersonal relationships [31].

Effects on Clinical Parameters
Some studies showed that nursing case management improved different clinical parameters. Low-density lipoprotein and total cholesterol levels were reduced, and highdensity lipoprotein in the blood was increased [40,42,44]. Although, the number of patients who achieved the objective controlling their lipid levels in the blood over time (18 months) was low [35].
Regarding blood pressure (BP), a decrease in BP levels was found in subjects who received continuity of care [40,44], although other authors did not observe significant changes [42].

Effects on Hospital Readmission
Regarding the readmission rate, no significant differences in the continuity of care group were found [32,33,36,38,44]. Only one study found a lower proportion in the intervention group compared with the control group (8% vs. 16% p = 0.048) for patients readmitted [43].
Additionally, the patients in nurse-led intervention groups experienced an increase in cardiac stability [32] and required fewer medical controls [37], and had less contact with general practitioners between groups (29% vs. 42%, p = 0.020) [43].

Discussion
This systematic review aimed to analyse the effects of nursing interventions based on continuity of care in patients with coronary artery disease. After hospital discharge, providing education, support, and continuous home monitoring to patients with coronary artery disease is necessary [4,45]. Therefore, patient education is a fundamental component in the continuity of care, being a nursing role [14,46]. Continuity of care should be used as a way to enhance quality of life, maintain or improve functional capacity, and prevent relapses of the disease [47,48].
This review found that nurse-led interventions increased the self-care capacity of patients who participated in educational programs, as corroborated by other studies [49,50]. After hospital discharge, these patients usually showed psychological disorders, changes in family dynamics, and even professional problems; therefore, home monitoring and social support allow them to improve self-efficacy [51]. In addition, as other authors indicate, providing information on the management of cardiovascular symptoms, reporting complications associated with surgical intervention and wound care is essential [45,49,52,53].
Additionally, a greater capacity for self-care increases self-efficacy, which in turn improves the quality of life by reducing levels of anxiety and depression [51]. Therefore, various authors indicate that information and learning needs depend on sociodemographic characteristics [53]. This fact shows the need to create different personalised educational programs [52], according to the characteristics of each population, being accessible to all hospitals and primary care centres that care for patients with coronary artery disease [54,55].
This research found that educational programs based on continuity of nursing care allow patients to develop healthy lifestyles, decreasing cardiovascular risk factors. Improvements were shown in reducing smoking, greater adherence to a balanced diet and pharmacological treatment, and an increase in physical activity. These results are consistent with the findings of other authors, where after a 6-month follow-up, up to 80.2% of patients changed their lifestyles [49]. Other authors. after analysing the perception of patients and nurses during a nursing care continuity program, showed that the main concern for patients was the information received about drug treatment and complications after the intervention, while for nurses, physical activity after hospital discharge was the most necessary strategy for patients [56].
Regarding the improvement in blood lipid values after the intervention, the results showed an improvement [57]. Although other studies found no differences, this fact may be due to a lack of adherence to lipid-lowering drug treatments, as well as to the prescribed drug plan [58,59]. This is one of the main barriers that health professionals face, together with a lack of knowledge or a lack of a personalised follow-up [60,61]. Focusing efforts at the individual level improves adherence and therapeutic management. Community nurses perform a relevant task in this regard [62]. In the readmission rate of the patients, there were no important changes. As other authors found, a lack of instructions after hospital discharge is often not effective enough to reduce hospital readmissions [13,63]. Other studies indicate that thanks to the continuity of care, the possibility of hospital readmission was reduced from 30% [47] to 12.3% [49]. This gap in the results may be due to the fact that continuous contact with the nursing staff helps the early medical referral after the onset of cardiac symptoms [64,65].
This review suggests the importance of providing support and counselling for coronary artery disease patients through nurse-led education programs. The interpersonal nursepatient relationships allow the development of programs based on a patient's needs in order to achieve real progress and good well-being. Health care organisations should promote centres with professionals trained in different domains to improve patients' selfmanagement and follow-up in patients with coronary artery disease [66]. Further research is still needed to determine the optimal follow-up time and duration of intervention, as well as to develop innovative strategies to improve healthy habits and therapeutic management.

Limitations
This study had a number of limitations. First, although all studies used a nurseled continuity program as an intervention, the great variability in the duration of the intervention may influence the heterogeneity of the results. In addition, the duration of the intervention and the different times in which the different parameters are measured can influence the results. A meta-analysis was not carried out because there was great variability in the intervention programs and also the assessment instruments were not homogeneous. Furthermore, the follow-up of the effects maintained over time was not analysed. Therefore, it is necessary to conduct more randomised controlled trials with larger samples and to examine the effects maintained over time.
Our results do not include some of the benefits of nurse-led continuity of care. The reduction in the cost per hospital stay, mortality or the recurrence of coronary problems are very interesting issues that should be analysed in future lines of research. Likewise, it would be interesting to analyse how continuity of care is related to the biomarkers of patients with coronary artery disease.

Conclusions
Programs based on continuity of care led by nursing professionals showed positive effects for patients with coronary artery disease, improving monitoring, the control of the disease, and their quality of life. The continuous follow-up made it possible to establish lifestyle changes, reducing risk factors and improving mental health, self-efficacy, and self-care capacity. Clinical parameters such as blood pressure and lipid levels decreased.