Effectiveness of Mindfulness Meditation Programs in the Promotion of Quality of Life in Patients with Heart Failure: A Systematic Review

Background: Despite optimal medical treatment , many heart failure (HF) patients continue to show a high prevalence of symptoms, which contributes to a high morbidity and poor health-related quality of life (HRQL). Mindfulness meditation may be effective in improving the quality of life in these patients. Objective: A systematic review was conducted to evaluate if mindfulness meditation programs are effective in promoting and improving the quality of life in patients with heart failure. Methods: The PubMed (MEDLINE), Cumulative Index of Nursing and Allied Health (CINAHL), LILACS, Cochrane Library, and Scopus databases were searched between October and November of 2019. Articles were selected if they evaluated mindfulness intervention, with an experimental or quasi-experimental design, in adults with heart failure and measured health-related quality of life. Results: This systematic review identified 108 studies through database searches. After applying the inclusion and exclusion criteria, a total of three studies were considered qualified. These studies took place in the Netherlands, the USA, and Brazil, and occurred between 2005 and 2015. Sample sizes varied from 19 to 215, and the average range of participants within each study varied from 43.2 to 75.4 years. Compared to control programs, mindfulness-based meditation programs improved the quality of life in two studies (p= 0.041 and p=0.03). Conclusion : Mindfulness-based meditation programs improved the quality of life in patients with HF. Therefore, there is limited data to strengthen this recommendation to this population, and future research is warranted in order to present consistency in the intervention protocols.

2][23][24] However, few studies have specifically explored this kind of intervention in HF patients.
Therefore, the aim of this article is to provide information regarding an additional treatment option for patients with heart failure -mindfulness meditation programs -and to evaluate their effectiveness.A systematic review was conducted to answer the PICO 25 (Problem/Population, Intervention, Comparison, and Outcome) question: "How are mindfulness meditation programs effective in promoting and improving the quality of life in patients with heart failure?"

Search strategy and selected studies
The PubMed (MEDLINE), Cumulative Index of Nursing and Allied Health (CINAHL), LILACS, Cochrane Library, and Scopus databases were searched between October and November of 2019, using the Descriptors in Health Sciences (DeCS) and MeSH (Medical Subject Headings) terms.
The following controlled descriptors cited below were used for all databases equally, using the boolean "and" operators for search: heart failure, mindfulness, meditation, and quality of life.Due to the specific characteristics of each database, search strategies were adapted according to the purpose and inclusion criteria of this study.This study's population included adults over 18 years of age, with heart failure, whether hospitalized or in outpatient follow-up, who evaluated mindfulness meditation programs that have been effective in patients' quality of life.

Study quality evaluation
Due to the need to evaluate only the interventions with better methodological rigor and effective results in the presented outcomes, this systematic review performed only quantitative content analysis of the following studies: those with an experimental or quasi-experimental design, such as studies without randomization with a single pre-and post-test; time series or control case; indexed in databases published in English, Spanish, or Portuguese, with a temporal cut between 2004 and 2019.The exclusion criteria were studies with no clear determination of methodology, theses and dissertations, and online publications that were impossible to access or print.
In order to reduce the risk of publication bias, full articles were made available for two evaluators to carry out an independent analysis.For this assessment, the Joana Briggs Institute Checklists 26,27 were used and those articles with a maximum of 3 negative items were deemed eligible.
Of three selected articles, two studies completed 11 items out of the 13 approved in the Randomized Controlled Trials (RCT) Checklist 26

Data extraction and Analysis
The titles and abstracts were evaluated separately by two independent evaluators.A database was constructed with the following information of each article found: year, journal / author, objectives, methods, interventions performed, sample size, evaluated outcomes, results, and conclusion, as well as the final evaluation of the inclusion or exclusion of justified studies, according to the criteria described above.
A descriptive analysis of the results found in the selected articles was performed, including study objectives, type of intervention, scenarios, sample characteristics, follow-up time, and outcomes.

Registration
This systematic review was registered on PROSPERO (International Prospective Register of Systematic Reviews) platform under the number CRD42020153597.

Search results
This systematic review identified 108 studies through database searches.After applying the inclusion and exclusion criteria, a total of 3 studies were qualified for this review, 20,28,29 revealing a limited number of studies addressing QoL as an outcome in patients undergoing a mindfulnessbased intervention.The higher scores meant a better methodological quality and are represented in Table 1.
A Preferred Reporting Items for Systematic review and Meta-Analysis (P.R.I.S.M.A.) flow diagram outlining the research results is presented in Figure 1.

Study design and samples
All three of the analyzed studies used controlled groups.Two were randomized controlled trials and one was a cohort study, using a geographic control group (> 90 miles from the treatment center). 29The studies took place in the Netherlands, the USA, and

Quality of Life measures
The QoL was measured with different instruments, i n c l u d i n g t h e M i n n e s o t a L i v i n g w i t h H e a r t Failure Questionnaire (MLHFQ), the Kansas City Cardiomyopathy Questionnaire (KCCQ), and the Visual Analogue Scale (VAS), which assessed the subjective, self-reported QoL, in which the patients described themselves in terms of overall "quality of life", ranging from 0 to 100, as represented in Table 1.

Intervention
The study intervention varied.Curiati et al used a meditation program including mindfulness exercises, such as conscious breathing, body scan, and simple self-compassion meditation, and included a relaxation-response technique. 28

Treatment effects
The two face-to-face studies 28,29 showed significant improvement in QoL (p = 0.047 and p = 0.033), while the web-based study did not. 20In addition to QoL, a wide range of outcomes were found, including exercise capacity, biomarkers, psychosocial, death and hospitalizations.This fact limited the comparison between studies.

Discussion
This systematic review evaluated three studies assessing the impact of mindfulness-based meditation programs on the QoL of patients with HF.Besides the relevant fact that quality of life is associated with prognosis, hospitalization, and mortality in HF patients, 14 previous studies have shown that these subjects prefer quality of life over longevity. 30t of the three evaluated studies, only two showed a significant impact on QoL.The web-based mindfulness program 20 showed no improvement in QoL or in the other psychological outcomes, although it has presented small positive changes in physiological parameters (functional capacity and heart rate).
2][33] The authors consider that the impact of the online training could be lower than that of personal in-group training.Nevertheless, online training has the potential to provide easy access and can reach a larger number of people.
The in-person interventions, on the other hand, presented positive trends towards HF patients' QoL, after the mindfulness-based intervention program (p = 0.047 and p =0.033) In the Brazilian study, the total score of QoL improvement was even similar to those obtained with enalapril, suggesting that nonpharmacologic interventions may be as effective as medical treatment. 34e American study also showed a significant reduction in anxiety and depression, which may well have contributed to improvement in QoL. 29Luskin et al., demonstrated that a psychosocial treatment applying stress management improved this population's quality of life. 35In chronic HF, psychosocial copings are strong predictors of quality of life and symptoms regardless of the patient's physiological state. 36,37 ecent study conducted by Rechenberg et al., showed that total mindfulness (measured by the Five Facets of Mindfulness Questionnaire) was significantly associated with lower anxiety (β = −0.491,P < .01),which was in turn associated with greater total QoL (β = 0.488, P < .01).The author concluded that Mindfulness might be a way of improving this population's QoL. 38

Limitations
The small number of studies evaluating the impact of mindfulness-based programs in the QoL of HF patients was a limitation in this systematic review.
The sample size of the studies also limited the recommendation of mindfulness-based intervention to improve the QoL in HF patients.The variation in the intervention protocols, including different techniques, length of the programs, daily dose of meditation, and type of interaction (in person or online) also limited the generalization of such interventions in this population.

Conclusion
According to the reviewed studies, mindfulness-based meditation programs can be useful to improve the QoL of patients with HF.
Coats suggested that this kind of intervention can play an important role in HF treatment programs, 39 Therefore, future studies are warranted so as to present consistency in the intervention's methodology in order to generalize the recommendation of this type of behavioral intervention for HF patients.
Brazil, between 2005 and 2015.Sample sizes varied from 19 to 215, and the average range of participants within each study varied from 43.2 to 75.4 years.In two studies, the subjects were exclusively heart failure patients, most of whom were of the NYHA class I and II.In the third study, the patients presented heart failure and other kinds of cardiomyopathy, including ischemic, valvular, and congenital.20 Sullivan et al., developed a mindfulness psychoeducational support group, 29 while Younge et al., worked with a web-based mindfulness intervention.including meditations, self-reflection, and yoga.20 Patients had to complete practical questions and assignments in order to be monitored in terms of adherence.Two studies provided face-to-face meditation sessions ranging from 2 to 2.5 hours plus at least 30 minutes of audio for guided meditation during 8 to 12 weeks.One was an online program of 12 weeks designed to be self-directed.20

Table 1 -Figure 1 -
Figure 1 -Preferred Reporting Items for Systematic Review and Meta-Analysis flow diagram.HF indicates heart failure, QoL indicates Quality of life.