European Journal of Cardiovascular Medicine

Heart failure (HF) is a complex clinical syndrome with symptoms and signs that result from any structural or functional impairment of ventricular filling or ejection of blood1.

The advent of echocardiography, cardiac catheterisation, and nuclear medicine had improved the diagnosis and investigation of patients with heart failure2. 

Prevalence of Heart failure (HF) in India is 1.3 to 4.6 million and Annual incidence is 491600 to 1.8 million rates. An estimated 64.3 million people are living with heart failure worldwide.3

Heart failure is classified into right heart failure, left heart failure, and biventricular heart failure.4

Aetiology of Heart Failure includes Coronary artery disease (acute myocardial infarction), Chronic hypertension, Cardiomyopathy (dilated, hypertrophic), Valve dysfunction (diseases of the aortic and mitral valve), Cardiac arrhythmias (heart block and atrial fibrillation), Pericardial disease (constrictive pericarditis), Infection (rheumatic fever, viral myocarditis)5.

Signs and Symptoms are shortness of breath (dyspnoea), profound fatigue, and dizziness or light-headedness, oedema - ankle or leg oedema, palpitations, irregular pulse6. 

Risk factors includes obesity, type 2 diabetes, smoking, high cholesterol levels, metabolic syndrome, sleep apnoea, alcohol or drug abuse7.

Cardiac Rehabilitation Program (CRP) including exercise training is one of the treatment options, and current guidelines recommend cardiac rehabilitation as safe and effective for patients with heart failure. Components of Cardiac rehabilitation (CR) are disease education, risk factor management, nutrition counseling, stress management and exercise training. Moderate-intensity continuous training, supplemented with resistance training, has traditionally been the most common form of exercise training in cardiac rehabilitation9. 

Cardiac rehabilitation has been known to improve exercise capacity and quality of life, minimize heart failure progression8. Despite its efficacy , however, CR participation and completion rates are markedly low compared with those of other evidence based heart failure treatments. It has already been well implemented in urban tertiary care centres. However, in rural back drop, implementation of CRP has significant limitations in the view of economical& geographical factor, especially distance between the home & hospital. Hence it was prudent to devise & implement a practically feasible CRP, that can be integrated during the outpatient visits.

AIM OF THE STUDY

Aim:  To assess the effectiveness of hybrid cardiac rehabilitation program on quality of life and cardiovascular risk factors in heart failure subjects.

OBJECTIVES OF THE STUDY

1. To determine the effect of cardiac rehabilitation program on cardiovascular risk factors and biophysiological parameters in heart failure patients.
2. To determine the effectiveness of cardiac rehabilitation program on health-related quality of life in heart failure subjects.
3. To assess the effect of cardiac rehabilitation program on functional capacity in heart failure subjects.

NEED OF THE STUDY

Most of the studies were on effect of cardiac rehabilitation on morbidity, mortality, and rehospitalisation, there are limited studies on the effectiveness of cardiac rehabilitation regarding improving quality of life, functional capacity, independence of activities of daily living in subjects with heart failure, hence the need to conduct research in this area. 

Most data is on a centre based cardiac rehabilitation programs which has a lot practical limitations in rural population.Our study aims to create a simple and easily implementable hybrid(centre and home based) cardiac rehabilitation program with patients being followed up over tele-consulataions and during outpatient visits.

HYPOTHESIS

RESEARCH HYPOTHESIS (HR): Hybridcardiacrehabilitation is effective in improving quality of life, functional capacity, activities of daily living in heart failure subjects.

NULL HYPOTHESIS (H0): There is no significant effect of hybrid cardiac rehabilitation program on improving quality of life, functional capacity, activities of daily living in heart failure subjects.

Study Design  -    Quasi experimental study

Study Population -Subjects diagnosed with heart failure

Study Setting         - Department of Cardiology, GSL general hospital,   

Study Duration-Study will be conducted during a period April 2023 to   September 2023

Sampling Method -Complete enumeration sampling

Sampling selection - All the patients, who satisfies the inclusion criteria, attending outpatient department of cardiology GSL general hospital, over the period of two months                      

PROCEDURE

This is a quasi-experimental study, which include 6 weeks protocol. Both male and female (above18- years) who were diagnosed with heart failure were recruited from GSL general hospital, Rajahmundry. 

The study wasexplained individually to the subjects who meet the inclusion criteria and gave informed consent wereincluded in the study. 

All subjects were subjected to thorough history taking and physical examination including general health status, risk factor assessment (alcohol, smoking, diabetes, hypertension, dyslipidemia, obesity), Biophysiological parameters such as body mass index (BMI), systolic and diastolic blood pressure, and serum cholesterol values were measured, laboratory assessment was done (FBS PPBS, HB), Vital signs like saturation levels (SpO2), resting pulse rate were measured. 

2D Echo (Ejection fraction) was recorded. 6-minute walk test (6-MWT) to assess the functional capacity was performed. NYHA [New York Heart Association] scale for dyspnoea was recorded. 

Health related QoL was assessed using the standard questionnaire, Short Form 36 Health Survey (SF-36), before they are included into the study.

Post-test was conducted after 6 weeks of intervention. Same data was collected both before and after intervention. In addition, telephonic interviews were made to all participants once every 2 weeks over the 6 weeks post-test period. Both pre-test and post- test results were compared and evaluated.

INCLUSION CRITERIA:

• Patients with age 18 and above years.
• Both the genders.
• Patients diagnosed with heart failure (both chronic heart failure and recovered from acute decompensation).
• Patients willing togive consent.

EXCLUSION CRITERIA:

• Patients with resting systolic BP>200 mm Hg or resting diastolic BP>110 mmHg.
• Patients with signs and symptoms of post procedure ischemia.
• All those patients who have been prescribed restricted mobility due to comorbidities such as aortic stenosis and dysrhythmias.
• All those patients who have altered quality of life due to comorbidities such as end-stage renal disease, liver failure and respiratory failure.

STUDY TOOLS

• Weighing machine & inch tape
• Sphygmomanometer
• Pulse oximeter (SPO2)
• Stopwatch
• Chair & cones

OUTCOME MEASURES

6- Minute walk Test (6MWT): The 6-minute walk test is a sub-maximal exercise test used to assess aerobic capacity and endurance. The distance covered over a time of 6 minutes is used as the outcome by which to compare changes in performance capacity.  

SF- 36 Questionnaire: The 36-item short form survey (SF- 36) is an outcome measure instrument that is well researched and self- reported measure of health. SF- 36 scores range from 0(equivalent to maximum disability) to 100(equivalent to no disability). This instrument addresses health concepts from the patient’s perspective. The score and, the disability were inversely proportional. As the score increases, disability decreases.

Lipid profile: lipid profile shows the cholesterol and level in the blood.

• Normal cholesterol levels of heart are:
• Total cholesterolunder 200,
• LDL cholesterol-under 100,
• HDL cholesterol-60 & higher

At risk:

• Total cholesterol-200 to 239,
• LDL cholesterol-100 to 159,
• HDL cholesterol-40 to 59 (for male), 50 to 59 (for female)

Dangerous levels:

• Total cholesterol-240 & higher,
• LDL cholesterol- 160 & higher,
• HDL cholesterol-under 40 (for male), under 50 (for female).

FBS& PPBS Test:

FBS normal value-below is 100mg/dl, Pre-diabetes is100 to 125 mg/dl. Diabetes is when FBS>126 mg/dl.

PPBS normal value is below 140mg/dl, in Pre-diabetes it is140-199 mg/dl, and in Diabetes it is >200 mg/dl.

INTERVENTION

Cardiac rehabilitation program consists of clinical status assessment, identification of cardio vascular risk factors (smoking, alcohol, DM, HTN) and information regarding modification of risk factors. Dietary modifications like reduced intake of salt (<2300mg), including more fruits & vegetables (variety of colorful vegetables) and legumes etc, which was explained. 

Life style modifications like tobacco and alcohol cessationwas encouraged and home care instructions were given.  

Exercise Training sessions were organized three to five times a week, and each session (main exercise) lasts 20-60 min. A training session includes the warm-up (arm raise, leg extension, leg said raise), Aerobic exercise (brisk walking, jogging, cycling) and cool-down (stretches). 

STATISTICAL ANALYSIS

All statistical analysis will be done by using SPSS software version 20.0 and MS Excel – 2010. All descriptive data will be presented as mean +/- standard deviation and percentage. Paired t- test will be used to compare the mean scores obtained from knowledge questionnaire before and after intervention. Chi square test will be used to analyze the association between categorical variables.  For all the statistical analysis p<0.05 will be considered as significant. 

Initially, a total of 102 subjects were enrolled for the study. 2 subjects were lost to follow-up and excluded from the study.

DEMOGRAPHIC DATA:

Out of the total study population of 100 heart failure subjects, 56 subjects were male and 44 were female. Most of the subjects were between 18 to 64 years of age (68%).Elderly population (> 65 years of age) comprised of 32%. Mean age of females is 57.0 and of males were 56.2. Mean age of total study population is 56.6.

This table presents the descriptive statistics for various health parameters measured before and after the intervention. Participants' ages range from 20 to 81 years, with a mean of 56.600 ± 13.974. Most of the subjects were between 18 to 64 years of age (68%). Elderly population (> 65 years of age) comprised of 32%. Pre-intervention SPO2 values range from 75 to 93, with a mean of 88.6 ± 2.712. Pre-intervention SBP values range from 90 to 160, with an average of 122 ± 16.576. Pre-intervention DBP values range from 50 to 110, with an average of 76.3± 11.070. Pre-intervention resting pulse values range from 63 to 94, with an average of 75.69 ±5.843. Pre-intervention BMI values range from 17.3 to 25.6, with an average of 21.396 ± 1.626. Pre-intervention LDL values range from 101 to 176, with an average of 120.997 ± 18.658. Pre-intervention HDL values range from 30 to 58, with an average of 41.924 ± 7.277. Pre-intervention RBS values range from 79 to 350, with an average of 150.330 ± 56.776. Pre-intervention 6MWT distances range from 356 to 594 meters, with an average of 502.950 ± 69.135 meters. Pre-intervention physical functioning scores range from 0 to 30, with an average of 15.950 ±7.872. Pre-intervention pain scores range from 20 to 67.5, with an average of 41.400 ± 10.579. Pre-intervention general health scores range from 25 to 50, with an average of 37.950 ± 7.354. Pre-intervention PCS scores range from 16.875 to 33.125, with an average of 23.825 ± 3.627. Pre-intervention energy/fatigue scores range from 20 to 55, with an average of 33.800 ± 8.993. Pre-intervention emotional wellbeing scores range from 23.636 to 50.909, with an average of 37.430 ±7.753. Pre-intervention social functioning scores range from 25 to 75, with an average of 46.375 ± 13.211. Pre-intervention MCS scores range from 19.148 to 39.091, with an average of 29.401 ±5.359. Post-intervention SBP values range from 80 to 130, with an average of 114.800 ±11.054. Post-intervention DBP values range from 60 to 90, with an average of 77.160 ± 8.581. Post-intervention resting pulse values range from 24 to 94, with an average of 75.270 ± 7.746. Post-intervention BMI values range from 17.1 to 25.6, with an average of 21.327 ± 1.661. Post-intervention LDL values range from 36 to 176, with an average of 120.217 ± 20.494. Post-intervention HDL values range from 30 to 111, with an average of 42.674 and a standard deviation of 10.012. Post-intervention RBS values range from 79 to 350, with an average of 150.480 ± 56.698. Post-intervention 6MWT distances range from 385 to 693 meters, with an average of 514.710 meters ± 66.306 meters. Post-intervention physical health scores range from 50 to 85, with an average of 66.680 ± 7.549. Post-intervention pain scores range from 42.5 to 90, with an average of 66.800 ±11.209. Post-intervention general health scores range from 55 to 75, with an average of 64.500 ± 6.416. Post-intervention PCS scores range from 144.375 to 160, with an average of 149.495 ± 3.489. There are no variations in role limitations due to emotional problems post-intervention, all participants scored 100. Post-intervention energy/fatigue scores range from 45 to 75, with an average of 59.375 ± 7.972. Post-intervention emotional wellbeing scores range from 40 to 84.44, with an average of 60.752 ± 9.715. Post-intervention social functioning scores range from 37.5 to 100, with an average of 73.875 ± 15.396. Post-intervention MCS scores range from 60.625 to 86.625, with an average of 73.501 ± 5.445. Post-intervention SPO2 values range from 92 to 99, with an average of 96.380 ± 1.953.

TABLE 2: Showing Association Between Smoking With Intervention

The table presents a crosstabulation of smoking status before and after intervention. The rows represent the smoking status before the intervention and the columns represent the smoking status after the intervention. 64 individuals who did not smoke before the intervention continued to not smoke (100.0%). The total number of individuals in this group was 64 (100.0%). 21 individuals who smoked before the intervention stopped smoking (58.3%). 15 individuals who smoked before the intervention continued to smoke (41.7%). The total number of individuals in this group was 36 (100.0%). A total of 85 individuals were not smoking after the intervention (85.0%). A total of 15 individuals were smoking after the intervention (15.0%). The P-value is 0.001, indicating a statistically significant difference in the distribution of smoking status before and after the intervention, suggesting that the observed changes are unlikely to have occurred by chance, implying that the intervention had a significant impact on the smoking behavior of the individuals.

TABLE 3: Showing Association Between Alcohol With Intervention

The table presents a crosstabulation of alcohol consumption status before and after a certain intervention or period. The rows represent the alcohol consumption status before the intervention and the columns represent the alcohol consumption status after the intervention 81 individuals who did not consume alcohol before the intervention continued to not consume alcohol (100.0%). 14 individuals who consumed alcohol before the intervention stopped consuming alcohol (73.7%). 5 individuals who consumed alcohol before the intervention continued to consume alcohol (26.3%). A total of 95 individuals were not consuming alcohol after the intervention (95.0%). A total of 5 individuals were consuming alcohol after the intervention (5.0%).The P-value is 0.001, indicating a statistically significant difference in the distribution of alcohol consumption status before and after the intervention, implying that the intervention had a significant impact on the alcohol consumption behavior of the individuals.

TABLE 4: showing association between study variable with intervention

This table presents the mean values and p-values for various health parameters measured before and after intervention. Mean SPO2 value before intervention is 88.600 ± 2.712 while the Mean SPO2 after intervention improved to 96.380 ± 1.953. There is statistically highly significant increase in SPO2 from before and after intervention (p = 0.000), indicating an improvement. Mean Systolic Blood Pressure before intervention is 122.000 ± 16.576 this was improved after intervention with a Mean of 114.800 ± 11.054 and P-VALUE: 0.000 is showing significant decrease in SBP with intervention. Similarly Diastolic Blood Pressure also improved with intervention. this improvement in Diastolic Blood Pressure is not significant statistically with a P-VALUE: 0.504. 6MWT (6-Minute Walk Test) showed improvement in the mean values before and after intervention (.950, ± 69.135 and 514.710 ± 66.306) and this improvement was statistically highly significant with a P-VALUE: 0.000. Similarly PCS (Physical Component Summary of SF-36) showed mean value of 23.825, ± 3.627 and 149.495 ±3.489 before and after intervention respectively. There is a significant increase in PCS with intervention (p < 0.05), indicating improvement. MCS (Mental Component Summary of SF-36)  had a mean of 29.401 ± 5.359 before intervention, which later improved significantly with a P-VALUE: 0.000 and had a mean of  73.501± 5.445. Significant improvements are observed in SPO2, SBP, 6MWT, PCS, and MCS. No significant changes are observed in DBP, Resting Pulse, BMI, LDL, HDL, and RBS.

TABLE 4: Showing Pre-Nyha Scale And Post-Nyha Scale

This table shows New York Heart Association (NYHA) functional classification grades before and after intervention. The table is split into rows representing the NYHA grade before the intervention and columns representing the NYHA grade after the intervention. 20 patients remained in GRADE-I (100.0%) after the intervention with no change. Of total 42 (100.0%) patients in this group 21 patients remained in GRADE-II (50.0%) while 21(50%) improved to GRADE-I. The total number of patients in grade-III  group prior to intervention was 26 (100.0%) from this 3 patients moved to GRADE-I (11.5%), 11 patients moved  in GRADE-II (42.3%) while 12 patients remained in GRADE-III (46.2%) after the intervention. The total number of patients in grade-IV group prior to intervention was 12 (100.0%). post intervention 2 patients remained in GRADE-IV (16.7%). 2 patients moved to GRADE-II (16.7%). 8 patients moved to GRADE-III (66.7%).44 patients were in GRADE-I (44.0%). 2 patients were in GRADE-IV (2.0%), 34 patients were in GRADE-II (34.0%), 20 patients were in GRADE-III (20.0%) after intervention. The P-value is 0.001, indicating a statistically significant difference in the distribution of NYHA grades before and after the intervention. This typically suggests that the intervention had a significant impact on the NYHA grades of the patients. The table shows a significant improvement or change in NYHA functional classification grades among patients, with some moving to lower (better) grades after the intervention.

This study re-iterates the importance of cardiac rehabilitation in the improvement of quality of life, functional capacity and cardiovascular risk factors in heart failure patients in a rural setting.

The Hybrid CR program implemented in OP visits and Tele consultations, of 6 weeks duration, (which was focused on improving disease knowledge, exercise, medication, and lifestyle habits, effectively improved QoL in the intervention group), is found to be effective ,  feasible and implementable as a cost effective intervention for heart failure patients in a rural area.Our study had a good representation of both male and female Heart failure patients.

Present study showed a significant reduction in Systolic blood pressure and functional capacity with improvement in NYHA class, 6 minute walk distance and PCS and MCS components of Quality of life in a 6 week short duration of cardiac rehabilitation training program.

This study could not achieve a significant reduction in blood sugars, cholesterol levels, LVEF and BMI This could be explained by the short duration of study.

Smoking and alcohol intake was significantly reduced at follow-up, thus showing that risk factor mitigation can be achieved with cardiac rehabilitation even with a hybrid program in a short duration.

On quality of life:

Present study showed significant improvement in physical and mental quality of life with our 6 week cardiac rehabilitation program. All eight sub components in SF-36 showed significant improvement. These finding were in accordance with studies done by Stahle et al.13 and Yohannes et al14 who reported long-term benefits of cardiac rehabilitation on quality of life.These results also validate the ones from Hung et al15. who showed the efficacy of physical exercise associated to weightlifting(threetimesaweekfor8 weeks total) on improving quality of life measured with the MacNew heart disease health related quality of life instrument in older patients with coronary artery diseases. The quick efficacy with a 6 week CR program, reported by our study could be explained by the multidisciplinary rehabilitation approach along with telephonic counselling and motivation. 2014 cochrane meta-analysis also showed an improvement in quality of life with MLHFQ score reduction16. Another study done by Hasanpour Dehkordi et al.17,showed that nurse-led CR program significantly and rapidly(within1month postintervention) improves the mental health components of QoL such as vitality, social functioning, role functioning emotional, and mental health. All these studies further conclude that receiving adequate knowledge regarding disease condition and lifestyle modification enhances the confidence of patients with HF to live a healthy life, thereby improving their functional abilities. Disease education, exercise, and improved 6-minute walk functional ability contribute to the identified improvements in QoL in present study group.

On Functional capacity:

6MWD:

6MWD (6 Minute Walk test Distance) is an independent predictor of mortality in patients with heart failure18. Arslan and colleagues showed mortality rates for patients with mild-to-moderate HF who walked <300 m to be significantly higher than those whose walked distances greater than 300 (79% vs. 7%).19. Present study showed a significant increase in mean 6MWD after our 6 week CR program. Baseline 6MWD was 502.95 ± 69.13 m and the 6MWD improved to 514.71 ± 66.3 m by the end of the study CR Program with a mean improvement of 11.76 m, indicating an improvement in the functional performance, the consequence of which is an enhancement of daily activity. According to an individual patient data meta-analysis called ExTraMATCH II performed by collecting data from 3990 patients with HF in 13 intervention studies CR improved 6-minute walk distance by a mean of 21 m (95% CI, 1.57–40.4 m)20.

However, According to the guidelines of the American Thoracic Society (ATS), the minimal clinically significant difference reported from the 6MWT in patients with CHF is 43 m.21 In present study the 6MWD showed a mean improvement was lesser because of higher 6MWD at baseline as patients were studied after complete decongestion.

NYHA:

The present study confirmed the well-known favourable effects of exercise training on cardiovascular functional capacity as there was a statistically highly significant improvement in the NYHA class of the patients in the current study population in which there was a shift of patients to a higher NYHA class .Similar findings were shown by Sarrafzadegan et al.22 as that study also showed significant improvement in functional capacity in the patients enrolled in CR Program.

On Bio Physiological Parameters:

BMI

This study did not show statistically significant reduction in BMI after the CR program, probably because the program was not long enough to cause a reduction in these physical parameters. However, CR programs in general lead to significant weight loss and decreased BMI due to physical activity and proper diet.

In this light, long-term cardiac exercise programs associated to a proper diet and nutrition seem quite necessary.23,24 However , a short-term CR program can increase patients’ self-confidence thus improving program compliance as well as their physical abilities.

Blood pressure & Pulse rate:

Our study showed a significant reduction in SBP after short term CR program, DBP and Pulse rate, however had no significant reduction yet at follow-up. A meta-analysis by Pescatello et al. reported a decrease in SBP and DBP at respectively 7.8 and 5.8 mmHg in patients with hypertension.25 Similarly, Sarrafzadegan et al26 showed significant reduction in  SBP in coronary patients enrolled in CR.The significant reduction in blood pressure is mostly due to frequent follow-up and counselling by medical personnel in which there is more accurate follow up of blood pressure & tailoring of antihypertensive medication.

The results showed no significant improvements in random blood sugar, LDL cholesterol and HDL cholesterol. The no significant results in our study could be explained by short follow-up period of the study. A study done by Haitham Galal Mohammed et al,27 showed a statistically no significant reduction in TG and LDL and statistically no significant increase in HDL.

On risk factors:

There was a statistically significant decrease in the percentage of smokers by the end of the 6 week rehabilitation program similar to studies by Francesco et al. in (2012) and H.G.mohammed et al27. The percentage of smokers at the end of CR Program in the present study has significantly decreased probably due to the shorter duration of the CR Program. It is yet to ascertain how many actually are successful in abstinence at longer follow-up.

MECHANISMS OF CR:

Cardiac rehabilitation improves exercise tolerance, elevates mood, improves muscle function, causes regression of atherosclerosis and improves autonomic balance, all of these leading improved outcomes.28-30. CR includes components absent in drug therapy such as drug adherence guidance, dietary and smoking cessation, counselling, and psychological management,31,32. and such comprehensive multidisciplinary interventions may have played a role in the improvement in outcomes seen in our study.33Indeed, when the results of previous intervention studies with drug therapy and exercise training for HFpEF were compared, no improvements in QoL or exercise tolerance were observed in any of the classic drug intervention studies.34-36 However, improvements in exercise tolerance and QoL have been consistently observed in exercise intervention studies for HFpEF.37-39  Exercise tolerance and QoL are important outcome indices that may affect prognosis of HF.

All these taken together, the results of the present study suggest that 6 week hybrid CR program including exercise training is likely effective in patients with all types of HF. It is possible to adopt telecounselling strategies to overcome the physical problems that typically impede access healthcare, an important healthcare implication in this study. Hybrid CR programs should be incorporated into the management plans for patients with HF.

STRENGTHS OF STUDY: 

The present study has a number of strengths:

1. Present study showed that a 6 week hybrid cardiac rehabilitation study is practically implementable with good QOL outcomes in rural settings.
2. This study had a reasonable representation of females (38%) and patients with HFpEF (39%) in our study group
3. Patients received current standard of heart failure therapy with our hybrid cardiac rehabilitation.

LIMITATIONS OF THE STUDY:

This study is a single centre study with a relatively small number of patients and there was a no control group available for the study.

This cardiac rehabilitationprogram being a hybrid program,could not directly monitor adherence,duration, frequency or intensity except by telephone call.

It couldn’t be determined if higher frequency of CR visits leads to further improvement in prognosis, as demonstrated in observational studies in ischemic heart disease,40,41so could not be tested in the present study. However, this study provides important insights for future clinical care of patients with HF because it is the first study on hybrid CR in rural Indian population.

However, the lack of significant correlations between the various QoL parameters and exercise tolerance could be due to the insufficient number of subjects and/or the short duration of our program. It seems necessary to look at a larger study with more patients and/or longer duration to discriminate the respective impact of each component of this therapeutic care.

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