Abstract
Background
Ischemic heart diseases including stable angina & acute events, represent a huge burden on both the individual & the society and represent an important source of disability.
Aim
We aimed to identify the effect of cardiac rehabilitation program (CRP) on the ischemic burden in patients with ischemic heart disease (IHD) unsuitable for coronary revascularization.
Methods
The study included 40 patients with IHD who were not suitable for coronary revascularization either by PCI or CABG (due to unsuitable coronary anatomy, co morbidities, high surgical/procedural risk or patient preference). All patients were subjected to sophisticated CRP protocols, including patient education, nutritional, medical, psychological and sexual counseling and group smoking cessation. All patients participated in low intensity exercise program twice weekly. The patient’s symptoms, vitals and medications were evaluated at each visit and clinical and laboratory data, echocardiography and stress myocardial perfusion imaging (SPECT) were evaluated before and 3 months after the end of the study.
Results
The mean age was 56.8 ± 3.1 years and only 2 patients (5%) were females. 22 (55%) patients were diabetic, 21 (53%) were hypertensive and 30 (75%) were smokers. It was found that 3 months after completion of CRP, there was a significant decrease in BMI (30.3 ± 2.9 vs. 31.2 ± 1.9, p < 0.001), and mean blood pressure (93.4 ± 11 vs. 105 ± 10.6 mmHg, p < 0.001). There was also a favorable effect on lipid profile and a significant improvement of the functional capacity in terms of NYHA functional class (2.1 ± 0.62 vs. 1.4 ± 0.6, p < 0.001). Despite that wall motion score index did not significantly change after CRP, there was a strong trend toward a better ejection fraction (53.7 ± 7.8 vs. 54.5 ± 6.3 %, p = 0.06) and significant improvement of Canadian cardiovascular class (1.42 ± 0.6 vs. 1.95 ± 0.5, p < 0.001) post CRP. Importantly, the difference between the SPECT-derived summed segmental scores at peak stress and at rest (SDS) was significantly lower after CRP (4.4 ± 3 vs. 7.2 ± 3, p < 0.001).
Conclusion
Participation in cardiac rehabilitation program improves ischemic burden in patients with IHD who are unfit or not suitable for conventional cardiac revascularization. In addition the decreased ischemic burden, functional capacity, hemodynamic and metabolic profiles also improve for this group of patients and thus, cardiac rehabilitation should be implemented for routine management of those patients.
Highlights
- •
We aimed to identify the effect of cardiac rehabilitation on the ischemic burden in patients with ischemic heart disease who are not candidate for coronary revascularization.
- •
Stress myocardial perfusion imaging (SPECT) was evaluated before and after enrollment in cardiac rehabilitation (CR) program in our institute.
- •
The difference between the SPECT-derived summed segmental scores at peak stress and at rest (SDS) was significantly lower after cardiac rehabilitation indicating that CR decreases the ischemic burden.
1
Introduction
Coronary heart disease (CHD) is an important source of disability; heart failure and residual angina symptoms disable the patient to carry out his work and role in the society. Cardiac rehabilitation is an essential component of the contemporary management of patients with CHD.
The objective of cardiac rehabilitation is to improve both the physiologic and psychosocial status of cardiac patients. The physiologic outcomes include improvement in exercise capacity and optimization of risk-factor status. Enhancement of myocardial perfusion and performance, as well as reduction in progression of the underlying atherosclerotic process, is additional goals . In this study we aimed to identify the effect of cardiac rehabilitation on the ischemic burden in patients with ischemic heart disease who are not candidate for revascularization.
2
Methods
2.1
Identification and recruitment of patients
The study included 40 patients with stable IHD (post ACS or incomplete revascularization) who are not suitable for revascularization either by PCI or CABG (due to unsuitable coronary anatomy, co morbidities, high surgical/procedural risk or patient preference). The patients were enrolled in cardiac rehabilitation unit in Ain Shams University Hospital.
We included only the patients who finished the 3 month course of cardiac rehabilitation in our unit attending > 80% of the sessions.
Exclusion criteria:
- ▪
Ischemic patients who had complete revascularization.
- ▪
Patients with contraindications to exercise:
- ○
Active pericarditis or myocarditis.
- ○
Uncontrolled congestive heart failure.
- ○
Atrioventricular conduction defect (except first-degree atrioventricular block).
- ○
History of sustained ventricular arrhythmia, uncontrolled atrial fibrillation.
- ○
Severe pulmonary hypertension.
- ○
End stage hepatic and/or renal failure.
- ○
Symptomatic valvular heart disease.
- ○
Fixed-rate pacemaker.
- ○
Intermittent claudication.
- ○
Anemia (hemoglobin < 9 g/dl).
- ○
Significant electrolyte abnormality.
- ○
2.2
Procedure
2.2.1
Proper history taking and examination
All patients were subjected to thorough history taking, full clinical examination including general and local cardiac examination and 12 lead E.C.G were done.
2.2.2
Biochemistry
Venous blood sample were drawn from the antecubital vein before and after rehabilitation program, HbA1c and lipid panel were measured using standard laboratory methods.
2.2.3
Echocardiographic study
All echocardiographic studies were performed before and after rehabilitation program, with commercially available echocardiography systems equipped with a 2.5-MHz multi frequency phased array transducer (Vivid 5 or Vivid 7, GE-Vingmed, Morton, Norway). Gain settings, sector width and the frame rate were adjusted for routine grayscale 2D imaging to optimize endocardial definitions. Standard apical and parasternal views at depths of 12–20 cm were obtained at end-expiratory apnea. LV end-diastolic volume, end-systolic volume (ESV), and ejection fraction were obtained using the modified biplane Simpson’s method from the apical 2- and 4-chamber images. All measurements were made in > 3 consecutive cardiac cycle and in > 5 cycles if the patient’s rhythm was atrial fibrillation (AF) and average values were used for the final analyses. SWMI was obtained by dividing the left ventricle into 17 segments. Each of the segments was assigned a score that is based on myocardial thickening. A normally contracting segment was assigned a score of 1; hypokinesia, 2; akinesia, 3; dyskinesia, 4; and aneurismal, 5. Wall motion score index was calculated by dividing the sum of scores by the number of segments visualized .
2.2.4
Stress test with myocardial perfusion scan (SPECT)
All patients included in the study underwent myocardial perfusion imaging before and after rehabilitation program by means of physical treadmill stress Tc99 sestamibi SPECT.
Data acquisition ECG-gated SPECT imaging was performed using a 2-day protocol (stress and rest) with 99mTc sestamibi (99mTcMIBI). All patients underwent physical treadmill exercise test with Bruce protocol and 99mTcMIBI (500 MBq) was injected intravenously at peak stress. Imaging was performed 120 min after radio-pharmaceutical injection using a dual-head SPECT gamma camera using low-energy, high-resolution collimators. Images were acquired using a circular 360° orbit, 60 projections and 40 s per projection .
The myocardium was divided into 17 segments and each segment was evaluated in consensus by two expert observers using a four-point scoring system (0 > 75% tracer uptake, 1: 50–75% tracer uptake, 2: 25–50% tracer uptake and 3: < 25% tracer uptake) . The summed stress score (SSS) and summed rest score (SRS) were obtained by summation of the individual segmental scores in stress and rest, respectively. The summed difference score (SDS) was calculated by subtracting the SRS from the SSS, which represents both the extent and severity of perfusion abnormalities. Using the gated images, regional wall motion was analyzed to improve differentiation between true perfusion abnormalities and attenuation artifacts. Images were evaluated for the presence of perfusion abnormalities as well as other non-perfusion abnormalities that may indicate extensive ischemia, including left ventricular dysfunction (defined as a left ventricular ejection fraction < 45%) and transient ischemic dilation . The segmental scores were assigned subjectively by the image interpreter and/or automatically by JEP Philips program (JET Stream workspace version 3 servicepack #3 jsws-gnm 320R01).
2.2.5
Cardiac rehabilitation program
All patients were subjected to formal cardiac rehabilitation program according to US Public Health Service (USPHS) definition including medical evaluation, risk factor modification, psychosocial management, nutritional counseling, physical activity counseling. Guideline based optimal medical treatment was prescribed and assessed every visit for side effects, tolerability and possibility to push the dose.
Low intensity exercise training twice weekly for 3 months was prescribed achieving target heart rate of 60–70% of HR max calculated from pre-exercise symptom limited stress test by Bruce protocol. The Borg scale of rate of perceived exertion (RPE) was used to follow up the progression of exercise intensity where the patients were exercised at an RPE of 11–13 in the absence of symptoms .
2.2.6
Statistical analysis
The data were tested for normal distribution using the Kolmogrov–Smirnov test. Continuous variables were presented as mean ± standard deviation (SD) and categorical variables were presented as percentage. Independent t test and chi-squre test were used to compare quantitive and categorical data, respectively, between groups. Differences were considered statistically significant when the P value was < 0.05. The Statistical Package for Social Sciences (SPSS version 16.0, SPSS, Inc., Chicago, IL, USA) version 20 was used for all calculations and statistical analyses. The authors had full access to the data and take full responsibility for their integrity.
2
Methods
2.1
Identification and recruitment of patients
The study included 40 patients with stable IHD (post ACS or incomplete revascularization) who are not suitable for revascularization either by PCI or CABG (due to unsuitable coronary anatomy, co morbidities, high surgical/procedural risk or patient preference). The patients were enrolled in cardiac rehabilitation unit in Ain Shams University Hospital.
We included only the patients who finished the 3 month course of cardiac rehabilitation in our unit attending > 80% of the sessions.
Exclusion criteria:
- ▪
Ischemic patients who had complete revascularization.
- ▪
Patients with contraindications to exercise:
- ○
Active pericarditis or myocarditis.
- ○
Uncontrolled congestive heart failure.
- ○
Atrioventricular conduction defect (except first-degree atrioventricular block).
- ○
History of sustained ventricular arrhythmia, uncontrolled atrial fibrillation.
- ○
Severe pulmonary hypertension.
- ○
End stage hepatic and/or renal failure.
- ○
Symptomatic valvular heart disease.
- ○
Fixed-rate pacemaker.
- ○
Intermittent claudication.
- ○
Anemia (hemoglobin < 9 g/dl).
- ○
Significant electrolyte abnormality.
- ○
2.2
Procedure
2.2.1
Proper history taking and examination
All patients were subjected to thorough history taking, full clinical examination including general and local cardiac examination and 12 lead E.C.G were done.
2.2.2
Biochemistry
Venous blood sample were drawn from the antecubital vein before and after rehabilitation program, HbA1c and lipid panel were measured using standard laboratory methods.
2.2.3
Echocardiographic study
All echocardiographic studies were performed before and after rehabilitation program, with commercially available echocardiography systems equipped with a 2.5-MHz multi frequency phased array transducer (Vivid 5 or Vivid 7, GE-Vingmed, Morton, Norway). Gain settings, sector width and the frame rate were adjusted for routine grayscale 2D imaging to optimize endocardial definitions. Standard apical and parasternal views at depths of 12–20 cm were obtained at end-expiratory apnea. LV end-diastolic volume, end-systolic volume (ESV), and ejection fraction were obtained using the modified biplane Simpson’s method from the apical 2- and 4-chamber images. All measurements were made in > 3 consecutive cardiac cycle and in > 5 cycles if the patient’s rhythm was atrial fibrillation (AF) and average values were used for the final analyses. SWMI was obtained by dividing the left ventricle into 17 segments. Each of the segments was assigned a score that is based on myocardial thickening. A normally contracting segment was assigned a score of 1; hypokinesia, 2; akinesia, 3; dyskinesia, 4; and aneurismal, 5. Wall motion score index was calculated by dividing the sum of scores by the number of segments visualized .
2.2.4
Stress test with myocardial perfusion scan (SPECT)
All patients included in the study underwent myocardial perfusion imaging before and after rehabilitation program by means of physical treadmill stress Tc99 sestamibi SPECT.
Data acquisition ECG-gated SPECT imaging was performed using a 2-day protocol (stress and rest) with 99mTc sestamibi (99mTcMIBI). All patients underwent physical treadmill exercise test with Bruce protocol and 99mTcMIBI (500 MBq) was injected intravenously at peak stress. Imaging was performed 120 min after radio-pharmaceutical injection using a dual-head SPECT gamma camera using low-energy, high-resolution collimators. Images were acquired using a circular 360° orbit, 60 projections and 40 s per projection .
The myocardium was divided into 17 segments and each segment was evaluated in consensus by two expert observers using a four-point scoring system (0 > 75% tracer uptake, 1: 50–75% tracer uptake, 2: 25–50% tracer uptake and 3: < 25% tracer uptake) . The summed stress score (SSS) and summed rest score (SRS) were obtained by summation of the individual segmental scores in stress and rest, respectively. The summed difference score (SDS) was calculated by subtracting the SRS from the SSS, which represents both the extent and severity of perfusion abnormalities. Using the gated images, regional wall motion was analyzed to improve differentiation between true perfusion abnormalities and attenuation artifacts. Images were evaluated for the presence of perfusion abnormalities as well as other non-perfusion abnormalities that may indicate extensive ischemia, including left ventricular dysfunction (defined as a left ventricular ejection fraction < 45%) and transient ischemic dilation . The segmental scores were assigned subjectively by the image interpreter and/or automatically by JEP Philips program (JET Stream workspace version 3 servicepack #3 jsws-gnm 320R01).
2.2.5
Cardiac rehabilitation program
All patients were subjected to formal cardiac rehabilitation program according to US Public Health Service (USPHS) definition including medical evaluation, risk factor modification, psychosocial management, nutritional counseling, physical activity counseling. Guideline based optimal medical treatment was prescribed and assessed every visit for side effects, tolerability and possibility to push the dose.
Low intensity exercise training twice weekly for 3 months was prescribed achieving target heart rate of 60–70% of HR max calculated from pre-exercise symptom limited stress test by Bruce protocol. The Borg scale of rate of perceived exertion (RPE) was used to follow up the progression of exercise intensity where the patients were exercised at an RPE of 11–13 in the absence of symptoms .
2.2.6
Statistical analysis
The data were tested for normal distribution using the Kolmogrov–Smirnov test. Continuous variables were presented as mean ± standard deviation (SD) and categorical variables were presented as percentage. Independent t test and chi-squre test were used to compare quantitive and categorical data, respectively, between groups. Differences were considered statistically significant when the P value was < 0.05. The Statistical Package for Social Sciences (SPSS version 16.0, SPSS, Inc., Chicago, IL, USA) version 20 was used for all calculations and statistical analyses. The authors had full access to the data and take full responsibility for their integrity.
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