Exercise In Coronary Artery Disease Patients Research Articles

Acute and subacute effects of strenuous exercise on platelet aggregation, coagulation and fibrinolysis in patients with stable coronary artery disease

IntroductionStrenuous exercise may occasionally cause coronary thrombosis with myocardial infarction and sudden cardiac death. Materials and methodsPatients with stable coronary artery disease (CAD) (n = 164) and healthy individuals (n = 25) performed strenuous exercise on a bicycle ergometer. Blood was drawn at baseline, immediately after exercise and 2 h later. Platelet aggregation was measured with Multiplate® Analyzer. Thrombin generation was determined using a thrombogram and by measuring prothrombin fragment 1 + 2 (F1 + 2). A clot lysis assay was used to investigate fibrinolysis. ResultsFrom baseline to immediately after exercise, thrombin receptor activating peptide (TRAP)-induced platelet aggregation increased in CAD patients (Δ77 AU × min, 95 % confidence interval (CI): 46;107) and in healthy individuals (Δ153 AU × min, 95%CI: 75;232). Endogenous thrombin potential (ETP) was unaffected by exercise, whilst F1 + 2 increased (Δ17%, 95%CI: 11;24) in CAD patients. Fibrin clot lysis time increased by 9 % (95%CI: 1–17) in CAD patients and by 26 % (95%CI: 8;45) in healthy individuals. When comparing baseline to 2 h post-exercise, TRAP-induced platelet aggregation remained slightly elevated in both CAD patients (Δ53 AU × min, 95%CI: 22;84) and healthy individuals (Δ140 AU × min, 95%CI: 62;219). In contrast, ETP and F1 + 2 decreased in CAD patients (Δ-6 %, 95%CI: −10;-1 and Δ-8 %, 95%CI: -14;-2). Moreover, clot lysis time decreased (Δ-19 %, 95%CI: −27;-11) in patients with CAD and returned to baseline in healthy individuals. All p-values were <0.05. ConclusionsPlatelet aggregation and F1 + 2 were substantially elevated immediately after exercise in CAD patients, indicating a pro-thrombotic state. After 2 h of recovery, they exhibited a markedly increase in fibrinolysis. Similar results were observed in healthy individuals.

Usefulness of the 6-minute walk test vs cardiopulmonary exercise test for exercise prescription in coronary artery disease patients going into a phase III cardiac rehabilitation program

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Determining the intensity of exercise is a very important component to obtain the dose-benefits associated with exercise, while maitaining the safaty of the patient with coronary artery disease (CAD) in a cardiovascular rehabilitation (CR) programme. The cardiopulmonary exercise test (CPET) is the gols standard for exercise prescription according to the intend intensisty of aerobic workout. However, its availability is not a reality in many CR centres. The 6-minute walk test (6MWT) is a valid and widely used method because it is low-cost and simple to apply. Nevertheless, it is still unknown the corresponding intensity reached on a 6MWT compared to the one reached on a CPET in already physically active patients with CAD starting a CR phase III programme. Purpose To use the peak heart rate (HR) of the 6MWT as a method to prescribe the intensity of aerobic exercise in CAD patients starting a phase III CR programme and to compare it with the ventilatory threshold (VT) of the CPET. Methods In this retrospective study, a cohort of patients with CAD enrolled in a phase III CR programme. At the beginning of the programme, all patients performed a 6MWT and a CPET in the same week with at least 48-hour difference. The HR on the 6MWT was recorded continuously using a HR polar (H10 Polar) and on CPET using a twelve-lead ECG. Other parameters were assessed such as objective physical activity (accelerometer) and body composition. Results Eighty patients (87.5% males, 60.8 ± 9.4 years old) with CAD were included in this study. Patients were, on average, physically active (361 ± 182 minutes/week of moderate to vigorous physical activity) and overweight (body mass index: 27.7 ± 3.5 kg/m2). The VO2 peak reached on the CPET was 20.3 ± 5.4 ml/kg/min and the percentage of predicted maximum HR was 78.3 ± 11.4 %. The first and second VT corresponded to 75.6 ± 7.8% and 91.2 ± 4.5% of the peak HR obtained with CPET, respectively. The 6MWT HR peak was 113 ± 16 bpm (90.0 ± 13.0 HR peak CPET) and did not differ from the HR of the second VT with a mean value of 115 ± 16 bpm (91.2 ± 4.5% HR peak CPET), p&amp;gt;0.05. Although, the 6MWT HR peak was significantly higher than the HR oh the first VT (95 ± 14 bpm, p&amp;lt;0.001). In a subgroup analysis, the patients who, during the 6MWT, reached more the 90% of the HR peak CPET (n=35, 44% oof the sample) were the ones with lower functional capacity (VO2 peak: 18.4 ± 5.4 ml/kg/min vs 21.7 ± 5.0 ml/kg/min, p=0.006) and higher age (64.4 ± 8.7 years old vs 60.8 ± 9.4 years old, p=0.002). Conclusion(s) In the absence of a CPET, the use of a 6MWT HR peak in physically active patients with CAD starting a phase III CR programme has shown to be an efficient method to prescribe moderate to vigorous exercise intensity, corresponding to the second VT. Higher intensities on the 6MWT might be reached in active elderly patients with reduced functional capacity.

Cardiopulmonary Fitness Correlates with Regional Cerebral Grey Matter Perfusion and Density in Men with Coronary Artery Disease

PurposePhysical activity is associated with positive effects on the brain but there is a paucity of clinical neuroimaging data in patients with coronary artery disease (CAD), a cardiovascular condition associated with grey matter loss. The purpose of this study was to determine which brain regions are impacted by cardiopulmonary fitness and with the change in fitness after 6 months of exercise-based cardiac rehabilitation.MethodsCAD patients underwent magnetic resonance imaging at baseline, and peak volume of oxygen uptake during exercise testing (VO2Peak) was measured at baseline and after 6 months of training. T1-weighted structural images were used to perform grey matter (GM) voxel-based morphometry (VBM). Pseudo-continuous arterial spin labeling (pcASL) was used to produce cerebral blood flow (CBF) images. VBM and CBF data were tested voxel-wise using VO2Peak and age as explanatory variables.ResultsIn 30 men with CAD (mean age 65±7 years), VBM and CBF identified 7 and 5 respective regions positively associated with baseline VO2Peak. These included the pre- and post-central, paracingulate, caudate, hippocampal regions and converging findings in the putamen. VO2Peak increased by 20% at follow-up in 29 patients (t = 9.6, df = 28, p<0.0001). Baseline CBF in the left post-central gyrus and baseline GM density in the right putamen predicted greater change in VO2Peak.ConclusionPerfusion and GM density were associated with fitness at baseline and with greater fitness gains with exercise. This study identifies new neurobiological correlates of fitness and demonstrates the utility of multi-modal MRI to evaluate the effects of exercise in CAD patients.

Acute and chronic effects of exercise on inflammatory markers and B-type natriuretic peptide in patients with coronary artery disease

Few studies have prospectively addressed the effects of exercise in the inflammatory activity of patients with coronary artery disease (CAD). We sought to evaluate the consequences of an acute bout of exercise on inflammatory markers and BNP in untrained CAD patients before and after randomization to a training program. 34 CAD patients underwent a 50-min acute exercise session on a cycle-ergometer at 65% peak oxygen uptake before and after blood sampling. They were then randomized to a 4-month chronic exercise program (15 patients) or general lifestyle recommendations (19 patients), undergoing a new acute session of exercise after that. In the overall population, acute exercise caused a significant increase in C-reactive protein [CRP; 1.79 (4.49) vs. 1.94 (4.89) mg/L, P<0.001], monokine induced by interferon-γ [Mig; 351 (324) vs. 373 (330) pg/mL, P=0.027] and vascular adhesion molecule-1 [VCAM-1; 226 (82) vs. 252 (110) pg/mL, P=0.02]. After 4-months, in exercise-trained patients, there was a significant decrease in the inflammatory response provoked by the acute exercise compared to patients in the control group reflected by a significant decrease in the differences between rest and post-exercise levels of CRP [-0.29 (0.84) mg/L vs. -0.11 (0.21) mg/L, P=0.05]. Resting BNP was also significantly lower in exercise-trained patients when compared to untrained controls [15.6 (16.2) vs. 9.7 (11.4) pg/mL, P=0.04 and 19.2 (27.8) vs. 23.2 (27.5) pg/mL, P=0.76; respectively]. Chronic exercise training might partially reverse the inflammatory response caused by acute exercise in CAD patients. These results suggest that regular exercise is an important nonpharmacological strategy to the improvement in inflammation in CAD patients.

Abstract 2195: Significant Relation of Arterial Stiffening to Hyperventilatory Response to Exercise in Patients with Coronary Artery Disease

Exercise intolerance is a common feature of patients with coronary artery disease (CAD). Enhanced ventilatory response is determinants of exercise capacity and marker of a poor prognosis irrespective of LV systolic function. Pulse wave velocity (PWV), which is a reliable marker of arterial stiffness, modulates left ventricular (LV) function and is related to exercise capacity in CAD patients; however, the relationship of PWV to ventilatory response to exercise in CAD patients has not been fully elucidated. In this study, we examined PWV and cardiopulmonary exercise testing (CPX) in CAD patients and evaluated the relationship between PWV and ventilatory response to exercise. We studied 81 CAD patients (69±8yo, 64men). All subjects underwent symptom limited CPX. Ventilatory response to exercise was determined by VE/VCO 2 slope. We also measured PWV using an automated device (form ABI/PWV, Colin, Japan) prior to CPX. LV function was assessed by echocardiogram. In univariate analysis, PWV was related to VE/VCO 2 slope (r=0.34, p&lt;0.01). PWV was also associated with exercise time (r=−0.22, p&lt;0.05), time to ST depression (r=−0.32, p&lt;0.01) and peak VO 2 (r=−0.44, p&lt;0.01). The relationship between PWV and VE/VCO 2 was still significant after adjustment for age, sex and blood pressure. Patients with high PWV (over 1800cm/sec, n=29) had higher BNP (140±214 vs 59±66 pg/ml, p&lt;0.05) and lower E/A ratio (0.7±0.2 vs. 0.9±0.3, p&lt;0.05) than those with low PWV (under 1800cm/sec, n=52). In exercise testing, patients with high PWV had higher VE/VCO 2 slope (30.9±2.6 vs. 29.0±3.4, p&lt;0.01), shorter time to ST depression than patients with low PWV (352±79 vs. 403±59 sec, p&lt;0.01), whereas severity of CAD, defined as number of diseased vessels, was comparable between the two groups. Arterial stiffening is associated with enhanced ventilatory response to exercise in CAD patients. Diastolic dysfunction and lowered threshold of myocardial ischemia associated with arterial stiffening are probably involved in the hyperventilatory response to exercise in CAD patients.

Beneficial effects of cardiac rehabilitation and exercise after percutaneous coronary intervention on hsCRP and inflammatory cytokines in CAD patients

Recent studies showed that tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), as well as high-sensitive C-reactive protein (hsCRP) levels are predictive factors of cardiovascular risk. However, the effect of cardiac rehabilitation (CR) intervention in coronary artery disease (CAD) patients on these factors is not known. The aim of this study was to evaluate the effects of CR and exercise on hsCRP and inflammatory cytokine levels in patients with CAD after percutaneous coronary intervention (PCI). CAD patients who underwent PCI were divided into a CR and exercise group (CRE, n = 29) or a control group (CON, n = 10). CR and exercise consisted of 6 weeks supervised exercise training and 8 weeks home-based, self-managed exercise. Compared to pre-experimental levels, TNF-alpha (by 20.4%; p = 0.006) and IL-6 (by 49.0%; p < 0.0001), as well as hsCRP (by 59.4%; p < 0.0001), were markedly decreased after CR and exercise in CAD patients but not in control group, except for IL-6 (by 41.6%; p = 0.001). However, there was no significant alteration of adiposity-related variables such as BMI, percent body fat, and waist circumferences, in both groups. We suggest that CR and exercise in CAD patients after PCI induce significant reduction in hsCRP and inflammatory cytokines (TNF-alpha and IL-6), and marked increase in exercise tolerance and capacity.

Abnormal postexercise systolic blood pressure response is a good indicator of impaired left ventricular filling during supine cycle ergometer exercise in patients with coronary artery disease.

To determine whether the postexercise systolic blood pressure (SBP) response is a useful marker of left ventricular filling abnormalities, supine leg exercise testing was conducted in 14 control subjects and 70 patients with coronary artery disease (CAD). An abnormal postexercise SBP response (the ratio of SBP after 3 min of recovery to the peak exercise SBP) was defined as 0.85 or more, which represented the cutoff point with the highest sensitivity and specificity for prediction of pulmonary artery wedge pressure (PAWP) of at least 20 mmHg at peak exercise in CAD patients. There was a significant difference between the SBP ratios of the two groups (Control, 0.72 +/- 0.05; CAD, 0.86 +/- 0.13; p < 0.01). There was no significant difference between the PAWP of the two groups at rest, but the PAWP at peak exercise was significantly higher in the CAD group (20.2 +/- 8.9 mmHg) than in the control group (11.5 +/- 4.0 mmHg)(p < 0.01). PAWP at peak exercise was > or = 20 mmHg in 35 (50%) of the 70 CAD subjects. The SBP ratio was significantly correlated with PAWP at peak exercise (r = 0.67, p < 0.01) in the CAD group, but not in the control group. An SBP ratio of > or = 0.85 showed a sensitivity of 80% and a specificity of 80% for predicting a peak exercise PAWP of > or = 20 mmHg in CAD patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Systolic time-interval evaluation by thermistor plethysmography during uninterrupted dynamic stress test in normals and in patients with coronary artery disease.

18 patients with coronary artery disease (CAD) and 21 normal subjects underwent a triangular bicycle exercise test. Systolic time intervals (STI) were calculated at rest and every 2 min during exercise. Under resting conditions, STI were similar in the two groups. During exercise, the ejection time index (ETI), i.e. left ventricular ejection time (LVET) corrected for HR, rose significantly more in CAD patients, as compared to normals. Pre-ejection period (PEP) was also differently affected by exercise in CAD patients, who showed a more shortened PEP (p less than 0.001) in the early stage of dynamic stress. PEP/LVET ratio, which in the control group decreased continuously, in CAD patients fell during exercise at lower work loads (p less than 0.001), whilst rose during strenuous exercise. Finally, significant differences (p less than 0.001) were found in the percent change (% delta) PEP/LVET ratio between the two groups during the early phase of exercise, in which no superimposition of single values was present. Therefore, this last parameter seems the most reliable to differentiate clearly CAD patients from normal subjects, but its use must be limited at early exercise.