Augusto Purcaro

Randomized, Controlled Trial of Long-Term Moderate Exercise Training in Chronic Heart Failure Effects on Functional Capacity, Quality of Life, and Clinical Outcome

BACKGROUND It is still a matter of debate whether exercise training (ET) is a beneficial treatment in chronic heart failure (CHF). METHODS AND RESULTS To determine whether long-term moderate ET improves functional capacity and quality of life in patients with CHF and whether these effects translate into a favorable outcome, 110 patients with stable CHF were initially recruited, and 99 (59+/-14 years of age; 88 men and 11 women) were randomized into 2 groups. One group (group T, n=50) underwent ET at 60% of peak &f1;O2, initially 3 times a week for 8 weeks, then twice a week for 1 year. Another group (group NT, n=49) did not exercise. At baseline and at months 2 and 14, all patients underwent a cardiopulmonary exercise test, while 74 patients (37 in group T and 37 in group NT) with ischemic heart disease underwent myocardial scintigraphy. Quality of life was assessed by questionnaire. Ninety-four patients completed the protocol (48 in group T and 46 in group NT). Changes were observed only in patients in group T. Both peak &f1;O2 and thallium activity score improved at 2 months (18% and 24%, respectively; P<0. 001 for both) and did not change further after 1 year. Quality of life also improved and paralleled peak VO2. Exercise training was associated both with lower mortality (n=9 versus n=20 for those with training versus those without; relative risk (RR)=0.37; 95% CI, 0.17 to 0.84; P=0.01) and hospital readmission for heart failure (5 versus 14; RR=0.29; 95% CI, 0.11 to 0.88; P=0.02). Independent predictors of events were ventilatory threshold at baseline (beta-coefficient=0.378) and posttraining thallium activity score (beta-coefficient -0.165). CONCLUSIONS Long-term moderate ET determines a sustained improvement in functional capacity and quality of life in patients with CHF. This benefit seems to translate into a favorable outcome.

Low intensity exercise training in patients with chronic heart failure

OBJECTIVES The present study was designed to evaluate whether a specific program of low intensity exercise training may be sufficient to improve the exercise tolerance of patients with chronic heart failure. BACKGROUND Recent studies have shown that exercise training can improve exercise tolerance in patients with stable chronic heart failure, mainly through peripheral adaptations. These changes have been observed with exercise regimens at intensities of 70% to 80% of peak oxygen uptake and > 8 weeks. METHODS We studied 27 patients (23 men, 4 women; mean [+/- SD] age 57 +/- 6 years) with mild chronic heart failure. We classified patients into two groups: trained group and untrained group. The trained group underwent a low intensity (40% of peak oxygen uptake) training program three times/week for 8 weeks. The untrained group performed no exercise. RESULTS An increase in peak oxygen uptake (17%, p < 0.0001), lactic acidosis threshold (20%, p < 0.0002) and peak work load (21%, p < 0.0002) were obtained in the trained group only. Cardiac output and stroke volume were unchanged. A high correlation was found between the increases in peak oxygen uptake and volume density of mitochondria of vastus lateralis muscle (r = 0.77, p < 0.0002). CONCLUSIONS Patients with stable chronic heart failure can achieve significant improvement in functional capacity from a low intensity exercise training regimen. The mechanism responsible for this favorable effect involves an increase in mitochondrial density, which reflects an improvement in oxidative capacity of trained skeletal muscles.

Exercise training intervention after coronary angioplasty: the ETICA trial ☆

OBJECTIVES The goal of this study was to determine the effects of exercise training (ET) on functional capacity and quality of life (QOL) in patients who received percutaneous transluminal coronary angioplasty (PTCA) or coronary stenting (CS), the effects on the restenosis rate and the outcome. BACKGROUND It is unknown whether ET induces beneficial effects after coronary angioplasty. METHODS We studied 118 consecutive patients with coronary artery disease (mean age 57+/-10 years) who underwent PTCA or CS on one (69%) or two (31%) native epicardial coronary arteries. Patients were randomized into two matched groups. Group T (n = 59) was exercised three times a week for six months at 60% of peak VO2. Group C (n = 59) was the control group. RESULTS Only trained patients had significant improvements in peak VO2 (26%, p < 0.001) and quality of life (26.8%, p = 0.001 vs. C). The angiographic restenosis rate was unaffected by ET (T: 29%; C: 33%, P = NS) and was not significantly different after PTCA or CS. However, residual diameter stenosis was lower in trained patients (-29.7%, p = 0.045). In patients with angiographic restenosis, thallium uptake improved only in group T (19%; p < 0.001). During the follow-up (33+/-7 months) trained patients had a significantly lower event rate than controls (11.9 vs. 32.2%, RR: 0.71, 95% confidence interval [CI]: 0.60 to 0.91, p = 0.008) and a lower rate of hospital readmission (18.6 vs. 46%, RR: 0.69, 95% CI: 0.55 to 0.93, p < 0.001). CONCLUSIONS Moderate ET improves functional capacity and QOL after PTCA or CS. During the follow-up, trained patients had fewer events and a lower hospital readmission rate than controls, despite an unchanged restenosis rate.

Effects of Moderate Exercise Training on Thallium Uptake and Contractile Response to Low-Dose Dobutamine of Dysfunctional Myocardium in Patients With Ischemic Cardiomyopathy

BACKGROUND There is evidence that exercise training can induce myocardial and coronary adaptations in both animals and humans. However, the significance of these potentially important changes remains to be determined in patients with ischemic heart disease and left ventricular (LV) systolic dysfunction. METHODS AND RESULTS To investigate whether exercise training can improve thallium uptake and the contractile response to low-dose dobutamine of dysfunctional myocardium, 46 patients (42 men, 4 women; mean age, 57+/-9 years) with chronic coronary artery disease and impaired LV systolic function (ejection fraction < 40%) were randomly assigned to two groups. The exercise group (n = 26) underwent exercise training at 60% of peak oxygen uptake for 8 weeks. The control group (n = 20) was not exercised. At baseline and after 8 weeks all patients underwent an exercise test with gas exchange analysis and stress echocardiography using low-dose dobutamine (5 to 10 microg/kg per minute) followed by thallium myocardial scintigraphy. Coronary angiography was performed in 23 patients at baseline and after 8 weeks. After 8 weeks, peak oxygen uptake increased significantly only in trained patients (24%). Significant improvements in the contractile response to dobutamine and thallium activity were observed in trained patients (28% and 31%, respectively; trained versus control: P<.001 for both). In a subgroup of trained patients, both improvements were correlated with an increase in the coronary collateral score (P<.005 and P<.001, respectively). CONCLUSIONS Moderate exercise training improves both thallium activity and the contractile response of dysfunctional myocardium to low doses of dobutamine in patients with ischemic cardiomyopathy. The implication of this study is that even a short-term exercise training may improve quality of life by improvement of LV systolic function during mild-to-moderate physical activity in patients with ischemic cardiomyopathy.

10-Year Exercise Training in Chronic Heart Failure: A Randomized Controlled Trial

OBJECTIVES This study investigated the effect of a very long-term exercise training program is not known in chronic heart failure (CHF) patients. BACKGROUND We previously showed that long-term moderate exercise training (ET) improves functional capacity and quality of life in New York Heart Association class II and III CHF patients. METHODS We studied 123 patients with CHF whose condition was stable over the previous 3 months. After randomization, a trained group (T group, n = 63) underwent a supervised ET at 60% of peak oxygen consumption (Vo(2)), 2 times weekly for 10 years, whereas a nontrained group (NT group, n = 60) did not exercise formally. The ET program was supervised and performed mostly at a coronary club with periodic control sessions twice yearly at the hospitals gym. RESULTS In the T group, peak Vo(2) was more than 60% of age- and gender-predicted maximum Vo(2) each year during the 10-year study (p < 0.05 vs. the NT group). In NT patients, peak Vo(2) decreased progressively with an average of 52 ± 8% of maximum Vo(2) predicted. Ventilation relative to carbon dioxide output (VE/Vco(2)) slope was significantly lower (35 ± 9) in T patients versus NT patients (42 ± 11, p < 0.01). Quality-of-life score was significantly better in the T group versus the NT group (43 ± 12 vs. 58 ± 14, p < 0.05). During the 10-year study, T patients had a significant lower rate of hospital readmission (hazard ratio: 0.64, p < 0.001) and cardiac mortality (hazard ratio: 0.68, p < 0.001) than controls. Multivariate analysis selected peak Vo(2) and resting heart rate as independent predictors of events. CONCLUSIONS Moderate supervised ET performed twice weekly for 10 years maintains functional capacity of more than 60% of maximum Vo(2) and confers a sustained improvement in quality of life compared with NT patients. These sustained improvements are associated with reduction in major cardiovascular events, including hospitalizations for CHF and cardiac mortality.

Diagnostic Criteria and Management of Subacute Ventricular Free Wall Rupture Complicating Acute Myocardial Infarction

In this prospective study we evaluated the value of the main diagnostic criteria for postinfarction subacute rupture of the ventricular free wall. Two-dimensional echocardiograms and recordings of right atrial pressure and waveform were immediately obtained in every patient exhibiting rapid clinical and/or hemodynamic compromise in the acute infarction setting. The same protocol was applied to patients referred from other hospitals for suspected myocardial rupture. In 28 cases a subacute free wall rupture was identified. In most of the patients the diagnosis was based on the demonstration of hemopericardium and cardiac tamponade by echocardiography, cardiac catheterization and, occasionally, by pericardiocentesis. In 2 instances, the identification of intrapericardial echo densities suggesting clots, in the absence of cardiac tamponade, allowed a diagnosis of subacute rupture. Direct, but indistinct visualization of myocardial rupture was obtained in 4 cases. Among the 28 patients with this complication, 4 died while awaiting surgery and 24 underwent surgical repair (mortality rate 33%). Long-term outcome of survivors was favorable. Various myocardial lesions underlie postinfarction subacute free wall rupture. Clinical presentation varied widely. The diagnosis was based, usually but not always, on the association of hemopericardium and signs of cardiac tamponade. An organized approach to management of this complication of acute myocardial infarction was suggested.

Comparison of impedance cardiography with thermodilution and direct fick methods for noninvasive measurement of stroke volume and cardiac output during incremental exercise in patients with ischemic cardiomyopathy

In the last decade, an inexpensive and simple noninvasive method (i.e., transthoracic electrical bioimpedance cardiography, has been tested in healthy subjects and patients with various heart disease for measuring stroke volume and cardiac output at rest and/or during exercise. However, the results are still controversial, especially when measurements are obtained during exercise and data on reproducibility during exercise are lacking. Twenty-five consecutive patients (20 men and 5 women, mean age 48 +/- 9 years) in sinus rhythm with documented coronary artery disease and a previous myocardial infarct were studied. Patients were divided into 2 groups. Group A had ischemic cardiomyopathy, characterized by left ventricular (LV) enlargement and LV ejection fraction depression (35 +/- 8%). Group B had normal LV dimensions and ejection fraction (62 +/- 9%). After a familiarization study, all patients underwent an exercise test with gas exchange analysis and hemodynamic measurements. Stroke volume and cardiac output were simultaneously obtained at rest and at the end of each work rate stage with 3 methods: impedance, thermodilution, and direct Fick. Group A reached a lower peak oxygen uptake (56%), peak work load (60%), and peak systolic blood pressure (69%) than group B. Cardiac output and stroke volume were significantly greater at submaximal and peak exercise in group B than in group A (p < 0.0001). There were no significant differences in stroke volume and cardiac output in the 3 techniques at any matched work rate. There was no significant difference between measurements obtained by 2 experienced observers or between those obtained on 2 exercise tests performed on 2 different days. These results demonstrate that impedance cardiography is a noninvasive, simple, accurate, and reproducible method of measurement of cardiac output and stroke volume over a wide range of workloads.

Effects of exercise training on left ventricular filling at rest and during exercise in patients with ischemic cardiomyopathy and severe left ventricular systolic dysfunction

The aim of our study was to determine whether exercise training can augment left ventricular diastolic filling at rest and during exercise in patients with ischemic cardiomyopathy and whether any correlation exists between changes in diastolic filling and changes in exercise tolerance. Forty-three consecutive patients (mean age, 54 +/- 8 years) with ischemic cardiomyopathy and severe left ventricular systolic dysfunction (election fraction <30%) were studied. Group T (29 patients) was exercised on a cycle ergometer 3 times a week for 8 weeks at 60% of peak oxygen uptake. Group C (14 patients) was not exercised. All patients underwent an exercise test and a radionuclide ventriculography at baseline and after 8 weeks. At the end, no changes were found in group C. In group T, exercise training increased peak oxygen uptake (1 5%; p < 0.0001), work rate (1 5%; p < 0.005), peak early filling rate (10%; p < 0.02), and peak filling rate (1 1%; p < 0.03). At submaximal exercise, peak filling rate increased at all matched heart rates. The increase in peak filling rate was correlated with the increase in cardiac index (r= 0.72; p < 0.0001) at peak exercise. The independent predictors of the increase in peak oxygen uptake were changes in work capacity and peak early filling rate. The data demonstrate that exercise training can improve the exercise capacity of patients with ischemic cardiomyopathy and severe systolic-dysfunction. The increase in early diastolic filling at rest and during exercise may contribute to the improvement in peak oxygen uptake.

Low dose dobutamine echocardiography predicts improvement in functional capacity after exercise training in patients with ischemic cardiomyopathy: prognostic implication.

OBJECTIVES This study sought to investigate whether the identification of hibernating myocardium by low dose dobutamine stress echocardiography (LDSE) may predict an improvement in functional capacity after moderate exercise training in patients with ischemic cardiomyopathy. Another objective was to assess whether exercise training may affect the outcome. BACKGROUND There is evidence that exercise training improves left ventricular (LV) function as well as functional capacity in patients with a previous myocardial infarction and LV dysfunction. We hypothesized that the magnitude of these improvements might be related to the extent of hibernating myocardium. METHODS We studied 71 consecutive patients 56+/-9 years old (mean +/- SD) with chronic heart failure secondary to ischemic cardiomyopathy (LV ejection fraction [LVEF] <40%). All patients were in sinus rhythm and were clinically stable during the previous 3 months. Patients were randomized into two matched groups. Group T (n = 36) underwent exercise training at 60% of peak oxygen uptake (Vo2) three times a week for 10 weeks. Group C (n = 35) did not exercise. At study entry and end, all patients underwent an exercise test with gas exchange analysis and LDSE (5 to 20 microg/kg body weight per min). RESULTS At baseline, a positive contractile response (CS+) to LDSE was observed in 317 of 576 segments in group T and 291 of 560 segments in group C. After 10 weeks, peak Vo2 and peak work rate increased only in trained patients (peak Vo2: from 16.2+/-3 to 20.8+/-4 ml/kg per min; work capacity: from 108+/-20 to 131+/-25 W, p < 0.001 vs. group C for both). The presence of CS+ at baseline was associated with a sensitivity of 70% and a specificity of 77% for predicting an increase in the functional capacity after exercise training. Positive and negative predictive values of LDSE were 84% and 59%, respectively. Independent predictors of cardiac events were a pre-to-posttraining difference in LVEF at peak dobutamine infusion and the presence of a viable response at baseline (p = 0.004 and 0.008, respectively). The log-rank test demonstrated that trained patients had a significantly lower probability of cardiac events during follow-up than sedentary control patients (p < 0.001). CONCLUSIONS The presence of hibernating myocardium as assessed by LDSE predicts the magnitude of improvement in functional capacity after moderate exercise training in patients with chronic heart failure. A significant increase in functional capacity after exercise training is associated with a lower incidence of cardiac events during follow-up.

A Four-Minute Submaximal Constant Work Rate Exercise Test to Assess Cardiovascular Functional Class in Chronic Heart Failure

To develop a submaximal constant work rate exercise test able to grade cardiovascular dysfunction in patients with chronic heart failure, 80 patients and 59 control subjects performed a symptom-limited incremental exercise test and a constant work rate exercise test at a fixed work rate (50 W for 4 minutes). The time constant of VO2 at the start of constant work rate exercise and time for gas exchange ratio (respiratory exchange ratio) to equal 1 were independent predictors of cardiovascular functional class and correctly classified the functional class in 89 +/- 9% and 83 +/- 11% of patients, respectively.