Exercise training intensity determination in cardiovascular rehabilitation: Should the guidelines be reconsidered?

AIMS: In the rehabilitation of cardiovascular disease patients a correct determination of the endurance-type exercise intensity is important to generate health benefits and preserve medical safety. It remains to be assessed whether the guideline-based exercise intensity domains are internally consistent and agree with physiological responses to exercise in cardiovascular disease patients. METHODS: A total of 272 cardiovascular disease patients without pacemaker executed a maximal cardiopulmonary exercise test on bike (peak respiratory gas exchange ratio >1.09), to assess peak heart rate (HRpeak), oxygen uptake (VO2peak) and cycling power output (Wpeak). The first and second ventilatory threshold (VT1 and VT2, respectively) was determined and extrapolated to %VO2peak, %HRpeak, %heart rate reserve (%HRR) and %Wpeak for comparison with guideline-based exercise intensity domains. RESULTS: VT1 was noted at 62 ± 10% VO2peak, 75 ± 10% HRpeak, 42 ± 14% HRR and 47 ± 11% Wpeak, corresponding to the high intensity exercise domain (for %VO2peak and %HRpeak) or low intensity exercise domain (for %Wpeak and %HRR). VT2 was noted at 84 ± 9% VO2peak, 88 ± 8% HRpeak, 74 ± 15% HRR and 76 ± 11% Wpeak, corresponding to the high intensity exercise domain (for %HRR and %Wpeak) or very hard exercise domain (for %HRpeak and %VO2peak). At best (when using %Wpeak) in only 63% and 72% of all patients VT1 and VT2, respectively, corresponded to the same guideline-based exercise intensity domain, but this dropped to about 48% and 52% at worst (when using %HRR and %HRpeak, respectively). In particular, the patient's VO2peak related to differently elicited guideline-based exercise intensity domains (P < 0.05). CONCLUSION: The guideline-based exercise intensity domains for cardiovascular disease patients seem inconsistent, thus reiterating the need for adjustment.

Reduction of cardiovascular event rate: different effects of cardiac rehabilitation in CABG and PCI patients.

OBJECTIVE: In coronary artery disease, the implementation of a cardiac rehabilitation (CR) programme favourably affects cardiovascular prognosis. However, it remains uncertain whether patients benefit to a similar extent from CR after coronary artery bypass graft surgery (CABG) or percutaneous coronary intervention (PCI). In this study, we have assessed whether CR is equally effective for suppressing the two-year cardiovascular event incidence after CABG or PCI. METHODS AND RESULTS: 194 PCI and 149 CABG patients participated in a three-month CR programme, while 245 PCI and 89 CABG patients received standard care. After the completion of CR during a two-year follow-up, data on cardiovascular risk factors, medication and cardiovascular events (repeat coronary revascularisation, acute myocardial infarction, and death) were collected from hospital files. Both CABG and PCI patients included into CR showed a significantly lower mortality, as compared to control patients (0.6% vs. 4.2%, P < 0.05). However, total cardiovascular disease incidence was significantly lower as a result of CR in CABG patients (4.7% vs. 14.0%, P < 0.05), but not in PCI patients (19.1% vs. 22.4%, P > 0.05). CONCLUSION: When following a similar 3-month cardiac rehabilitation programme, the reduction of cardiovascular disease incidence during 2 years of follow-up is different between PCI and CABG patients.

Importance of exercise training session duration in the rehabilitation of coronary artery disease patients.

BACKGROUND: In cardiac rehabilitation, 40-60-min exercise training sessions are advised. However, because of the increasing coronary artery disease (CAD) prevalence and higher workload for cardiac rehabilitation centres, it remains unclear whether 40-min exercise training sessions are equally effective as 60-min exercise training sessions. DESIGN: Prospective randomized clinical trial. METHODS: One hundred and thirty-four CAD patients were included in a 7-week rehabilitation programme. All patients exercised 3 days per week, at a heart rate corresponding to 65% of baseline peak oxygen uptake (VO2peak). Patients were randomized in two groups: 40 versus 60-min exercise training sessions. Changes of body anthropometrics, resting haemodynamics, exercise capacity and ventilatory threshold, blood plasma lipid profile and C-reactive protein level were assessed. RESULTS: As a result of rehabilitation, exercise capacity, ventilatory threshold, and blood plasma lipid profile improved significantly in the total population (P<0.05), without differences between subgroups (P>0.05). Body weight and waist circumference decreased significantly in total population (P<0.01), but with a greater magnitude in the 40 versus 60-min exercise session group (P<0.05). CONCLUSIONS: In the early rehabilitation of CAD patients, 40-min exercise training sessions seem to be at least as effective for improving body anthropometrics, blood plasma lipid profile and exercise capacity, as compared with 60-min exercise training sessions.

Cardiac rehabilitation reduces the rate of major adverse cardiac events after percutaneous coronary intervention.

BACKGROUND: Despite multiple publications on effects of rehabilitation in cardiac patients, rehabilitation is not fully known to be of value in post-percutaneous coronary intervention (PCI) patients. AIMS: To investigate the influence of cardiac rehabilitation on the incidence of major adverse cardiac events (MACEs) in post-PCI patients. METHODS: Retrospectively and nonrandomized 140 post-PCI patients (107 males, mean age 62 (7) years) participated in a 3-month rehabilitation program, starting 2 weeks post-PCI, while 83 post-PCI patients (54 males, mean age 68 (8) years) did not and were all followed up for 15 months. Data on cardiac medication prescription and incidence of MACE (including angina pectoris with or without reintervention, restenosis, myocardial infarction, revascularisation with re-PCI or CABG, and death) were collected. The relationship with cardiovascular risk factors including sex, smoking behaviour, obesity, diabetes mellitus, hypertension, familiar predisposition, and hypercholesterolemia was analysed. RESULTS: The incidence of total MACE in the rehabilitation group is significantly lower than in the control group (24% vs. 42%, respectively; P<0.005). The incidence of documented restenosis, angina pectoris with resulting reintervention, all revascularisations, and death is significantly lower in the rehabilitation group, compared with the control group. CONCLUSION: The incidence of MACE and restenosis is significantly lower when PCI patients are included in a cardiac rehabilitation program.

Combined endurance/resistance training reduces NT-proBNP levels in patients with chronic heart failure.

AIMS: This study was designed to evaluate the effects of combined endurance/resistance training on NT-proBNP levels in patients with chronic heart failure (CHF). The safety of resistive weight training for patients with CHF is questioned. Possible detrimental effects include an increase in ventricular diastolic pressure and secondary unfavourable remodelling. Circulating levels of the N-terminal fragment of brain natriuretic peptide (NT-proBNP) reflect left ventricular diastolic wall stress and are strongly related to mortality and treatment success in CHF. METHODS AND RESULTS: In this study, 27 consecutive patients with stable CHF and left ventricular ejection fraction (LVEF) <35% were enrolled in a 4 months non-randomized combined endurance/resistance training programme. Blood sampling for measurement of NT-proBNP, functional assessment, cardiopulmonary exercise testing, echocardiography and radionuclide angiography were performed at entry and after 4 months. After 4 months, exercise training caused a significant reduction in circulating concentrations of NT-proBNP (2124+/-397 pg/ml before, 1635+/-304 pg/ml after training, p=0.046, interaction), whereas no changes were observed in an untrained heart failure control group. NYHA functional class (p=0.02, interaction), maximal (peak VO2: p=0.035, interaction; maximal workload: p<0.00001, interaction) and submaximal (workload at anaerobic threshold: p=0.001, interaction; rate-pressure product at anaerobic threshold: p=0.001, interaction) exercise parameters as well as work efficiency (Wattmax/VO2peak: p=0.0001, interaction) were significantly improved. In addition, a decrease in left ventricular end-systolic diameter was observed in the trained heart failure group (p=0.016). CONCLUSION: Four months of combined endurance/resistance training significantly reduced circulating levels of NT-proBNP in patients with CHF, without evidence of adverse remodelling. Exercise training might offer additional non-pharmacological modulation of the activated neurohormonal pathways in the setting of CHF.