Background-After mechanical heart valve replacement (MHVR), long-term use of unfractionated heparin is sometimes required because vitamin K antagonists (VKA) are temporarily contraindicated or because the time to reach the target international normalized ratio is long. The aim of this study was to investigate the feasibility of low-molecular-weight heparin treatment in these patients. Methods and Results-This work was conducted as a prospective study. We selected all patients (nϭ695) who underwent MHVR and were transferred to a postoperative cardiac rehabilitation center between January 2000 and January 2005. The study focused on patients who had not yet started VKA therapy or who had a below-target international normalized ratio despite VKA therapy. Unfractionated heparin was replaced by enoxaparin (100 IU/kg BID) until VKA treatment was fully effective. Two hundred fifty patients (60Ϯ11 years old) were enrolled 16Ϯ11 days after surgery (aortic valve replacement, nϭ190; mitral valve replacement, nϭ34; double valve replacement, nϭ26). Of these, 50% had permanent or transient atrial fibrillation, 40% had hypertension, 13% had diabetes, and 19% had a history of cardiac surgery. The mean duration of low-molecular-weight heparin treatment was 8.3Ϯ6.0 days. Patients were followed for 90 days, during which there were two major and three minor bleeding episodes and one transient ischemic attack. There were no cases of valve thrombosis and no deaths. Conclusions-After MHVR, one third of patients leave the cardiac surgery unit before VKA treatment is fully effective.Bridging anticoagulation therapy with enoxaparin appears to be feasible during this high-risk period for thromboembolism and could shorten the length of hospital stay. (Circulation. 2006;113:564-569.)

These results suggest that healing of the infarct-related lesion requires more than 1 month and that an "unstable" yellow plaque with adherent thrombus is common during that period. This finding may partly explain the unique behavior of recent infarct-related lesions, which are more prone to occlude than other lesions.

The Karvonen formula underestimates the heart rate at the anaerobic threshold in beta-blocked patients, which may lead to undertraining of patients with coronary artery disease; we propose another formula more adapted to these patients.

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Exercise training performed in cardiac rehabilitation centres is an adjuvant therapy in chronic heart failure patients with left ventricular dysfunction; it decreases the deleterious consequences of chronic heart failure. Exercise training attenuates neurohormonal stimulation, the production of proinflammatory cytokines and natriuretic peptide overexpression. Trained patients showed a significant decrease in the peripheral organ injuries encountered in chronic heart failure, with a reduction in vascular resistance and improvements in endothelial dysfunction and the oxidative capacity of peripheral muscles, without a deleterious effect on left ventricular remodelling. Ultimately, exercise training leads to a notable improvement in ventilatory capacity. These beneficial effects are accompanied by improvements in symptoms at rest, exercise capacity and quality of life. Several training programmes are in current use: exercise training sessions always include endurance exercise performed either at a constant load intensity or with interval training, combining periods of exercise performed at high intensity with periods performed at low intensity. Most of the time, training programmes also include resistance training sessions, which improves large muscle strength. Exercise training programmes seem to have a favourable effect on prognosis, even if the results of Heart Failure: a Controlled Trial Investigating Outcomes of Exercise Training (HF-ACTION) remain controversial, emphasizing the difficulty in monitoring observance and the importance of compliance with a long-term exercise training programme. Patients who do not improve their exercise capacity significantly after an exercise training programme have a poorer prognosis.