Study on the Therapeutic Effect of Phase I Cardiac Rehabilitation on Elderly Patients With Coronary Heart Disease Complicated by Sarcopenia:A Single Center, Randomized Control Study in China

The purpose of this clinical trial is to explore whether Phase I cardiac rehabilitation can treat elderly patients with coronary heart disease complicated by sarcopenia. It will also investigate the mechanism of Phase I cardiac rehabilitation. The main questions it aims to answer are: * Can Phase I cardiac rehabilitation enhance muscle strength ? * Can Phase I cardiac rehabilitation reduce in vivo inflammatory indicators? Researchers will compare the experimental group (Phase I cardiac rehabilitation + drug therapy + general treatment) with the control group (drug therapy + general treatment) to see if Phase I cardiac rehabilitation can treat elderly patients with coronary heart disease complicated by sarcopenia and reduce inflammatory indicators. Participants will: * Receive Phase I cardiac rehabilitation training（mainly includes low-intensity resistance training, breathing training and bedside cycling） or conventional drug therapy for 3 consecutive months. * Undergo examinations 10 days after training, 1 month after discharge, and 3 months after discharge respectively. * Record changes in their muscle strength and blood inflammatory indicators.