This study will evaluate whether adding Yiqi Fumai lyophilized injection to stable guideline-directed treatment improves symptoms, physical limitations, and NT-proBNP in adults with stable chronic heart failure caused by coronary heart disease. About 100 participants at four hospitals in China will receive 8 vials of Yiqi Fumai once daily by intravenous infusion for a planned 10 days. The two main outcomes will be the proportion of participants with at least a 5-point improvement in the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score and the proportion with at least a 30% decrease in NT-proBNP at the Day 11 end-of-treatment visit after the 10-day treatment course. Participants will be followed through Day 90 for heart function, exercise capacity, quality of life, safety, healthcare use, costs, and clinical events. A randomly selected subgroup of 50 participants will provide paired blood samples on Day 1 before the first infusion and on Day 11 at the end-of-treatment visit for exploratory transcriptomic, proteomic, and metabolomic analyses.