This prospective, multicenter, randomized controlled trial aims to evaluate whether non-intubated spontaneous ventilation anesthesia (NISVA) supported by a supraglottic airway can reduce cardiopulmonary complications and promote postoperative recovery in adults undergoing isolated orthotopic heart transplantation. Approximately 220 participants will be randomly assigned in a 1:1 ratio to either the NISVA group or the conventional endotracheal general anesthesia group. The study will primarily evaluate a cardiopulmonary composite endpoint within 30 days after transplantation. Postoperative invasive mechanical ventilation duration, pulmonary function recovery, intensive care unit length of stay, and other postoperative recovery outcomes will also be assessed. Participants will be followed during hospitalization and at 30 days, 3 months, and 1 year after transplantation to evaluate cardiopulmonary function, safety, postoperative recovery, rehospitalization, and survival.