40. COMPLIANCE WITH THE USE OF VITAMIN K ANTI-COAGULANT DRUGS IN PATIENTS AFTER MECHANICAL HEART VALVE REPLACEMENT SURGERY AT THE CARDIOLOGY CLINIC, DA NANG HOSPITAL. YHCĐ. 2025;66(CĐ10-HNKH Trường ĐH Phenikaa). doi:10.52163/yhc.v66iCD10.2647