First successful HeartMate 3 in Vietnam: Anatomical challenges of a small, spherical ventricle, and an oval-shaped thoracic morphology.

Advanced heart failure remains a significant global health burden, with limited access to mechanical circulatory support in developing nations. We report the first successful implantation of a HeartMate 3 (HM3) left ventricular assist device (LVAD) in Vietnam, marking a critical milestone in the country's cardiovascular surgery. The patient, a 46-year-old female with stage D heart failure (NYHA class IIIB, INTERMACS profile 4) secondary to dilated cardiomyopathy, presented with dual anatomical constraints. Preoperative imaging revealed a technically challenging, small, and spherical left ventricle (long-axis: 52 mm). Furthermore, thoracic anthropometry demonstrated a distinct oval-shaped chest morphology common in Asian populations, with a low Thoracic Index of 0.67 (AP diameter 206.1 mm; transverse diameter 305.6 mm), significantly restricting the retrosternal space for device housing. Despite these constraints, the HM3 was successfully implanted through a full sternotomy, with meticulous attention to inflow cannula angulation. At the 6-month follow-up, the patient exhibited dramatic functional recovery (NYHA class I). Her Kansas City Cardiomyopathy Questionnaire (KCCQ-12) score surged from 51.04 to 91.67, and the 6-min walking distance improved from 315 to 450 m, without any device-related adverse events. This case confirms the feasibility of the HM3 in restricted anatomical settings and underscores the importance of considering race-specific thoracic morphology in the planning of advanced mechanical circulatory support.