A swine model for long-term evaluation of prosthetic heart valves

Background: The objective of this study was to develop a porcine model of mitral valve replacement (MVR) for long-term evaluation of prosthetic heart valves. Methods: Sixteen 25-kg male Bama miniature pigs underwent MVR using St Jude Medical valve (21 mm). Each animal was allocated to an anticoagulation protocol after surgery (group I, s.c. heparin injection and warfarin (n = 8); group II, s.c. low-molecular-weight heparin and warfarin (n = 8)) and was followed for up to 20 weeks. Terminal studies were carried out on all animals having survived for more than 140 days or died. Results: Fourteen animals survived for more than 1 month without signs of heart failure. One of group I animals died from haemorrhagic (haemopericardium) complications on the 9th postoperative day, and another animal of group I died on the 18th postoperative day because of valve thrombosis. Conclusions: Compared with other species, humans and pigs show remarkable anatomical and physiological similarities. This model is promising for long-term preclinical evaluation of prosthetic heart valves and evaluation of postoperative anticoagulant agents.