**5. Conclusion**

The usefulness of large animal models in cardiovascular medicine, especially pigs, was outlined on the basis of literature. Although the advantages and disadvantages of large animals should be further evaluated, there is a possibility that large animalbased approaches may contribute to the investigations in cardiovascular medicine. On the other hand, it is also recognized that there are opinions not to welcome large animal models for research purpose use and accurate regulation is indispensable. The number of animals used should be reduced to a minimum following the three R's principle (to reduce, refine, and replace animal models). Experiments using animals should be optimized and standardized considering their translatability and the welfare of the animals [82].
