Human heart failure remains a challenging illness despite advances in the diagnosis and treatment of heart failure patients. There is a need for further improvement of our understanding of the failing myocardium and its molecular deterioration. Porcine models provide an important research tool in this respect as molecular changes can be examined in detail, which is simply not feasible in human patients. However, the human heart failure syndrome is based on symptoms and signs, where pig models mostly mimic the myocardial damage, but without decisive data on clinical presentation and, therefore, a heart failure diagnosis. In perspective, pig models are in need of some verification in terms of the clinical definition of the experimental condition. After all, humans are not pigs, pigs are not humans, and the difference between the species needs to be better understood before pig models can fully be used to elucidate the human heart failure syndrome.