Pet insurance data obtained from a study during years 2003–2006 in Sweden puts the median lifespan of the Maine Coon at > 12.5 years. 74% lived to 10 years or more and 54% lived to 12.5 years or more. Maine Coons are generally a healthy and hardy breed that is adapted to survive the challenging climate of New England. The most severe threat is feline hypertrophic cardiomyopathy (HCM), the most common heart disease seen in cats, whether purebred or not. In Maine Coons, it is thought to be inherited as an autosomal dominant trait. Middle-aged to older cats and males are thought to be predisposed to the disease. HCM is a progressive disease and can result in heart failure, paralysis of the hind legs due to clot embolization originating in the heart, and sudden death.