Despite decreasing coronary heart disease mortality among both men and women, this disease still remains the leading cause of death in the United States. In addition to known physiologic factors, such as hypertension, smoking, and elevated plasma cholesterol, psychosocial factors including anxiety, marital status, and social isolation have been shown to contribute to the risk of coronary heart disease. There is increasing evidence suggesting that pet ownership causes measurable short term psychological and physiological effects in people, including reduction of blood pressure and mitigation of psychological indicators of anxiety. There is also evidence that pet ownership is associated with clinically significant health effects in people, including improved survival after a coronary event. We hypothesize that pet ownership, though its ability to positively influence psychosocial risk factors, results in a lowered risk of coronary heart disease and increased survival after a coronary event if it occurs, and that increased pet ownership would further reduce mortality from coronary heart disease.