 Parsonnet conducted research and studies with pioneers of the heart surgery field, Michael DeBakey and Denton Cooley (the first person in the United States to perform a heart transplant in 1968).Parsonnet was the first surgeon in New Jersey to implant a permanent pacemaker (1961) and to complete a heart transplant (1985) and kidney transplant.When asked about his success, he simply says, "I was in the right place at the right time."