Dr. Christopher Petit is the co-director of the Children's Heart Center at NewYork-Presbyterian Morgan Stanley Children's Hospital and division chief of pediatric cardiology at Columbia University, and… a stubborn optimist. That optimism has made all the difference in his years of treating a rare heart disease in newborns: Pulmonary Vein Stenosis (PVS). Dr. Petit’s determination to better understand and treat PVS has led him and his team to make important breakthroughs in the field, including the use of sirolimus– an immune-targeted medication usually used for cancer treatments– as a systemic oral therapy to treat PVS, as well as the development of a hybrid surgical method for treating patients with severe disease, performed in collaboration with Dr. Emile Bacha. The results: drastically improved survival rates for his patients.