
Diana Cepeda takes the subway between her Brooklyn home and her Times Square office. Up until a year ago, it was a daily commute that could have killed her. "I was born with heart disease," she said. In and out of cardiologists' offices since she was eight years old, Cepeda's heart condition worsened last year. "As I got older, my aortic valve started deteriorating, and my mitral valve had a little pinhole in it," she said. When she was 53, her failing heart led her to New York-Presbyterian Hospital's Columbia campus to visit one of the best-known heart valve surgeons in the country -- Dr. Mehmet Oz, the celebrity doctor famous for his appearances on Oprah Winfrey's show and his own daytime talk show.