A new era in medicine is dawning. And it's just in time for a culture that worships youth and beauty, and that has witnessed a parade of scientific and technological triumphs. We don't just hope to stay young and vital, healthy and happy, forever - we expect it. What is surprising is how far medical science has come towards meeting those expectations. Now there are treatments to repair or replace tissues and organs, therapies that compensate for defective genes, devices that stand in for failing body parts, and treatments to keep us thin and wrinkle-free.

Repair or Replace

Rebuilding the heart The motto of this new era might be "Repair it if you can. Replace it if you can't." Ron Trachtenberg, now 59, needed some repairs. At 34, he was a self-described Type A person with a young family and a burgeoning accounting practice, when he was diagnosed with severe coronary artery disease. By 46, after a quadruple bypass operation, a heart attack and a second bypass, his poor health had forced him to sell his business. For years afterwards, he mostly stayed home, where his wife and two adult children helped care for him. He experienced the severe chest pain of angina as often as three times a day. "It felt like an eight-tonne elephant," he says.

Trachtenberg's cardiologist referred him to Dr Douglas Losordo, chief of cardiovascular research at Caritas St Elizabeth's Medical Centre in Boston. Losordo...