sentences:  In the subsequent three years, Dr. Gruentzig performed coronary angioplasties in 169 patients in Zurich, while teaching the practice of coronary angioplasty to a field of budding interventional cardiologists.Ten years later, nearly 90 percent of these individuals were still alive.By the mid 1980s, over 300,000 PTCAs were being performed on a yearly basis, equalling the number of bypass surgeries being performed for coronary artery disease.