Eugene Braunwald, a groundbreaking cardiologist, whose research helped transform heart disease from near-certain killer into a condition often manageable with medications procedures and careful monitoring, died on April 21 in Newton, MA. He was 96.

Regarded as one of the most influential cardiologists of the 20th and early 21st centuries, Dr. Braunwald’s research reshaped how doctors understood heart attacks, heart failure, and coronary artery disease, and helped lead to therapies that saved millions of lives — medications that lowered the heart’s workload and reduced blood pressure, and treatments that reopened blocked arteries.

Dr. Braunwald remained deeply involved in research well into the 21st century, publishing papers mentoring younger physicians, and contributing to clinical trials. In 2014, he was a leader of a study that found an alternative cholesterol-lowering drug could protect people from heart attacks and strokes. The study validated previous findings that lowering cholesterol prevents heart disease — settling the issue once and for all, Dr. Braunwald insisted. “People,” he said, “can stop yapping.”