1970s: Growth and innovation

Key events in the 1960s set the stage for the cardiac cath lab practice of the 1970s. Until the first reported successful coronary bypass surgery in 1967, angina pectoris therapy relied mainly upon pharmacologic reduction in myocardial oxygen demand. Evidence of sustained postoperative enhanced coronary blood flow, symptom relief, and survival triggered a critical need for coronary angiography to guide therapy. Procedure volumes tripled, and remarkable advances in invasive procedures, imaging, and computer applications occurred throughout the 1970s. New staff and fellows from around the world with new ideas, skill sets, and personalities accelerated this transformation. Invasive training programs and research increased, and application for NIH funding was initiated. In one case, NIH funds were inadvertently delayed, so Mayo investigators started the study on Mayo funds alone. When apprised of this, the NIH Committee chair concluded, tongue in cheek, that "if NIH funding was delayed long enough, this critically important study could be completed without any NIH funds." It was completed, and NIH funds helped, belatedly. Highlights included evaluation of Prinzmetal's angina and Mayo's participation as a leading recruitment and thought leader in the Coronary Artery Surgery Study (CASS) of surgery versus medical therapy, and many subsequent multicenter NIH-funded prospective randomized clinical trials. Migration to electronic records enabled computer analysis and facilitated important clinical research studies, such as the powerful predictive value of ejection fraction upon survival in coronary heart disease. In 1979, the laboratory transformed from predominant diagnostic studies to include therapy. The primary Mayo value "the needs of the patient came first" guided the first percutaneous coronary angioplasty, resulting in a successful procedure and a grateful patient for the next decade. None of these advances happened by chance. The initiation of coronary angioplasty included rigorous debate with clinicians and cardiac surgeons to develop guidelines and protocols and obtain institutional approval. This paved the way for the cardiac lab to move from being one of the earliest adopters to becoming an international leading center in coronary angioplasty and its critical evaluation in the 1980s.