The cardiac catheter is an important tool, whose use over the latter half of the twentieth century has provided unprecedented improvements in the clinical care of patients with heart disease while extending our understanding of circulatory physiology and vascular pathobiology. In the process, it has defined two new areas of special expertise within our broader parent specialty: invasive and interventional cardiology.
Initially, use of the cardiac catheter was limited to the measurement of pressures and blood flow within the various chambers, elucidating both normal physiology and the pathophysiology of various disease states. With the advent of selective coronary angiography in the 1960s, the main emphasis of cardiac catheterization began to shift from hemodynamic measurements to the evaluation of coronary anatomy before bypass surgery, prompting the emergence of a cadre of “invasive” cardiologists who were skilled in the performance of such procedures.
Although Forssmann's original goal in 1929 to improve treatment of circulatory collapse through catheterization and limited therapeutic techniques had been developed in pediatric cardiology, it was not until 1977 (when Gruentzig introduced his concept of percutaneous transluminal coronary angioplasty) that the field of “interventional cardiology” was launched in earnest. By the mid-1980s, use of coronary angioplasty had grown to 300,000 procedures per year, equaling the number of bypass surgeries. Its scope broadened further in the late 1980s, with the introduction of several new therapeutic modalities (valvuloplasty, stent, atherectomy, and laser procedures), whose use in the 1990s grew to dominate coronary intervention. This has allowed progressive improvements in the success, safety, and durability of intervention (as demonstrated in an unprecedented series of clinical trials) and has boosted the annual interventional volume beyond 700,000 procedures. In 1999, the unique and substantial body of knowledge subsumed by this new discipline was further recognized by the creation of separate fellowships and a Certificate of Additional Qualification in the field of Interventional Cardiology.