INTERVENTIONAL CARDIOLOGY AND CLINICAL TRIALS
On September 16, 1977, Andreas Gruentzig performed the first coronary angioplasty on a 38-year-old businessman with unstable angina and a discrete proximal left anterior descending (LAD) artery lesion. The procedure was a success, and on subsequent angiograms at 10 years and 23 years, the patient continued to have a patent artery.1,2 Gruentzig reported his first series of favorable results and immediately called for a prospective randomized trial comparing it to bypass surgery.3,4 The field of interventional cardiology was born, and percutaneous transluminal coronary angioplasty (PTCA) quickly spread, with multiple operators in many countries gaining experience.
Today, percutaneous coronary intervention (PCI) is the dominant form of coronary revascularization. The practice of interventional cardiology has changed dramatically to include numerous diagnostic, pharmacologic, and technologic advances. The challenge for the practicing interventionalist is deciding when to adopt new therapies or technologies, in which patients and clinical situations to apply them, and at what cost. Fortunately, in keeping with Gruentzig’s initial emphasis, the field now requires rigorous scientific studies to evaluate these new therapies and technologies. As a consequence, the interventional cardiologist is faced with a large body of medical literature of varying quality.
Therefore, a framework for reading and evaluating the medical literature is necessary to make the best decisions for patient care. This practice, termed evidence-based medicine, is defined by Sackett et al5 as “the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients.” Much of the general framework used in this chapter and in most of the current practice of evidence-based medicine has been adapted from the in-depth guide on evaluating and teaching the medical literature provided by Sackett et al.6 The goal of this chapter is to provide some tools and specific examples that help the reader become facile at reading and evaluating the medical literature, specifically clinical trials with a focus on interventional cardiology.
Sackett and colleagues5,6 have identified 3 steps as integral to the practice of evidence-based medicine. They are as follows: (1) asking a clinical question and finding an answer, (2) reading the answer article, and (3) applying the results to individual patient care. The first step, asking a clinical question and finding an answer, is not addressed directly in this chapter. With the increase in electronic resources, including PubMed, MEDLINE, and additional online references, most clinicians have access to the medical literature. The majority of the discussion focuses on reading the clinical trial article. Finally, there is a section on applying the results to the care of the individual patient. Many of the principles used in this chapter for evaluating the medical literature can be found in detail in the JAMA User’s Guide to the Medical Literature series.7-10
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