CardioSource WorldNews December 2014 - Page 33

CLINICAL NEWS American College of Cardiology Extended Learning ACCEL interviews and topical summaries of cardiology’s most interesting research areas Niacin, Fibrates, and the Highly ‘Difficult’ Lipoprotein Is add-on therapy on its way out? F rom the beginning, it just sounded too good to be a true: a vitamin that reduced “bad cholesterol” while simultaneously raising – often dramatically – the level of “good cholesterol.” Indeed, when niacin was first popularized in the late 1980s, criticism from the medical community was harsh. As papers began to be presented at major meetings, the discussions generally devolved to something dangerously close to playground name-calling. Part of the problem: niacin was first popularized in the general press and, only then, did the data back-fill begin to establish clinically what the public already believed. Over time, the data did indeed establish the effectiveness of niacin; as long as the irritating flush was acceptable, it performed as promised. At the same time niacin was being promoted as “a cholesterol cure,” the first statin (lovastatin) was approved by the US Food and Drug Administration (FDA). For most people, statins proved easier to tolerate than high-dose niacin, producing comparable (and eventually superior) LDL-C lowering than niacin. Given the residual risk of patients on statin therapy, niacin became a second-line agent. Early trials evaluating the combination of statin and niacin therapy enrolled a relatively modest number of patients over a relatively short treatment period. Therefore, a randomized clinical trial (RCT) powered for clinical endpoints was required to determine whether combined niacin/statin therapy was more effective than statin monotherapy alone. NIACIN FALLS SHORT IN AIM-HIGH AIM-HIGH (the Atherothrombosis Intervention in Metabolic Syndrome With Low HDL/High Triglycerides: Impact on Global Health Outcomes trial) compared therapy with niacin/simvastatin to simvastatin alone, but failed to demonstrate an incremental benefit of niacin among patients with ASCVD and on-treatment LDL-C values < 70 mg/dl.1 More than a failure of niacin, the results suggested a general failure of the HDL-C hypothesis. Soon thereafter, Michos and colleagues (including Roger S. Blumenthal, MD) reviewed the epidemiologic evidence s \ܝ[