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Thursday 23 January 2014

Love 'Em or Leave 'Em: Experts on Both Sides Debate the New Lipid Guidelines

DALLAS, TX and WASHINGTON, DC — It has been two months since the new clinical guidelines for the treatment of cholesterolwere published[1], and feedback is starting to slowly emerge as clinicians begin incorporating the recommendations into clinical practice.
The American College of Cardiology (ACC) and American Heart Association (AHA) guidelines, which were developed in conjunction with the National Heart, Lung, and Blood Institute (NHLBI), were a radical departure from previous iterations, most notably in their abandonment of LDL-cholesterol targets. In the past, clinicians were advised to treat patients with cardiovascular disease to less than 100 mg/dL or the optional goal of less than 70 mg/dL.
As reported by heartwire at the time, the expert panel stated there was simply no evidence from randomized, controlled clinical trials to support treatment to a specific target. As a result, the new guidelines make no recommendations for specific LDL-cholesterol or non-HDL targets for the primary and secondary prevention of atherosclerotic cardiovascular disease.
For one clinician, Dr Stanley Hazen (Cleveland Clinic, OH), the strict adherence to only clinical-trial data is a limitation and not a strength of the new guidelines.
"First, it ignores a wealth of information on the pathophysiology of the disease process. Second, it presumes that the reason trials are designed is to answer guideline questions," he told heartwire . "They aren't. Trials are designed by pharmaceutical companies trying to get claims issued on their drugs. More important, the absence of randomized clinical-trial data does not justify inaction if LDL cholesterol remains elevated."
Accelerating Vascular Age
In his commentary published January 8, 2014 in the Cleveland Clinic Journal of Medicine, Hazen, along with first author Dr Chad Raymond (Cleveland Clinic, OH), lay out their concerns with the clinical guidelines and highlight some of the shortcoming with the new recommendations[2].
For Hazen, there are multiple reasons that physicians should continue to treat to specific LDL-cholesterol targets, the first and foremost being that patients are different and no single treatment fits such a large and heterogeneous patient population at risk for cardiovascular disease and stroke. The guidelines simply call for a moderate- or high-dose statin in high-risk patients depending on the clinical scenario and no subsequent assessment of LDL cholesterol.
"In the very highest-risk patients, the ones with extraordinarily high levels of cholesterol, those who get maximally tolerated statins, if there is still a substantial LDL-cholesterol burden, they are going to have substantial residual risk," he said. "The preponderance of data in aggregate shows that there is higher residual risk proportionate to the LDL level that's remaining. The new guidelines completely ignore the pathophysiology of the disease process—a disease that takes decades to develop."
The clinical guidelines are unique among documents past in that the emphasis is strictly on statin therapy rather than LDL-cholesterol-lowering medications more generally. In individuals with atherosclerotic cardiovascular disease, high-intensity statin therapy—such as rosuvastatin (Crestor, AstraZeneca) 20 to 40 mg or atorvastatin 40 to 80 mg—should be used to achieve at least a 50% reduction in LDL cholesterol unless otherwise contraindicated or when statin-associated adverse events are present. In that case, doctors should use a moderate-intensity statin. Similarly, for those with LDL-cholesterol levels >190 mg/dL, a high-intensity statin should be used with the goal of achieving at least a 50% reduction in LDL-cholesterol levels.
For Hazen, the new clinical guidelines "turn back the clock on cardiovascular disease prevention" and have the potential to both overtreat older low-risk patients and undertreat those who are young yet are at higher lifetime risk.
For example, he cites a 25-year-old man who presents because his 45-year-old father just died from a heart attack. He has a fasting total cholesterol level of 310 mg/dL, HDL cholesterol of 50 mg/dL, triglyceride level of 400 mg/dL, and LDL cholesterol of 180 mg/dL. Even with the strong family history of premature coronary disease, because of his young age, the current guidelines do not suggest treatment because they do not apply to those less than 40 years old. However, even if his age were 40, his calculated 10-year risk would be <7.5% based on a new and controversial risk calculator published alongside the guidelines.
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