Room for Improvement in Heart Disease Prevention Guidelines, Say Experts
Preventive cardiologists from Johns Hopkins and the Mayo Clinic have issued a list of suggested recommendations to the 2013 heart disease prevention guidelines issued by the American Heart Association and the American College of Cardiology (AHA/ACC). The list of upgrades is published in Mayo Clinic Proceedings.
The recommendations are intended to improve subsequent guidelines and clarify confusion regarding risk prediction and treatment of heart attacks and strokes. Study authors pointed out that reduced clinician adherence and dampened patient trust may have come from uncertainty or controversy on best practice. Though the guidelines were important in the improvement of heart attacks and stroke prevention, some parts still remain unpopular among clinicians and public health experts.
Current guidelines recommend preventive statins in patients with high cholesterol but no overt heart disease who have a 10-year risk for suffering a heart attack or stroke of ≥7.5%. However, clinicians have expressed concern about potential over-treatment since the risk-scoring "calculator" can overestimate the likelihood of a heart attack or stroke. Risk overestimation plus the reduction of the risk threshold could lead to expanded consideration of statin therapy in the general population and lead a greater proportion of asymptomatic patients with subclinical atherosclerotic disease or significant coronary stenoses to statin therapy, but there has been concern about it also leading to unnecessary treatment in more patients that are unlikely to experience cardiovascular events. Instead, the researchers say new formulas should estimate risk based on outcomes from modern vs. historical populations, and should be recalibrated periodically to reflect updated data.
The authors also suggest diversifying risk scores to factor in other races and ethnicities such as Latin American, South Asian, or East Asian as well as paying more attention to patients with borderline risk scores where a clinical decision may not be as clear. The next revised guidelines can offer test options to better clarify a patient's risk.
Because coronary artery calcium (CAC) is usually considered to be the most accurate tool for cardiovascular disease (CVD) risk assessment, future guidelines should also consider combining the traditional risk factor-based paradigm with a more personalized atherosclerosis imaging model. The finding of a CAC score >100 may bring about statin therapy initiation discussions among clinicians and patients; CAC could also be used to motivate statin-reluctant patients and aid decision making in patients at risk for drug-drug interactions.
Current U.S. guidelines urge clinicians to gauge treatment success by calculating the percentage drop in a patient's cholesterol levels. But European and Canadian guidelines call on physicians to aim for a fixed cholesterol number instead. The "percentage" approach is not only discordant with international guidelines, say senior author Seth Martin, MD, MHS, an assistant professor of medicine at the Johns Hopkins University School of Medicine.Martin, but requires confusing and messy arithmetic that often discourages clinicians from using it. Moreover, the authors write, the "percentage" approach has fueled the misconception that cholesterol levels no longer matter. They do, the authors say. Harmonizing the "percentage drop" and "target number" approach to measuring therapeutic success would go a long way to improving clarity in clinical decisions.
The next set of guidelines should include concrete tips on how to communicate risk in concrete rather than abstract terms and how clinicians can strike a balance between being the active problem-solvers patients expect them to be while giving patients autonomy and final say.
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