Framingham Risk Calculator
Using Canadian Lipid Guidelines

Features of this Calculator:

1. This is a tool for primary prevention. Patients with established disease are at high risk and require no further risk factor evaluation.
2. Based on Canadian Cardiovascular Society Guidelines on Dyslipidemia 2009.
3. ASA information based on U.S. Preventive Services Task Force recommendations 2009. Patients outside the age for potential benefit are not flagged.
4. Designed primarily as a tool for primary prevention of cardiovascular disease.
5. Framingham tables used now include 10-year risk for MI, cardiovascular death, stroke, coronary artery disease, peripheral arterial disease and congestive heart failure.
6. Family history in a first-degree relative prior to age 60 is included in risk stratification.
7. hsCRP (C-reactive protein) can be included to further clarify risk of patients at intermediate risk (10-19%), and above a certain age, who have normal lipids. Patients who might benefit from hsCRP evaluation will be flagged.
8. Outcomes include percentage risk, nominal risk, ASA recommendation, threshold LDL for statin treatment, and goal LDL.
9. Available in SI units (mmol/L) and US units (mg/dl).
10. Diabetics are scored similarly to other patients unless they are flagged at high risk by virtue of age or age combined with at least one other risk factor.
11. Numbers needed to treat are included for each calculation for the purpose of placing the prospect of therapy into perspective for the patient. This number implies no great degree of precision, and is based on a number of arguable suppositions:

· Relative statin benefit is broadly similar across a wide range of LDL levels (1,2). Absolute benefit carries larger impact on events at higher Framingham risk scores.

· Relative statin benefit has been best studied in the Heart Protection Study (3) using simvastatin 40 mg. daily, where 27% reduction in events was achieved.

· There is no good evidence for use of one statin over another in terms of primary prevention event rates (4).

· Relative risk reduction is similar in primary prevention to that found in secondary prevention (2).

· Hs-CRP levels add no increased precision in risk calculation (3,5). Use of this value is optional in this calculator.

· Use of higher dose, higher potency statins will achieve higher relative risk reductions, but 2/3 of the statin benefit will be achieved with the initial dose (6).

· Generally this NNT reflects the benefit of a daily dose of generic simvastatin 40 mg (3).

References:

1. Mills EJ, et al. Primary prevention of cardiovascular mortality and events with statin treatment. J American Coll Cardiol 2008; 52(22): 1769-81.

2. Pignone M. Treatment of lipids (including hypercholesterolemia) in primary prevention. In: Freeman MW, Rind DM, eds. UpToDate. 19.1; 28 February 2011.

3. Heart Protection Study Collaborative Group. C-reactive protein concentration and the vascular benefits of statin therapy: an analysis of 20 536 patients in the Heart Protection Study.

4. Mills EJ, et al. Efficacy and safety of statin treatment for cardiovascular disease: a network meta-analysis of 170 255 patients from 76 randomized trials. Q J Med 2011; 104:109–124. Lancet. 2011 February 5; 377(9764): 469–476.

5. Sattar N, et al. C-Reactive protein and prediction of coronary heart disease and global vascular events in the prospective study of pravastatin in the elderly at risk (PROSPER). Circulation 2007;115;981-989.

6. Shepherd J. Resource management in prevention of coronary heart disease: optimising prescription of lipid-lowering drugs. Lancet 2002; 359: 2271-2273.