Cardiovascular Risk Assessment for Primary Care

August 1, 2018

Cardiovascular risk assessment is mostly science but also an art, in part. Get an at-a-glance review here of the risk factors and algorithms that combine both.

The science of cardiovascular (CV) risk assesment is grounded in population-based scoring algorithms that use traditional risk factors to predict CV morbidity and mortality. The art in CV risk assessment is largely about incorporating individual nontraditional risk factors, biological surrogates, and judicious use of noninvasive measures to help identify more patients at risk - particularly asymptomatic patients and those a truly low risk - in order to refine treatment.

Khambhati et al, in a recent issue of Clinical Cardiology, provide a comprehensive review of traditional, nontraditional, and emerging CV risk factors as well as a number of risk scores and algorithms beyond the well-known Framingham Risk Score and ACC/AHA ASCVD Pooled Cohort Risk Calculator. Click through the short slide show above for our at-a-glance highlights of the article for pimary care.

First steps in comprehensive CV risk asssessment include a detailed patient history and physical examination to evaluate for risk factors. Next, a population-based risk calculator is used to assess both absolute and lifetime CVD risk. Evidence-based guidelines will suggest appropriate therapy (eg, statin, aspirin, hypertension Rx) which becomes the basis for a discussion and shared decision-making process with the the patient.

The term "risk factor" was coined in 1961 after identification in the Framingham Heart Study of an initial set of traditional risk factors for coronary heart disease. Added later to the original list of factors was family history of premature ahterosclerotic cardiovascular disease (ASCVD).

The original Framingham Risk Score (FRS) was developed in 1998. It was refined in 2002 by the third Adult Treatment Panel with a focus on hard CHD endpoints, death, and nonfatal myocardial infarction. In 2008 the FRS incorporated stroke, heart failure, and PAD as endpoints. The 2013 ACC/AHA Pooled Cohort ASCVD Risk Score is based on:
- Framingham original and offspring cohorts
- The Atherosclerosis Risk in Communities (ARIC) sutdy
- The Coronary Artery Risk development in Young Adults (CARDIA) study
- The Cardiovascular Health Study (CHS)

The 4 multivariate risk calculators above are among risk stratification tools incorporated into international guidelines. They differ in endpoints evaulated and in the predictor variables used. Risk estimates using these are often different from results using either FRS or the ACC/AHA Pooled Cohort Calculator.

SCORE - European Systematic Coronary Risk Evaluation algorithm
QRISK - prediction algorithm used by the British National Institute for Health and Care Excellence in place of the FRS
PROCAM - Prospective Cardiovascular MÃ¼nster Model
RRS - Reynolds Risk Score (includes hs-CRP)

Risk factors outside of the original Framingham set, thus non-traditional, have been identified as contributing to CVD pathogenesis and are used to help refine classification of individual risk. For example, the presence of metabolic syndrome adds increased risk for ASCVD that may be underrecognized. Women with rheumatoid arthritis are two times more likely to have an MI and up to 50% of mortality in RA patients has been attributed to CVD. In patients with HIV, accelerated atherosclerosis is seen in both HAART-naive and HAART-treated patients. Comorbidities associated with underlying low-grade inflammation (eg, COPD) contribute to CVD and chronic liever and kidney disease contribute to CV morbidity and mortality.

High sensitivity c-reactive protein (hs-CRP) is a surrogate marker of subclinical systemic inflammation and has been shown to independently predict CV events in asymptomatic patients.
Lipoprotein(a) (Lp[a]) is a proatherogenic biomarker that confers a genetic risk of CVD. When added to FRS and RRS calcuations, Lp(a) has been shown to enhance predictive capability of patients stratified as intermediate risk. Apolipoprotein B (apoB) can be measured directly to calculate atherogenic burden.

Noninvasive measures of the atherscleroticprocess at the vascular level are of widespread interest although not fully adopted by professional guidelines. An abnormal ankle-brachial index is associated with increased CV risk as well as atherosclerosis in other vascular regions. Coronary artery calcium, detected using CT scan, is a noninvasive measure of coronary calcification. A score of 0 suggests no identifiable diseae a low risk of ASCVD event over 10-15 years.

End notes: The current authors cite a 2012 editorial from JAMA, Cardiovascular risk assessment in the 21st century. Those writers note the ongoing efforts to improve CV risk prediction by adding additional risk factors to prediction models and that leads them to the question: "What makes a good prediction rule?" Their thoughts, above.

Reference: Khambhati J, Allard-Ratick M, Dhindsa D, et al. The art of cardiovascular risk assessment. Clin Cardiol. 2018;41:677-684.