Considerable variability exists among cardiovascular guidelines

Medical societies typically develop guidelines to help physicians and patients understand the best way to prevent and treat certain diseases. When it comes to cardiovascular risk assessment, though, there is considerable variability among the recommendations.

A systematic of 17 primary prevention guidelines on adult cardiovascular risk assessment found there was a consensus on performing cardiovascular disease risk screening and using prediction models for risk stratification and guiding treatment. However, there was no consensus on the ideal target population, the best risk prediction model, screening strategy or treatment thresholds.

Lead researcher M.G. Myriam Hunink, MD, PhD, of Erasmus Medical Center in Rotterdam, The Netherlands, and colleagues published their results online in the Annals of Internal Medicine Sept. 13.

“Cardiovascular screening guidelines still have considerable discrepancies, with no consensus on optimum screening strategies or treatment threshold,” the researchers wrote. “Physicians should assess the strength of the recommendations and the level of evidence to decide which of the recommendations they should implement.”

The researchers searched the MEDLINE and CINAHL databases for guidelines published between May 3, 2009, and June 30, 2016, as well as websites of guideline development organizations. They also searched the following guideline-specific databases: National Guideline Clearinghouse in the U.S., National Library for Health Guidelines Finder in the U.K., Canadian Medical Association Clinical Practice Guidelines Infobase and Guidelines International Network International Guideline Library.

They identified 21 guidelines containing recommendations for cardiovascular risk assessment among healthy adults who were not receiving treatment for diabetes, hypertension, hypercholesterolemia and other high-risk cardiovascular conditions. The guidelines were written in English and came from the U.S., Canada, United Kingdom, Australia and New Zealand.

Of the 21 guidelines, 17 had a rigor score of 50 percent or greater. There were five guidelines for total cardiovascular screening, seven for dysglycemia screening, two for dyslipidemia screening and three for hypertension screening.

All but one of the guidelines supported cardiovascular disease risk assessment, including five as the primary approach and 11 as the secondary approach. In addition, 14 of 17 guidelines recommended record-based screening or case finding or opportunistic screening.

Although there was no consensus of the best cardiovascular disease risk prediction model, the researchers found that most guidelines recommended integrating age, sex, smoking, blood pressure and lipid levels into the models. Most also agreed that ethnicity should be considered as a risk factor.

The researchers added that thresholds for initiating treatment were typically based on 5- or 10-year absolute risk for cardiovascular disease or the combination of age and additional cardiovascular disease risk factors.

Further, they noted that guidelines in the U.S. and Canada usually advocate to begin screening when people are 20 years old, while guidelines in Europe, the U.K. and Australia suggest screening beginning after people turn 40 years old.

In addition, they found that the five guidelines that assessed total cardiovascular risk used different calculators, had different endpoints and included different risk factors.

The researchers mentioned a few limitations of their review, including that they only analyzed guidelines developed by Western national or international medical organizations. They also were not blinded to the organization names that developed the guidelines or the countries of origin. They did not assess the clinical validity of the recommendations or review them for lifestyle interventions, either.

“The optimal strategy for systematic screening of the apparently healthy population remains to be found,” the researchers wrote. “Some groups advocate continuing with the current strategy of screening with the aim of trying to mold it into a system that eventually shows benefit, whereas others are asking for the programs to be halted until such a time that the evidence of benefit justifies the resources invested. Recent publications ad- dressing some of these gaps and future research in identifying the most effective strategies will help shape future guideline recommendations.”