Charts help predict risk of cardiovascular disease in 182 countries

Researchers have developed risk charts to help healthcare professionals predict the risk of fatal and nonfatal cardiovascular disease events for people in 182 countries.

They found that the predicted risks for people with the same risk factor profile were usually lower in high-income countries compared with low-income and middle-income countries. With the charts, doctors, nurses and other providers do not need to take laboratory measurements to predict cardiovascular disease risk.

Lead researcher Peter Ueda, PhD, of the Harvard School of Public Health, and colleagues published their results online Jan. 23 in Lancet Diabetes and Endocrinology.

“Our results suggest that urgent action is needed to strengthen the primary health care system in many low- and middle-income countries to detect individuals at high risk of [cardiovascular disease] and to provide lifestyle counseling or medications to lower their risk,” Ueda said in a news release.

Previously, the researchers developed a laboratory-based prediction model (Globorisk) and predicted the 10-year risk of fatal cardiovascular disease in 11 countries.

For this analysis, they searched the PubMed database through Oct. 2016 and identified eight prospective studies related to cardiovascular disease risk prediction in global populations. Their laboratory-based risk score included age, sex, smoking, blood pressure, diabetes and total cholesterol, while their non-laboratory/office-based risk score replaced diabetes and total cholesterol with body mass index. The researchers then recalibrated the models by using data on cardiovascular disease risk factor levels and rates for each country.

The researchers defined fatal and nonfatal cardiovascular disease as deaths from ischemic heart disease, sudden cardiac death or stroke as well as nonfatal MI and stroke.

The two risk scores yielded similar mean 10-year risks of fatal and nonfatal cardiovascular disease. When the researchers used 10 percent as the risk threshold in the eight studies, they found that the laboratory-based risk score categorized 1,956 of the 3,005 participants that later had a cardiovascular disease event as high risk. Meanwhile, the office-based risk score categorized 1,881 of the 3,005 participants as high risk.

The laboratory-based and office-based risk scores similarly classified more than 80 percent of adults as being low or high risk, but the office-based model substantially underestimated the risk among patients with diabetes, according to the researchers.

Although the predicted 10-year risk of cardiovascular disease varied among countries and models, the researchers mentioned that the highest risk were in southeast and central Asia and eastern Europe. They added that when the risk scores were applied to data from national health surveys, the prevalence of high cardiovascular disease risk also varied but was typically lower in high-income countries.

Among the high-income countries, the proportion of people from 40 to 64 years old at high risk of cardiovascular disease ranged from 1 percent for South Korean women to 42 percent for Czech men using 10 percent or high risk threshold. Among low-income countries, the risk ranged from 2 percent in Ugandan men and women to 13 percent in Iranian men using a 20 percent or higher risk threshold.

“Our risk scores and risk charts will be particularly useful in [low-income and middle-income countries] because most of these countries do not have locally developed risk scores,” the researchers wrote. “Additionally, the office-based risk score allows for risk prediction in environments where there is little or no access to a laboratory, such as during home care visits.”

The researchers acknowledged that the study had a few limitations, including that they estimated fatal and nonfatal cardiovascular disease rates using national ischemic heart disease and stroke death rates from the World Health Organization. They also mentioned the coefficients were only derived from cohorts in the U.S. and Puerto Rico.

In addition, they did not account for patients with a previous cardiovascular disease event who were at a high risk of a future event and should receive treatment. Further, they noted that 10-year cardiovascular risks underestimate lifetime risk and can lead to under-treatment.

“Further research is needed to identify the most cost-effective interventions for high-risk individuals,” the researchers wrote. “Trials are ongoing to establish whether the efficacy of multidrug treatment and lifestyle advice in [low-income and middle-income countries] is similar to those in high-income countries. Research is also ongoing into whether non-physician clinicians, aided by new information technologies such as risk charts, can successfully identify and manage high-risk individuals, especially if regular contact leads to better adherence.”