JAMA: Uphill battle to reach 2020 goals on CVD reduction

The American Heart Association (AHA) faces hurdles in its goal to reduce cardiovascular disease (CVD) mortality and morbidity by 20 percent by 2020, judging from results of a study published online March 16 in the Journal of the American Medical Association. An analysis of time trends in seven cardiovascular health metrics found few people meet most of the metrics, but those who do have a much lower risk of all-cause, CVD and ischemic heart disease (IHD) mortality.

Quanhe Yang, PhD, of the Centers for Disease Control and Prevention’s division for heart disease and stroke prevention in Atlanta, and colleagues wrote that several studies have examined prevalence and trends of CVD risk. A few also have looked at the prevalence in terms of the AHA’s seven metrics identified as ideal cardiovascular health behaviors and factors: diet, physical activity, body mass index (BMI), tobacco use, blood pressure, total cholesterol and fasting blood glucose. They noted that none had studied the seven metrics over time, though.

For their study, they used National Health and Nutrition Examination Survey (NHANES) data from 1988 to 1994, 1999 to 2004 and 2005 to 2010 as well as the NHANES III Linked Mortality File through 2006 to analyze trends over time in a nationally representative sample of 44,959 non-pregnant adults who were 20 years old or older. They used Cox proportional hazards models to estimate hazard ratios for all-cause, CVD and IHD mortality; calculated adjusted population-attributable fractions to estimate the proportion of all-cause and CVD mortality; and conducted numerous sensitivity analyses.

On the positive side, they reported a drop in the prevalence from current smoking, from 27.9 percent in the NHANES 1988 to 1994 cohort to 22.6 percent in the 2005 to 2010 group. The prevalence of adults with desirable total cholesterol levels and blood pressure was mostly unchanged.

But the prevalence of following a healthy diet, having a BMI of less than 25 and a fasting glucose level of less than 100 mg/dL tumbled between 1988 to 1994 and 2005 to 2010, and only 2 percent met all seven health metrics. They noted a 1.5 percentage point decline in the prevalence of those meeting six or more health metrics between 1988 to1994 and 2005 to 2010 and a 1.6 percentage point increase in the prevalence of those meeting one or fewer metrics.

“During a median of 14.5 years of follow-up in the NHANES III Linked Mortality File cohort, participants who met six or more vs. one or fewer cardiovascular health metrics had a 51 percent lower risk of all-cause mortality, a 76 percent lower risk of CVD mortality, and a 70 percent lower risk of IHD mortality,” Yang and colleagues wrote. “In addition, meeting a greater number of cardiovascular health metrics also appeared to be associated with lower risk for all-cancer mortality.”

They listed evidence that showed awareness, treatment and management of hypertension and cholesterol, curtailing smoking and obesity, and increasing physical activity and healthy diet can have a significant impact on mortality and morbidity.

“Healthy People 2020 and the AHA’s national strategy to reduce CVD morbidity and mortality by 20 percent by 2020 through promoting ideal cardiovascular health metrics represents a great challenge but also an achievable goal,” they wrote. “Coordinated efforts, such as the recently announced Million Hearts initiative, align CVD prevention and control activities across the public and private sectors, creating opportunities to reduce the burden of CVD across a large segment of the population.”

While the research pointed to some bright spots, the decreasing proportion of adults meeting metrics on diet, obesity and fasting glucose levels was “alarming,” according to the author of an accompanying editorial. “Given these trends, it is clear that reaching the AHA 2020 goals will be difficult,” wrote Donald M. Lloyd-Jones, MD, MSc, of the cardiology division at Northwestern University Feinberg School of Medicine in Chicago.

Lloyd-Jones wrote that Yang et al’s findings are consistent with other results linking the health metrics to outcomes. He proposed that the next steps are to study quality-of-life outcomes and healthcare expenditures. He recommended that longitudinal cohort studies to look at individual changes in the metrics and the effect on outcomes.

“Attaining the 2020 goals will require a concerted effort to improve health factors and health behaviors across the spectrum of cardiovascular health, and in all segments of the population, rather than just a marginal increase in the small proportion (less than 2 percent) who have ideal levels of all seven metrics,” he proposed.

Yang and colleagues added that there were limitations in their study, many related to changes in protocols between the various NHANES surveys as well as limitations within the NHANES mortality file.