Survey Results Reveal Potential Factors Slowing the Decline in Cardiovascular Mortality Rate

Downward trend | Image credit: adragan – stock.adobe.com

While cardiovascular mortality declined between 2000 and 2019, researchers found that this rate slowed down over time. According to new research published in the Journal of the American Heart Association, the following factors may have contributed to this deceleration:

• Worsened glycemic control
• Worsened blood pressure control
• Worsened obesity management
• Increased alcohol consumption
• Leveled lipid control
• Persistent socioeconomic disparities

These findings are based on a study of 55,021 individuals who participated in the 1999-2018 National Health and Nutrition Examination Survey. Of this group, 5717 participants had atherosclerotic cardiovascular disease (ASCVD), with the prevalence of ASCVD oscillating between 7.3% and 8.9% during the survey period. All participants were aged 20 years and older with a median (SD) age of 47.03 (0.17) years.

Risk factor control in this study was defined as hemoglobin A1c (HbA1c) <7%, blood pressure <140/90 mm Hg, and non–high‐density lipoprotein cholesterol (non–HDL-C) levels <100 mg/dL. Among participants with ASCVD, the researchers observed stagnation in the initial improvements in blood pressure and non–HDL-C, alongside a decline in glycemic control.

For example, the percentage of individuals with ASCVD who had non–HDL‐C control <100 mg/dL doubled from 7.1% in 1999-2002 to 15.7% in 2003-2006, with a similar increase to 22.5% in 2007-2010. However, this increase leveled off later, with 27.3% in 2011-2014 and 30.9% in 2015-2018 (P trend < .001).

Meanwhile, the prevalence of blood pressure control increased from 62.6% to 74.1% between 1999 and 2014, but declined to 70.1% in the 2015-2018 period (P_trend < .001). Additionally, the percentage of surveyed adults with HbA1c <7% started off the highest of the 3 at 87.4% in 1999-2002 and peaked at 89.6% in 2003-2006. Unlike the other 2 categories, this percentage steadily dropped after 2006, getting as low as 81.7% in the final period of the study ((P_trend < .001).

The researchers also noted a slowed-down increase of participants achieving all 3 controlled targets—non–HDL-C, blood pressure, and glycemic control—starting around the 2007-2010 period. The percentage of surveyed adults with ASCVD who had all 3 controlled targets started off at 4.5% in 1999-2002, increasing to 9.4% in 2003-2006 and further increasing at a similar rate to 14.8% in 2007-2010. This number only slightly rose to 18.4% in 2011-2014 and then leveling off at 18.6% in 2015-2018.

Interestingly, these trends slightly differed after 2006 between men and women. Men overall had higher percentages than women in this category and plateaued in a similar way as the overall trend. However, the percentage of surveyed women with ASCVD who achieved control for all 3 risk factors further jumped from 9.6% to 15.1% between 2007-2010 and 2011-2014, and then dropped to 13.6% in 2015-2018.

The researchers also saw an increase in diabetes, obesity, and self‐reported hypertension prevalence across the survey period, saying these trends may have contributed to the decelerated decrease in ASCVD mortality.

The percentage of surveyed adults with ASCVD with heavy alcohol consumption fluctuated throughout the study period, increasing from 15.7% to 17.8%, then dropping slightly to 16.4%, increasing again to 19.4%, and finally spiking up to 28.4% (P_trend < .001). The researchers did not include any further analysis into this drastic increase in the current study.

Effective lipid control—defined in the study as non–HDL‐C <100 mg/dL or low‐density lipoprotein cholesterol (LDL‐C) <70 mg/dL—is crucial for individuals with ASCVD to prevent recurring cardiovascular events. While previous studies have demonstrated a significant reduction in all-cause mortality with each decrease in LDL-C levels, the current analysis revealed a plateauing trend in lipid control rates after 2006 after an initial sharp increase in lipid control. Specifically, between 2015 and 2018, only around 30.9% and 58.3% of adults with ASCVD achieved non–HDL-C control of <100 and <130 mg/dL, respectively, and lipid-lowering agent usage was reported in only 63.3% of cases.

“Controversy over the risk‐benefit balance of intensive cholesterol control might contribute to the plateau,” the researchers said. “In 2007, Alsheikh‐Ali et al reported in a meta‐analysis of 23 trials that cancer incidence was associated with lower achieved LDL‐C levels, which provoked great dispute over safety of intensive cholesterol control. Although a larger meta‐analysis conducted later by the Cholesterol Treatment Trialists' Collaborators showed no such association, safety concerns persist, which may conceivably be related to the slight decline in lipid‐lowering medication or statin use after 2011 to 2014.”

The analysis revealed significant disparities in risk factor control and medication utilization among various demographic groups, notably between genders and racial/ethnic populations. In Accordance with previous studies, women with ASCVD were less likely to receive statin therapy and had poorer risk factor control compared with men, suggesting potential gender biases in health care according to the researchers. Similarly, non-Hispanic Black individuals demonstrated lower rates of achieving blood pressure and glycemic control targets compared with non-Hispanic White individuals, indicating persistent racial and ethnic disparities in health care access and delivery.

Socioeconomic factors such as insurance coverage and income level were associated with statin use, highlighting the role of socioeconomic status in cardiovascular risk management. According to the researchers, rhese disparities may contribute to higher cardiovascular mortality rates among certain demographic groups, necessitating targeted interventions to address them. Additionally, the finding that middle-aged adults with ASCVD had poorer risk factor control than younger adults raises concerns and warrants further investigation into potential gaps in health care delivery and health behaviors among different age groups.

“The alarmingly low risk factor control rate, the increasing prevalence of obesity, heavy alcohol consumption, and the observed disparities in ASCVD management between different socioeconomic subgroups, especially male and female adults and non‐Hispanic Black and White populations, may inform policy makers and health care professionals to take action to bridge these gaps to further reduce the cardiovascular disease mortality,” the researchers said.

Reference

Li J, Zhang J, Somers VK, Covassin N, Zhang L, Xu H. Trends and disparities in treatment and control of atherosclerotic cardiovascular disease in US adults, 1999 to 2018. J Am Heart Assoc. Published online April 19, 2024. doi:10.1161/JAHA.123.032527