Decades-Long Drop in Cardiovascular Deaths Slowing Down

Damian McNamara

August 28, 2019

The dramatic decreases in deaths from heart disease, stroke, diabetes, and hypertension seen between 1999 and 2009 have started to level off since 2010, portending a future where these gains could be lost, new research suggests.

The age-adjusted mortality rate (AAMR) for heart disease prior to 2010 translated to 8.3 fewer deaths per 100,000 US population per year. However, a new study shows that since the start of this decade the rate has slowed to 1.8 fewer deaths per 100,000 US population per year.

Deaths from stroke and diabetes plateaued, and the AAMR for hypertension actually increased over time, "although hypertension as an underlying cause of death remained infrequent," the authors note. 

"The fact that improvements in death rates due to heart disease, stroke, and diabetes have halted and deaths due to hypertension are increasing is surprising and alarming," study author Sadiya S. Khan, MD, Division of Cardiology, Department of Medicine and Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, told Medscape Medical News.

"This is in spite of the remarkable progress that we have made in terms of novel pharmaceuticals, devices, and surgical treatments for cardiovascular disease," Khan said. "The toll of cardiometabolic deaths may undo this positive progress in the years to come."

The findings were published online August 27 in a research letter in JAMA.

Slowing Death Rate

Despite a decrease of approximately 36% in death rates from cardiovascular disease (CVD) reported in prior research, Khan and colleagues note that CVD remains the leading cause of mortality among US adults.

Furthermore, less impressive annual decreases in CVD-related deaths (0.7% per year) reported in prior research between 2011 and 2014 makes it appear "unlikely that strategic goals from the American Heart Association...will be achieved," the investigators write. The association's goal is a 20% reduction by 2020.

To get a clearer picture, including the most recent national trends, the researchers evaluated CVD and other cardiometabolic diseases using ICD-10 codes from 1999 to 2017, adjusting for sex and race. They matched these findings with death certificate data from the CDC's Wide-Ranging Online Data for Epidemiologic Research (WONDER).

Age-Adjusted Mortality Rate by Condition, 1999-2017

Condition Condition Total Deaths 1999 AAMR Death Rate 1999 Total Deaths 2017 AAMR Death Rate 2017
Heart Disease 725,192 266.5 647,457 165.0
Stroke 167,366 61.6 146,383 37.6
Diabetes 68,399 25.0 83,564 21.5
Hypertension 16,968 6.2 35,316 9.0
AAMR = age-adjusted mortality rate per 100,000 US population

"Deaths due to hypertension are increasing," Khan said. "Even more alarming is the fact that cardiometabolic death rates for black Americans remain higher than those for white Americans."

The investigators also compared death rates in men vs women and white vs black Americans. Between 1999 and 2017, 85.1% of fatal cardiometabolic events occurred in white individuals and another 12.3% occurred in black individuals. The researchers did not evaluate rates in other racial/ethnic groups.

At the same time, women experienced slightly more fatal cardiometabolic events overall (51.3%).

In general, despite overall decreases in death rates over time, "racial disparities in cardiometabolic causes of death persisted," the researchers write.

Black individuals consistently experienced higher AAMRs compared with whites. In 2017, the highest AAMR ratios were in black vs white women associated with diabetes (2.09 deaths per 100,000 population) and in black vs white men due to hypertension (2.18 deaths per 100,000 population).

In addition, the AAMR for hypertension increased in most sex-race groups except for black women, in whom the rate generally stayed the same over time.

"Black men consistently had the highest AAMRs across all underlying causes of death," the investigators note.

Heart of the Matter

"One of the greatest success stories of the past four decades has been the marked reduction in deaths due to cardiovascular disease. However, death from cardiovascular diseases continues to be the number one killer for men and women in the United States, and the improvements in death rates have stopped," Khan said.

"The reversal of these trends are concerning," she added. "We are losing ground in the battle against cardiometabolic diseases."

Use of death certificate data, which may be subject to miscoding, is a potential limitation of the study. In addition, it remains unknown if AAMR changes are attributable to changing disease incidence or case-fatality rates.

"The key take-home message is that cardiometabolic disease is largely preventable. We know that prevention of risk factor development and aggressive management of risk factors, beginning early in the life course, is critical," Khan said.  

"For physicians, targeting individuals early in the life course — focusing on prevention even in childhood and young adulthood — is needed," she added.

'Very Important Data'

Commenting on the study for Medscape Medical News, Adam Bress, PharmD, assistant professor of health sciences at the University of Utah and an investigator at the VA Salt Lake City Health Care System, said the "very important data" came from a high-quality source and esteemed scientists.

He noted that there were several findings that "popped out" to him.

"The decline in heart disease from 1999 to 2010 has slowed substantially in 2011 to 2017, which may reflect residual risk related to higher prevalence of use of preventative therapies or increase in risk factors such as obesity," said Bress, who was not involved with the study.

Furthermore, "mortality rates due to stroke and diabetes have not changed between 2010 to 2017, highlighting the need for primordial prevention and optimizing treatment initiation and adherence for those with established disease," he added.

Bress also pointed to the finding that hypertension-related mortality is increasing overall and is more than twofold higher in blacks than whites. 

"This is a public health missed opportunity as safe, effective, and inexpensive antihypertensive medications are widely available — and proven implementation strategies exist, such as team-based care, that more effectively control blood pressure than usual care," he said.

In addition, "community and ethnic-group specific interventions are highly effective in focused and controlled settings, but need to be adapted to scale for pragmatic and cost-efficient implementation across the country," Bress concluded.

The study was supported by the National Center for Advancing Translational Sciences, National Institutes of Health. Khan has reported no relevant financial relationships. Bress has reported receiving grants from the National Heart, Lung, and Blood Institute to study hypertension and is a consultant for Amarin. In addition, his institution receives support from Novartis to study heart failure and from Amgen related to lipid-lowering research.

JAMA. Published online August 27, 2019. Full article

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