Antihypertensive therapy is probably the main reason why stroke fatalities have dropped dramatically in the United States over the past 50 years, according to an American Heart Association study published Dec. 5 in Stroke.
Despite an aging and heavier population, “the accelerated decline in stroke mortality that began in the 1970s is consistent with the aggressive hypertension treatment and control strategies implemented in that period. … The decrease in blood pressure with drug therapy … appears to be the major determinant of reduction in the risk of stroke and stroke deaths,” wrote lead author Dr. Daniel Lackland, professor of epidemiology at the Medical University of South Carolina, Charleston, and his colleagues (Stroke 2013 Dec. 5 [doi:10.1161/01.str.0000437068.30550.cf]).
Statins, diabetes drugs, public health efforts, increased research, improved imaging, and quicker and better stroke treatment, among other things, have helped, too. People have also begun to lose weight, cut salt from their diets, and eat and smoke less.
But when it comes to accounting for the stroke mortality rate reduction from 88/100,000 in 1950 to 23/100,000 in 2010 – a reduction that holds across racial, age, and gender lines – the evidence is strongest for hypertension control, the authors said.
“Although the decline in stroke mortality in the United States started at the beginning of the 20th century, decades before hypertension treatment, the slope of the decline in mortality accelerated significantly after the introduction of tolerable antihypertensive drug therapy in the 1960s,” they wrote. Stroke is now the fourth leading cause of death in the United States, instead of the third, and both recurrent and first-time strokes are down. Europe has had a similar decline.
Although great racial disparities still exist in stroke mortality, particularly for blacks, “the decline in stroke mortality for all racial/ethnic groups has reduced the magnitude of the racial/ethnic gap in stroke mortality risks and likewise the variation in stroke mortality by geographic area, with particular emphasis in the Stroke Belt,” Dr. Lackland and his colleagues wrote.
“The decline is real, not a statistical fluke or the result of more people dying of lung disease, the third leading cause of death,” Dr. Lackland said in a statement. It’s also not due to changes in billing codes, diagnostic improvements, death certificate causes of death, or other factors the team considered. Instead, it is “one of the major public health successes of the past 50 years,” the authors wrote.
The findings are based on literature reviews, morbidity and mortality reports, clinical and public health guidelines, expert opinion, and other sources.
The authors noted that “increased application of advanced neuroimaging … might improve the diagnosis of milder, less-fatal strokes over time. This would result in an apparent decline in the stroke case-fatality rate, solely as a result of improved detection. However, this should not result in a change in stroke mortality over time unless technological advances improve the diagnosis of more severe, fatal strokes also, which seems unlikely.”
Dr. Lackland said he had no relevant financial disclosures. One of the 13 authors on the paper is a speaker and consultant for Allergan and a consultant for Reata.
Steven S. Shayani, MD, FACC, FASNC 