ORLANDO – After 100 years as America’s No. 1 killer, the combination of coronary disease and stroke is about to fall below cancer as the nation’s top cause of mortality.
The changeover occurred 3 years ago, in 2008, for the approximately 1.9 million adults enrolled in Kaiser Permanente of Northern California, and the ascendancy of cancer over coronary disease and stroke will happen throughout the United States sometime before the end of this decade, Dr. Stephen Sidney said while presenting a poster at the annual scientific sessions of the American Heart Association.*
Dr. Stephen Sidney
The main driver of this shift is the huge progress made in curbing coronary and stroke deaths during the past half century, especially since 2000, said Dr. Sidney, associate director for clinical research of Kaiser Permanente of Northern California in Oakland.
"It’s a huge public health success from multifactorial interventions for primary prevention and secondary prevention," he said in an interview. During the 2000s alone, coronary disease mortality among Kaiser adults at least 30 years old fell by 27%, and stroke mortality plunged by 42%. In contrast, cancer mortality among adult members of Kaiser Permanente of Northern California dropped by 11%. "We’ve made huge progress and policy makers need to start thinking that [coronary disease and stroke] are not the biggest causes of mortality," he said.
Coronary disease first topped America’s killer list in 1910 and stayed in place for decades, but then started a trajectory of substantial decline by about 1970, he said. As recently as 2000, among adult members of Kaiser Permanente of Northern California, coronary disease alone accounted for about 300 deaths per 100,000 person-years, putting it on par with cancer, whereas coronary disease plus stroke together sat atop the killer list with a rate of about 400 deaths per 100,000 person-years in 2000. By 2008, coronary deaths alone had fallen to 200 per 100,000 person-years, while coronary and stroke deaths together dropped just below the 270 per 100,000 person-years level that cancer reached that year.
Although the crossing of the cardiovascular and cancer mortality rates has not yet happened throughout the United States, similar trends are at work. During 2000-2007, the gap in age-adjusted death rates between coronary disease and cancer fell by 88%, he said.
Dr. Sidney cited two Kaiser programs begun during the 2000s that he believes led to the big cardiovascular mortality drop of that era.
One was a concerted effort to diagnose and treat hypertension, a prime cardiovascular-event risk factor. As recently as 2001, only 38% of hypertensive patients in Kaiser Permanente of Northern California had their blood pressure controlled. Kaiser physicians perceived this as a major shortcoming, and launched a campaign to address it, so that by 2010 the percentage of controlled hypertensives had risen to 80%, he said.
The other initiative was a Kaiser program to treat all patients with coronary disease, cerebrovascular disease, peripheral arterial disease, chronic kidney disease, and those with an abdominal aortic aneurysm with aspirin, a statin, and an angiotensin-converting enzyme inhibitor.
Parallel efforts to bring the cancer rate down are much harder, because cancer is "a diverse set of etiologically distinct diseases with a myriad of interventions, making implementation of population-based approaches more complex, resulting in a slower rate of mortality decline," Dr. Sidney said in his poster.
Dr. Sidney said that he had no disclosures.
*Correction, 12/16/2011: An earlier version of this story misstated the number of adults enrolled in Kaiser Permanente of Northern California.