Despite the global impact and advances in understanding the pathophysiology of cerebrovascular diseases, the term “stroke” is not consistently defined in clinical practice, in clinical research, or in assessments of the public health. The classic definition is mainly clinical and does not account for advances in science and technology. The Stroke Council of the American Heart Association/American Stroke Association convened a writing group to develop an expert consensus document for an updated definition of stroke for the 21st century. Central nervous system infarction is defined as brain, spinal cord, or retinal cell death attributable to ischemia, based on neuropathological, neuroimaging, and/or clinical evidence of permanent injury. Central nervous system infarction occurs over a clinical spectrum: Ischemic stroke specifically refers to central nervous system infarction accompanied by overt symptoms, while silent infarction by definition causes no known symptoms. Stroke also broadly includes intracerebral hemorrhage and subarachnoid hemorrhage. The updated definition of stroke incorporates clinical and tissue criteria and can be incorporated into practice, research, and assessments of the public health.

Background and Purpose Stroke mortality has been declining since the early twentieth century. The reasons for this are not completely understood, although the decline is welcome. As a result of recent striking and more accelerated decreases in stroke mortality, stroke has fallen from the third to the fourth leading cause of death in the United States. This has prompted a detailed assessment of the factors associated with this decline. This review considers the evidence of various contributors to the decline in stroke risk and mortality and can be used in the design of future interventions regarding this major public health burden. Methods Writing group members were nominated by the committee chair and co-chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association (AHA) Stroke Council’s Scientific Statement Oversight Committee and the AHA’s Manuscript Oversight Committee. The writers used systematic literature reviews, references to published clinical and epidemiology studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize evidence and indicate gaps in current knowledge. All members of the writing group had the opportunity to comment and approved the final version of this document. The document underwent extensive AHA internal peer review, Stroke Council Leadership review and Scientific Statements Oversight Committee review before consideration and approval by the AHA Science Advisory and Coordinating Committee. Results The decline in stroke mortality over the past decades represents a major improvement in population health and is observed for both genders, and all race and age groups. In addition to the overall impact on fewer lives lost to stroke, the major decline in stroke mortality seen among individuals less than 65 years of age represents a reduction on years of potential life lost. The decline in mortality results from reduced stroke incidence and lower case fatality rates. These significant improvements in stroke outcomes are concurrent with cardiovascular risk factor control interventions. While it is difficult to calculate specific attributable risk estimates, the hypertension control efforts initiated in the 1970s appears to have had the most substantial influence on the accelerated stroke mortality decline. Although implemented later in the time period, diabetes and dyslipidemia control and smoking cessation programs, particularly in combination with hypertension treatment, also appear to have contributed to the stroke mortality decline. Telemedicine and stroke systems of care, while showing strong potential effects, have not been in place long enough to show their influence on the decline. Other factors had probable effects, but additional studies are needed to determine their contributions. Conclusion The decline in stroke mortality is real and represents a major public health and clinical medicine success story. The repositioning of str...

IMPORTANCE While stroke mortality rates have decreased substantially in the past 2 decades, this trend has been primarily limited to older adults. Increasing trends in stroke incidence and hospitalizations have been noted among younger adults, but there has been concern that this reflected improved diagnosis through an increased use of imaging rather than representing a real increase.OBJECTIVES To determine whether stroke hospitalization rates have continued to increase and to identify the prevalence of associated stroke risk factors among younger adults. DESIGN, SETTING, AND PARTICIPANTS Hospitalization data from the National Inpatient Sample from 1995 through 2012 were used to analyze acute stroke hospitalization rates among adults aged 18 to 64 years. Hospitalization data from 2003 to 2012 were used to identify the prevalence of associated risk factors for acute stroke. Acute stroke hospitalizations were identified by the principal International Classification of Diseases, Ninth Revision, Clinical Modification code and associated risk factors were identified by secondary International Classification of Diseases, Ninth Revision, Clinical Modification codes for each hospitalization. MAIN OUTCOMES AND MEASURES Trends in acute stroke hospitalization rates by stroke type, age, sex, and race/ethnicity, as well as the prevalence of associated risk factors by stroke type, age, and sex. RESULTS The 2003-2004 set included 362 339 hospitalizations and the 2011-2012 set included 421 815 hospitalizations.The major findings in this study are as follows: first, acute ischemic stroke hospitalization rates increased significantly for both men and women and for certain race/ethnic groups among younger adults aged 18 to 54 years; they have almost doubled for men aged 18 to 34 and 35 to 44 years since 1995-1996, with a 41.5% increase among men aged 35 to 44 years from 2003-2004 to 2011-2012. Second, the prevalence of stroke risk factors among those hospitalized for acute ischemic stroke continued to increase from 2003-2004 through 2011-2012 for both men and women aged 18 to 64 years (range of absolute increase: hypertension, 4%-11%; lipid disorders, 12%-21%; diabetes, 4%-7%; tobacco use, 5%-16%; and obesity, 4%-9%). Third, the prevalence of having 3 to 5 risk factors increased from 2003-2004 through 2011-2012 (men: from 9% to 16% at 18-34 years, 19% to 35% at 35-44 years, 24% to 44% at 45-54 years, and 26% to 46% at 55-64 years; women: 6% to 13% at 18-34 years, 15% to 32% at 35-44 years, 25% to 44% at 45-54 years, and 27% to 48% at 55-65 years; P for trend < .001). Finally, hospitalization rates for intracerebral hemorrhage and subarachnoid hemorrhage remained stable, with the exception of declines among men and non-Hispanic black patients aged 45 to 54 with subarachnoid hemorrhage (13.

Increases in the prevalence of ischemic stroke hospitalizations and coexisting traditional stroke risk factors and health risk behaviors were identified among acute ischemic stroke hospitalizations in young adults. Our results from national surveillance data accentuate the need for public health initiatives to reduce risk factors for stroke among adolescents and young adults.