Declining Stroke Mortality: Good News and Future Challenges

Updated:May 19,2014
Disclosure: Dr. Koroshetz has nothing to disclose.
Pub Date: Thursday, Dec. 5, 2013
Author: Walter J. Koroshetz, MD
Affiliation: Deputy Director of National Institutes for Neurological Disorders and Stroke
 

Citation

Lackland DT, Roccella EJ, Deutsch AF, Fornage M, George MG, Howard G, Kissela BM, Kittner SJ, Lichtman JH, Lisabeth LD, Schwamm LH, Smith EE, Towfighi A; on behalf of the American Heart Association Stroke Council, Council on Cardiovascular and Stroke Nursing, Council on Quality of Care and Outcomes Research, and Council on Functional Genomics and Translational Biology. Factors influencing the decline in stroke mortality: a statement from the American Heart Association/American Stroke Association. Stroke. 2013; published online before print December 5, 2013, 10.1161/01.str.0000437068.30550.cf.
http://stroke.ahajournals.org/content/early/2013/12/05/01.str.0000437068.30550.cf.full.pdf+html 

Article Text

The statement from the American Heart Association (AHA)/American Stroke Association (ASA) on the “Factors Influencing the Decline in Stroke Mortality” emphasizes the remarkable public health impact that science can have when it leads practice and policy.1 Hundreds of thousands of lives have been saved and many more have been rescued from a life permanently changed by tragic brain injury as stroke rates have decreased. However, the AHA/ASA statement is more than self-congratulatory; it establishes a number of guideposts for the future of stroke prevention and treatment. First and foremost the most recent evidence tells us that dropping stroke rates are continuing and there is no plateau in sight. This implies that our current management of stroke is not yet optimal and we can still improve given current knowledge. Thousands still suffer “preventable strokes.” My mentor, Dr. C. Miller Fisher, argued that every stroke represented a failure of primary care. As noted in the AHA/ASA statement the marked decrease in stroke in persons with symptomatic intracranial stenosis in the second of two sequential trials, Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) first,2 Stenting versus Aggressive Medical Therapy for Intracranial Arterial Stenosis (SAMMPRIS) second,3 was associated with a much more aggressive and effective risk factor reduction program in the latter. In the LEAPS trial of stroke recovery, intensive rehab was associated with much improved ambulatory skills as compared to standard of care.4 Both these trials question whether the current “standard of care” is really an unacceptable standard. Would aggressive control of blood pressure, lipids, exercise level, and body weight halve stroke risk in all? Would intensive rehab bring most stroke victims to a higher functional level? The core message in the AHA/ASA statement cannot be overemphasized: “It is estimated that the overwhelming majority of strokes each year could be prevented through awareness, optimal treatment of hypertension, and lifestyle changes to healthier diet, greater physical activity, and smoking cessation.” Given that the tragedy of stroke affects nearly 800,000 people every year, it is a profound indictment of our healthcare.

Progress in reducing stroke has been dramatic but new challenges present themselves. Further progress is necessary to control the rising burden that will otherwise occur due to aging of the population and the epidemic of childhood obesity and diabetes. The AHA/ASA statement makes the point that many have not shared equally in the reduction in stroke mortality. Multiple studies documented the tragic disparity of stroke in the African American community.5 African Americans less than 75 years old have twice the risk of stroke death compared to whites. This is most striking in young African American males.6 The burden of illness due to stroke is substantially greater in the Southeastern US.7 What are we doing wrong? Are we treating hypertension too late in life in this more vulnerable population? Are we not treating blood pressure aggressively enough? Though stroke dropped to the fourth leading cause of death in the US, stroke rates are increasing at an alarming rate in developing countries. Around the world stroke is the second leading cause of death,8 a tragic statistic given that we know how preventable stroke can be.

The other exploding public health problem facing the US is the rising burden of dementia in our aging population. The most common dementia diagnosis in population studies is a mix of ischemic brain disease and Alzheimer’s pathology.9,10 The modifiable risk factors for dementia are all the usual cardiovascular risk factors. Silent stroke on MRI scans occurs in up to 40% of the elderly and is strongly associated with a dementia diagnosis.11. Diffuse white matter disease is seen on 80% of MRIs in the elderly and is also associated with dementia risk.12 In the Nun study, a stroke, no matter how small, was a strong driver for the development of dementia.13 The exact nature of the relationship between vascular disease, diffuse white matter disease, stroke, and dementia is still a mystery that needs to be investigated. Yet, despite our incomplete understanding of the biological relationship, one would expect that reduction in stroke incidence should result in a decrease in dementia rates. Some suggestive evidence for a decrease in dementia rates has come from studies in Europe.14

The AHA/ASA statement should direct those who set policy and practice guidelines to maximize the public health impact of our current body of knowledge. For too long the public health information programs about vascular health have minimized the stroke message. The Million Hearts campaign missed a golden opportunity to include the Brain along with the Heart. Heart attack has become so well-known and treatments so effective that the public has been lulled into complacency. Indeed, seeing Vice President Cheney on TV announces to the country that the sickest hearts can be replaced. The brain is not as forgiving. The US populace is acutely aware of the value of intact brain function. They can be rallied to a health campaign to protect the brain. The core message of the AHA/ASA statement is simple; the overwhelming majority of permanent brain damage due to stroke is preventable, NOW! The price is steep for not pursuing prevention NOW!. 

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References

  1. Lackland DT, Roccella EJ, Deutsch AF, Fornage M, George MG, Howard G, Kissela BM, Kittner SJ, Lichtman JH, Lisabeth LD, Schwamm LH, Smith EE, Towfighi A; on behalf of the American Heart Association Stroke Council, Council on Cardiovascular and Stroke Nursing, Council on Quality of Care and Outcomes Research, and Council on Functional Genomics and Translational Biology. Factors influencing the decline in stroke mortality: a statement from the American Heart Association/American Stroke Association. Stroke. 2013; published online before print December 5, 2013, 10.1161/01.str.0000437068.30550.cf.
  2. Chimowitz MI, Lynn MJ, Derdeyn CP, Turan TN, Fiorella D, Lane BF, Janis LS, Lutsep HL, Barnwell SL, Waters MF, Hoh BL, Hourihane JM, Levy EI, Alexandrov AV, Harrigan MR, Chiu D, Klucznik RP, Clark JM, McDougall CG, Johnson MD, Pride GL, Jr., Torbey MT, Zaidat OO, Rumboldt Z, Cloft HJ. Stenting versus aggressive medical therapy for intracranial arterial stenosis. N Engl J Med. 2011;365:993-1003.
  3. Chimowitz MI, Lynn MJ, Howlett-Smith H, Stern BJ, Hertzberg VS, Frankel MR, Levine SR, Chaturvedi S, Kasner SE, Benesch CG, Sila CA, Jovin TG, Romano JG. Comparison of warfarin and aspirin for symptomatic intracranial arterial stenosis. N Engl J Med. 2005;352:1305-16.
  4. Duncan PW, Sullivan KJ, Behrman AL, Azen SP, Wu SS, Nadeau SE, Dobkin BH, Rose DK, Tilson JK, Cen S, Hayden SK, for the LEAPS investigator team. Body-weight-supported treadmill rehabilitation after stroke. N Engl J Med. 2011;364:2026-36.
  5. Kleindorfer DO, Khoury J, Moomaw CJ, Alwell K, Woo D, Flaherty ML, Khatri P, Adeoye O, Ferioli S, Broderick JP, Kissela BM. Stroke incidence is decreasing in whites but not in blacks: a population-based estimate of temporal trends in stroke incidence from the Greater Cincinnati/Northern Kentucky Stroke Study. Stroke. 2010;41:1326-31.
  6. Howard G, Lackland DT, Kleindorfer DO, Kissela BM, Moy CS, Judd SE, Safford MM, Cushman M, Glasser SP, Howard VJ. Racial differences in the impact of elevated systolic blood pressure on stroke risk. JAMA Intern Med. 2013;173:46-51.
  7. Cushman M, Cantrell RA, McClure LA, Howard G, Prineas RJ, Moy CS, Temple EM, Howard VJ. Estimated 10 year stroke risk by region and race in the United States. Ann Neurol. 2008: 64: 507-513.
  8. Feigin VL, Forouzanfar MH, Krishnamurthi R, Mensah GA, Connor M, Bennett DA, Moran AE, Sacco RL, Anderson L, Truelsen T, O’Donnell M, Venketasubramanian N, Barker-Collo S, Lawes CMM, Wang W, Shinohara Y, Witt E, Ezzati M, Naghavi M, Murray C, on behalf of the Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010) and the GBD Stroke Experts Group* Global and regional burden of stroke during 1990–2010: findings from the Global Burden of Disease Study 2010. Lancet. 2013;6736:61953-4.
  9. White L, Petrovitch H, Hardman J, Nelson J, Davis DG, Ross GW, Masaki K, Launer L, Markesbery WR. Cerebrovascular pathology and dementia in autopsied Honolulu-Asia aging study participants. Ann NY Acad Sci. 2002; 977:9-23.
  10. Sonnen JA, Larson EB, Crane PK, Haneuse S, Li G, Schellenberg GD, Craft S, Levernz JB, Montine TJ. Pathological correlates of dementia in a longitudinal, population-based sample of aging. Ann Neurol. 2007;62:406-13.
  11. Vermeer SE, Longstreth WT, Koudstaal PJ. Silent brain infarcts: a systematic review. Lancet Neurol. 2007;6:611-9.
  12. Debette S, Markus HS. The clinical importance of white matter hyperintensities on brain magnetic resonance imaging: systematic review and meta-analysis. BMJ. 2010;341:c3666.
  13. Snowdon DA, Greiner LH, Mortimer JA, Riley KP, Greiner PA, Markesbery W. Brain infarction and the clinical expression of Alzheimer disease. The Nun Study. JAMA. 1997;277:813-7.
  14. Matthews FE, Arthur A, Barnes LE, Bond J, Jagger C, Robinson L, Brayne C, on behalf of the Medical Research Council Cognitive Function and Ageing Collaboration. A two-decade comparison of prevalence of dementia in individuals aged 65 years and older from three geographical areas of England: results of the Cognitive Function and Ageing Study I and II. Lancet. 2013: Published Online July 16, 2013 http://dx.doi.org/10.1016/S0140-6736(13)61570-6.

-- The opinions expressed in this commentary are not necessarily those of the editors or of the American Heart Association -- 
 

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