CONTRIBUTING FACTORS FOR STROKE: HYPERTENSION AND HYPERCHOLESTEROLEMIA Melissa R. Stephens, MD, FAAFP Associate Professor of Clinical Sciences William Carey University College of Osteopathic Medicine
LEARNING OBJECTIVES The learner will be able to explain the mechanisms by which hypertension may lead to stroke. The learner will be able to understand the impact of high cholesterol on stroke risk. The learner will be ready to apply key recommendations from published guidelines on blood pressure and cholesterol management.
HYPERTENSION One of every 3 American adults or approximately 67 million adults (31%) has hypertension. Only one third of hypertensive patients have blood pressure controlled to recommended levels of <140/90 mm Hg for uncomplicated hypertension.
HYPERTENSION AND STROKE Hypertension is a major independent risk factor for coronary artery disease, stroke, heart failure, and renal failure. High blood pressure is the single most important risk factor for stroke, causing about 50 percent of ischemic strokes and increasing the risk of hemorrhagic stroke.
HYPERTENSION AND STROKE In a US population based study, the estimation of population attributable risks has revealed that 9% to 16% of all ischemic stroke cases can be avoided by simply eliminating hypertension alone.
HYPERTENSION AND STROKE The strain hypertension places on blood vessels makes them weaken and predisposes them to damage. Weakened blood vessels are more likely to become blocked (ischemic stroke) or burst (hemorrhagic stroke).
CHOLESTEROL AND STROKE Cholesterol is the fatty substance in the blood. Cholesterol can be either produced by the body or be found in foods consumed within our diet.
CHOLESTEROL AND STROKE In the Framingham study, cholesterol was associated with ischemic stroke among people who had high levels of inflammation-sensitive plasma proteins, but not among people with low levels of these markers. Thus, cholesterol may not be a risk factor in isolation, but may interact with other factors to aid the progression of atherosclerosis.
CHOLESTEROL AND STROKE In a recent meta-analysis of cohort studies conducted in the Asia-Pacific region, there was a positive association between cholesterol levels and ischemic stroke.
CHOLESTEROL AND STROKE Meta-analysis of early trials of lipid-lowering therapy with the use of dietary or drug intervention with fibrates and resins provides evidence that, among people with elevated cholesterol levels, reducing cholesterol levels per se does not reduce the risk of stroke.
CHOLESTEROL AND STROKE Use of HMG-CoA reductase inhibitors ( statins ) among patients has been reported to produce a 24% relative risk reduction of all stroke and a 30% relative risk reduction of ischemic stroke.
TREATMENT GUIDELINES: HYPERTENSION In 2014, the Eighth Joint National Committee (JNC 8) published the evidence-based guideline for the management of high BP in adults. The new guideline was characterized by a systematic review of the literature with an emphasis on randomized, controlled clinical trials.
TREATMENT GUIDELINES: HYPERTENSION There is strong evidence to support treating persons aged 60 years or older to a BP goal of <150/90 mm Hg and persons 30 through 59 years of age to a diastolic goal of <90 mm Hg
TREATMENT GUIDELINES: HYPERTENSION The same thresholds and goals are recommended for hypertensive adults with diabetes or nondiabetic chronic kidney disease as for the general hypertensive population younger than 60 years.
TREATMENT GUIDELINES: HYPERTENSION There is insufficient evidence in hypertensive persons younger than 60 years for a systolic goal, or in those younger than 30 years for a diastolic goal.
TREATMENT GUIDELINES: HIGH CHOLESTEROL The 2013 American College of Cardiology/American Heart Association Guideline on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults was commissioned to reflect new evidence since the previous Adult Treatment Panel III guidelines were last updated in 2004. 2013 ACC/AHA guidelines expanded the focus to atherosclerotic CVD, including CHD, stroke, and PAD.
TREATMENT GUIDELINES: HIGH CHOLESTEROL The 2013 ACC/AHA guideline for cholesterol treatment made several notable changes to the older ATP III guidelines. The 3 most impactful changes are as follows: Introducing the Pooled Cohort equations as the preferred risk assessment tool Lowering the risk threshold for considering statin therapy in primary prevention settings to a 10-year absolute ASCVD risk of 7.5% Removing cholesterol treatment targets
TREATMENT GUIDELINES: HIGH CHOLESTEROL Pooled Cohort Equation uses only traditional risk factors. Age Sex Black or white race Systolic blood pressure Total cholesterol and HDL Hypertension Diabetes Current Smoking Status
TREATMENT GUIDELINES: HIGH CHOLESTEROL
TREATMENT GUIDELINES: HIGH CHOLESTEROL
RESOURCES American Heart Association World Heart Federation American Stroke Association National Stroke Association
REFERENCES Hernandez-Vila, Eduardo. A Revew of the JNC 8 Blood Pressure Guideline. Texas Heart Institute Journal, Volume 42, Issue 3, June 2015, Pages 226-228. Hisham, Nur Fatirul, et al. Epidemiology, Pathophysiology, and Treatment of Hypertension in Ischaemic Stroke Patients. Journal of Stroke & Cerebrovascular Disease, Volume 22, Issue 7, October 2013, Pages e4-e14.
REFERENCES James, Paul, et al. 2014 Evidence-Based Guideline for the Management of High Blood Pressure in Adults Report From the Panel Members Appointed to the Eighth Joint National Committee (JNC 8). JAMA, Volume 311, Issue 5, February 2014, Pages 507-520. Nayor, Matthew, et al. Recent Update to the US Cholesterol Treatment Guidelines: A Comparison With International Guidelines. Circulation, Volume 133, Issue 18, May 2016, Pages 1795-1806.
REFERENCES Thrift, Amanda. Cholesterol Is Associated With Stroke, but Is Not a Risk Factor. Stroke, Volume 35, Issue 6, June 2004, Pages 1524-1525.