CVD Prevalence, Risk, and Pathophysiology

CVD Prevalence, Risk, and Pathophysiology - MNT in...

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Unformatted text preview: MNT in Cardiovascular Disease Prevalence and Incidence The United States ranks 14th and 16th, among industrialized nations for the prevalence of CVD in women and men, respectively. More than 61 million Americans have at least one form of CVD (i.e., hypertension, CHD, stroke, rheumatic heart disease, or congestive heart failure). The incidence of CHD is high; an American experiences a coronary event almost every 29 seconds. Leading Causes of Death U.S. 2000 From http://www.nhlbi.nih.gov/resources/docs/02_chtbk.pdf; accessed 3-05 Percentage Breakdown of Deaths From Cardiovascular Diseases United States:2002 Preliminary Coronary Heart Disease 13% Stroke 0% 4% Congestive Heart Failure 5% High Blood Pressure 6% 53% Diseases of the Arteries Rheumatic Fever/Rheumatic Heart Disease 18% Congenital Cardiovascular Defects Other Source: CDC/NCHS. Prevalence of Coronary Heart Diseases by Age and Sex NHANES :1999-2002 Percent of Population 20 16.8 15 11.6 10 11.5 6.3 5 0 10.3 0.0 0.3 20-34 1.4 3.0 0.2 35-44 3.6 1.6 45-54 55-64 Ages Men Source: CDC/NCHS and NHLBI. Women 65-74 75+ Ne w and Rec urrent Attac ks Annual Number of Americans Having Diagnosed Heart Attack by Age and Sex ARIC: 1987-2000 500,000 410,000 372,000 400,000 300,000 250,000 200,000 100,000 88,000 34,000 10,000 0 29-44 45-64 65+ Ages Men Women Source: Extrapolated from rates in the NHLBI’s ARIC surveillance study, 1987-2000. These data don’t include silent MIs. Prevalence of Stroke by Age and Sex NHANES: 1999-2002 Percent of Popul ation 14 12.0 11.5 12 10 8 6.6 6.3 6 4 2 0.4 0.3 1.1 0.8 0 20-34 35-44 3.1 3.0 2.1 1.2 ` 45-54 55-64 Ages Men Women Source: CDC/NCHS and NHLBI. 65-74 75+ Pe rc e nt of Population Prevalence of High Blood Pressure in Americans by Age and Sex NHANES: 1999-2002 100 74.0 80 60 46.6 69.2 34.1 34.0 40 20 55.5 60.9 83.4 11.1 21.3 18.1 5.8 0 20-34 35-44 45-54 55-64 Ages Men Source: CDC/NCHS and NHLBI. Women 65-74 75+ Prevalence of Congestive Heart Failure by Age and Sex NHANES: 1999-2002 9.8 10.9 P e r c e n t o f P o p u l a ti o n 10 8 6 4.1 4 2 6.2 5.8 1.8 0.3 0.3 0.5 2.3 1.5 0.4 0 20-34 35-44 45-54 55-64 Age s Men Source: CDC/NCHS and NHLBI. W omen 65-74 75+ Cardiovascular Disease Mortality Trends Cardiovascular for Males and Females Ye a rs M ales Source: CDC/NCHS. F em ales 01 99 97 95 93 91 89 87 85 83 81 520 500 480 460 440 420 400 380 79 D e a th s i n T h o u s a n d s United States: 1979-2002 United CVD in Men and Women CVD mortality in men is holding steady; in women it is increasing Women have comparable CVD rates about 10­15 years later than men, but the gap diminishes with age 82% of coronary events in women are attributable to unhealthy diet, lack of activity, cigarette use, and overweight CVD in Women Women post MI are less likely to receive aspirin, beta­blockers, intravenous heparin, or nitrate therapies within the first 24 hours of hospital admission They were less likely to undergo coronary angiography, angioplasty, or bypass surgery, but they were more likely to die in the hospital. CVD in Women Women have a higher prevalence of white­coat hypertension than men. Women may have atypical symptoms when suffering a heart attack or angina When they are sent home from the hospital, they are more than twice as likely to die as those who are admitted A Nation at Risk 49 million Americans smoke 42 million have total cholesterols >240 mg/dl 63 million have total cholesterols 200­ 239 17 million Americans have diabetes 61 million Americans are obese; 68 millionare overweight There is Encouraging News! Framingham Milestones 1960: cigarette smoking found to increase the risk of heart disease 1961: Cholesterol level, blood pressure, and EKG abnormalities found to increase the risk of heart disease 1967: physical activity found to reduce the risk of heart disease; obesity found to increase the risk of heart disease 1970: High blood pressure found to increase the risk of stroke Framingham Milestones 1976: Menopause found to increase the risk of heart disease 1978: Psychosocial issues found to affect the risk of heart disease 1988: High levels of HDL found to reduce risk of death 1994: Enlarged left ventricle found to increase the risk of stroke 1996: Progression from hypertension to heart failure described Favorable Trends Over past 30 years, mortality and in­ hospital case fatality has declined 50% Prevalence of risk factors of smoking, hypertension, high cholesterol has declined 25 to 46% Cigarette smoking among men, women, high school students, and mothers during pregnancy: United States, 1965-2003 60 50 Men 40 Percen t High school students Women 30 20 Mothers during pregnancy 1 0 0 1965 1970 1975 1985 1980 1990 1995 Year NOTES: Percents for men and women are age adjusted. See Data Table for data points graphed, standard errors, and additional notes. Cigarette smoking is defined as: (for men and women 18 years of age and older) at least 100 cigarettes in lifetime and now smoke every day or some days; (for students in grades 9-12) 1 or more cigarettes in the 30 days preceding the survey; and (for mothers with a live birth) during pregnancy. SOURCES: Centers for Disease Control and Prevention, National Center for Health Statistics, National Health Interview Survey (data for men and women); National Vital Statistics System (data for mothers during pregnancy); National Center for Chronic Disease Prevention and Health Promotion, Youth Risk Behavior Survey (data for high school students). Centers for Disease Control and Prevention, National Center for Health Statistics. Health, United States, 2004 2003 Percent of Population 20­74 with High Serum Cholesterol by Race and Sex 1971­74 to 1988­94 http://www.nhlbi.nih.gov/resources/docs/02_chtbk.pdf accessed 3-05 THE BAD NEWS: Overweight and obesity by age: United States, 1960-2002 70 60 50 Overweight including obese, 20-74 years 40 Overweight, but not obese, 20-74 years 30 20 Obese, 20-74 years Overweight, 6-11 years 1 0 Overweight, 12-19 years 0 1960-62 1963-65 1966-70 1971-74 1976-80 1988-94 Year Centers NOTES: Percents for adults are age adjusted. For adults: "overweight including obese" is defined as a body mass index (BMI) greater than or equal to 25, "overweight but not obese" as a BMI greater than 25 but less than 30, and "obese" as a BMI greater than or equal to 30. For children: "overweight" is defined as a BMI at or above the sex- and age-specific 95th percentile BMI cut points from the 2000 CDC Growth Charts: United States. "Obese" is not defined for children. See Data Table for data points graphed, standard errors, and additional notes. Data are for the civilian noninstitutionalized population and are age adjusted. See Data Table for data points graphed and dditional notes. foraDisease Control and Prevention, National Center for Health Statistics. 19992002 SOURCES: Centers for Disease Control and Prevention, National Center for Health Statistics, National Health Examination Survey and National Health and Nutrition Examination Survey. Health, United States, 2004 The Decrease in CVD Mortality 25% is due to primary prevention 75% is due to behavioral changes affecting risk factors or improvements in treatment Benefits of Risk Factor Reduction 50­70% lower risk in former vs current smokers within 5 years of cessation 2­3% decline in risk for each reduction of 1% serum cholesterol 2­3% decline in risk for each reduction of 1 mm Hg in diastolic blood pressure 35­55% lower risk for those who maintain desirable body weight as compared to those 20%+ above Benefits of Risk Factor Reduction 45% lower risk for those who maintain an active lifestyle compared with a sedentary lifestyle 35% lower risk in aspirin users compared with nonusers Coronary Heart Disease (CHD) or Coronary Artery Disease (CAD) Disease involves impeded blood flow to the network of blood vessels surrounding and serving the heart Major cause is atherosclerosis; structural and compositional changes in the inner wall of the arteries Manifested in clinical end points of myocardial infarction (MI) and sudden death Pathophysiology of Atherosclerosis Vessel lining is injured (often at branch points) → Plaque is deposited to repair injured area → Plaque thickens, incorporating cholesterol, protein, muscle cells, and calcium (rate depends partly on level of LDL­C in the blood) → Pathophysiology of Atherosclerosis (cont) Arteries harden and narrow as plaque builds, making them less elastic → Increasing pressure causes further damage → A clot or spasm closes the opening, causing a heart attack Pathophysiology of Atherosclerosis Proliferation of smooth­muscle cells, macrophages, and lymphocytes Formation of smooth muscle cells into a connective tissue matrix Accumulation of lipid and cholesterol in the matrix around the cells Endothelial Injury Caused by Hypercholesterolemia Oxidized low­density lipoprotein Hypertension Cigarette smoking Diabetes Obesity Homocysteine Diets high in saturated fat and cholesterol Natural Progression of Atherosclerosis (From Harkreader H. Fundamentals. Philadelphia: W.B. Saunders, 2000) Plaque or Atheroma Lipid deposits and other materials (cellular waste products, calcium, fibrin) that build up in the intimal layer Heart Attack (Myocardial Infarction) Heart Attack (Myocardial Infarction) When blood supply to the heart is disrupted, the heart is damaged May cause the heart to beat irregularly or stop altogether 25% of people do not survive their first heart attack Symptoms of a Heart Attack Intense, prolonged chest pain or pressure Shortness of breath Sweating Nausea and vomiting (especially women) Dizziness (especially women) Weakness Jaw, neck and shoulder pain (especially women) Irregular heartbeat Factors That May Bring On Heart Attack (in at­risk) Dehydration Emotional stress Strenuous physical activity when not physically fit Waking during the night or getting up in the morning Eating a large, high­fat meal (increases risk of clotting) Cerebrovascular Accident (CVA) or Brain Attack Brain Attack (Stroke) or Cerebrovascular Accident Symptoms of Stroke (Brain Attack) Sudden numbness or weakness of the face, arm or leg, especially on one side of the body Sudden confusion, trouble speaking or understanding Sudden trouble seeing in one or both eyes Sudden trouble walking, dizziness, loss of balance or coordination Sudden severe headache Functions of Lipoproteins Lipids are transported in the blood bound to protein Lipoproteins vary in composition, size, and density Consist of varying amounts of triglyceride, cholesterol, phospholipid, and protein The ratio of protein to fat determines the density (HDLs have more protein than LDLs) Lipoproteins combine Lipids (triglycerides, cholesterol) Protein Phospholipids Functions of the Plasma Lipoproteins Chylomicron—Transport of dietary triglyceride VLDL—Transport of endogenous triglyceride IDL—LDL precursor LDL—Major cholesterol transport lipoprotein HDL—Reverse cholesterol transport Lipoprotein Summary Lipoprotein Assessment Includes measurement of total cholesterol, LDL cholesterol, HDL cholesterol, and triglyceride level after fasting Total Cholesterol Captures cholesterol contained in all lipoprotein fractions 60%­70% is carried on LDL 20%­30% is carried on HDL 10%­15% on VLDL Total Cholesterol Direct, positive association between TC and CHD risk Diets high in saturated fats raise total cholesterol and CHD incidence and mortality ATP­III Guidelines: lowering total cholesterol and LDL­C reduces CHD risk 10% reduction in TC decreases CHD risk by about 30% Factors Affecting Total Cholesterol Age Diets high in fat, saturated fat, cholesterol Genetics Endogenous sex hormones (pre­ menopause) Exogenous steroids Drugs (beta blockers, thiazide diuretics) Body weight Glucose tolerance Physical activity Season of the year Diseases Prevalence of High Total Cholesterol Serum cholesterol levels in the U.S. population have been declining since 1960 More than half that decline occurred between 1976 and 1991, when national preventive education efforts were begun Proportion of adults with TC>240 mg/dl fell from 27% to 19%, while HDL and VLDL remained unchanged Total Triglycerides Triglyceride­rich lipoproteins include chylomicrons, VLDL, remnants or intermediary products Are atherogenic At very high levels, ↑ risk of pancreatitis Can be evidence of metabolic syndrome Chylomicrons Largest particles Transport dietary fat and cholesterol from the small intestine to the liver In the bloodstream, triglycerides are hydrolyzed by lipoprotein lipase (LPL) in muscle and adipose tissue When 90% of triglyceride is hydrolyzed, released into blood as a remnant Liver metabolizes remnants, but some deliver cholesterol to the arterial wall Absent in fasting studies Very­Low­Density­ Lipoproteins Manufactured in the liver to transport endogenous triglyceride and cholesterol 60% is triglyceride Large VLDL may be nonatherogenic VLDL remnants or IDL appear to be atherogenic Not routinely measured, but TG in them is measured in total triglyceride Intermediate­Density Lipoprotein Formed with catabolism of VLDL, a precursor of LDL Rich in cholesterol and apo E High concentrations of IDL and VLDL remnants directly related to lesion progression and coronary events Not routinely measured, though components can be Low­Density Lipoprotein Primary cholesterol carrier in blood Total cholesterol and LDL­cholesterol are strongly correlated 95% of apolipoproteins in LDL are apo­B­ 100 LDL is formed in VLDL catabolism, 60% is taken up by LDL receptors in liver, adrenals, other tissues; rest is metabolized via alternative pathways Number and activity of receptors determines LDL cholesterol levels in the blood LDL­C Particles heterogeneous in size, density, lipid components Phenotype A: large particles, not associated with disease risk Phenotype B typified by small, dense LDL particles; triglyceride rich, cholesterol depleted; predictive of CHD risk in men and women High Density Lipoproteins (HDL) Contain more protein than the other lipoproteins Apo A­1 is involved in tissue cholesterol removal High HDL is associated with low levels of chylomicrons, VLDL remnants, and small, dense LDL Lipoprotein Profile Measures total cholesterol, LDL­ cholesterol, HDL­cholesterol, and triglycerides 8­12 hour fast allows chylomicrons to clear Friedenwald formula for calculating LDL­C = (TC) – (HDL­C) – (TG/5) ATP III Guidelines Adult Treatment Panel for the Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults convened by the National Heart, Lung & Blood Institute of the NIH Published 2002 Updated in 2004 Next revision expected in 2009 (panel convened 2/08) Lipoprotein Profile If nonfasting, can measure total and HDL cholesterol If TC>200 mg/dl or HDL­C is <40 mg/dl, get fasting analysis Evaluating Blood Lipids: Total Cholesterol <200 mg/dL Desirable 200­239 mg/dL Borderline high ≥240 mg/dL High Source: ATP-III Guidelines, NHLBI, accessed 2-2005 Evaluating Blood Lipids: Triglycerides <150 mg/dL Normal 150­199 Borderline high 200­499 High >500 mg/dl Very high Source: ATP-III Guidelines, NHLBI, accessed 4-2005 Evaluating Blood Lipids: LDL <100 mg/dL Optimal 100­129 Near optimal 130­159 Borderline high 160­189 High ≥190 Very high Source: ATP-III Guidelines, NHLBI, accessed 2-2005 Evaluating Blood Lipids: HDL < 40 mg/dL Low ≥ 60 mg/dL High Source: ATP-III Guidelines, NHLBI, accessed 2-2005 Risk Factors affect Lipid Targets Major, independent risk factors Life­habit risk factors Emerging risk factors Major Risk Factors That Modify LDL Goals Cigarette smoking Hypertension (BP ≥ 140/90 mmHg or on antihypertensive medication) Low HDL cholesterol (<40 mg/dL)† Family history of premature CHD – – – † CHD in male first degree relative <55 CHD in female first degree relative <65 Age (men ≥ 45 years; women ≥ 55 years) Life­Habit Risk Factors Obesity (BMI ≥ 30) Physical inactivity Atherogenic diet Emerging Risk Factors Lipoprotein (a) Homocysteine Prothrombotic factors Proinflammatory factors Impaired fasting glucose Subclinical atherosclerosis Risk Assessment Count major risk factors* For patients with multiple (2+) risk factors – Perform 10­year risk assessment For patients with 0–1 risk factor – 10 year risk assessment not required – Most patients have 10­year risk <10% *HDL cholesterol ≥ 60 mg/dL counts as a “negative” risk factor; its presence removes one risk factor from the total count. CHD Risk Equivalents Risk for major coronary events equal to that in established CHD 10­year risk for hard CHD >20% Hard CHD = myocardial infarction + coronary death Diabetes In ATP III, diabetes is regarded as a CHD risk equivalent. Diabetes as a CHD Risk Equivalent 10­year risk for CHD ≅ 20% High mortality with established CHD – High mortality with acute MI – High mortality post acute MI CHD Risk Equivalents Other clinical forms of atherosclerotic disease (peripheral arterial disease, abdominal aortic aneurysm, and symptomatic carotid artery disease) Diabetes Multiple risk factors that confer a 10­year risk for CHD >20% Calculate Your 10­Year Risk of Heart Attack Risk Calculation http://hp2010.nhlbihin.net/atpiii/calculator.as At­A­Glance treatment guidelines: http://www.nhlbi.nih.gov/guidelines/cho lesterol/atglance.htm Three Categories of Risk that Modify LDL­C GOALS Risk Category LDL Goal (mg/dL) CHD and CHD risk equivalents <100 Multiple (2+) risk factors Zero to one risk factor <130 <160 ATP III Guidelines Goals and Treatment Overview Primary Prevention With LDL­Lowering Therapy Public Health Approach Reduced intakes of saturated fat and cholesterol Increased physical activity Weight control Causes of Secondary Dyslipidemia Diabetes Hypothyroidism Obstructive liver disease Chronic renal failure Drugs that raise LDL cholesterol and lower HDL cholesterol (progestins, anabolic steroids, and corticosteroids) Secondary Prevention W/ LDL­Lowering Therapy Benefits: reduction in total mortality, coronary mortality, major coronary events, coronary procedures, and stroke LDL cholesterol goal: <100 mg/dL Includes CHD risk equivalents Consider initiation of therapy during hospitalization (if LDL ≥ 100 mg/dL) LDL­C Goals in Different Risk Categories Risk Category CHD or CHD Risk Equivalents (10­year risk >20%) Moderately high risk 2+ Risk Factors (10­year risk 10­ LDL Goal (mg/dL) LDL for Total Lifestyle Change LDL for Drug Therapy ≥ 100 ≥ 100 (<100: consider drug options (TLC) (mg/dL) <100; optional goal <70 mg/dL <130 ≥ 130 20%) ATP-3 update, Circulation, 2004 (mg/dL) >130 mg/dL (100­129 mg/dL, consider drug options) LDL­C Goals in Different Risk Categories Risk Category LDL for Total Lifestyle Change LDL Goal (mg/dL) (TLC) (mg/dL) LDL for Drug Therapy (mg/dL) Moderate risk: 2+ <130 mg/dL risk factors (10 >130 mg/dL >160 mg/dL Lower risk (0­1 risk factors) >160 mg/dL >190 mg/dL (160­ 189 mg/dL, drug year risk<10%) <160 mg/dL optional) ATP-3 update, Circulation, 2004 ...
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This note was uploaded on 12/24/2011 for the course STEP 1 taught by Professor Dr.aslam during the Fall '11 term at Montgomery College.

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