Cardiovascular Disease in Black Women

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Cardiovascular Disease in Black Women

• Rozann Hansford, R.N.
• MPH Candidate

2
Cardiovascular Heart Disease

• Cardiovascular disease (CVD) refers to a wide
  variety of heart and blood vessel disorders
  including CHD, HTN, stroke, rheumatic heart
  disease
• Coronary Heart Disease (CHD) refers to several
  disorders that decrease blood supply to the heart
  muscle

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Pathophysiology of CHD

• Atherosclerosis is the underlying disease process
• Typically begins in childhood
• Slowly progressive,thickening of the inner layer
  of the arteries walls
• Incidence increases with age
• Not an inevitable consequence of aging

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Pathophysiology of CHD

• Disease progression starts with fat deposition
  and advances to fatty streaks with lipid core and
  calcium deposits
• As atherosclerosis progresses, arteries narrow
  enhancing possibility of endothelial disruption,
  hemorrhage and occlusive thrombosis (3)

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Pathophysiolgy of CHD

• Contributing factors include inflammatory,
  immunologic and hemostatic processes involving
  multiple systems and cellular types
• Persons most likely to suffer a myocardial
  infarction have lt50 occlusion, not gt70
  occlusion as previously thought

6
Biological differences between blacks and whites?

• It is not known whether cellular and molecular
  mechanisms of atherogenesis differ between races
• Blacks with hypertension respond less to
  angiotensin converting enzyme (ACE) inhibitors
• Blacks demonstrate greater fibrinolysis when
  receiving tissue plasmin activator (TPA) for
  myocardial infarction (4)

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Epidemiology of CHD in Black Women (US)

• Black Americans experience a higher
  morbidity/mortality compared with other
  racial/ethnic groups and have the highest age
  adjusted CHD mortality (1). CVD accounts for
  41.6 of deaths in black women
• CHD death rates are 67 higher for black women
  compared to white women

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Epidemiology of CHD in Black Women

• CHD is particularly prevalent in black women
  younger than 55 years old who have 2.5 times the
  risk of CHD death compared to white women (6).
• Are black women deriving the same benefit from
  estrogen as white women?
• Black women have 2 times the rate of angina
  compared with white women and five times the rate
  of angina compare to black men.

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CHD Risk Factors in Black Women

• Framingham Heart Study.defined and quantified
  cardiac risk factors and related finding to
  cardiovascular outcomes
• Enrollment limited almost exclusively to whites
• Should this data be generalized to include all
  racial/ethnic mixes?

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CHD Risk Factors in Black Women Clinical Trials

• CHSCardiovascular Heart Study..enrollment
  limited to white men and women
• Charleston Heart Study, MRFIT study and Chicago
  Heart Study enrollment limited to men

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CHD Risk factors in black women Clinical trials

• Atherosclerosis in the Community (ARIC) included
  large cohort of black women
• Four communities in the US, 1987-1997
• Included 14,026 black and white men
• Included 10 years follow-up
• Hypertension a particularly strong risk factor in
  black women

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CHD Risk Factors in black women

• National Health and Nutrition Evaluation Survey I
  (NHANES I)
• 14,000 black and white persons from 1982-1992
• Elevated systolic blood pressure and smoking in
  black women predictive of CHD
• Excess risk of CHD in black women relates to
  higher levels of identified risk factors

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CHD Risk factors in black women Smoking

• Not specifically studied in black women
• In women, first MIs occur 19 years earlier if
  woman smokes
• May be a strong risk factor in black women
  because of effects of co-morbidity (black women
  have a high incidence of HTN,diabetes and
  hypercholesterolemia

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CHD Risk factors in black women Hypertension

• A major risk factor for the development of CHD
  and stroke.
• Associated with pathologic changes in the
  arterial walls and endothelium, decreased of
  small peripheral arteries, increased left
  ventricular wall thickness and abnormal diastolic
  function (15).

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CHD risk factors in black women Hypertension

• Particularly strong risk factor in Black women
  (ARIC) study
• Left ventricular hypertrophy is an independent
  risk factor for development of CHD

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CHD risk factors in black women Diabetes

• Incidence of CHD is 2 to 4 times higher in
  persons with Diabetes
• Incidence of type II Diabetes is 9.1 in black
  women compared with 4.5 in white women

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CHD risk factors in black women Diabetes

• Implicated as a possible etiology of increased
  CHD incidence in young black women
• Animal Studies suggest that hyperglycemia and
  hyperinsulinemia-insulin may prevent the
  cardiovascular effects of insulin
• Black women have a higher incidence of obesity
  and diabetes relative to white women,protection
  from CHD that sex usually provides may not be as
  strong in black women

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CHD risk factors in black women Syndrome X

• Syndrome Xcumulative effects of hypertension,
  glucose intolerance and dyslipidemia
• Associated with a higher cardiovascular
  mortality
• Has a synergistic effect on atherogenesis
• Seen more often in black women than other
  racial/ethnic mixes

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CHD risk factors in black women Obesity

• Approximately 75 of African American women are
  obese, more than any other racial gender mix
• Body Mass Index (BMI), body fat distribution and
  central obesity are all predictive of CHD risk in
  women
• Major cause is inactivity

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CHD risk factors in black women
Hypercholesterolemia

• Incidence of elevated cholesterol is 20 in black
  women..relationship to CHD not studied in black
  women
• In black men, relationship of elevated
  cholesterol to CHD development is confusing, may
  have implications for black women

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CHD risk factors in black women
Hypercholesterolemia

• In whites, higher socioeconomic is associated
  with higher HDLs..the reverse is true in black
  men
• Black men have higher levels of lipoprotein but
  these levels are less predictive of CHD in black
  men compared to white men

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Socioeconomic factors

• CHD in black women results from a complex
  interplay between established risk factors,
  access to health care, behavioral and coping
  mechanisms and socioeconomic status
• Differences in access to care and economic
  factors may play an important role

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Socioeconomic factors

• Because black women do not access health care
  facilities as often as white women, community
  based interventions at churches, work places and
  schools may be useful for prevention
• Heart, Body and Soul partnership between Clergy
  and Johns Hopkins University minimizes barriers
  associated with mistrust of health personal

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Research needed!!!

• Insufficient data available for resolving
  questions related to racial/gender comparisons
• Need to determine if differences, clinical
  paradoxes and inconsistencies are related to
  chance findings, artifacts in reporting,
  environmental differences or biological
  differences

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Research Needed!!!

• Data already collected needs to be pooled and
  examined a first step would include a national
  screening policy
• Culturally validated data tools needed
• Need to study efficacy of prevention strategies

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Conclusions

• Most large scale clinical trials to date have
  excluded black women. Results have been
  generalized to include black women and this may
  be very misleading
• Small studies, incidental findings, responses to
  some meds and animal research hint at the
  possibility of biological differences between
  black women and other racial/ethnic mixes

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Conclusions

• Black women tend to get CHD 10 years earlier than
  white women. The reasons for this though
  hypothesized, have not been established.
• Hypertension appears to be the single most
  important risk factor for the development of CHD
  black women.

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Conclusions

• The excessive incidence of CHD in black women is
  likely due to a complex relationship between
  social, behavioral, genetic and economic factors.
  Teasing out the contributions of these factors so
  that appropriate public health measures can be
  implemented is likely to be a very difficult task!

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