1

Coronary Heart Disease : Epidemiology

Presented ByDr Garima Gupta

MBBS , MD Post Graduate studentUniversity College Of Medical Sciences & GTB Hospital,

Delhi

Cardio-Vascular Disease• Cardiovascular diseases (CVDs) are a group of disorders of the

heart and blood vessels.

Coronary heart disease/ Coronary artery disease

Cerebrovascular diseasePeripheral arterial diseaseRheumatic heart diseaseCongenital heart diseaseDeep vein thrombosis and

pulmonary embolism.

Proportions of death from CVD due to coronary heart disease, cerebrovascular disease and other CVDs in

males

Global atlas on cardiovascular disease prevention and control, World Health Organisation

11%1% 2%

6%

34%

46%

Other CVD Rheumatic Heart Disease Inflammatory Heart DiseaseHypertensive Heart Disease Cerebrovascular Disease Coronary Heart6 Disease

Proportions of death from CVD due to coronary heart disease, cerebrovascular disease and other CVDs in

females

Global atlas on cardiovascular disease prevention and control, World Health Organisation

14%1%2%

7%

37%

38%

Other CVD Rheumatic Heart Disease Inflammatory Heart DiseaseHypertensive Heart Disease Cerebrovascular Disease Coronary Heart Disease

CAD-epidemiology • Descriptive epidemiology - Describing distribution of

coronary artery disease by means of certain characteristics such as : PERSON (i.e., age, gender, ethnicity) TIME and PLACE

• Analytical epidemiology - Analysing relationships between CAD and risk factors (which elevate the probability of a disease at population level), risk model and multicausal developments

• Interventional epidemiology - Strategies of cardiovascular prevention (primordial, primary, secondary, tertiary; individual and community levels)

Coronary Artery Disease

• Enas EA. How to Beat the Heart Disease Epidemic among South Asians: A Prevention and Management Guide for Asian Indians and their Doctors. Downers Grove: Advanced Heart Lipid Clinic  USA; 2010.

Type

I • Young individuals < 50 years

• Marked prematurity , severity

• High prevalence of emerging risk factors

Type

II • Older individuals > 65 years

• Mild – moderate severity

• High prevalence of traditional risk factors.

Type

III • Also known as

“MIXED VARIETY”

• Individuals between 50-65 years of age

• Role of both classes of risk factors present.

Descriptive Epidemiology

Descriptive Epidemiology :Distribution Patterns in the World

Disease burden (World)(expressed as percentage of DALYs Lost)

• World Health Organisation ( WHO) Report 2002

HIV/AIDS CHD Stroke UDD RTA TB COPD Hearing loss

0.00%

100.00%

200.00%

300.00%

400.00%

500.00%

600.00%

700.00%

800.00%

900.00%

1000.00%

Males Females

Perc

enta

ge o

f DAL

Ys L

ost

India• Indians with Coronary Artery Disease (in millions)

• * - 780 million adults > 20 years of age• ** - 800 million adults > 20 years of age

• National Commission on Macroeconomics and Health.• Enas EA, Mehta J. Malignant coronary artery disease in young Asian Indians: thoughts on

pathogenesis, prevention, and therapy. Coronary Artery Disease in Asian Indians (CADI) Study. Clin Cardiol. Mar 1995;18(3):131-135.

Age 2010* 2015** Increase from 2010 to 2015 (%)

All 47.0 61.8 32

<50 yrs of age 28.4 37.3 31

<40 yrs of age 17.4 23.0 32

<30 yrs of age 8.3 10.5 27

Deaths due to CAD (India)

• * - 780 million adults > 20 years of age• ** - 800 million adults > 20 years of age

• National Commission on Macroeconomics and Health.• Enas EA, Mehta J. Malignant coronary artery disease in young Asian Indians: thoughts on

pathogenesis, prevention, and therapy. Coronary Artery Disease in Asian Indians (CADI) Study. Clin Cardiol. Mar 1995;18(3):131-135.

Age 2010* 2015** Increase from 2010 to 2015 (%)

All 2.3 2.9 26

< 50 years of age 1.14 1.5 32

< 40 years of age 0.70 0.92 31

< 30 years of age 0.33 0.42 27

Deaths from coronary artery disease

Coronary heart disease mortality (in percentages) between Developed Nations and Developing Nations (1990 and 2020)

1990 20200%

10%

20%

30%

40%

50%

60%

70%

80%

44%

31%

56%

69%

Developed nations Developing Nations

World trends and International Comparisons

• Cardiovascular disease (CVD) and coronary heart disease (CHD) deaths (millions) in India, China, and established market economies (EME) from the Global Burden of Diseases Study. (Ezzati et al., 2004)

1990 2000 2010 2020INDIA CHIN

AEME INDIA CHIN

AEME INDIA CHINA EME INDI

ACHINA

EME

CVD 2.26 2.57 3.18 3.01 3.30 3.49 3.80 3.81 3.53 4.77 4.53 3.66

CAD 1.18 0.76 1.67 1.59 0.99 1.84 2.03 1.15 1.87 2.58 1.37 1.95

119 % Increase

• EME- Established Market Economies

1990 2000 2010 20200

0.5

1

1.5

2

2.5

3

1.18

1.59

2.03

2.58

0.76

0.991.15

1.37

1.671.84 1.87

1.95

Deaths due to Coronary heart disease India China Linear (China) EME

Deat

hs i

n m

illio

ns

Model of the Stages of Epidemiologic Transition

Stages of development

Deaths from CVD

Predominant CVD and Risk Factor Regional Examples

Age of pestilence and famine

5-10 % of total deaths

Rheumatic heart disease, infections, and nutritionalcardiomyopathies

Sub-Saharan Africa, rural India,South America

Age of receding pandemics

10-35 As above hypertensive heart disease and hemorrhagic strokes

China

Age of degenerative andman-made diseases

35-65 All forms of strokes, ischemic heart disease at young ages,increasing obesity, and diabetes

Urban India, former socialisteconomies, aboriginalcommunities

Age of delayed degenerativediseases

< 50 Stroke and ischemic heart disease at old age

Western Europe, North America,Australia, New Zealand

Age of health regression andsocial upheaval

35-55 Re-emergence of deaths from rheumatic heart disease,infections, increased alcoholism, and violence; increase inischemic and hypertensive diseases in the young

Russia

• Regression Dilution Bias• Lag Effect

Economic burden

Cost of CAD

Cost to the individual and family

Cost to government

of health care

Cost of “HUMAN

LIFE”

Cost to country of

lost productivity

• A cross-sectional study was conducted by Huffman et al Patients in Argentina, China, India, and Tanzania bear a significant burden of out-of-pocket payments, as defined by Catastrophic Health Spending and Distress Financing, following CHD hospitalization, though substantial variations exist across and within countries.

• A Cross-Sectional Study of the Microeconomic Impact of Cardiovascular Disease Hospitalization in Four Low- and

Middle-Income Countries

Descriptive Epidemiology :Distribution Patterns as per Age and Gender

• National Health and Nutrition Examination Survey: 2009–2012. • Mozaffarian D et al. Circulation. 2015;131:e29-e322• American Heart association

20-39 40-59 60-79 80+0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.60%6.30%

19.90%

32.20%

0.60%5.60%

9.70%

18.80%

Prevalence of coronary heart disease by age and gender

Age in years

Perc

ent o

f pop

ulati

on

Descriptive Epidemiology :Distribution Patterns as per Gender

• Higher rates of coronary heart disease among men compared with women (premenopausal age)

• Heart disease affects women approximately 10 years later than men, possibly due to the protective effect of estrogen. A woman’s risk of a heart attack increases steeply after menopause, when her LDL-C and triglyceride levels begin to increase and her good cholesterol (HDL-C) level begins to fall.

• After menopause, women’s cholesterol levels are, on average, higher than those of men of about the same age.

Descriptive Epidemiology :Distribution Patterns as per Ethnicity

Prevalence of CVD for specific degrees of carotid atherosclerosis. The prevalence of CVD increases with increasing carotid atherosclerosis in each ethnic group.

• Although both Chinese and Asian Indians in the US are classified as Asian Americans, they are diametrically opposite in terms of morbidity and mortality from CAD (coronary artery disease).

• Despite very high rates of smoking and high blood pressure, the Chinese have very low and the Japanese have the lowest rates of heart disease .

• In sharp contrast Asian Indians have the highest rates of heart disease despite having similar or lower levels of traditional risk factors, with the exception of diabetes

Asian-Indian paradox

• Asian Indian paradox refers to the excess burden of heart disease among Asian Indians despite having a low prevalence of traditional risk factors. Studies in the US, UK, Canada, Singapore, and other countries have shown prevalence of traditional risk factors such as smoking, obesity, hypertension, and high cholesterol levels is similar or lower in Asian Indians compared to Europids.

• Coronary artery disease (CAD) rates and lipoprotein levels are similar among vegetarians and non-vegetarians. This is in sharp contrast to the findings from Western vegetarians, who have a favourable lipid profile and low rates of CAD.

• Although the prevalence of insulin resistance, glucose intolerance, metabolic syndrome, and diabetes are very high, these conditions do not fully explain the excess burden of premature death from CAD among Asian Indians.

• Prospective studies have shown that the incidence and mortality from CAD is at least two-fold higher among Asian Indians, even when adjusted for standard risk factors including diabetes and metabolic syndrome.

Analytical epidemiology

Non Modifiable factors and Modifiable factors

Non-Modifiable factors Modifiable factors

Advancing Age High Blood Pressure

Gender Obesity

Heredity / Family history Abnormal Blood Lipids

Ethnicity / Race Unhealthy Diet

Tobacco use

Diabetes

Physical inactivity

Other Modifiable Risk Factors Novel Risk Factors

Socio-economic Status Excess homocysteine in blood

Alcohol Use Abnormal blood coagulation

Mental Ill health Inflammation

Psycho-social stress

Lipoprotein(a)

CRP

Vitamin - D

Genetics• Recent genome wide association studies indicate that genetic

factors predisposing to heart attack in patients with heart disease are distinct from those that associate with the presence of heart disease.

• Having ABO blood group “O” may reduce the risk of heart attack by up to 20%.

• Reilly M P, Li M, He J, et al. Identification of ADAMTS7 as a novel locus for coronary atherosclerosis and association of ABO with myocardial infarction in the presence of coronary atherosclerosis: two genome-wide association studies. Lancet. Jan 29 2011;377(9763):383-392.

• A study which compared 12,393 individuals with coronary artery disease (CAD) with 7383 controls (without any narrowing on angiography) , identified a new locus, ADAMTS7, to be a common genetic risk factor for heart disease, with a 19% increased risk for carriers.

• Nine genome wide studies have found 14 chromosomal loci at which one or more common single nucleotide polymorphisms (SNPs) are associated with CAD or heart attack. Almost all these studies have implicated the 9p21.3 locus, considered as the most widely and consistently replicated genetic risk factor for CAD.

• Reilly M P, Li M, He J, et al. Identification of ADAMTS7 as a novel locus for coronary atherosclerosis and association of ABO with myocardial infarction in the presence of coronary atherosclerosis: two genome-wide association studies. Lancet. Jan 29 2011;377(9763):383-392.

Blood Pressure• High blood pressure (hypertension) is one of the most

important preventable causes of premature death worldwide.• Even a blood pressure at the top end of the normal range

increases risk. • High BP is SBP >140 mmHg and/or DBP >90 mmHg

Predictor in relation to CAD /CHD

• Does the Relation of Blood Pressure to Coronary Heart Disease Risk Change With Aging? The Framingham Heart Study

< 50 years of age DBP strong predictor

50-59 years of age SBP + DBP + PP (Transition state)

> 60 years of age PP as best predictor

ROLE OF HDL-C AND LDL-C

HDL-C< 40 mg/dl in men

< 50 mg/dl in women

LDL-C > 100 mg/dlTriglycerides >150

mg/dl

BALANCE OF CAD

INDEPENDENT RISK FACTOR

Lipoprotein (a) “The Deadly Cholesterol”

• Lipoprotein (a) is a strong, putative, and causal risk factor for heart disease. It is a genetic variant of LDL.

• Lp (a) is one of the strongest biological markers for premature heart disease.

• Enas EA, Chacko V, Senthilkumar A, Puthumana N, Mohan V. Elevated lipoprotein(a)–a genetic risk factor for premature vascular disease in people with and without standard risk factors: a review. Dis Mon. Jan 2006;52(1):5-50.

Multiplicative effects of Lp(a)

• Enas EA, Chacko V, Senthilkumar A, Puthumana N, Mohan V. Elevated lipoprotein(a)–a genetic risk factor for premature vascular disease in people with and without standard risk factors: a review. Dis Mon. Jan 2006;52(1):5-50.

Risk outcome

Elevated levels of Lp(a) present only *3

+ low HDL-C *8

+ high LDL-C *12-14

+ high TC/ HDL-C Ratio *25

+ high homocysteine *12-30

+ other risk factors Can extend up to *122

Tobacco• Tobacco causes a fifth of cardiovascular disease worldwide.• India is the home to 12% of world’s smokers. (WHO)• In the USA, up to 62 000 people die each year from heart

disease caused by passive smoking.• Quitting smoking effectively reduces cardiovascular risk to

close to that of a person who has never smoked.

25 cigarettes/day – risk by 8 timesHigh BPRisk in women who use OCPRisk of death and re-infarction after CABG

Beneficial effects of physical activityLife expectancyIN

CREA

SEDECREASE

EFFECT OF SMOKING TOBACCO

Physical inactivity• A coalescence of anthropological estimations of Homo

sapiens’ phenotypes in the late Palaeolithic era 10,000 years ago, with Darwinian natural selection synergized with Neel’s idea of the so-called thrifty gene suggests that humans inherited genes that were evolved to support a physically active lifestyle.

• Worldwide, physical inactivity causes about 1.9 million deaths, 20% of cardiovascular disease and 22% of coronary heart disease.

• Being physically inactive increases your risk of coronary heart disease and ischaemic stroke by around 1.5 times.

Obesity• Abdominal girth and waist-to-hip ratio are useful indicators of

obesity.

• The Body Mass Index (BMI), a measure of weight in relation to height, is commonly used for classifying overweight and obesity.

Diabetes and CAD

DIAB

ETIC

S

12-40 times the rate of CAD as in non-diabetic

More advanced atherosclerosis

. High blood glucose is a greater risk factor for CAD and

stroke than smoking

poor success and survival rates following angioplasty and

bypass surgery

2 Times more mortality rate

Socio-economic status

In developing countries, higher socioeconomic class has been associated with a higher prevalence of CAD.

• Coronary artery disease in the developing world - Karen Okrainec, MSc, a Devi K. Banerjee, MD, b and Mark J. Eisenberg, MD, MPHc Montreal, Quebec, Canada

High SES Low SES0%

10%20%30%40%50%60%70%80%90%

100%

61%

30%

20%9%

Prevalence of CAD in Urban Population as per SES status

Males Females

Psychological

• Contrary to common belief, type A personality is not associated with an excess of coronary artery disease (CAD). Moreover, the prognosis of CAD among type A persons is better than in type B patients.

• Type “D” personality: defined as the joint tendency towards negative affectivity and social inhibition. It is associated with coronary heart disease. [??]

• Enas EA, Garg A, Davidson MA, Nair VM, Huet BA, Yusuf S. Coronary heart disease and its risk factors in first-generation immigrant Asian Indians to the United States of America. Indian Heart J. 1996;48(4):343-353.

hs-CRP• Acute phase reactant ( inflammatory marker)

• CRP level has been proposed as biomarker for CVD and CAD risk prediction and as a selection marker for initiating statin treatment.

• More than 70% of obese women and more than 50% of obese men having elevated levels of CRP

• Smokers have 38% higher CRP levels than Non-smokers

• Ridker PM, Wilson PW, Grundy SM. Should C-reactive protein be added to metabolic syndrome and to assessment of global cardiovascular risk? Circulation. Jun 15 2004;109(23):2818-2825.

• Jeemon P, Prabhakaran D, Ramakrishnan L, et al. Association of high sensitive C-reactive protein (hsCRP) with established cardiovascular risk factors in the Indian population. Nutrition & metabolism. Mar 28 2011;8(1):19.

Vitamin-D• Low vitamin D levels are highly associated with endothelial

dysfunction, atherosclerosis, heart attack, heart failure, stroke as well as silent and symptomatic CAD (coronary artery disease), CVD (cardiovascular disease) and death.

• Vitamin D concentrations are inversely associated with insulin resistance (IR) and metabolic syndrome (MS).

• Anagnostis P, Athyros VG, Adamidou F, Florentin M, Karagiannis A. Vitamin D and cardiovascular disease: a novel agent for reducing cardiovascular risk? Curr Vasc Pharmacol. Sep 2010;8(5):720-730

• Wang TJ, Pencina MJ, Booth SL, et al. Vitamin D deficiency and risk of cardiovascular disease. Circulation. Jan 29 2008;117(4):503-511

Risk assessment scores

• Framingham risk score• Lifetime risk• Risk estimation by disease status• SCORE (Systematic COronary Risk Evaluation) • German PROCAM Risk score• Pooled cohort risk score

Interventional epidemiology

Primordial preventionprevention of the risk factors for CVD,

such as efforts aimed to prevent hypertension, obesity, or

dyslipidaemia

Primary preventionmodification of these and other known risk factors, is aimed at preventing the clinical manifestations of CVD, such as

myocardial infarction and stroke

Secondary preventionfocuses on those who already have

manifestations of disease, but where aggressive control of risk factors can have a major impact in preventing

recurrences of disease.

Tertiary preventionuse of expensive coronary

interventional procedures such as coronary angioplasty, stent, bypass surgery, pacemakers, defibrillators, and left ventricular assist devices

(LVAD).

ABCDE Approach

• Oxford Textbook of Global Public Health

Aspirin / Anti-platelet therapy

Blood pressure monitoring

Cholesterol & Dyslipidaemia management

Diet and Nutrition

Exercise and Physical Activity

ABCDE

Three Pronged Approach

Individual

Policies/legislati

on

Individual level

Take moderate physical activity for a total of 30 minutes on most days of the week.

Avoid tobacco use and exposure to environmental smoke; make plans to quit if you already smoke.

Diet: fruits, vegetables and avoid saturated fats and calorie-dense meals.

Maintain a normal body weight. Reduce stress at home and work.

Population / community level• Significant health gains in cardiovascular health can be made

within short time spans, through public health and treatment interventions that have an impact on large segments of the population.

• Population based observational studies in Finland, Norway, Mauritius, Poland and the US reported substantial reduction in cholesterol levels and coronary artery disease (CAD) mortality, following the introduction of fiscal policies which reduced animal fat and increased vegetable fat consumption

FINLANDNorth Karelia Project

By 2005, CAD mortality in men and women had declined by 80%.

POLANDMortality due to CAD fell 40% from 1990 to 2002 (decrease of 3% per year), reversing the

previous steady rises (increase of 6% per year)

MAURITIUSTotal cholesterol levels in the population fell

by 32 mg/dl between 1987 and 1992.This followed an intervention by the government

in 1987, to change the composition of the commonly used cooking oil from mostly palm oil (high in saturated fatty acids) to soya bean

oil exclusively

NORWAYBetween 1975 and 1993 dietary saturated fat

consumption reduced by 18% of energy intake, leading to a reduction in blood

cholesterol of 10% in the general population and decreasing CAD mortality by 50% among

middle-aged men

Policies and Legislations• Global Action Plan for the Prevention and Control of NCDs 2013-2020

• National Programme For Prevention And Control Of Cancer, Diabetes, CVD And Stroke (NPCDCS)

Recommendations to address the CAD epidemic in the Indian

subcontinent

Suggested policy interventions• Establishment of a national regulatory agency to enforce

already existing tobacco control legislation (e.g., the Tobacco Control Act and the World Health Organization’s Framework Convention on Tobacco Control).

• High rates of use of smoked beedies and of smokeless tobacco (chewing tobacco and paan).

• Promote healthy dietary patterns and physical activity in schools and workplaces.

• Identification of cultural norms that might hinder CHD prevention efforts

Suggested capacity building measures

• Development of research infrastructure and training of clinical researchers.

• Establishment of high-quality national surveillance programmes

• Assessment of the knowledge of the CHD burden

Suggested research initiatives• Generation of reliable statistics on prevalence and incidence

of CAD and its risk factors and CAD-related mortality through the initiation of large cohort studies and trial registries.

• Randomized controlled clinical trials based in South Asian countries to answer research questions of high relevance to the Indian subcontinent (e.g., effectiveness of the polypill in CHD prevention, homocysteine lowering in subjects with vascular disease).

• Studies documenting childhood risk factors, such as obesity, in both urban and rural settings.

• Large registries and case-control studies to document the burden of CHD and its determinants in the Indian subcontinent.

Prevention Paradox

Population at Low Risk / Moderate Risk

High Risk Population

Majority of cases Minority of cases

Barriers to prevention• The physicians themselves need to be educated about the

importance of prevention and the patients should be willing to accept and act on the advice of the physicians.

• As urbanization and globalization bring beneficial changes to LMIC countries, it also increases the risk factors for CHD and promotes unhealthy practices.

• The cost of preventive care is rarely reimbursed by the government or the insurance companies like that of the curative care.

• Enas  EA, Singh V, Gupta R, Patel R, et al. Recommendations of the Second Indo-US Health Summit for the prevention and control of cardiovascular disease among Asian Indians. Indian heart journal. 2009;61:265-74.

• Rankin J, Bhopal R. Understanding of heart disease and diabetes in a South Asian community: cross-sectional study testing the ‘snowball’ sample method. Public Health. 2001;115(4):253-260.

Barriers…. • Reducing excess risk in South Asians requires multilevel,

positive, mainstream and targeted measures using multiple approaches. These should address awareness, access, services, discrimination, cultural sensitivity and biologic factors, modified for different countries, situations and contexts.

• The Indo-US Healthcare Summit provides comprehensive, detailed and practical recommendations, advocating primordial, primary, and secondary prevention by government, medical communities, the public, industry and the media.

• Policy, grass-roots change, and community building should encourage healthy living at all ages, and remove barriers. Population screening, awareness and change should start early and tap community strengths.

Future• Predictions are by their nature speculative. Nevertheless, this

much is certain: the global epidemic of cardiovascular disease is not only increasing, but also shifting from developed to developing nations.

• No matter what advances there are in high-technology medicine, the fundamental message is that any major reduction in deaths and disability from CAD will come from prevention, not cure. This must involve robust reduction of risk factor

• “Live sensibly - among a thousand people, only one dies a natural death; the rest succumb to irrational modes of living.”

- Maimonides

Thank You

Objectives of NPCDCS• 1) Prevent and control common NCDs through behaviour and

life style changes,• 2) Provide early diagnosis and management of common NCDs,• 3) Build capacity at various levels of health care for

prevention, diagnosis and treatment• of common NCDs,• 4) Train human resource within the public health setup viz

doctors, paramedics and• nursing staff to cope with the increasing burden of NCDs, and• 5) Establish and develop capacity for palliative & rehabilitative

care.

Strategies

• The Strategies to achieve above objectives are as follows:• 1) Prevention through behaviour change• 2) Early Diagnosis• 3) Treatment• 4) Capacity building of human resource• 5) Surveillance, Monitoring & Evaluation