Coronary heart disease (Public Health Aspect)

Coronary heart disease (Public Health Aspect)

1. CORONARY HEART DISEASES Dr. Anuj Singh Asst. Professor, Community Medicine Dept. UIMS , Prayagraj 1

2. Overview Introduction Definition Burden of disease Risk factors Prevention Interventional trial studies Conclusion References 2

3. Introduction 3

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7. Introduction Cardiovascular diseases comprise of a group of diseases of the heart and the vascular system. The major conditions are coronary heart disease , cerebrovascular disease , congenital heart disease and rheumatic heart disease . Coronary heart disease( ischaemic heart disease) is prototype example of lifestyle diseases. 7

8. Coronary heart disease has been defined as- “impairment of heart function due to inadequate blood flow to the heart compared to its needs, caused by obstructive changes in the coronary circulation to the heart” 8

9. It is the cause of 25-30 percent of deaths in most developed countries. The WHO has drawn attention to the fact that CHD is our modern epidemic i.e ,: “ a disease that affects populations not an unavoidable attribute of aging ” 9

10. CHD has a wide range of disease spectrum . Ranging from silent coronary atherosclerosis at one end , passing through asymptomatic ECG abnormalities suggestive of ischaemia , angina pectoris, myocardial infarction and its complications, to sudden death at the other end . 10

11. Importance of CHD for public health 11

12. Importance of CHD for public health As a disease group, CVD is the number one cause of deaths worldwide . As per current estimates almost 50% of all deaths in developed countries and 28% of all deaths in developing countries occur due to CVD. The disease has a very high “killing power ” even in developed countries with well established treatment and ambulance services. 12

13. Even for those who survive, the quality of life in terms of physical capabilities is compromised . The silver lining is that a large number of factors that place an individual to high risk of getting affected with CHD are well known to the medical world and potentially amenable to preventive efforts. CHD, thus is a very much preventable disease , The medical fraternity has clear knowledge about the coronary risk factors and their prevention. 13

14. Global Burden of the disease- Leading Cause of Death: Coronary heart disease remains the leading cause of death globally. In 2019, it accounted for about 16% of all deaths worldwide, equivalent to roughly 8.9 million deaths. Prevalence : CHD is particularly prevalent in both high-income and low-to-middle-income countries, with a significant burden in countries undergoing economic transitions due to changing lifestyles, diet, and increased risk factors like obesity and diabetes. 14

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16. India: Over the past four decades the prevalence of CHD has risen two fold in rural and six fold in urban areas. At present, an estimated 13-14% of rural and 18-20% of urban adults are affected by CHD. 16

17. Problem Statement 17

18. Problem Statement- (a) Proportional mortality ratio : The simplest measure is the proportional mortality ratio, i.e., the proportion of all deaths currently attributed to it. For example, CHD is held responsible for about 30% of deaths in men and 25 % of deaths in women in most western countries. 18

19. Problem Statement- cont.. (b) Loss of life expectancy ; CHD cuts short the life expectancy. Calculations have been made for the average gain in life expectation that would follow a complete elimination of all cardiovascular deaths if other mortality rates remain unchanged. The benefit would range for men from 3.4years to 9.4 years and even greater for women. 19

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21. Risk factors Non modifiable risk factors- 1) Age :incidence of CHD is high above 50 years and maximum between 50 and 60 years of age. 2) Sex :it is more among men than among women. 3) Family history 4) Genetic factors: play a role indirectly by determining the total cholesterol and low density lipoprotein levels . 21

22. Risk factors Modifiable risk factors 1)Cigarette smoking: major risk factor, because of following mechanisms -carbon monoxide, induces atherogenesis -nicotine stimulates the release of adrenaline resulting in hypertension. -nicotine also increases myocardial oxygen demand and decreases high density lipoprotein(HDL) level. The risk of developing CHD is directly proportional to the number of cigarettes smoking per day and the duration of exposure. 22

23. Modifiable risk factors: cont.. Hypertension : it increases the risk of CHD by accelerating the atherosclerotic process. Serum cholesterol : increase in serum cholesterol level increases the risk of CHD. The threshold level is 220 mg/dl , beyond which the risk increases. The risk increases progressively with higher levels of low density lipoprotein ( LDL ) cholesterol, because LDL is atherogenic . However, the risk of CHD decreases with higher levels of High density lipoprotein ( HDL ) cholesterol because HDL transports cholesterol from the tissues to liver, thus prevents atherosclerosis. The ratio of LDL to HDL more than 5 indicates the risk. 23

24. Modifiable risk factors: cont.. Diabetes mellitus : the risk of CHD is 2 to 3 times higher among diabetics than non-diabetics. Obesity : increases the risk of CHD because of its association with LDL cholesterol, HTN and diabetes. Physical activity : regular physical exercise increases the concentration of HDL, a protective factor and decreases both body weight and blood pressure, which are beneficial to cardiovascular health. Sedentary life style is associated with a greater risk of the development of early CHD. 24

25. Modifiable risk factors: cont.. Serum homocysteine : high serum levels of this amino acid more than 15.5 mol/l, damages the intima of the arteries, corelating positively with the presence of coronary artery disease. Such levels are related to a diet low in pyridoxine and folates . Hormones: hyperestrogenemia favours the development of CHD. Women on oral contraceptives are more to develop CHD than those not using them. 25

26. Type A personality: -people with type A behavior are characterized by competitive drive, restlessness, impatience, irritability, short-temper, sense of urgency etc. are at a higher risk of CHD than the calmer type B personality people. Alcohol: CHD is more common in heavy drinkers. Soft water: Incidence of CHD has been found to be higher among those consuming soft water than those consuming hard water. The salts in the hard water are protective to the cardiac muscles. Drugs: Misuse of fenfluramine and phentermine used for reduction of weight can be damaging to the heart. 26 Modifiable risk factors: cont..

27. Prevention of CHD 27

28. Prevention of CHD WHO expert committee on the prevention of CHD recommended the following strategies- Primordial prevention: Primary prevention: - Population strategy - High risk strategy Secondary prevention: 28

29. Primordial prevention 29

30. Primordial prevention - This consists of the prevention of the emergence or development of risk factors among the population groups in whom they have not yet appeared . - Since many adult health problems like HTN, Obesity have their early origins in childhood, so efforts are directed towards discouraging the children from adopting harmful lifestyle such as smoking, eating pattern, physical exercise, alcoholism, etc. The main intervention is through mass education . 30

31. Primary Prevention 31

32. Primary Prevention - This consists of elimination and modification of risk factors of disease with the following approaches. 32

33. 1.Population strategy (Mass primary prevention) This is directed towards the whole population focusing mainly on the control of underlying risk factors, irrespective of individual risk levels. 33

34. This is based on the principle that a small reduction in the blood pressure or serum cholesterol level in a population helps in reducing the incidence of CHD. This requires large community wide efforts to alter the lifestyle practices as follows – Dietary changes: Dietary modification is the principle preventive strategy in the prevention of CHD. Reduction of fat intake to 20-30% of total energy intake. Consumption of saturated fats must be limited to less than 10% of total energy intake. Reduction of dietary cholesterol level to below 100mg per 1000kcal per day. An increase in complex carbohydrate consumption( i.e., vegetables, fruits, whole grains and legumes.) Avoidance of alcohol consumption Reduction of salt intake 5g daily or less 34

35. 2) Smoking -The goal to be to achieve a smoke free society. -To achieve the goal of a smoke free society, a comprehensive health problem would be required which includes effective information and education activities, legislative restrictions, fiscal measures and smoking cessation programs. 35

36. 3) Blood Pressure- It has been estimated that even a small reduction in the average blood pressure of the whole population by a mere 2 or 3 mmHg would produce a large reduction in the incidence of cardio vascular complications. The goal of the population approach to high blood pressure is to reduce mean population blood pressure levels. This involves multi factorial approach based on prudent diet (Reduced salt intake and avoidance of high alcohol intake), Regular physical activity and weight control. 36

37. 4)Physical Activity -Regular physical activity should be a part of normal daily life. It is particularly important to encourage children to take up physical activity that they can continue throughout their life. -This will prevent obesity, HTN and indirectly CHD. 37

38. Primary Prevention- cont.. High Risk Strategy 1) Identifying risk : The high-risk group of individuals can be identified by simple screening tests like recording BP, estimation of serum cholesterol, history of smoking, strong family history of CHD and history of taking oral pills among women and estimation of fasting blood sugars to detect diabetes. 38

39. 2) Specific advice: Having identified those high risk persons preventive care is taken by motivating them to take action against risk factors. Individuals with HTN are given treatment Smokers to give up smoking Nicotine chewing gum can be tried to wean patient smoking. Persons with hyperlipidemia are treated . 39

40. Secondary Prevention 40

41. Secondary Prevention The aim of secondary prevention is to prevent the recurrence of coronary artery disease. The principles governing secondary prevention are cessation of smoking, control of hypertension and diabetes, healthy nutrition and exercise promotion. 41

42. RISK FACTOR INTERVENTIO TRIALS -Framingham Study, a large prospective study has played a major role in establishing the nature of CHD risk factors and their relative importance. -The major risk factors of CHD are elevated serum cholesterol , smoking , HTN and sedentary habits. 42

43. - The widely reported intervention trials are :- 1)The Stanford-Three-Community Study in California. 2)The North Kerelia Project 3)MRFIT 4) Oslow diet/smoking Intervention Study 5)Lipid Research Clinics Study 43

44. 1)The Stanford-Three-Community Study in California . To determine whether community health education can reduce the risk of cardio vascular disease, a field experiment was undertaken in 1972 in three Northern California towns with populations varying between 12,000 and 15,000. In two of these towns intensive mass education campaigns against cardio vascular disease over a period of two years. The third town was kept as a control. In the control community risk of cardiovascular disease increased over two years but in the intervention community there was substantial decrease in risk. 44

45. 2)The North Kerelia Project A multiple risk factor intervention trial was started in 1972. The project had two aims: (a) to reduce the high levels of risk factors for cardiovascular disease ( e.g.smoking , blood pressure, and serum cholesterol) and (b) to promote the early diagnosis, treatment and rehabilitation of patients with CV disease. - A control population was established in a neighbouring county which has similar CV mortality. The main strategy employed was mass community action against risk factors and advice on their avoidance. 45

46. Follow-up "surveys at 5-years demonstrated a significant reduction in all three major risk factors. By 1979, mortality began to decline by 24 per cent in men and 51 per cent in women in North Kerelia , compared with rest of Finland. It exhibited its effect on CHD deaths - more than twice the reduction achieved in the rest of Finland during the same period. 46

47. 3)MRFIT - The multiple risk factor intervention trial (MRFIT) carried out in USA was aimed at high risk adult males aged 35-57 years. A total of 12,866 men who showed no evidence of CHD either clinically or on ECG were enrolled for the study. Half the group was randomly allocated to an intensive intervention programme, being seen at least every four months to ensure adequate control of risk factors. The other half (control group) received a medical examination once yearly, and no specific advice was given to them about the control of risk factors. 47

48. The intervention procedures included cessation of smoking, controlling blood pressure and altering diet to reduce hypercholesterolemia Over the 7 year follow-up period, IHD mortality was reduced by 22 per cent more in the intervention group 48

49. 4) Oslow diet/smoking intervention study This study began in 1973. 16,202 Norwegian men aged 40-49 years were screened for coronary risk factors; of these 1232 healthy normotensive men at high risk (total serum cholesterol 290-379 mg/dl; smoking) of CHD were selected for a 5 year randomized trial. The aim of the study was to determine whether lowering of serum lipids and cessation of smoking would reduce the incidence of first attack of CHD in males aged 40-50. 49

50. The intervention group underwent techniques designed to lower serum cholesterol level through dietary means (e.g., a polyunsaturated fat diet), and to decrease or eliminate smoking. At the end of 5 years, the incidence of myocardial infarction (fatal and nonfatal) was lower by 47 per cent in the intervention group than in the control group With this study, primary prevention of CHD entered the practical field of preventive medicine in an impressive manner. 50

51. Lipid research clinics study- This double-blind, randomized clinical trial involved 3806 asymptomatic "high-risk" American men aged 35-59 years with type ll hyperlipoproteinemia . The trial was designed to test whether reducing serum cholesterol would prevent CHD events. The men were randomized into two groups, one receiving cholestyramine and the other receiving a placebo. Both the groups were followed for an average of 7 .4 years . 51

52. The treatment group had an 8.5 per cent and 72.6 per cent greater reduction in total cholesterol and LDL cholesterol levels respectively than the placebo-treated group 52

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54. Conclusion Coronary heart disease is the major cause of mortality and morbidity in the developed and developing countries. It has large number of modifiable risk factors So the prevention strategies should be more intensified.

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56. National Program for Prevention and Control of Diabetes, Cardiovascular Diseases and Stroke (NPCDCS) Achievements: NPCDCS has led to increased awareness, early detection, and better management of NCDs in several regions. However, the program continues to evolve to address the growing burden of NCDs in India. 56

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