|Year : 2019 | Volume
| Issue : 1 | Page : 1-5
Review of current global evidences for prevention of coronary heart disease
Meenakshi Khapre, Vartika Saxena
Department of Community and Family Medicine, AIIMS, Rishikesh, Uttarakhand, India
|Date of Web Publication||21-May-2019|
Dr. Meenakshi Khapre
Department of Community and Family Medicine, AIIMS, Rishikesh, Uttarakhand
Source of Support: None, Conflict of Interest: None
India is experiencing epidemiologic transition with sharp increase in coronary heart disease (CHD). Fatality rate of CHD is alarmingly high leading to the most common cause of premature mortality in 2016. There is the growing burden of coronary risk factors owing to rapid urbanization and changes in lifestyle, including diabetes mellitus (DM), hypertension, dyslipidemia, smoking, alcohol consumption, dietary patterns, central obesity physical inactivity, and psychological factors. These risk factors attribute 90% of CHD in population. The global evidences of preventive strategies is being reviewed in this paper with the aim to get the glimpse of study on CHD and find gaps in the research.
Keywords: Coronary heart disease, diabetes, hypertension, obesity, prevention, review
|How to cite this article:|
Khapre M, Saxena V. Review of current global evidences for prevention of coronary heart disease. J Datta Meghe Inst Med Sci Univ 2019;14:1-5
| Introduction|| |
Coronary heart disease (CHD) is the most common manifestation of cardiovascular diseases (CVDs). CHD manifested by fatal or nonfatal myocardial infarction (MI), angina pectoris, and/or heart failure (HF). CHD represents approximately 50% of the total first CVD events. Globally, CHD is a major cause of mortality and morbidity. As per the World Health Organization (WHO) report of 2012, CVD caused 17.5 million (46.2% of noncommunicable disease [NCD] deaths) of the 58 million deaths that occurred worldwide. While the prevalence and mortality due to CHD are declining in developed nations, the same cannot be held true for developing countries. The PURE study has confirmed the increasing trend of CHD in the middle- and low-income countries related to major cardiovascular event and case fatality rate. Ischemic heart disease was the largest contributor to the increase in the number of cardiovascular deaths (2.4 million of the overall increase of 5 million cardiovascular deaths), despite an estimated decline of 34.4% owing to global epidemiologic changes such as decreased exposure to tobacco smoking, improvements in diet, and improved treatment of CVD and cardiometabolic risk factors targeting the prevention of CVD, and improved treatment of CVD.
| Coronary Heart Disease in India|| |
India is undergoing a dramatic epidemiologic transition, whereby burden of communicable diseases has been declining slowly, whereas that of NCDs has been rising rapidly, thus leading to a dual burden. The National Commission of Macroeconomics and Health estimated that absolute number of CHD patients in India will increase from 38 million in 2005 to 66 million in 2015, i.e., 72% increase. There has shown a 4-fold rise in CHD prevalence during the past 40 years. The number of cases of CHD was estimated to be nearly 3.6 crores for the year 2005, which is expected to reach a figure of nearly 6.1 crore cases in the year 2015. This pattern is nearly same across all adult age groups . The prevalence of ischemic heart disease in 1960 in urban India was 2% and increased 7-fold to ≈14% by 2013. Similarly, it more than quadrupled in rural areas, from 1.7% to 7.4% between 1970 and 2013. However, this can be the underestimation due to insensitive tool used or higher case fatality following acute coronary syndrome.
According to the Global Burden of Diseases 2016 nearly in India, 28.09% of total deaths are attributed to CVD, of which CHD itself constitute 17.8% of total death, i.e., around 61% of total CVD deaths. Age-specific mortality rate (50–69 years) CHD constitutes 22% of total death. CHD which was the third-most common cause of premature death in 2005 now shifted to the most common cause in 2016. The Global Burden of Diseases study reported that the disability-adjusted life years lost by CHD in India during 1990 was 19 million, 30 million in 2006, and crossed 40 million in 2016.
The growing burden of CHD in India can be explained by the alarming rise in the prevalence of coronary risk factors owing to rapid urbanization and changes in lifestyle.
| Methodology|| |
All the literature databases such as PubMed, Embase, Google scholar, Journal seek, INDMed, and Cochrane were extensively searched with articles published preferably after the year 2005 with key search terminologies like “Cardiovascular* OR Coronary Heart disease OR Atherosclerosis OR Ischemic heart disease OR Myocardial* OR Heart Attack OR “angina,” “heart” AND “Preventi* OR treatment OR Drug OR Diet OR Physical activity OR Lifestyle.” Apart from this, it was also searched under MESH heading. Although restricted to the past 15 years, large cohort study or meta-analysis was included in the study.
| Global Evidences of Prevention of Coronary Heart Disease|| |
Population attributable risk (PAR) of CHD for various risk factors is smoking (35.7%), raised ApoB/ApoA1 ratio (49.2%), history of hypertension (HTN) (17.9%), diabetes (9.9%), abdominal obesity (20.1%), psychosocial factors (32.5%), of fruits and vegetables (13.7%). lack of regular physical activity irrespective of age, sex and ethnicity (12.2%). Collectively, these risk factors accounted for 90% of PAR in males and 94% in women.
Primary prevention in coronary heart disease
Primary prevention reduces the risk of MI and HF, decreases the need for coronary revascularization procedures, and extends and improves the quality of life. It includes lifestyle modifications smoking cessation, weight management, diet, and physical activity.
The secondary prevention relies on the early detection of disease process and application of interventions to prevent the progression of the disease.
| Smoking|| |
Recent evidence from the interheart study has highlighted the adverse effects of the use of any tobacco product and importantly, the harm caused by even very low consumption. Stopping smoking is the single most cost-effective intervention in CVD prevention, and some benefits are seen within months of cessation.,, All standard treatment guidelines recommend cessation irrespective of length or intensity of smoking habit. Mortality declines by an average of 35%, and mortality or nonfatal myocardial (re-) infarction by 36% in those who have stopped smoking. The relative risk of mortality following a coronary event for quitters compared to permanent smokers ranged from 0.13 to 0.72, whereas the relative risk of MI ranged from 0.23 to 0.68.
All patients should be asked about their tobacco use and where relevant, given advice and counseling on quitting, as well as reinforcement at follow-up. There is evidence that advice and counseling on smoking cessation delivered by health professionals (such as physicians, nurses, psychologists, and health counselors) are beneficial and effective.,,
Similarly, nicotine replacement therapy can increase the rate of smoking cessation by odds of 1.5–2 times irrespective of any setting or additional support.
There is evidence that tobacco consumption decreases markedly as the price of tobacco products increases. Bans on advertising of tobacco products in public places, sales of tobacco to young people, and strict market regulations are essential components of any primary prevention program addressing noncommunicable diseases. Cigarettes and Other Tobacco Products (Prohibition of Advertisement and Regulation of Trade and Commerce, Production, Supply and Distribution) Act, 2003 is the principal comprehensive law governing tobacco control in India. The prevalence of current smokers is decreasing in India, but the rate of change for cessation of smoking is negligible.
| Diet|| |
Vegetarians had lower levels of total cholesterol (β = −0.1 mmol/L [95% confidence interval (CI): −0.03–−0.2], P = 0.006), triglycerides (β = −0.05 mmol/L [95% CI: −0.007–−0.01], P = 0.02), low-density lipoprotein (LDL) (β = −0.06 mmol/L [95% CI: −0.005–−0.1], P = 0.03), and lower diastolic blood pressure (DBP) (β = −0.7 mmHg [95% CI: −1.2–−0.07], P = 0.02). Vegetarians also had decreases in systolic blood pressure (SBP) (β = −0.9 mmHg [95% CI: −1.9–0.08], P = 0.07) and fasting blood sugar level (β = −0.07 mmol/L [95% CI: −0.2–0.01], P = 0.09) when compared to nonvegetarians.
Wheat, rice, and oils' pattern had the most favorable health profile. Wheat, rice, and oils' pattern had lowest odds of being obese (odds ratio [OR] =0.43; 95% CI: 0.33–0.56). Consumers of the “Wheat and pulses” pattern had raised odds of a high waist-to-hip ratio (OR = 1.23; 95% CI: 1.01–1.51). Consumers of the “Rice and fruit” pattern had the greatest odds of obesity (OR = 1.19; 95% CI: 0.97–1.46) and reduced odds of HTN (OR = 0.72; 95% CI: 0.58–0.90). In fully-adjusted models, the dietary pattern was not significantly associated with an unhealthy total: high-density lipoprotein-cholesterol (HDL-C) or diabetes.
Replacing saturated and transunsaturated fats with monounsaturated and polyunsaturated fats are more effective in preventing CHD events than reducing overall fat intake., Dietary cholesterol is a determinant of serum cholesterol concentration. Reducing dietary cholesterol by 100 mg a day appears to reduce the serum cholesterol by about 1%. Reduce salt intake to <6 g is recommended.
Recommendations to increase fruit and vegetable consumption should not be limited to increased education on diet and physical activity but extend to levying a tax on foods of low-nutritional value, improved food labeling, and stricter controls on the marketing of foods. In addition, establishing nutrition policies is essential to ensure that all people at all times have equitable and dignified access to sufficient, safe, healthy, and culturally appropriate food including adequate fruits and vegetables.
| Physical Activity|| |
Berlin and Colditz  found a summary relative risk of death from CHD of 1.9 (95% CI: 1.6–2.2) for people with sedentary occupations compared with those with active occupations. A meta-analysis of studies in women showed that physical activity was associated with a reduced risk of overall CVD, CHD, and stroke in a dose-response fashion.
The WHO recommends that individuals perform at least 150 min of daily physical activity (moderate to vigorous) per week for the maintenance of health. Most of the Indians do not meet this expectation. The individual derives most of their physical activity from the occupational domain, but as physical activity in occupation is decreasing the individual would need to derive it from leisure-time pursuit. The 2013 American Heart Association (AHA)/American College of Cardiology (ACC) lifestyle management guidelines recommend to reduce LDL-cholesterol (LDL-C), non-HDL-C, and blood pressure (BP), 3–4 sessions each week that last an average of 40 min per se ssion and involve moderate-to-vigorous intensity physical activity.
In a review of 17 randomized controlled trials (RCTs) promoting physical activity in adults, found that professional advice and guidance with continued support had a moderate effect on self-reported physical activity and cardiorespiratory fitness, but not on achieving a predetermined level of physical activity. Specific interventions included individual and group counseling, self-directed or prescribed physical activity, supervised and unsupervised physical activity, home-or facility-based physical activity, face-to-face and telephone support, written materials, and self-monitoring. However, the high-quality study is still lacking in this aspect.
| Weight (Obesity)|| |
Obesity is strongly related to major cardiovascular risk factors, such as raised BP, glucose intolerance, type 2 diabetes, and dyslipidemia., The relative risk among the heaviest death due to CHD was 1.57 times when compared with the those within the lowest body mass index category. For nearly all obese individuals, weight loss is currently recommended for primary and secondary prevention of CHD. Many studies have documented that decrease in weight up to 5% results in increase in HDL 8%–30% decrease LDL 8%–21% and improved cardiac fitness. The physician or dietician should enforce on weight management during frequent contacts to sustain the benefit.
| Diabetes|| |
The risk of cardiovascular events is 2–3 times higher in people with type 1 or type 2 diabetes., Abnormal glucose regulation tends to occur together with other known cardiovascular risk factors, such as central obesity, elevated BP, low HDL-C, and high triglyceride level. Men with the metabolic syndrome as defined by the WHO were 2.9–3.3 times more likely to die of CHD after adjustment for conventional cardiovascular risk factors. The UK prospective diabetes study reported for each 1% increase in glycated hemoglobin level was associated with a 14% increase in the incidence of fatal or nonfatal MI. However, no reduction in cardiovascular mortality or event in a patient of type 2 diabetes was found on intensive glucose lowering regimen on the contrary increase in deaths due to other causes was found.,,
| Hypertension|| |
Hypertension is a major risk factor for cerebrovascular disease, CHD, and cardiac and renal failure. The Framingham Heart Study has shown that, with increasing age, there is a gradual shift from DBP to SBP and then to PP as a predictor of CHD risk. Prolonged differences in usual DBP of 5, 7.5, and 10 mmHg were, respectively, at least 21%, 29%, and 37% less CHD.
Several trials , support the view that, in patients at high cardiovascular risk, with BPs in the range 140–160 mmHg (systolic) and 90–100 mmHg (diastolic), lowering BP reduces the number of cardiovascular events. These trial results suggest that treatment for such high-risk patients should begin at the lower BP thresholds. Therefore, the Joint National Committee 8 recommends target BP for individuals with CHD or CHD equivalents such as: diabetes mellitus, chronic renal disease, peripheral arterial disease, carotid artery disease, and abdominal aortic aneurysm as <140/90 mmHg, while for general population, or those <60 years is 150/90 mmHg.
| Dyslipidemia|| |
Several RCT's had examined the benefits of lipid lowering in primary and secondary prevention of coronary artery disease. Studies like West of Scotland Coronary Prevention Study, Air Force Coronary Atherosclerosis Prevention Study/Texas Coronary Atherosclerosis Prevention Study, Heart Protection Study, Anglo-Scandinavian Cardiac Outcomes Trial-Lipid Lowering Arm, Collaborative Atorvastatin Diabetes Study, and Prospective Study of Pravastatin in the Elderly at Risk  had shown reduction in cardiovascular event, including CHD by 27%–37% and fatal CHD incidences.
Many meta-analysis confirmed the benefits of lipid-lowering agents in relative reduction of coronary events (by 60%), coronary revascularization, CVD mortality, nonfatal stroke, and mortality in both primary and secondary prevention.,,,
The AHA/ACC guidelines of 2013, American Association of Clinical Endocrinologists and the American College of Endocrinology 2017 guidelines recommended varying intensities of statin therapy to four groups of primary- and secondary-prevention patients recommend LDL goals of <55 mg/dL, <70 mg/dL, <100 mg/dL, and <130 mg/dL for individuals at extreme, very high, high/moderate, and low risk for cardiovascular events, respectively.
However, other lipid-lowering drug like fenofibrate is not been found to be effective in reducing the risk of the primary outcome of coronary events.
Role of aspirin in preventing CHD is still controversial.
| Conclusion|| |
Obesity, diabetes, HTN, and dyslipidemia are alarmingly on rising trend. Instead of decreasing fat intake, replacement of saturated and transsaturated fat with monounsaturated fatty acid and polyunsaturated fatty acid should be enforced. It was found there is no reduction of CVD mortality or event on intensive glucose lowering agent. Lowering BP decreases CVD events. High-quality trails on the effect of physical activity on CVD are still missing. Statin was effective in reducing the CHD-related death but no other lipid-lowering agents. Role of aspirin is still controversial.
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Conflicts of interest
There are no conflicts of interest.
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