Original Article

Coronary Heart Disease in Rural Population of Himachal - A Population Based Study

Rajeev Bhardwaj*, Arvind Kandoria**, Rajeev Marwah***, Piyush Vaidya****, Parvesh Dhiman#, Bakshish Singh##

*Associate Professor, **Assistant Professor, ***Senior Resident, ****Senior Resident, #Junior Resident, ##Junior Resident, Department of Cardiology and Medicine, Indira Gandhi Medical College, Shimla.
Received: 10.10.2007; Revised: 13.2.2009; Accepted: 25.3.2009

Abstract

Background: Cardiovascular disease has emerged as a major health burden worldwide. There is no study in Himachal about the prevalence of coronary heart disease (CHD), hence the purpose of the study.

Material and Methods: Population based study was done in three different villages of different districts of Himachal Pradesh. The people were well notified about the survey in advance. We tried to cover all persons above the age of 30 years. We could cover around 70% of population. Total 812 persons were examined. History regarding presence and nature of chest pain was taken. Detailed physical examination was done. The detailed history about risk factors was taken. ECG of all patients was taken. Patients known to have suffered myocardial infarction, having typical angina on exertion or having undergone coronary angioplasty or coronary artery bypass surgery were labeled to have CHD.

Results: Eight hundred twelve patients were examined. Mean age was 47.44±12.2 yrs. Three hundred ninty-nine were males and 413 were females. Thirty three patients were found to have coronary heart disease, giving the prevalence of 4.06%. Twenty six of 399 males had CHD (6.9%) and 26 of 413 females had CHD (1.69%). Seventeen of these CHD patients were hypertensive, two were diabetic and 10 patients had family history of CHD.

Conclusion: The prevalence of CHD was low in rural population of Himachal Pradesh, being around 4%, more in males than in females.

Introduction

Coronary heart disease(CHD) contributed to 15.9 million deaths in 1996, of which 5.9 millions were from developing countries.1 A rise in prevalence of CHD in early half of 20th century and a subsequent decline in latter half have been well documented in industrialized countries. However the scenario is reversed in developing countries, especially in India, with a steady rise in prevalence of CHD.2 With explosive rise in incidence of CHD, it is now estimated that this will be leading cause of mortality and morbidity, even in developing countries by the year 2015.3 While there have been many studies about prevalence of CHD from different parts of country, there is no study from Himachal Pradesh, and we still do not know the prevalence of CHD in the community. Hence the aim of the study was to find out the prevalence of CHD in rural population of Himachal Pradesh.

Material and Methods

This was a community based study carried out in three villages of Himachal Pradesh- Kunihar in Solan District, Sahu in remote Chamba District and Haripur Dhar in Sirmaur District. The institutional clearance was taken. A team of six doctors from Indira Gandhi Medical College, Shimla, included two consultants in Cardiology, two senior residents of Cardiology and two junior residents of Internal Medicine. Team also included three ECG technitians. The study was done on three consecutive holidays in Kunihar, one day in Sahu and one day in Haripur Dhar. The study was done on holidays, so that maximum people could be contacted. The people were informed well in advance through local leaders and through advertisement in posters about the study. All persons above the age of 30 yrs were part of the study. The detailed history about chest pain, old myocardial infarction (MI), history of having undergone coronary angioplasty (PTCA)/ bypass surgery (CABG) was taken. The questions to determine CHD included the presence of chest pain, site, its duration, its relation to exertion, and how quickly it is relieved on rest. Any history of claudication or history suggestive of previous cerebrovascular accidents was also noted. History of smoking, diabetes and hypertension and family history of CHD was also taken. A current smoker was defined as someone who currently smokes tobacco products; the definition includes daily and non-daily smokers.

All persons were subjected to general physical examination and cardiovascular examination. BP was recorded in all patients, and if found high, the reading was repeated after 10 minutes. Patients found to have systolic BP≥ 140 mmHg, and/or diastolic BP≥ 90 mm Hg were labeled to have hypertension. Presence of clinical cardiomegaly or heart murmurs was noted. ECG was done in all cases, irrespective of history. ECG was read by cardiologists for presence of pathological q waves, any ST segment depression or any T wave inversion. Patients having typical angina were advised treadmill test (TMT). Patient with positive TMT were subjected to coronary angiography, provided they gave consent for the same and were then advised PTCA or CABG if indicated. Patients having ECG changes suggestive of old myocardial infarction but having no history suggestive of coronary event were subjected to echocardiography to see the regional wall motion abnormality.

Diagnostic criteria for CHD:

1. Patients known to have suffered MI (Hospital records checked)
2. Patients having undergone PTCA or CABG.
3. Patients having typical angina with positive TMT.
4. Coronary angiography showing ≥ 50% stenosis in any of the coronary vessels.
5. Patients without history of coronary event but having ECG changes of old myocardial infarction and showing regional wall motion abnormality on echocardiography.

Results

Total 812 persons were examined, 599 in Kunihar, 157 in Sahu and 56 in Haripur Dhar. This covered around 70% population of these villages. Three hundred ninety-nine were males and 413 were females. Mean age was 47.44±12.20 yrs. Thirty-three persons were suffering from CHD (4.06%), out of which 26 were males and seven were females. Table1 shows the characteristics of the patients who were found to have CHD. Thus out of 399 males, 26 had CHD (6.5%) and out of 413 females only seven had CHD (1.69%). Fourteen out of 33 patients of CHD had old MI, 13 had undergone coronary angiography, five had undergone PTCA and four had undergone CABG.

Maximum number of patients of CHD were in the age group of 50-59 years, both males and females (Table 2). None of the female patients with CHD was below 50 years of age (Table 2). Seventeen patient were known to have CHD and 16 patients were newly diagnosed

Discussion

CHD has assumed epidemic proportion in India. Disease is more prevalent in urban population and there is clear gradient in prevalence from rural to semi-urban and urban population. The disease occurs at a younger age in Indian subjects compared to Western nations.

A study from Rajasthan reported that CHD contributes to 8% of patients attending a specialist physician’s clinic.4

In urban population, the prevalence increased from 1.05% (Agra, 1962),5 and 1.04% (Delhi, 1962)6 to 6.6% (Chandigarh, 1968).7 In recent years, high prevalence of CHD has been reported from Delhi (9.67%),8 Jaipur (7.8%, 1995),9 and Chennai (9.0%, 2001).10 In rural areas, the prevalence increased from 2,06% (Haryana, 1974)11 and 1.69% (Vidharbha, 1988)12 to 2,71% (Haryana, 1989),13 3.09% (Punjab, 1994),14 3.46% (Rajasthan, 1994).15

There is only one study in Himachal about the prevalence of CHD in which only multipurpose workers were involved. It found the prevalence of CHD to be 5%-6.4% in males and 4% in females.

The present study is the first proper study, conducted by trained doctors under the supervision of cardiologists. The prevalence was found quite low in females, whereas in males it was almost as in other parts of the country. The striking feature of the study is that more than 50% patients of CHD found in the community were already known to have CHD and around 40% of the patients of CHD underwent coronary angiography either prior to study or after the advice. This is due the fact that village Kunihar, which was the largest village of study, is situated around 40 Km from the state medical college with facilities of coronary angiography, PTCA and CABG and these people can reach the medical college within one and half hour and in case of emergency, they directly come to the medical college.

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