Overview

• Despite universal access to free and comprehensive medical care, numerous studies over the past 40 years have shown a higher incidence, prevalence, and mortality from CAD among South Asians with significant differences among the three groups.¹  Death rate from heart disease among South Asians is 50% to 150% higher than the national average with Pakistanis and Bangladeshis having higher rates than Indians.² (see Figure 028 in UK Indians)¹

• Coronary artery disease (CAD) mortality rates have been decreasing in the United Kingdom (UK), since the 1970s. Between 1981 and 2000, CAD mortality rates decreased by 62% in men and 45% in women, resulting in significantly fewer (68,230 fewer in 2000) deaths.

• More than half the CAD mortality decrease in UK was attributable to reductions in major risk factors, principally smoking and cholesterol; the remainder is attributed to improvements of treatment in people with CAD (secondary prevention).³ CAD now accounts for only 16% of all deaths.

• Despite this decline, death rates from CAD in the UK are among the highest in the world, next only to the countries of the former Soviet Union.¹ Cardiovascular disease (CVD) accounts for 35% of all deaths in the UK. CAD accounts for 46% of all CVD deaths and stroke accounts for 28% of CVD deaths.¹

• Over 2 million south Asian people have settled in the UK, representing 4% of the total population.⁴ The three major South Asian populations ─ Indians, Pakistanis, and Bangladeshis ─ have been extensively studied both separately and collectively in the UK.

• Among south Asian men, CAD accounts for 27% of all deaths compared to 16% among whites. For south Asian women, CAD accounts for 18% of all deaths compared to 13% among whites.¹

• Among men, CAD  accounts 16% of all deaths in whites but 27% of all deaths among South Asians; For women,  CAD accounts for 13% of all deaths in whites and 18% of all deaths among South Asians.¹

• South Asians develop extensive and malignant heart disease resulting in premature death at a very young age compared to Europids. Advanced inoperable heart disease and triple-vessel disease is twice as common among South Asians than Europids.^{5, 6}

• The first heart attack occurs approximately 5 years earlier for south Asian men than Europids.^7-10  Furthermore, the excess mortality in south Asian immigrants steadily increases with decreasing age. For example, CAD mortality among South Asian men 20- 29 years of age is three times higher than Europids compared to barely 50% after age 65.⁸

• In the UK the CAD deaths among Asian Indians is expected to double in the next 30 years and the National Health Service has been exploring strategies to tackle this burden for several decades.¹¹

• Among patients deemed appropriate for coronary artery bypass surgery, south Asian patients are less likely than white patients to receive it. This difference is not explained by physician bias.¹² Asian Indians undergoing bypass surgery have almost twice the mortality of Whites.¹³

• Recent studies indicate that the incidence of heart attack is 45% higher among south Asian men and 80% higher among south Asian women in UK but the death following a heart attack was 41% lower compared to whites, reflecting better survival among South Asians.¹⁴ A similar observation has been made in Canada due to advances in primary and secondary prevention.¹⁵

• Earlier studies showed a 2-fold higher mortality following a heart attack among south Asians in the UK.¹⁶  In the past 15 years, death from heart attack among South Asian men (but not women) has declined at a rate similar to that seen in white patients. This is largely attributed to reductions in severity of heart attack which in turn is due to treatment and control of major modifiable risk factors.^{14, 17}

• From 1971 to 1991, CAD mortality of the whole population fell by 29% for men and 17% for women, whereas, in South Asians it fell by 20% for men and 7% for women. However, the changes in CAD mortality rates were not uniform among the South Asian subgroups.

• As result of slower decline in the CAD mortality among South Asians, difference in CAD and stroke mortality between whites and South Asians (born outside the UK), have widened over the past 30 years.^{2, 18}  This is probably true for the first and second-generation of South Asians as well.^{2, 18}

• From 1979 to 2003 the excess CAD mortality increased from 14% to 93% in Pakistani men, from 36% to 112% in Bangladeshi men and from 27% to 145% in Pakistani women.²  Greater socioeconomic disadvantage appears to explain the slower decline in CAD mortality in Pakistanis and Bangladeshis.

Sources

1.  www.heartstats.org. CHD Statistics. Mortality. 2011. Accessed July 15, 2011.

2. Harding S, Rosato M, Teyhan A. Trends for coronary heart disease and stroke mortality among migrants in England and Wales, 1979-2003: slow declines notable for some groups. Heart (British Cardiac Society). Apr 2008;94(4):463-470.

3. Unal B, Critchley JA, Capewell S. Explaining the decline in coronary heart disease mortality in England and Wales between 1981 and 2000. Circulation. Mar 9 2004;109(9):1101-1107.

4. Barnett AH, Dixon AN, Bellary S, et al. Type 2 diabetes and cardiovascular risk in the UK south Asian community. Diabetologia. Oct 2006;49(10):2234-2246.

5. Enas EA, Yusuf S, Mehta J. Prevalence of coronary artery disease in Asian Indians. Am J Cardiol. 1992;70:945 – 949.

6. Lowry PJ, Glover DR, Mace PJ, Littler WA. Coronary artery disease in Asians in Birmingham. Br Heart J. 1984;52(6):610-613.

7. McKeigue PM, Ferrie JE, Pierpoint T, Marmot MG. Association of early-onset coronary heart disease in South Asian men with glucose intolerance and hyperinsulinemia. Circulation. 1993;87(1):152-161.

8. Balarajan R. Ethnic differences in mortality from ischaemic heart disease and cerebrovascular disease in England and Wales. Bmj. Mar 9 1991;302(6776):560-564.

9. Chaturvedi N, Fuller JH. Ethnic differences in mortality from cardiovascular disease in the UK: do they persist in people with diabetes? J Epidemiol Community Health. 1996;50(2):137-139.

10. Hughes LO, Raval U, Raftery E. First myocardial infarctions in Asian and White men. BMJ. 1989;298:1345-1350.

11. Lowy AG, Woods KL, Botha JL. The effects of demographic shift on coronary heart disease mortality in a large migrant population at high risk. J Public Health Med. 1991;13(4):276-280.

12. Feder G, Crook AM, Magee P, Banerjee S, Timmis AD, Hemingway H. Ethnic differences in invasive management of coronary disease: prospective cohort study of patients undergoing angiography. Bmj. 2002;324(7336):511-516.

13. Zindrou  D, Bagger JP, Smith P, Taylor KM, Ratnatunga CP. Comparison of operative mortality after coronary artery bypass grafting in Indian subcontinent Asians versus Caucasians. Am J Cardiol. 2001;88(3):313-316.

14. Fischbacher C. M, Bhopal R, Povey C, et al. Record linked retrospective cohort study of 4.6 million people exploring ethnic variations in disease: myocardial infarction in South Asians. BMC Public Health. 2007;7:142.

15. Khan NA, Grubisic M, Hemmelgarn B, Humphries K, King KM, Quan H. Outcomes after acute myocardial infarction in South Asian, Chinese, and white patients. Circulation. Oct 19 2010;122(16):1570-1577.

16. Wilkinson P, Sayer J, Laji K, et al. Comparison of case fatality in south Asian and white patients after acute myocardial infarction: observational study. Bmj. 1996;312(7042):1330-1333.

17. Liew R, Sulfi S, Ranjadayalan K, Cooper J, Timmis AD. Declining case fatality rates for acute myocardial infarction in South Asian and white patients in the past 15 years. Heart (British Cardiac Society). Aug 2006;92(8):1030-1034.

18. www.heartstats.org. CHD Statistics. mortality. 2010. Accessed January 25,2011.