Trends and Characteristics of Caucasian, Indian &

Pakistani Patients Undergoing Coronary

Angioplasty

St. Mary’s Hospital PTCA Registry

Introduction

• Asians are thought to have higher risk of complications and poorer outcome after PTCA

• However, there is no data comparing the characteristics of Asians to that of Caucasians undergoing PTCA

• There is also no data comparing the characteristic differences that may exist between South Asian originating from different countries or races

• Coronary Artery Bypass Grafting (CABG)

• Percutaneous Transluminal Coronary Angioplasty (PTCA)

Aims

This study examines the differences in risk factors and general trends between Caucasians and Asians patients and between Indians and Pakistanis to determine factors that may explain differences in outcome following PTCA

Methods (1)

• Data sources:– Database: PTCA data was prospectively collected

on a dedicated database from 1986 to 1996

• Data was Validated using– Catheter lab registry notes– Radiography registry notes– Hospital PAZ system– Patient notes

Methods (2) – Database

Variables on database

– Date of birth– Gender– Date of operation– Ethnic origin– Lesion site & size– Number of vessels diseased &

treated– Emergency presentation

– FHx of CAD– History of:

• Hypertension• Stroke• Diabetes• Cholesterol• Uric acid• PVD• Smoking

Statistics (1) Continuous Data

• Unpaired t-test– Unmatched patients

• eg. Age at procedure, vessel diameter

• Paired t-test– Matched pairs (age/sex/year of procedure)

• Mann-Whitney test – Parametric - variances unequal

Statistics (2)Categorical Data

• Chi-squared test– Unmatched patients

• eg. Diabetes, smoking

• McNemar test– Matched pairs

Results(1) - Patient Population

• 3629 entries (3064 patients) – 565 repeats

• 2171 Caucasian patients

• 254 Asians patients

Results (2) – Population

Country of origin

PTCA

NumberTOTAL 3629

England 2593 (428)

(South Asia) (290)

Pakistan 158 (20)

Malta 146

India 132 (16)

Gibraltar 86

Ireland 73

Cyprus 66

Iran 46 (3)

Greece 32

Egypt 27

Poland 24

Dominican Republic

22

Results (3) - Cases Per Year

0

100

200

300

400

500

600

700

800

Pat

ient

s

1985 1987 1989 1991 1993 1995

Data for 1996 is only available for the first 6 months

Results (4) - All Patients

(n=3064)

Age (SD) 59.1 years (10.2)

Males 78.8% (2450)

Diseased vessels (SD) 1.41 (0.61)

Vessel Diameter (SD) 2.63mm (1.10)

Emergency procedure 37.2% (1350)

Results (5) - All Patients

FH of CAD 52.0% (1592)

Hypertension 38.9% (1191)

CVA 1.8% (55)

Diabetes 13.8% (424)

Cholesterol 31.6% (967)

Uric Acid 1.5% (46)

PVD 7.3% (223)

Smoking 34.1% (1046)

Results (6) – UnmatchedCaucasians Asians p-value

Age (SD) 60.4 (10.1) 56.0 (9.56) <0.0001

Male 76.1% 89.8% <0.0001

Diabetes 11.0% 28.2% <0.0001

Uric Acid 1.5% 3.1% 0.047

Diseased vessels

1.38 (0.61) 1.49 (0.65) 0.0024

Vessel width (mm) (SD)

2.66 (1.17) 2.53 (0.85) 0.007

Caucasians

Asians p-value Iran

Age (SD) 60.4 (10.1) 56.0 (9.56)

<0.0001 57.6 (9.6)

Male 76.1% 89.8% <0.0001 90.7%

Diabetes 11.0% 29.4% <0.0001 18.6%

Uric Acid 1.5% 3.1% 0.047 2.3%

Diseased vessels

1.38 (0.61) 1.49 (0.65)

0.0024 1.46 (0.7)

Vessel width (mm) (SD)

2.66 (1.17) 2.53 (0.85)

0.007 2.65 (0.43)

Results (7) – Matched Pairs

Caucasians Asians p-value

Hypertension 35.3% 42.1% 0.036

Diabetes 12.4% 29.4% <0.0001

Diseased vessels(SD)

1.37 (0.60) 1.49 (0.66) 0.012

Vessels treated (SD)

1.17 (0.67) 1.28 (0.84) 0.046

Vessel width (mm) (SD)

2.64 (0.67) 2.53 (0.85) 0.026

Caucasians Iranian p-value

Hypertension 43% 20.9% 0.01

Diabetes 13.9% 18.6% NS

Vessel treated 1.42 1.23 NS

Diseased vessels(SD)

1.54 (0.63) 1.46 (0.7) NS

Chol 32.6 23.2 NS

SMK 27.9 32.6 NS

FH 51.2 39.5 NS

PVD 11.6 2.3 NS

Emergency 23.2 20.9 NS

Matched Caucasian Vs Iran

Results (9) – Trends in Age

30

35

40

45

50

55

60

65

70

Pat

ient

Age

85 86 87 88 89 90 91 92 93 94 95 96

Pakistanis Vs Indians

Pakinstanis(%) (N= 138)

Indians (%)(N= 112)

Hypertension 50.7 31 <0.0001

High Chol 32.6 21.6 0.05

Emergency 56.1 19.3 <0.0001

FH 42.8 56.9 0.02

No DiseasedVessel

1.33 ± 0.59 1.68 ± 0.68 <0.0001

Discussion (1)

• This is one of the first studies looking at ethnic variation in patients attending for coronary angioplasty

Discussion (2) - Asians

• Younger age

• More vessel disease– Hughes et al.(MI - 5.5 years earlier, 3VD)

• Smaller vessels– Dhawan & Bray (quantative angiography)

• Diabetes (29% vs. 11%)– McKeigue et al. (19% vs 4%, known CAD)

Discussion (3)Indians Vs. Pakistanis

• Pakistanis– Hypertension– Cholesterol– Emergency

• Indians– FH of CAD

– More vessel disease (1.68 vs. 1.33)

Discussion (4)Indians Vs. Pakistanis

Inherited factors may have greater role in determining the extent of CAD and factors other than raised cholesterol and hypertension may be involved

Limitations

• Ensuring accuracy of database

• Long-term outcome study

• Coronary artery size

• Changing acceptable level

Conclusions

• Asians patients have significantly greater risk factors than Caucasians

• Pakistanis exhibit more risk factors, but Indians have more widespread disease

• Asians should not be considered a homogenous group

References• Bhopal R et al. Heterogeneity of coronary heart disease risk factors in Indian, Pakistani,

Bangladeshi, and European origin populations: cross sectional study. BMJ 1999;319:215-220

• Dhawan J, Bray CL. Are Asian coronary arteries smaller than Caucasian? A study on angiographic coronary artery size estimation during life. International Journal of Cardiology 1995;49:267-269

• Dhawan J, Bray CL, Warburton R, Ghambhir DS, Morris J. Insulin resistance, high prevalence of diabetes, and cardiovascular risk in immigrant Asians. Genetic or environmental effect? British Heart Journal 1994;72:413-421

• Farooqi IS, Beevers G, Lip GYH. Insulin resistance, high prevalence of diabetes, and cardiovascular risk in immigrant Asians [letter]. British Heart Journal 1993;73:584

• Hughes LO, Raval U, Raferty EB. First myocardial infarctions in Asians and white men. BMJ 1989 May 20;298:1345-1350

• Khattar RS, Swales JD, Senior R, Lahiri A. Racial variation in cardiovascular morbidity and mortality in essential hypertension. Heart 2000;83:267-271

• McKeigue PM, Shah B, Marmot MG. Relation of central obesity and insulin resistance with high diabetes prevalence and cardiovascular risk in South Asians. Lancet 1991;337:382-386