Are Asian coronary arteries smaller than Caucasian? A study on angiographic coronary artery size estimation during life

Comparing coronary artery cross-sectional area among asymptomatic South Asian, White, and Black participants: the MASALA and CARDIA studies

BACKGROUND

South Asian individuals have high risk of atherosclerotic cardiovascular disease (ASCVD). Some investigators suggest smaller coronary artery size may be partially responsible.

METHODS

We compared the left anterior descending (LAD) artery cross-sectional area (CSA) (lumen and arterial wall) among South Asians in the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study with White and Black participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study, adjusting for BMI, height, and other ASCVD risk factors. We used thin-slice non-contrast cardiac computed tomography to measure LAD CSA. We used linear regression models to determine whether race/ethnicity was associated with LAD CSA after adjusting for demographic factors, BMI, height, coronary artery calcium (CAC), and traditional cardiovascular risk factors.

RESULTS

Our sample included 3,353 participants: 513 self-identified as South Asian (44.4% women), 1286 as Black (59.6% women), and 1554 as White (53.5% women). After adjusting for age, BMI, height, there was no difference in LAD CSA between South Asian men and women compared to White men and women, respectively. After full adjustment for CVD risk factors, LAD CSA values were: South Asian women (19.9 mm2, 95% CI [18.8 - 20.9]) and men (22.3 mm2, 95% CI [21.4 - 23.2]; White women (20.0 mm2, 95% CI [19.4-20.5]) and men (23.6 mm2, 95% CI [23.0-24.2]); and Black women (21.6 mm2, 95% CI [21.0 - 22.2]) and men (26.0 mm2, 95% CI [25.3 - 26.7]). Height, BMI, hypertension, CAC, and age were positively associated with LAD CSA; current and former cigarette use were inversely associated.

CONCLUSIONS

South Asian men and women have similar LAD CSA to White men and women, and smaller LAD CSA compared to Black men and women, respectively, after accounting for differences in body size. Future studies should determine whether LAD CSA is associated with future ASCVD events.

Examining the Influence of Gender, Age, and Dominance on the Caliber of Normal Coronary Arteries in the South Indian Population

Background The diameter of coronary arteries serves as a potential predictor of coronary artery diseases (CADs) that can lead to sudden death. Factors such as gender, age, and coronary artery dominance play a role in influencing the size of normal coronary arteries. The outcome of coronary interventions, to a certain extent, depends on luminal size. Given the considerable variability in luminal size within the normal population, establishing the baseline size of normal coronary arteries in a specific population can aid in estimating the severity of coronary disease and predicting the outcome of interventional procedures. The current study focuses on estimating the luminal diameter of normal coronary arteries within the context of age, gender, and cardiac dominance in the South Indian population. Methods A retrospective study was conducted utilizing coronary angiograms with normal findings from 453 patients, comprising 257 males and 196 females, with a mean age of 54.66±10.66 years. These patients attended the outpatient service of the Cardiology Department at Amrita Institute of Medical Sciences, Kochi, a quaternary care center, between 2015 and 2017. The luminal diameter of coronary arteries is represented as mean±SD in millimeters. Results In the present study, we noted that the largest coronary artery was the left main coronary artery (LMCA, 3.59±0.58 mm), followed by the left anterior descending artery (LAD, 3.50±0.52 mm), the left circumflex artery (LCX, 3.31±0.57 mm), and the right coronary artery (RCA, 3.18±0.57 mm). We further broke down the statistics to evolve a gender pattern. In the raw comparison of data, the luminal size of coronary arteries in males was greater than in females, and statistical significance was noted in all except LAD. In males, the largest coronary artery was LMCA (3.70±0.60 mm), followed by LAD (3.54±0.48 mm), LCX (3.36±0.58 mm), and RCA (3.25±0.62 mm). In females, no significant size difference was observed between LMCA (3.45±0.53 mm) and LAD (3.46±0.55 mm). Females exhibited an increase in the size of LMCA with advancing age. Regardless of right or left cardiac dominance, LMCA was consistently larger than RCA in both genders. However, in cases of co-dominance, only males demonstrated significantly larger LMCA. Conclusion Precise knowledge of the size of normal coronary arteries and their influence by gender, age, and dominance can be crucial for the comprehensive evaluation of CADs and the success of interventional procedures.

Performance of DAPT Score and ESC Criteria for Predicting Clinical Outcomes in Chinese Patients with Acute Coronary Syndrome

Purpose

The values of European Society of Cardiology (ESC) criteria and dual antiplatelet therapy (DAPT) score in the stratification of ischemic risk were assessed in this study.

Methods

A total of 489 patients with acute coronary syndrome who received DAPT at discharge between June 2020 and August 2020 were enrolled. The primary endpoint was the occurrence of major adverse cardiovascular events (MACE), which included recurrent ACS or unplanned revascularization, all-cause death, or ischemic stroke during a 27-month follow-up period.

Results

Patients with ESC-defined high-risk showed a significantly higher risk of MACE (HR 2.75, 95% CI 1.78-4.25), all-cause death (HR 2.49, 95% CI 1.14-5.43), and recurrent ACS or unplanned revascularization (HR 2.80, 95% CI 1.57-4.99) than those with ESC-defined low/medium-risk during follow-up. The results of landmark analysis showed that patients in the high-risk group had a significantly higher risk of MACE (HR 2.80,95 CI% 1.57-4.97), recurrent ACS or unplanned revascularization (HR 3.19,95 CI% 1.47-6.93) within one year, and a higher risk of MACE (HR 2.69,95 CI% 1.38-5.23) after one year. There was no significant difference in the incidence of MACE between patients with a DAPT score ≥2 and a DAPT score <2. The C-indices of ESC criteria and DAPT score for prediction of MACE were 0.63 (95% CI 0.57-0.70) and 0.54 (95% CI 0.48-0.61), respectively. The predictive value of ESC criteria for MACE was better than the DAPT score according to the DeLong test (z-statistic=2.30, P=0.020).

Conclusion

Patients with ESC-defined high-risk had a higher risk of MACE compared to those with ESC-defined low/medium-risk. The discriminant ability of the ESC criteria was better than the DAPT score for MACE. The ESC criteria demonstrated moderate discriminatory capacity of MACE in ACS patients treated with DAPT.

Quantification of the internal mammary artery size in Aboriginal and Torres Strait islanders

BACKGROUND

Variation in size of the internal mammary artery has been demonstrated in ethnic groups, but not reported in Aboriginal patients. We hypothesised that the left internal mammary artery is smaller in Aboriginal patients compared to non-Aboriginal patients and aimed to determine the impact on survival following coronary artery bypass graft (CABG) surgery.

METHODS

Left internal mammary artery size was compared between Aboriginal (n = 345) and non-Aboriginal (n = 1819) in 2343 patients undergoing CABG at Flinders Medical Centre from January 2010 to June 2021. To determine the association with-survival we used Kaplan-Meier survival analysis and Cox proportional hazard models adjusted for preoperative variables.

RESULTS

There was a significant difference in left internal mammary artery (LIMA) size-Aboriginal 1.8 ± 0.4 mm; non-Aboriginal 2.1 ± 0.4 mm (P < 0.001)-and left anterior descending (LAD) artery size-Aboriginal 1.7 ± 0.3 mm; non-Aboriginal 1.9 ± 0.3 mm (P < 0.001). Aboriginal patients were more likely to have the LIMA discarded (9.3% vs. 0.4%) and to receive a LAD vein graft (17% versus 3%) (P < 0.001). There was no difference in 30-day mortality or survival <5 years.

CONCLUSION

This study supports the hypothesis that the left internal mammary artery is smaller in Aboriginal patients compared to non-Aboriginal patients. Although Aboriginal patients were more likely to receive a venous conduit to the LAD, we observed no difference in survival up to 5 years. This data contrasts with reported outcomes of other ethnic groups.

Gender Specific Coronary Artery Diameters in CT Coronary Angiogram: A Comparative Study in Female and Male Population

Objectives:

Women show significant in-hospital morbidity and mortality with greater extent of symptoms, poorer post-revascularization outcome with increased restenosis and repeat revascularization after angioplasty, than men. Smaller sized coronary arteries in females can be attributable for this differential outcome, which is also similar in case of Indians, compared to Caucasians. Our aim is to assess the gender-specific difference in coronary arteries using noninvasive Multidetector Computed-Tomography Coronary-Angiogram(CT-CAG) and comparing the same with other racial database.

Materials and Methods:

With Ethics committee approval, present retrospective comparative study conducted in 128CT-CAG scans in 18-45years aged 100 women and 89 men with no atherosclerotic burden excluding pathological coronaries and high calcium score>100. Diameter measurements of proximal (≤10mm) segments of right coronary artery(RCA), left main coronary artery(LMCA), left anterior descending(LAD) and circumflex(LCx) arteries were taken, averaged and compared using 2-sample z-test. Considering the obtained mean diameters of total sample as South-Indian dataset which is then compared with Caucasians dataset taken from previous study.

Results:

Women showed smaller coronary artery diameters compared to men in all the arteries, with greater gender-specific age-adjusted difference in LMCA, followed by LAD, RCA and least in LCX. South-Indians showed statistically significant smaller diameters of all the coronary arteries compared to Caucasians.

Conclusion:

Gender-specific difference among the coronary arteries does exist, with females having smaller dimensions; South-Indians also show smaller diameters. This warrants a clinician for gender-specific approaches during the interventions because of technical difficulties.

The Morphology of Coronary Artery Disease in South Asians versus White Caucasians and its Implications

South Asians (SAs) experience a higher prevalence and earlier onset of coronary artery disease and have worse outcomes relative to White Caucasians (WCs) following invasive revascularization procedures, a mainstay of coronary artery disease (CAD) management. We sought to review the differences in the CAD pattern and risk factors between SA and WC patients and discuss their potential impact on the development of coronary disease, acute coronary syndrome and revascularization outcomes. SAs have a more diffuse pattern with multi-vessel involvement compared to WCs. However, less is known about other morphological characteristics such as calcification of atherosclerotic plaque and coronary diameter in SA populations. Despite a similar coronary calcification burden, higher non-calcified plaque composition, elevated thrombosis and inflammatory markers likely contribute to the disease pattern. While the current evidence on the role of coronary vessel size remains inconsistent, smaller coronary diameters in SAs could play a potential role in the higher disease prevalence. This is especially important given the impact of coronary artery diameter on revascularization outcomes. In conclusion, SAs have a unique CAD risk profile comprised of traditional and novel risk factors. Our findings highlight the need for additional awareness of healthcare professionals of this specific risk profile and potential therapeutic targets, as well as the need for further research in this vulnerable population.

Pitfalls in comparison of coronary artery measurements of Indian population with different geographical area studies

Introduction

Coronary artery disease (CAD) is the most common cause of morbidity and mortality especially in the developing countries. Coronary artery measurements (CAM) are the most important factor affecting the procedure and outcome of coronary angioplasty (PCI) as well as coronary by-pass operations (CABG). In this study, we aimed to establish a database for the normal CAM as well as for gender difference among the Indian population using quantitative coronary angiography (QCA) with an objective of assessing normal coronary vessel morphology of patients with normal coronaries.

Materials and methods

Four thousand angiograms from patients of Indian origin were studied prospectively after procuring the sanction for the same from the ethical committee of the pre-selected hospitals of four states in India. Informed consents were obtained. Post CABG, post PCI patients and patient being diabetic for ≥5 years were also excluded from the study.

Results

Ten segments from right and left coronary arteries were taken for diameter measurements. These coronary diameters were indexed to body surface area (BSA) (mean diameter mm/m² BSA). Among, 4000 patients, 933(23.3%) [M:F-521:412] had normal coronaries and 3067 (76.7%) were diseased.

Discussion and conclusion

The dimensions of the coronary artery segments of Indians were smaller (in BSA indexed and non-indexed data), compared to studies from other continents which can be due to their smaller BSA.

Inter-ethnic differences in normal coronary anatomy between Caucasian (Polish) and Asian (Korean) populations

PURPOSE

Little is known about ethnic differences in the size of coronary arteries in disease-free individuals. Our aim was to compare coronary artery dimensions between Asian and Caucasian population without atherosclerosis.

METHODS

One hundred and twelve Caucasian patients without any discernible atherosclerosis detected on coronary computed tomography angiography were matched with 112 Asian patients using sex, age, coronary dominance pattern and body surface area (BSA). Maximal and minimal lumen areas (LA) and diameters (LD) of proximal and middle coronary segments were measured, and the mean values were used for analyses.

RESULTS

Caucasians had larger LA and LD than Asian patients in all proximal coronary segments. Overall, the mean difference in LA and LD was 11.4 % and 5.2 %, respectively. Significant differences were observed for all proximal segments (left anterior descending: 13 % and 6%, left circumflex 14 % and 8% and right coronary artery 8% and 4% for LA and LD), but not for mid segments. The greatest difference between Caucasians and Asians was found in left main coronary artery (LMCA) LA (21.2 ± 6.5 vs.16.8 ± 5.4 mm², p < 0.01 respectively). The independent predictors of larger LA and LD of LMCA and proximal coronary segments were male sex (p < 0.05), Caucasian ethnicity (p < 0.05), and left dominance pattern (p < 0.05).

CONCLUSION

In subjects without atherosclerosis, Asians have smaller dimensions of all proximal coronary arteries, most prominently displayed in LMCA, than the Caucasians regardless of age, sex, or body size.

Demographic and Clinical Factors Associated with Development of Type 2 Diabetes: A Review of the Literature

Diabetes mellitus is a complex and chronic condition that requires lifelong management and interaction with a healthcare system. Failure to control risk factors through preventive care may lead to a host of diabetes-related complications. Underperforming healthcare systems and poor awareness among the general population/healthcare professionals has been suggested as reasons why so many patients remain undiagnosed. Due to the asymptomatic nature of early and even intermediate diabetes mellitus, several years may pass without any diagnosis before complications begin to manifest. Other factors include age, gender, ethnicity, education, marital and unemployment status which may also increase the risk of developing morbidity and mortality associated with diabetes mellitus. This review summarizes the current demographic risk factors and clinical characteristics associated with diabetes mellitus. A literature search was conducted using PubMed, MEDLINE, and Sabinet by using the following search terms: diabetes mellitus, risk factors, characteristics and complications.

Coronary artery size in North Indian population - Intravascular ultrasound-based study

Objective

The coronary artery dimensions have important diagnostic and therapeutic implications in management of coronary artery disease (CAD). There is paucity of data on the coronary artery size in the Indian population as measured by intravascular ultrasound (IVUS).

Methods

A total of 303 patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) with intravascular ultrasound underwent analysis along with quantitative coronary angiography (QCA). Of the 492 proximal coronary segments; 221 relating to left main (LM), 164 to left anterior descending artery (LAD), 45 to left circumflex artery (LCX), and 62 to right coronary artery (RCA) were considered.

Results

Patient's mean age was 53.37 ± 3.5 years; men 80%; hypertension 35% and diabetes 24.8%. On IVUS, mean minimal lumen diameter as compared to QCA in LM (4.60 mm versus 4.50 mm, p < 0.001), LAD (3.71 mm versus 3.45 mm, p < 0.001), LCX (3.55 mm versus 3.16 mm, p < 0.001) and RCA (3.85 mm versus 3.27 mm, p < 0.001) were significantly larger. Lumen and external elastic membrane (EEM) cross-sectional area (CSA) were larger in males as compared to females with statistical significance for lumen CSA in LM (p = 0.04); RCA (p = 0.02) and EEM CSA in LM (p = 0.03); RCA (p = 0.006) but no significance for adjusted body surface area (BSA). In multivariate models, BSA and age were independent predictors of LM and LAD diameters and areas, but age was an independent predictor indexed to BSA.

Conclusion

The coronary artery dimensions by IVUS are significantly larger than QCA. No gender difference in coronary artery size. Age was an independent predictor of coronary artery size in left main and LAD. The coronary artery size may not be a risk factor for acute coronary syndrome.

Lipoprotein(a): An underrecognized genetic risk factor for malignant coronary artery disease in young Indians

Malignant coronary artery disease (CAD) refers to a severe and extensive atherosclerotic process involving multiple coronary arteries in young individuals (aged <45 years in men and <50 years in women) with a low or no burden of established risk factors. Indians, in general, develop acute myocardial infarction (AMI) about 10 years earlier; AMI rates are threefold to fivefold higher in young Indians than in other populations. Although established CAD risk factors have a predictive value, they do not fully account for the excessive burden of CAD in young Indians. Lipoprotein(a) (Lp(a)) is increasingly recognized as the strongest known genetic risk factor for premature CAD, with high levels observed in Indians with malignant CAD. High Lp(a) levels confer a twofold to threefold risk of CAD-a risk similar to that of established risk factors, including diabetes. South Asians have the second highest Lp(a) levels and the highest risk of AMI from the elevated levels, more than double the risk observed in people of European descent. Approximately 25% of Indians and other South Asians have elevated Lp(a) levels (≥50 mg/dl), rendering Lp(a) a risk factor of great importance, similar to or surpassing diabetes. Lp(a) measurement is ready for clinical use and should be an essential part of all CAD research in Indians.

Gender-associated dimensional differences among normal to non-flow limiting coronary artery dimensions

Aim and objectives

To study gender-specific differences in coronary artery diameters among subjects with normal to non-flow limiting disease (NFLD) coronary arteries (up to 0 - 20% of stenosis) and to assess the possible association of body-mass index (BMI) with coronary dimensions, among the west coastal population of Karnataka and Kerala.

Materials and Methods

A prospective cohort study was conducted for a period of one year. Two thousand angiograms samples were collected and assessed from two study centers (one from each state), after obtaining the ethical clearance. Patients with past history of myocardial infarction and those with recanalized normal looking coronary arteries and those who had diabetes for more than five years were excluded. Ten segments of coronary arteries- left main coronary artery, ostial and proximal segments of left anterior descending artery and its first diagonal branch, ostial and proximal segments of left circumflex coronary artery and its obtuse marginal branch, ramus intermedius and the ostial and proximal segments of the right coronary artery- were included in diameter measurement. BMI values of the patients were calculated.

Results

Out of 2000 patients included in the study, 454 (22.7%; mean age 53.4 ± 14.2 years) had normal to NFLD coronaries of which 253 (55.7%) were males and 201 (44.3%) were females. As compared to women, men had larger diameters of coronary arteries for eight segments, except the obtuse marginal branch and the proximal right coronary artery. A weak, yet statistically significant, negative correlation existed between BMI and coronary artery diameters in total cohort, indicating that an increase in BMI was associated with a decrease in artery diameters. No such association was seen when men and women were assessed separately.

Conclusions

The present study indicates that men have higher caliber for coronary arteries compared to women. The study also indicates that when BMI increases there is a relative decrease in the coronary artery diameter.

Predictors of Clinical Outcome in Patients with Angiographically Intermediate Lesions with Minimum Lumen Area Less than 4 mm2 Using Intravascular Ultrasound in Non-Proximal Epicardial Coronary Artery

We investigated predictors of major adverse cardiac events (MACE) with two years after medical treatment for lesions with angiographically intermediate lesions with intravascular ultrasound (IVUS) minimum lumen area (MLA) <4 mm² in non-proximal epicardial coronary artery. We retrospectively enrolled 104 patients (57 males, 62±10 years) with angiographically intermediate lesions (diameter stenosis 30–70%) with IVUS MLA <4 mm² in the non-proximal epicardial coronary artery with a reference lumen diameter between 2.25 and 3.0 mm. We evaluated the incidences of major adverse cardiovascular events (MACE including death, myocardial infarction, target lesion and target vessel revascularizations, and cerebrovascular accident) two years after medical therapy. During the two-year follow-up, 15 MACEs (14.4%) (including 1 death, 2 myocardial infarctions, 10 target vessel revascularizations, and 2 cerebrovascular accidents) occurred. Diabetes mellitus was more prevalent (46.7% vs. 18.0%, p=0.013) and statins were used less frequently in patients with MACE compared with those without MACE (40.0% vs. 71.9%, p=0.015). Independent predictors of MACEs with two years included diabetes mellitus (odds ratio [OR]=3.41; 95% CI=1.43–8.39, p=0.020) and non-statin therapy (OR=3.11; 95% CI=1.14–6.50, p=0.027). Long-term event rates are relatively low with only medical therapy without any intervention, so the cut-off of IVUS MLA 4 mm² might be too large to be applied for defining significant stenosis. The predictors of long-term MACE were diabetes mellitus and statin therapy in patients with angiographically intermediate lesions in non-proximal epicardial coronary artery.

Differences in coronary plaque morphology between East Asian and Western White patients: an optical coherence tomography study

AIMS

Prevalence of coronary artery disease as well as cardiac mortality varies between Asian and White patients. However, the link between race and plaque characteristics in patients with coronary artery disease remains largely unexplored. Thus, we aimed to investigate the detailed culprit plaque characteristics between East Asian and White patients using optical coherence tomography.

PATIENTS AND METHODS

A total of 101 East Asians were matched to 101 White patients. Matching parameters included age, sex, clinical presentation, hyperlipidemia, diabetes mellitus, and lesion location.

RESULTS

There were no differences in underlying pathology (rupture vs. erosion) of acute coronary syndrome (P=0.935). Lesion length was longer (18.0±6.0 vs. 14.6±5.4 mm; P<0.002), lipid length was greater (9.4±4.6 vs. 7.2±3.8 mm; P<0.023), lipid index was higher (1635±987 vs. 1104±730; P=0.002), and mean reference area was larger (8.1±3.0 vs. 6.5±2.4 mm; P<0.021) in White patients compared with East Asian patients.

CONCLUSION

There are significant differences in plaque morphology between East Asian and White patients even after controlling for confounders. Our findings underscore key differences in atherosclerosis between East Asian and White populations, and may have to be taken into consideration when interpreting the results of future research.

Correlation of increased corrected TIMI frame counts and the topographical extent of isolated coronary artery ectasia

Background

The precise relationship between increased thrombolysis in myocardial infarction (TIMI) frame counts and the topographical extent of isolated coronary artery ectasia (CAE) has not been fully explained. New parameters of linear dimension (LD) and the estimated ectatic area (EEA) together with the diameter and ectasia ratio may be associated with the corrected TIMI frame count (CTFC) in isolated CAE patients.

Methods

The topographical parameters of ectatic coronary arteries and/or segments of 77 isolated CAE patients were consecutively studied. The CTFC for each coronary artery was determined by angiographic frame count.

Results

Right coronary artery (RCA) was the most frequently affected. The RCA and left circumflex (LCX) had significantly longer LD (p < 0.001 for both), and greater EEA (p < 0.001 for both) than those of left anterior descending artery (LAD). Similarly, the RCA and LCX have higher CTFCs (p = 0.001 and p = 0.008, respectively) than LAD. All topographic parameters and CTFCs were positively correlated with Markis classification. Linear regression analyses revealed that CTFCs were strongly correlated with diameter, LD, ectasia ratio and EEA, while EEA was the best predictor for the CTFC. Among multiple linear and nonlinear regression models, the cubic model between the CTFC and EEA exhibits the best Goodness-of-Fit.

Conclusion

The severity of the topographical extent of CAE was significantly correlated with increased CTFCs. Both the linear dimension and ectatic diameter (combined as EEA) were important for evaluating decreased coronary flow in isolated CAE patients.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0833-1) contains supplementary material, which is available to authorized users.

Comparison of the Diameters of the Major Epicardial Coronary Arteries by Angiogram in Asian-Indians Versus European Americans <40 Years of Age Undergoing Percutaneous Coronary Artery Intervention

Coronary artery disease (CAD) rates are higher in Asian-Indians than in Caucasians. CAD occurs at an earlier age in this group, with about a quarter of all myocardial infarctions occurring under the age of 40. Previous reports have suggested smaller coronary artery size in Asian-Indians as a major cause for increased CAD in this population. This study sought to evaluate the size of normal "atheroma-free" segments of the epicardial coronary arteries in Asian-Indians and Caucasians aged ≤40 years undergoing coronary artery intervention in other diseased segments. A total of 69 consecutive patients (41 whites, 28 Asian-Indians) aged ≤40 years were evaluated. Angiograms were analyzed using standard quality control analysis software with digital acquisition. The arteries measured were the left main, left anterior descending, left circumflex, and the right coronary artery. Conventional risk factors, including hypertension, smoking, and diabetes, that could influence coronary size were also assessed. The coronary arteries of Asian-Indian patients showed significantly smaller values in the mean diameters of the left main (2.96 mm vs 4.04 mm, p = 0.0004), left anterior descending (2.48 mm vs 3.24 mm, p = 0.0005), left circumflex (2.52 mm vs 3.06 mm, p = 0.00002), and right coronary artery (2.71 mm vs 3.65 mm, p = 0.0008) as compared with Caucasians. Even after correction for body surface area, a statistically significant difference remained in coronary artery diameters. In conclusion, statistically significant difference in the mean diameter size even after correction for body surface area in Asian-Indians has implications for predisposition to atherosclerosis, and more challenging performance of procedures such as coronary artery bypass grafting, stent implantation, or atherectomy.

Coronary artery dimensions in normal Indians

Background

Diameter of coronary artery is an important predictor of outcome after percutaneous coronary interventions and coronary artery bypass graft surgery. There is very limited data available about coronary artery dimensions in an Indian population.

Aims

To study the normal dimensions of the coronary artery segments in Indians without coronary artery disease by using quantitative coronary angiography and also to compare the dimensions in Indians with Western.

Material and method

229 patients who have undergone coronary angiography with entirely normal coronary angiogram were included in our study.

Results

This study showed the diameter of vessels in males and females when taken together the left main was larger in size followed by proximal LAD, proximal RCA & proximal LCX respectively (4.08 ± 0.44 mm, 3.27 ± 0.23 mm, 3.20 ± 0.37 mm, 2.97 ± 0.37 mm).When the vessel diameter was indexed to body surface area there was no statistical difference between male and female (p value > 0.05). The computed value of proximal coronary artery diameter unadjusted for individual body surface area, when compared to Caucasians showed that Caucasians have larger coronary artery dimensions than Indians. But when the proximal vessel diameter was indexed to body surface area there was no statistical significant difference between Indians and Caucasians (p value > 0.05).

Conclusions

We found that coronary artery size when indexed to body surface area is not statistically different in Indian males and females and compared to Caucasians. However with a smaller body habitus Indians have smaller coronary arteries.

Comparison of Endothelial Function in Asian Indians Versus Caucasians

BACKGROUND

Asian Indians have markedly increased mortality due to coronary artery disease (CAD). Impaired endothelial function has been linked to an increased risk of acute cardiovascular events. We tested the hypothesis that endothelial function was attenuated in Asian Indians and Caucasians.

METHODS

We studied 14 Asian Indians [mean age: 30 ± 6 years; mean body mass index (BMI): 25 ± 3 kg/m(2)] and 11 Caucasians (mean age: 30 ± 5 years; mean BMI: 26 ± 2 kg/m(2)). All 25 subjects were healthy men and nonsmokers without any history of CAD or diabetes and were not taking medications. Endothelial function was evaluated by ultrasound measures of flow-mediated dilatation (FMD) and endothelium-independent nonflow mediated vasodilatation (NFMD) of the brachial artery, in the morning immediately after awakening (6 a.m.) in a fasting state.

RESULTS

Mean age, BMI, apnea-hypopnea index, heart rate, and blood pressure were similar in both groups (P = >0.05). When correcting for body surface area, brachial artery diameter was not different between the two groups (2.1% ± 0.3% vs. 2.2% ± 0.4%; P = 0.29). FMD and NFMD were similar in Asian Indians and Caucasians (5.9% ± 4.1% vs. 5.7% ± 2.6%, P = 0.70; 16.4% ± 8% vs. 14.8% ± 4.1%, P = 0.58, respectively).

CONCLUSION

Endothelial function in Asian Indian men is not attenuated in comparison to Caucasian men.

Normal Proximal Coronary Artery Diameters in Adults from India as Assessed by Computed Tomography Angiography

INTRODUCTION

The normative data of coronary artery size among Indians are sparse. It is often essential to know the coronary dimensions especially during interventions such as stenting to choose the appropriate size of the stent and to decide the very need for stenting. In current practice it is the luminal angiography which is most widely employed to assess the coronary artery size. However, luminal angiography is not very accurate in estimating the epicardial coronary artery size as it does not take into account the mural thickness of the arterial wall. Hence it is prudent to assess coronary artery size by other methods such as Computed Tomography (CT) coronary angiography, quantitative coronary angiogram, Magnetic Resonanace (MR) angiogram, etc. In this study we chose computed tomography as it demonstrates mural thickness along with lumen of the vessels and hence measures the diameter more accurately.

AIM

To establish normative data for diameters of the proximal coronary artery segments during life by using MDCT in a cohort of individuals without any structural heart disease.

MATERIALS AND METHODS

Between October 2012 and April 2013, 168 consecutive patients who did not have any structural heart disease underwent CT coronary angiography for evaluation of Coronary Artery Disease (CAD) with atypical symptoms with low pretest probability. Patients who were found to have no coronary artery disease on CT-CAG were recruited in this study. The baseline clinical status and demographic data were obtained from the hospital records.

RESULTS

In our study we found that the mean indexed diameter to BSA among females for LMCA 2.32±0.12mm, LAD 1.95±0.15mm, LCX 1.73±0.20mm and RCA 1.84±0.22mm. For males the values were LMCA 2.33±0.13mm, LAD 1.94±0.16mm, LCX 1.74±0.21mm, and RCA 1.79±0.20mm. These values are comparable to other studies.

CONCLUSION

We attempted to establish normative data for normal proximal coronary artery dimensions among South Indian population. Coronary artery dimensions in Indians (in-dexed to BSA) for proximal major epicardial coronary arteries are similar to that reported in the West.

Coronary artery dimensions: Iranian population versus Indo-Asians and Caucasians

BACKGROUND

The dimensions of the coronary arteries have been shown to vary among ethnic groups. There are no data available regarding the normal size of coronary arteries in Iranians. This study aimed to investigate normal coronary artery dimensions in a Northwestern Iranian population and to compare it with pooled data of Indo-Asians and Caucasians in previous studies.

METHODS

The study included 200 adults with suspected coronary disease who were referred for elective coronary angiography between June 2012 and March 2013 and were found to have normal epicardial flow in the coronary arteries. Quantitative coronary angiography was carried out on the longest atheroma-free part of the proximal segment of each coronary artery in all patients. Two Indo-Asian and Caucasian groups were selected and pooled for comparison with the available reports on individuals without coronary artery disease.

RESULTS

The mean diameters of the left main coronary artery, proximal left anterior descending artery, proximal left circumflex, and proximal right coronary artery were 4.58 ± 0.80, 3.69 ± 0.64, 3.37 ± 0.73, and 3.47 ± 0.68 mm, respectively. The dimensions of the proximal part of the left main coronary artery and right coronary artery were significantly greater in the Northwestern Iranian population compared to the pooled Caucasian group. This difference was maintained even after correction for body surface area.

CONCLUSION

Our data indicate larger coronary diameters in the Iranian population compared to Caucasians or South-Asians. Hence the high prevalence of coronary artery disease in Iran cannot be explained by coronary dimensions.

Management of Coronary Artery Disease in South Asian Populations: Why and How to Prevent and Treat Differently

The South Asian (SA) population constitutes one of the largest ethnic groups in the world. Several studies that compared host and migrant populations around the world indicate that SAs have a higher risk of developing cardiovascular disease (CVD) than their native-born counterparts. Herein, we review the literature to address the role of the screening tools, scoring systems, and guidelines for primary, secondary, and tertiary prevention in these populations. Management based on screening for the CVD risk factors in a high-risk population such as SAs can improve health care outcomes. There are many scoring tools for calculating 10-year CVD risk; however, each scoring system has its limitations in this particular ethnicity. Further work is needed to establish a unique scoring and guidelines in SAs.

South Asian Ethnicity and Cardiovascular Risk

South Asians (SAs), in their countries or after migration, are at high risk of coronary artery disease (CAD) and mortality compared to other ethnic groups. It has been shown that >90% of CAD global risk could be attributed to 9 modifiable risk factors (RFs) worldwide. However, these conventional RFs may not fully explain this high risk of CAD among SAs. Therefore, attention has been directed toward nonconventional RFs. In this narrative review, we evaluate the conventional and emerging cardiovascular RFs characterizing SAs. These factors may explain the high morbidity and mortality among SAs. Further prospective studies are urgently needed to set algorithms for the optimal management of these RFs in high-risk populations like SAs.

Clinical Outcomes in Patients with Intermediate Coronary Stenoses: MINIATURE Investigators (Korea MultIceNter TrIal on Long-Term Clinical Outcome According to the Plaque Burden and Treatment Strategy in Lesions with MinimUm Lumen ARea lEss Than 4 mm(2) Using Intravascular Ultrasound)

Background and Objectives

We evaluated the two-year clinical outcomes in patients with angiographically intermediate lesions according to the plaque burden and treatment strategy.

Subjects and Methods

We prospectively enrolled patients with angiographically intermediate lesions (diameter stenosis 30-70%) with an intravascular ultrasound (IVUS) minimum lumen area (MLA) <4 mm² with 50-70% plaque burden of 16 Korean percutaneous coronary intervention centers. Patients were divided into medical therapy group (n=85) and zotarolimus-eluting stent group (ZES; Resolute) group (n=74). We evaluated the incidences of two-year major adverse cardiovascular events (MACE).

Results

A two-year clinical follow-up was completed in 143 patients and MACE occurred in 12 patients. There were no significant differences in the incidences of death (1.3% vs. 3.0%, p=0.471), target vessel-related non-fatal myocardial infarction (0.0% vs. 0.0%, p=1.000) and target vessel revascularizations (7.8% vs. 4.5%, p=0.425) between medical and ZES groups. Independent predictors of two-year MACE included acute myocardial infarction {odds ratio (OR)=2.87; 95% confidence interval (CI) 1.43-6.12, p=0.014}, diabetes mellitus (OR=2.46; 95% CI 1.24-5.56, p=0.028) and non-statin therapy (OR=2.32; 95% CI 1.18-5.24, p=0.034).

Conclusion

Medical therapy shows comparable results with ZES, and myocardial infarction, diabetes mellitus and non-statin therapy were associated with the occurrence of two-year MACE in patients with intermediate lesion with IVUS MLA <4 mm² with 50-70% of plaque burden.

Diabetes and coronary artery disease in South Asians

South Asians originate from the Indian sub-continent and represent roughly one fifth of the world’s population. This ethnic group contributes to the highest proportion of coronary artery disease (CAD) burden, mainly attributed to the high prevalence of diabetes. However, other established and emerging risk factors are overrepresented in this population at a younger age. Further large scale research is needed to identify various genetic and environmental mechanisms underlying the increased diabetes and vascular risk in the South Asian population. Effective clinical strategies to reduce the risk of diabetes and CAD in the South Asian population are the need of the hour.

Effects of off-pump and on-pump coronary-artery bypass grafting at 1 year

BACKGROUND

Previously, we reported that there was no significant difference at 30 days in the rate of a primary composite outcome of death, myocardial infarction, stroke, or new renal failure requiring dialysis between patients who underwent coronary-artery bypass grafting (CABG) performed with a beating-heart technique (off-pump) and those who underwent CABG performed with cardiopulmonary bypass (on-pump). We now report results on quality of life and cognitive function and on clinical outcomes at 1 year.

METHODS

We enrolled 4752 patients with coronary artery disease who were scheduled to undergo CABG and randomly assigned them to undergo the procedure off-pump or on-pump. Patients were enrolled at 79 centers in 19 countries. We assessed quality of life and cognitive function at discharge, at 30 days, and at 1 year and clinical outcomes at 1 year.

RESULTS

At 1 year, there was no significant difference in the rate of the primary composite outcome between off-pump and on-pump CABG (12.1% and 13.3%, respectively; hazard ratio with off-pump CABG, 0.91; 95% confidence interval [CI], 0.77 to 1.07; P=0.24). The rate of the primary outcome was also similar in the two groups in the period between 31 days and 1 year (hazard ratio, 0.79; 95% CI, 0.55 to 1.13; P=0.19). The rate of repeat coronary revascularization at 1 year was 1.4% in the off-pump group and 0.8% in the on-pump group (hazard ratio, 1.66; 95% CI, 0.95 to 2.89; P=0.07). There were no significant differences between the two groups at 1 year in measures of quality of life or neurocognitive function.

CONCLUSIONS

At 1 year after CABG, there was no significant difference between off-pump and on-pump CABG with respect to the primary composite outcome, the rate of repeat coronary revascularization, quality of life, or neurocognitive function. (Funded by the Canadian Institutes of Health Research; CORONARY ClinicalTrials.gov number, NCT00463294.).

Altered health status and quality of life in South Asians with coronary artery disease

BACKGROUND

People of South Asian (SA) ancestry are susceptible to coronary artery disease (CAD). Although studies suggest that SA with CAD has a worse prognosis compared with Europeans, it is unknown whether corresponding differences in functional status and quality-of-life (QOL) measures exist. Accordingly, we compared symptoms, function, and QOL in SA and European Canadians with CAD using the Seattle Angina Questionnaire (SAQ).

METHODS

Using the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease, an outcomes registry that captures patients undergoing cardiac catheterization in Alberta, Canada, we identified 635 SA and 18,934 European patients with angiographic CAD from January 1995 to December 2006 who reported health status outcomes using the SAQ at 1 year after the index catheterization. To obtain comparable clinical variables among SA and Europeans, we used a propensity score-matching technique.

RESULTS

One-year adjusted mean (SD) scores were significantly lower in SA compared with European Canadians for most SAQ domains: exertional capacity (75 [23] vs 80 [23], P = .011), anginal stability (77 [28] vs 77 [27], P = .627), anginal frequency (86 [23] vs 88 [20], P < .001), treatment satisfaction (86 [19] vs 89 [16], P < .001), and SAQ QOL (71 [24] vs 76 [21], P < .001). These results could not be accounted for by differences in baseline QOL scores or changes in health status from baseline to 1 year.

CONCLUSION

South Asian Canadians with established CAD have significantly worse health status outcomes at 1 year after angiography compared with European Canadians. Further studies are warranted to improve functional outcomes in SA with CAD.

A Simple Economical Method for Assay of Atherogenic Small Dense Low-Density Lipoprotein-Cholesterol (sdLDL-C)

In the present study, we report a simple and economical precipitation method for the quantitative determination of small, dense LDL-cholesterol (sdLDL-C) in serum that is considered to be an emerging risk factor for cardiovascular disease. This method consisted of precipitation of lipoproteins of density <1.044 g/ml using heparin-MnCl(2) and quantification of cholesterol existed in the supernatant using reagents for routine cholesterol assay instead of the costly direct low density lipoprotein-cholesterol assay kit. The supernatant contained sdLDL and high-density lipoprotein (HDL) that was confirmed by polyacrylamide gel electrophoresis. sdLDL-C concentration can be calculated by subtracting the HDL-C value from the total cholesterol concentration of the supernatant. sdLDL-C values obtained by this modified method were similar to those obtained by direct assay of sdLDL-C and there was significant correlation between the two methods. In conclusion, this method is highly economical, do not require special equipments and is useful to evaluate atherogenic risk.

New set of intravascular ultrasound-derived anatomic criteria for defining functionally significant stenoses in small coronary arteries (results from Intravascular Ultrasound Diagnostic Evaluation of Atherosclerosis in Singapore [IDEAS] study)

We sought to determine the intravascular ultrasound-derived anatomic criteria for functionally significant lesions in small coronary arteries with a reference segment diameter <3 mm. A fractional flow reserve (FFR) of <0.75, as determined by pressure wire using high-dose (100 to 150 microg) intracoronary adenosine, was used as the reference standard for functional significance. For the 94 patients/lesions involved in the present study, the average reference vessel diameter was 2.72 mm. The FFR was <0.75 in 38 patients (40.4%) and > or =0.75 in 56 patients (59.6%). Logistic regression analysis identified the minimal lumen area, plaque burden, and lesion length as the 3 most important determinants of the FFR. Using classification and regression tree analysis, the best cutoff values for these determinants to discriminate a FFR of <0.75 versus > or =0.75 were a minimal lumen area of < or =2.0 mm(2) (sensitivity 82.35%, specificity 80.77%), plaque burden of > or =80% (sensitivity 87.9%, specificity 78.9%), and lesion length of > or =20 mm (sensitivity 63.6%, specificity 78.9%). A significant increase was found in the area under the receiver operating characteristic curve of the combined parameters (minimal lumen area plus plaque burden plus lesion length) compared to the plaque burden (p = 0.014) and other individual parameters (p <0.001). In conclusion, we found that intravascular ultrasound-derived anatomic criteria are able to predict the functional significance of intermediate lesions in small coronary arteries. A minimal lumen area of < or =2.0 mm(2), plaque burden of > or =80%, and lesion length of > or =20 mm predicted a FFR of <0.75 with good sensitivity and specificity.

Short- and medium-term survival following coronary artery bypass surgery in British Indo-Asian and white Caucasian individuals: impact of diabetes mellitus

Previous studies have suggested that South Asian (SA) ethnicity is a predictor of poorer outcome after coronary artery bypass grafting (CABG). Our aim was to identify potential reasons for the higher postoperative mortality in SA patients and investigate all these reasons. All individuals undergoing isolated CABG in a tertiary cardiac centre from April 2002 to September 2007. In total, there were 2897 subjects (2623 white subjects; 274 SA subjects) who were included in an observational study showing the effect of ethnicity on the medium-term survival following CABG. Survival at 30 days and survival up to five years (median 2.7 years) were measured. SA subjects undergoing CABG were younger (62+/-9 vs. 66+/-9 years, P<0.001), less obese [body mass index (BMI) 26+/-4 vs. 28+/-4 kg/m(2), P<0.001] and had a higher prevalence of diabetes mellitus (58% vs. 33%, P<0.001) compared with white subjects. Thirty-day mortality was higher in SA subjects (2.6% vs. 1.0%, P=0.02). Non-diabetic SA had similar 30-day mortality, five-year survival and life expectancy compared to non-diabetic white subjects. In contrast, diabetic SA had a higher 30-day mortality (3.8% vs. 1.4%, P=0.01) and worse life expectancy compared to diabetic white subjects. The higher early postoperative mortality observed in SA patients is related to higher incidence of diabetes among them. SA diabetics have a significantly higher postoperative mortality and worse overall life expectancy. Ethnicity per se is not an independent predictor of short- or medium-term survival after CABG.

ACE (I/D) polymorphism and response to treatment in coronary artery disease: a comprehensive database and meta-analysis involving study quality evaluation

BACKGROUND

The role of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism in modifying the response to treatment modalities in coronary artery disease is controversial.

METHODS

PubMed was searched and a database of 58 studies with detailed information regarding ACE I/D polymorphism and response to treatment in coronary artery disease was created. Eligible studies were synthesized using meta-analysis methods, including cumulative meta-analysis. Heterogeneity and study quality issues were explored.

RESULTS

Forty studies involved invasive treatments (coronary angioplasty or coronary artery by-pass grafting) and 18 used conservative treatment options (including anti-hypertensive drugs, lipid lowering therapy and cardiac rehabilitation procedures). Clinical outcomes were investigated by 11 studies, while 47 studies focused on surrogate endpoints. The most studied outcome was the restenosis following coronary angioplasty (34 studies). Heterogeneity among studies (p < 0.01) was revealed and the risk of restenosis following balloon angioplasty was significant under an additive model: the random effects odds ratio was 1.42 (95% confidence interval:1.07-1.91). Cumulative meta-analysis showed a trend of association as information accumulates. The results were affected by population origin and study quality criteria. The meta-analyses for the risk of restenosis following stent angioplasty or after angioplasty and treatment with angiotensin-converting enzyme inhibitors produced non-significant results. The allele contrast random effects odds ratios with the 95% confidence intervals were 1.04(0.92-1.16) and 1.10(0.81-1.48), respectively. Regarding the effect of ACE I/D polymorphism on the response to treatment for the rest outcomes (coronary events, endothelial dysfunction, left ventricular remodeling, progression/regression of atherosclerosis), individual studies showed significance; however, results were discrepant and inconsistent.

CONCLUSION

In view of available evidence, genetic testing of ACE I/D polymorphism prior to clinical decision making is not currently justified. The relation between ACE genetic variation and response to treatment in CAD remains an unresolved issue. The results of long-term and properly designed prospective studies hold the promise for pharmacogenetically tailored therapy in CAD.

Stress-induced cardiomyopathy: A review

In clinical practice it is essential to bear stress-induced cardiomyopathy (SICMP) in mind as it is an insufficiently known cardiac pathology that mimics acute coronary syndromes (ACS), often with signs of cardiac failure. In the chronic phase, it poses differential diagnostic problems with regard to coronary artery pathology. Taxonomic confusion, due to the pathology also being called "takotsubo" or "ampulla cardiomyopathy", has resulted in inappropriate diagnoses and therapy. Available evidence strongly suggests that, in the presence of several cardiac risk factors, excessive sympathetic stimulation may induce this cardiomyopathy. The predilection of this cardiomyopathy for Mediterranean and Indo-Asian women, who represent 85% of cases, is probably explained by the fact that there is a significant correlation between female gender, a short (<158 cm) stature, a small (<1.9 m(2)) body surface area, and hypoplastic coronary arteries. Furthermore, 40% of SICMP patients have a hypoplastic branching of the coronary arteries in the apical region of the heart. This anomaly strongly favors the apical localization of the dyskinesia. The prognosis of SICMP is good as far as life expectancy is concerned. However, in most cases, the symptoms become chronic, medical treatment rarely improves dyspnea and chest pain, and the quality of life is, therefore, reduced. In this paper, we address diagnostic misunderstandings and we review the clinical and pathophysiological features of SICMP.

Differences in cause-of-death patterns between the native Dutch and persons of Indonesian descent in the Netherlands

We studied differences in cause-specific mortality between highly integrated first- and second-generation Indonesians and native Dutch. We used the municipal population registers and cause-of-death registry to estimate rate ratios via Poisson regression analyses. Although overall mortality levels were similar, cause-of-death patterns varied between Indonesian migrants and native Dutch; the similar levels in overall mortality coincided with the high degree of integration of Indonesians within Dutch society. The differences in cause-of-death patterns may reflect persistent influences of country of origin and migration history.

Ethnicity and cardiovascular disease prevention in the United Kingdom: a practical approach to management

The United Kingdom is a diverse society with 7.9% of the population from black and minority ethnic groups (BMEGs). The causes of the excess cardiovascular disease (CVD) and stroke morbidity and mortality in BMEGs are incompletely understood though socio-economic factors are important. However, the role of classical cardiovascular (CV) risk factors is clearly important despite the patterns of these risk factors varying significantly by ethnic group. Despite the major burden of CVD and stroke among BMEGs in the UK, the majority of the evidence on the management of such conditions has been based on predominantly white European populations. Moreover, the CV epidemiology of African Americans does not represent well the morbidity and mortality experience seen in black Africans and black Caribbeans, both in Britain and in their native African countries. In particular, atherosclerotic disease and coronary heart disease are still relatively rare in the latter groups. This is unlike the South Asian diaspora, who have prevalence rates of CVD in epidemic proportions both in the diaspora and on the subcontinent. As the BMEGs have been under-represented in research, a multitude of guidelines exists for the 'general population.' However, specific reference and recommendation on primary and secondary prevention guidelines in relation to ethnic groups is extremely limited. This document provides an overview of ethnicity and CVD in the United Kingdom, with management recommendations based on a roundtable discussion of a multidisciplinary ethnicity and CVD consensus group, all of whom have an academic interest and clinical practice in a multiethnic community.

Redefining the normal angiogram using population-derived ranges for coronary size and shape: validation using intravascular ultrasound and applications in diverse patient cohorts

OBJECTIVES

To develop a method for quantitating coronary angiographic abnormalities of segmental size and shape (tapering) in comparison to gender- and segment-specific, population derived, normal values.

BACKGROUND

In the absence of obvious focal stenoses, remodeling renders the angiogram insensitive to the presence of atherosclerosis and invalidates use of a "normal reference segment" for calculation of percent diameter stenosis.

METHODS

Equations were created for detection of size/shape abnormalities of coronary angiographic segments. After validation using intravascular ultrasound (IVUS), the equations were applied to a cohort of segments judged to be completely normal by a panel of highly experienced, core laboratory technicians; and a cohort of patients judged by an experienced interventionalist to have completely normal coronaries.

RESULTS

In patients assessed by core technicians, 53% (162/303) of males, 39% (209/538) of normal segments in males, 60% (56/94) of females, and 40% (81/205) of normal segments in females had quantifiable abnormalities. In patients with normal coronaries as judged by an experienced interventionalist, 100% of males (n = 14) and females (n = 19), 37% (67/182) of segments in males and 43% (105/247) of segments in females had abnormalities. The left main segment was most commonly abnormal.

CONCLUSIONS

We propose a set of equations validated using IVUS and based on gender- and segment-specific normal values for coronary angiographic size and shape that markedly improves the sensitivity of the coronary angiogram for detection of abnormalities. The method should replace the unfounded practice of labeling coronary angiograms as "normal" based solely on the failure to detect focal stenoses.

Coronary heart disease in South Asia: Need to redefine risk

South Asian population has a high incidence of coronary artery disease. There are a number of risk factors that are almost unique to the south Asians. The classical risk factors do not account for such high rates of CHD as are present in south Asia. We have discussed some important aspects of CHD that can help in improving prevention in south Asia.

Coronary artery diameter as a risk factor for acute coronary syndromes in Asian-Indians

Asian-Indians have high rates of coronary artery disease (CAD), which also occurs at an earlier age, with 50% of all heart attacks occurring in patients <55 years old and 25% in those <40 years old. Previous studies have cited structural factors in Asian-Indians, specifically smaller coronary arteries, as the cause of increased CAD in this population. We found that Asian-Indian patients have smaller coronary arteries, with a statistically significant difference in the mean diameter even after correction for body surface area.

Genetic analysis of a polymorphism in the human apoA-V gene: effect on plasma lipids

Recent discovery and characterization of APOAV suggests a role in metabolism of triglyceride (TG)-rich lipoproteins. Previously, variation at the APOAV locus was shown to modestly influence plasma TGs in normolipidemic samples. The aims of this study were to assess the effects of a polymorphism in APOAV (T-1131C) in terms of its frequency among three dyslipidemic populations and a control population, differences of allele frequency across available ethnic groups, and associations with specific lipoprotein TG and cholesterol compartments. We found a striking elevation in the frequency of the rare allele in a Chinese population (P = 0.0002) compared with Hispanic and European populations. The rare allele of the polymorphism was associated with elevated plasma TG (P = 0.012), VLDL cholesterol (P = 0.0007), and VLDL TG (P = 0.012), LDL TG (P = 0.003), and HDL TG (P = 0.016). Linear regression models predict that possession of the rare allele elevates plasma TG by 21 mg/dl (P = 0.009) and VLDL cholesterol by 8 mg/dl (P = 0.0001), and reduces HDL cholesterol by 2 mg/dl (P = 0.017). The association of the polymorphism with altered lipoprotein profiles was observed in combined hyperlipidemia, hypoalphalipoproteinemia, and hyperalphalipoproteinemia, and in controls. These findings indicate that APOAV is an important determinant of plasma TG and lipoprotein cholesterol, and is potentially a risk factor for cardiovascular disease.

Evaluation of patient characteristics and utilisation of invasive cardiac procedures in a UK ethnic population with unstable angina pectoris

OBJECTIVES

To evaluate patient characteristics and utilisation of invasive cardiac procedures in a UK ethnic population with unstable angina pectoris (UAP).

DESIGN

Retrospective, observational study.

SETTING

Tertiary referral cardiology centre in the United Kingdom serving a large Asian ethnic population.

SUBJECTS

White and Asian patients undergoing PTCA for UAP over a 2.5-year period at a UK referral cardiology centre from a comprehensive PTCA database. Data were also collated for all emergency admissions with unstable angina, or angina (type unspecified), to our institute.

MAIN OUTCOME MEASURES

Demographic and angiographic characteristics of patients undergoing PTCA. Frequency of usage of invasive cardiac procedures was determined in emergency angina admissions.

RESULTS

From January 1997 to July 1999, 435 White and 36 Asian patients underwent PTCA for UAP at our institute. Asian patients were on average 4.4 years younger (P=0.015), had 19.3% more diabetes (P=0.003) and 19.7% less smoking (P=0.007). Trends to more single vessel disease in Whites and more double vessel disease in Asians were observed, with similar rates of triple vessel disease. Interestingly, Asians also had trends towards more left-sided coronary artery disease and revascularisation, smaller vessels and less bail-out stenting. Asian patients were significantly less likely to undergo coronary angiography, OR 0.64 (CI 0.45-0.91, P=0.012), during the index admission, and showed a trend to less PTCA.

CONCLUSIONS

Asian patients with unstable angina pectoris appear to have clinical and angiographic differences from their White counterparts, and are less likely to have invasive cardiac procedures deployed. The reasons for these observations require elucidation and the prognostic significance of these findings is uncertain.