Table 3. The association of ethnicities with CAD .

CAD: Coronary artery disease, CHD: Coronary heart disease, ARIC: Atherosclerosis Risk Communities study, CHS: Cardiovascular Health Study, REGARDS: Reasons for Geographic and Racial Differences in Stroke study, CVD: Cardiovascular diseases, NHW: Non-Hispanic White, PVD: Peripheral vascular disease, DM: Diabetes mellitus, AMI: Acute myocardial infarction

Identification and Year of Publication	Outcome Measures	Key Findings	Limitations
Mital et al. (2021) [49]	The article reviews the ethnic and racial discrepancies persisting in the care of patients with CAD and stroke.	CAD predominantly affected the Black population. Racial discrimination and CAD may be linked for decades; therefore, racial prejudice in childhood or adolescence may increase the risk of CAD in adults. Unjust treatment based on race in childhood is linked to an increased cumulative chronic biological risk.	This is a review study and, hence, doesn't establish a cause-and-effect relationship. The psychological, social, and environmental factors pertaining to different racial and ethnic groups need to be further evaluated. Lack of sufficient data and underrepresentation of minority groups further diminish the true results of the study.
Colantonio et al. (2017) [50]	In the Atherosclerosis Risk Communities study (ARIC), the Cardiovascular Health Study (CHS), and the Reasons for Geographic and Racial Differences in Stroke study (REGARDS), the fatal and nonfatal CHD incidence and CHD case-fatality were compared among Blacks and Whites by sex.	In comparison to White men, the risk for fatal CHD was higher in Black men, whereas the risk for nonfatal or total CHD was similar or lower after keeping age as a control. On the other hand, there was a greater risk of fatal, nonfatal, and total CHD in Black women than White women, particularly among those over 65. In comparison to White men and women, the risk of fatal CHD was similar in Black men and women, whereas the risk of nonfatal and fatal CHD was reduced after keeping social determinants of health and cardiovascular risk factors under control. It was also found that social determinants of cardiovascular risk factors and health could not explain the higher case-fatality rates in the Black population when compared to the White population, including both men and women.	The three cohorts used different data collection methods. Not many non-White and non-Black participants in ARIC were included in the analysis, as non-Whites and non-Blacks are indistinguishable from Whites using the publicly accessible dataset. Results from ARIC and CHS may not be generalizable to the entire US population due to their restricted geographic coverage. In REGARDS, nonfatal CHD occurrences are adjudicated based on participants who self-reported CHD-related hospitalization, which may lead to an underestimation of incidence rates.
Rodriguez et al. (2017) [51]	The multicenter study included the three largest US Hispanic subgroups, i.e., Mexicans, Puerto Ricans, and Cubans, and aimed to articulate a decade of national CVD (cardiovascular diseases) mortality data.	Younger patients were seen in Puerto Ricans and Mexicans than in Cubans and NHWs when it came to CVD deaths. Cubans and Puerto Ricans exhibited CVD death rates that were equivalent to NHWs after age adjustment but overall had higher rates of ischemic and hypertensive heart disease. Higher mortality rates from cerebrovascular illness were seen in Mexicans than those of other Hispanic groupings but remained lower than those of NHWs.	Further disaggregation of a heterogeneous population of Dominicans, Spaniards, Latin Americans, and South and Central Americans that were included in the comparison groups of Hispanics could not be accomplished owing to inconsistencies in data collection. Certain discrepancies are possible in mortality data. Factors underlying the racial and ethnic differences, like area of residence, acculturation metrics, health behaviors, etc., were not considered.
Holland et al. (2011) [52]	The study includes Asian-American subgroups (Asian Indian, Filipino, Chinese, Japanese, Vietnamese, and Korean) and NHW subjects to compare the prevalence of coronary heart disease (CHD), peripheral vascular disease (PVD), and stroke in a mixed-payer, outpatient health care organization in California.	The risk for CHD was higher in Asian Indians and Filipinos, whereas an elevated risk for total stroke was seen in Filipino women. The risk of ischemic and hemorrhagic stroke in Filipino women was significantly higher than that of NHWs. Chinese men and women had a much lower risk of CHD when compared to NHWs. The ORs for CHD and stroke are close to one and not statistically significant because certain subgroups have higher rates than NHWs and others have lower rates when comparing the Asian group to NHWs. In contrast, the probability of PVD decreased across the board for all Asians. The prevalence of traditional risk factors for CAD, like type 2 DM and hypertension, is higher in Filipinos and Asian Americans.	The study's limitations include a specific geographic area and a very small sample size in the Asian subgroups (i.e., Korean and Vietnamese populations). The prevalence definitions of CVD were built on outpatient visits only, which might have led to an underestimation of CVD prevalence.
Gijsberts et al. (2015) [53]	The study explores the interactions between risk factors and ethnicity on the CAD severity of four ethnic groups: White, Chinese, Indians, and Malay, while using multivariable ordinal regression. Also, multivariable Cox regression analysis was used to compare all-cause mortality among the ethnic groups.	Indians (South Asians) tend to develop CAD earlier in life. CAD severity was higher and independently associated with Chinese and Malay ethnicities compared to the White population. The risk factor burden was found to be higher in Chinese, especially due to diabetes. Survival rates following CAD events were similar in all ethnic groups except Malay, which showed a comparatively higher mortality rate primarily due to more conservative treatment and less use of preventive medicines.	There was no correction of confounding factors like diet, lifestyle, and socioeconomic factors. The health care delivery system in Singapore and the Netherlands, where the study was conducted, is different and hence may impact the findings.
Rai et al. (2014) [54]	The comprehensive review and meta-analysis looked at the association between CAD and three polymorphic variants of the NOS3 gene, specifically Glu298Asp, T786-C, and 27bp VNTR b/a. It also examined their connection independently among published studies with a predominance of Middle Eastern, Asian, European, African, and Asian-Indian ancestry in a subgroup analysis.	The research supports the global link of CAD with the three frequent NOS3 gene polymorphisms: Glu298Asp, T786-C, and 4a/b VNTR. The results between various ancestral subgroups were quite enlightening. The Middle Eastern grouping exhibited the strongest correlation with both the examined NOS3 SNPs, Glu298Asp and 4b/a. However, among individuals of Asian descent, the highest risk for CAD is carried by T786-C and its minor allele.	The South Asian region was underrepresented. The association study also doesn't establish causal relationships; it only measures statistical associations. Also, the presence of selection bias, the possibility of errors in genotyping, and the risk of an inadequate sample size cannot be ruled out.
Hammershaimb et al. (2023) [55]	This retrospective study evaluated patients with acute myocardial infarction (AMI) for differences in risk factors, treatment, and outcomes based on race or ethnicity. Patients aged 18 to 50 who were hospitalized for AMI between 2006 and 2016 were included in the study. The association of race or ethnicity with all-cause mortality was evaluated using Cox regression models.	Smoking, diabetes, and hypertension are major cardiovascular risk factors for Black patients, while obesity and diabetes are for Hispanic patients, and smoking is a huge risk factor for White patients. No difference was noted in revascularization rates or initial medical treatment between racial and ethnic groups, but long-term medication adherence did, with Black and Hispanic patients being more likely to take their medications as prescribed.	Only patients who went through coronary angiography were included in the study. Patients who were medically managed for AMI were not part of the study. Ancestral backgrounds were not taken into consideration, although patients were divided into broad racial and ethnic groups. There could be possible errors in measuring medication adherence as information was collected from the pharmacies.
Mochari-Greenberger and Mosca (2015) [56]	The review’s aim is to investigate factors associated with differential outcomes by race and ethnicity among CHD patients by highlighting and evaluating recently published research.	High rates of mortality and hospital readmissions have been seen in minority groups of different races and ethnicities when compared to White individuals. The difference was explained by socioeconomic factors and the presence of other medical conditions.	Additional factors that may contribute to racial and ethnic differences in CHD outcomes have not yet been identified or measured well enough, as disparities existed even after controlling for clinical and socioeconomic conditions. Also, most of the information used in the study was related to Black and White populations only.
Wu et al. (2013) [57]	The comprehensive meta-analysis evaluates the impact of the CYBA C242T polymorphism on CAD and potential biases.	The C242T polymorphism has a heterogeneous influence on CAD among various ethnicities, being moderate in the White population but lacking influence in Asians. Study design and BMI were the two confounding factors responsible for between-study heterogeneity.	The meta-analysis focused on a single variant in the CYBA gene and did not take into consideration the potential synergistic effects of additional candidate genes or polymorphisms. The interplay of polygenic and environmental variables is most likely at the root of genetic susceptibility to CAD, and optimal models addressing these elements are necessary.
Xu et al. (2016) [58]	The meta-analysis aimed to evaluate the effects of apolipoprotein E gene variants on coronary artery diseases across various ethnic groups.	In the stratified analysis, the risk of CAD was high in the Mongolian group and mild in the White group for the allele genetic variation, demonstrating that the ApoEε4 allele contributed to the increased risk of CHD while having differences in genetic background. In addition, the ε2 allele variant demonstrated a lower risk of CHD in White patients but not among Mongolians.	The ApoE gene is a suitable and common gene to study gene-environment interactions. However, a lack of sufficient data limited further evaluation of potential gene-gene and gene-environment interactions.
Lian et al. (2014) [59]	The meta-analysis aimed to establish the link between CDKN2A rs1333049 polymorphism and coronary heart disease (CHD) and its effect on various ethnic groups.	CDKN2A rs1333049 polymorphism contributed to an increased risk of CAD by 38%. CHD risk was increased in both Europeans and Asians by 30% and 27%, respectively, after performing a subgroup analysis by ethnicity showing the association of rs1333049.	Only one variant of the CDKN2A gene was included in the study. Not much information was available for the African population. The results may have been affected due to the small statistical power (p = 0.377) of the case-control study in the subgroup analysis on sex and age.