Long-term survival with revascularization in South Asians admitted with an acute coronary syndrome (from the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease Registry)

Predictors of outcome after CABG in the South-Asian community: a propensity matched analysis

BACKGROUND

Ethnicity is not incorporated into standardized pre-operative risk-stratification tools for cardiac surgery. This study compared short-term outcomes following coronary artery bypass graft (CABG) surgery in South Asian and non-Asian patients.

METHODS

Consecutive patients undergoing isolated CABG surgery via sternotomy between the years 2011 and 2019 were retrospectively analyzed. Initially, 1957 patients were identified (799 South-Asian, 40.8%). The patient groups were then propensity matched according to 10 relevant pre-operative covariates (age, body mass index, pulmonary disease, renal failure, smoking, diabetes, ventricular function, renal failure): 675 non-Asian patients were matched against 675 Asian patients.

RESULTS

Operative mortality was 1.77% and similar between the two groups (p = 0.447). Multivariate regression analysis found predictors of operative mortality to be pre-operative serum creatinine, age, left ventricular (LV) impairment, and extent of coronary disease. The effect of creatinine on mortality was selective for South-Asian patients (p = 0.015). LV impairment was a predictor of mortality in non-Asian patients, however this effect did not exist in South-Asian patients. Predictors of short-term complications (composite of death, stroke, reoperation, hemofiltration, and pneumonia) were age and creatinine (coefficient 0.002, 95% CI 0.0004-0.004, p = 0.019) in the overall cohort. Subgroup analysis found age to remain a selective negative predictor of complications in South-Asian patients. Cox regression analysis found creatinine, age, and LVEF to influence 10-year survival, whilst ethnicity was not a predictor.

CONCLUSION

This study highlights the cumulative risk associated with ethnicity and renal disease in predicting short-term outcomes following CABG. This warrants further investigations in larger populations, thus guiding pre-operative risk-stratification.

Ethnic differences between South Asians and White Caucasians in cardiovascular disease-related mortality in developed countries: a systematic literature review

BACKGROUND

Cardiovascular disease is the leading cause of death worldwide, with significantly worse mortality-related outcomes in ethnic minorities in developed countries. A systematic literature review and meta-analysis of observational studies was conducted to investigate cardiovascular disease-related mortality inequalities between South Asian and White Caucasian ethnic groups.

METHODS

Published studies on mortality between South Asians and Whites in developed countries were retrieved from MEDLINE, PubMed, Embase, Web of Science, and grey literature sources (inception-April 2021) and critically appraised using the Quality in Prognosis Studies tool. Bayesian random-effects meta-analyses were performed for both primary and secondary outcomes. Heterogeneity was determined using the I² statistic.

RESULTS

Of the 9879 studies screened originally, 41 were deemed eligible. A further 3 studies were included via the later search. Of these, 15 reported cardiovascular disease-related mortality, 23 reported all-cause mortality, and 6 reported both. The meta-analysis results showed that South Asians had a significantly increased risk of cardiovascular disease mortality compared to Whites (risk ratio = 1.32; 95% credible interval = 1.14 to 1.54) and a decreased risk of all-cause mortality (risk ratio = 0.95; 95% credible interval = 0.83 to 1.12).

DISCUSSION

South Asians had statistically significantly higher odds of cardiovascular disease-related mortality compared to Whites, but not for all-cause mortality. Risk of bias was a serious concern mainly due to a lack of confounders being reported.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42021240865.

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.

The attributes of hospital-based coronary artery diseases registries with a focus on key registry processes: A systematic review

BACKGROUND

The management of data on coronary artery disease (CAD) plays a significant role in controlling the disease and reducing the mortality of patients. The diseases registries facilitate the management of data.

OBJECTIVE

This study aimed to identify the attributes of hospital-based CAD registries with a focus on key registry processes.

METHOD

In this systematic review, we searched for studies published between 2000 and 2019 in PubMed, Scopus, EMBASE and ISI Web of Knowledge. The search terms included coronary artery disease, registry and data management (MeSH terms) at November 2019. Data gathering was conducted using a data extraction form, and the content of selected studies was analysed with respect to key registry processes, including case finding, data gathering, data abstracting, data quality control, reporting and patient follow-up.

RESULTS

A total of 17,604 studies were identified in the search, 55 of which were relevant studies that addressed the 21 registries and were selected for the analysis. Results showed that the most common resources for case finding included admission and discharge documents, physician's reports and screening results. Patient follow-up was mainly performed through direct visits or via telephone calls. The key attributes used for checking the data quality included data accuracy, completeness and definition.

CONCLUSION

CAD registries aim to facilitate the assessment of health services provided to patients. Putting the key registry processes in place is crucial for developing and implementing the CAD registry. The data quality control, as a CAD registry process, requires developing standard tools and applying appropriate data quality attributes.

IMPLICATIONS

The findings of the current study could lay the foundation for successful design and development of CAD registries based on the key registry processes for effective data management.

The Burden of Atherosclerotic Cardiovascular Disease in South Asians Residing in Canada: A Reflection From the South Asian Heart Alliance

South Asians (SAs), originating from the Indian subcontinent (India, Pakistan, Sri Lanka, Bangladesh, Nepal, and Bhutan), represent one quarter of the global population and are the largest visible minority in Canada. SAs experience the highest rates of coronary artery disease in Canada. Although conventional cardiovascular risk factors remain predictive in SA, the excess risk is not fully explained by these risk factors alone. Abdominal obesity, metabolic syndrome, and insulin resistance likely contribute a greater risk in SAs than in other populations. The South Asian Heart Alliance has been recently formed to investigate and recommend the best strategies for the prevention of cardiometabolic disease in SAs in Canada. This topic review represents a comprehensive overview of the magnitude of cardiovascular disease in SAs in Canada, with a review of conventional and novel risk markers in the SA population. Both primary and secondary prevention strategies are suggested and when possible, adapted specifically for the SA population. The need for SAs and their healthcare professionals to be more aware of the problem and potential solutions, along with the need for population-specific research, is highlighted.

The Association between Chronic Obstructive Pulmonary Disease and Coronary Artery Disease in Patients Undergoing Coronary Angiography

Chronic obstructive pulmonary disease (COPD) and coronary artery disease (CAD) are leading causes of morbidity and mortality. There are conflicting results regarding the association between COPD and CAD. We sought to measure the association between COPD and angiographically diagnosed CAD in a population-based cohort. We performed a retrospective analysis using data from the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH), a prospectively collected registry capturing all patients undergoing coronary angiography in Alberta, Canada, since 1995. We included adult patients who had undergone coronary angiogram between April 1, 2007 and March 31, 2014. CAD was present if at least one coronary artery had a significant stenosis ≥50%. COPD was present if the patient had a documented COPD history and was prescribed bronchodilators or inhaled steroids. We evaluated the association between COPD and CAD using univariable and multivariable logistic regression. There were 26,137 patients included with a mean age of 63.3 ± 12.2 years, and 19,542 (74.8%) were male. The crude odds ratio (OR) of having CAD was 0.83 (95% CI 0.74-0.92) for patients with COPD compared to those without COPD. The adjusted OR was 0.75 (95% CI 0.67-0.84) after controlling for age, sex, smoking history, body mass index, hypertension, diabetes, hyperlipidemia, peripheral artery disease and cardiac family history. In patients undergoing coronary angiography, COPD was negatively associated with CAD with and without the adjustment for classic risk factors. COPD patients should be properly examined for heart disease to reduce premature mortality.

Outcomes following percutaneous coronary revascularization among South Asian and Chinese Canadians

Background

Previous data suggest significant ethnic differences in outcomes following percutaneous coronary revascularization (PCI), though previous studies have focused on subgroups of PCI patients or used administrative data only. We sought to compare outcomes in a population-based cohort of men and women of South Asian (SA), Chinese and “Other” ethnicity.

Methods

Using a population-based registry, we identified 41,792 patients who underwent first revascularization via PCI in British Columbia, Canada, between 2001 and 2010. We defined three ethnic groups (SA, 3904 [9.3%]; Chinese, 1345 [3.2%]; and all “Others” 36,543 [87.4%]). Differences in mortality, repeat revascularization (RRV) and target vessel revascularization (TVR), at 30 days and from 31 days to 2 years were examined.

Results

Adjusted mortality from 31 days to 2 years was lower in Chinese patients than in “Others” (hazard ratio [HR] 0.72; 95% confidence interval [CI] 0.53-0.97), but not different between SAs and “Others”. SA patients had higher RRV at 30 days (adjusted odds ratio [OR] 1.30; 95% CI: 1.12-1.51) and from 31 days to 2 years (adjusted hazard ratio [HR] 1.17; 95% CI: 1.06-1.30) compared to “Others”. In contrast, Chinese patients had a lower rate of RRV from 31 days to 2 years (adjusted HR 0.79; 95% CI: 0.64-0.96) versus “Others”. SA patients also had higher rates of TVR at 30 days (adjusted OR 1.35; 95% CI: 1.10-1.66) and from 31 days to 2 years (adjusted HR 1.19; 95% CI: 1.06-1.34) compared to “Others”. Chinese patients had a lower rate of TVR from 31 days to 2 years (adjusted HR 0.76; 95% CI: 0.60-0.96).

Conclusions

SA had higher RRV and TVR rates while Chinese Canadians had lower rates of long-term RRV, compared to those of “Other” ethnicity. Further research to elucidate the reasons for these differences could inform targeted strategies to improve outcomes.

Effects of Ethnicity on the Prevalence of Obstructive Sleep Apnoea in Patients with Acute Coronary Syndrome: A Pooled Analysis of the ISAACC Trial and Sleep and Stent Study

BACKGROUND

Obstructive sleep apnoea (OSA) is an emerging risk factor for acute coronary syndrome (ACS). We sought to determine the effects of ethnicity on the prevalence of OSA in patients presenting with ACS who participated in an overnight sleep study.

METHODS

A pooled analysis using patient-level data from the ISAACC Trial and Sleep and Stent Study was performed. Using the same portable diagnostic device, OSA was defined as an apnoea-hypopnoea index of ≥15 events per hour.

RESULTS

A total of 1961 patients were analysed, including Spanish (53.6%, n=1050), Chinese (25.5%, n=500), Indian (12.0%, n=235), Malay (6.1%, n=119), Brazilian (1.7%, n=34) and Burmese (1.2%, n=23) populations. Significant differences in body mass index (BMI) were found among the various ethnic groups, averaging from 25.3kg/m² for Indians and 25.4kg/m² for Chinese to 28.6kg/m² for Spaniards. The prevalence of OSA was highest in the Spanish (63.1%), followed by the Chinese (50.2%), Malay (47.9%), Burmese (43.5%), Brazilian (41.2%), and Indian (36.1%) patients. The estimated odds ratio of BMI on OSA was highest in the Chinese population (1.17; 95% confidence interval: 1.10-1.24), but was not significant in the Spanish, Burmese or Brazilian populations. The area under the curve (AUC) for the Asian patients (ranging from 0.6365 to 0.6692) was higher than that for the Spanish patients (0.5161).

CONCLUSION

There was significant ethnic variation in the prevalence of OSA in patients with ACS. The magnitude of the effect of BMI on OSA was greater in the Chinese population than in the Spanish patients.

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.