Sudden death is less common than might be expected in underprivileged ethnic minorities at high cardiovascular risk

Race, ethnicity, and the risk of sudden death<sup/>

Sudden cardiac death (SCD) is a major cause of death worldwide, with an estimated U.S. annual incidence of 350,000 [1]. This review will examine the influence of race and ethnicity on SCD burden and risk factors, and review the available literature on resuscitation outcomes and primary prevention of SCD. An improved understanding of associations between race, ethnicity, and SCD may provide clues to mechanisms, lead to improved prevention of SCD, and ultimately reduce racial and ethnic disparities in the burden of SCD.

Ethnicity and the first diagnosis of a wide range of cardiovascular diseases: Associations in a linked electronic health record cohort of 1 million patients

BACKGROUND

While the association of ethnic group with individual cardiovascular diseases has been studied, little is known about ethnic differences in the initial lifetime presentation of clinical cardiovascular disease in contemporary populations.

METHODS AND RESULTS

We studied 1,068,318 people, aged ≥30 years and free from diagnosed CVD at baseline (90.9% White, 3.6% South Asian and 2.9% Black), using English linked electronic health records covering primary care, hospital admissions, acute coronary syndrome registry and mortality registry (CALIBER platform). During 5.7 years median follow-up between 1997-2010, 95,224 people experienced an incident cardiovascular diagnosis. 69.9% (67.2%-72.4%) of initial presentation in South Asian <60 yrs were coronary heart disease presentations compared to 47.8% (47.3%-48.3%) in White and 40.1% (36.3%-43.9%) in Black patients. Compared to White patients, Black patients had significantly lower age-sex adjusted hazard ratios (HRs) for initial lifetime presentation of all the coronary disease diagnoses (stable angina HR 0.80 (95% CI 0.68-0.93); unstable angina- 0.75 (0.59-0.97); myocardial infarction 0.49 (0.40-0.62)) while South Asian patients had significantly higher HRs (stable angina- 1.67 (1.52-1.84); unstable angina 1.82 (1.56-2.13); myocardial infarction- 1.67 (1.49-1.87). We found no ethnic differences in initial presentation with heart failure (Black 0.97 (0.79-1.20); S Asian 1.04(0.87-1.26)). Compared to White patients, Black patients were more likely to present with ischaemic stroke (1.24 (0.97-1.58)) and intracerebral haemorrhage (1.44 (0.97-2.12)). Presentation with peripheral arterial disease was less likely for Black (0.63 (0.50-0.80)) and South Asian patients (0.70 (0.57-0.86)) compared with White patients.

DISCUSSION

While we found the anticipated substantial predominance of coronary heart disease presentations in South Asian and predominance of stroke presentations in Black patients, we found no ethnic differences in presentation with heart failure. We consider the public health and research implications of our findings.

TRIAL REGISTRATION

NCT02176174, www.clinicaltrials.gov.

Ethnic differences in ST height in the multiethnic study of atherosclerosis

BACKGROUND

ST elevation in precordial leads has been associated with genetic syndromes of arrhythmias and sudden death. ST height data in different ethnic groups are limited.

METHODS

ST height was determined in 4612 African-American, Chinese, Hispanic, and non-Hispanic white men and women aged 45-84 years in the Multiethnic Study of Atherosclerosis (MESA). For leads I, II, and V(1) to V(6,) ST height, measured at the J point and 60 ms after the J point, adjusted for covariates were compared between non-Hispanic white and other ethnic groups using analysis of covariance (ANCOVA).

RESULTS

Among men, ST height was significantly different across all ethnic groups at both time points for all leads (P < 0.01), except at the J point for limb lead II (P = 0.2). Among women, differences were also significant at the J point and 60 ms past the J point (P < 0.01). ST height was lowest for non-Hispanic whites in all leads and at both time points. At the J point, Chinese had the highest ST height for leads V(1) and V(2), whereas African Americans had the greatest ST height for leads I and V(3) to V(6). At 60 ms past the J point, Chinese men had the greatest ST height for lead I and V(1) to V(6;) and Chinese women had greatest ST height for leads V(1) to V(3).

CONCLUSIONS

There were significant differences in ST height among ethnic groups in all ECG leads. The physiological mechanisms and clinical significance of these differences and the possible association with arrhythmias require further study.