The sickle cell trait in African Americans may not confer increased risk for myocardial infarction or coronary heart disease, according to research published in JAMA Network Open.

A team of investigators conducted an analysis of 5 large, prospective, population-based cohorts to determine whether the sickle cell trait was associated with an incidence of myocardial infarction or composite coronary heart disease outcomes among African American patients.

The presence of the sickle cell trait was determined using either direct genotyping or high-quality imputation of the sickle cell variant (rs334). The primary outcomes were incident myocardial infarction and incident coronary heart disease. Patients with either sickle cell disease or a history of coronary heart disease were excluded from the study.


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The combined sample included 23,197 African American participants (70.2% women); 1781 patients had the sickle cell trait (mean prevalence, 7.7%). Of the 1034 participants who experienced myocardial infarction, 76 patients were carriers of the sickle cell trait. In addition, 137 of 1714 patients with the composite coronary heart disease outcomes were carriers of the sickle cell trait.

Both cohort-specific and meta-analyses indicated that the crude incidence rates of myocardial infarction did not vary significantly between participants with and without the sickle cell trait (3.8 per 1000 person-years vs 3.6 per 1000 person-years, respectively). Results for crude incidence of composite coronary heart disease were also similar among participants with and without the sickle cell trait (7.3 per 1000 person-years vs 6.0 per 1000 person-years, respectively).

Results from the meta-analysis of the 5 studies also suggested that no significant association existed between sickle cell trait status and myocardial infarction (hazard ratio [HR], 1.03) or composite coronary heart disease (HR, 1.16).

A limitation of note was the inability to “account for the modifying effect of other genetic factors, such as alpha-thalassemia, which is a modifier of the effect of the sickle β-globin variant, although this variant has not been associated with [coronary heart disease].”

“Although prior studies showed that [sickle cell trait] is associated with sudden death, our findings suggest that these disorders may not be associated with [sickle cell trait]-related sudden death,” concluded the investigators.

Disclosure: Some authors have declared affiliations with the pharmaceutical industry. Please refer to the original study for a full list of disclosures.

Reference

Hyacinth HI, Franceschini N, Seals SR, et al. Association of sickle cell trait with incidence of coronary heart disease among African American individuals. JAMA Network Open. Published online January 5, 2021. doi:10.1001/jamanetworkopen.2020.30435