CVD Burden Higher Among American Indian, Alaska Native Medicare Beneficiaries

American Indian and Alaska Native patients with Medicare face a significant burden of cardiovascular disease (CVD) and cardiometabolic risk factors, according to a large cohort study published in JAMA Network Open.

The population-based study was conducted between January 2015 and December 2019, utilizing Medicare administrative data and focusing on American Indian and Alaska Native beneficiaries aged 65 and older who were enrolled in both Medicare Part A and B fee-for-service programs. The statistical analyses were conducted between November 2022 and April 2023, looking at annual incidence, prevalence, and mortality linked to coronary artery disease (CAD), heart failure (HF), atrial fibrillation (AF), and cerebrovascular disease including stroke or transient ischemic attack (TIA).

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Among a cohort of 220,598 American Indian and Alaska Native Medicare beneficiaries, the median (IQR) age was 72.5 (68.5-79.0) years, with 57.8% being female. The study authors also noted that 38.8% of individuals in the cohort hailed from communities in the most economically distressed quintile, according to the Distressed Communities Index.

Of the full cohort, 44.8% of patients had diabetes, 61.3% had hyperlipidemia, and 72.2% had hypertension during the study period.

Between 2015 and 2019, the prevalence of CAD decreased from 38.6% to 36.7% (P < .001). The incidence of stroke or TIA also slightly decreased from 12.7 per 1000 person-years in 2015, to 12.1 per 1000 person-years in 2019, reflecting a percentage change of 5.08% (P = .004).

On the other hand, HF exhibited a prevalence of 22.9% in 2015 and 21.4% in 2019, with an increasing incidence from 26.1 per 1000 person-years to 27.0 per 1000 person-years that represents a percentage change of 4.08% (P < .001). The incidence of acute myocardial infarction also rose from 6.9 per 1000 person-years in 2015 to 7.7 per 1000 patient-years in 2019, reflecting a percentage change of 4.79% (P < .001).

Meanwhile, AF maintained a stable prevalence of 9% during the study period, with a 2015 prevalence of 9.4% and a 2019 prevalence of 9.3%.

The authors found that half of the patients experienced at least 1 severe cardiovascular condition, with an overall mortality rate of 19.8% for the cohort, impacting 43,589 patients.

The large burden of CVD and cerebrovascular disease observed in this cohort aligns with the outcomes of the Strong Heart Study, formerly the most extensive population-based cohort study among the American Indian and Alaska Native population. The study, which involved a geographically diverse sample of American Indian individuals, revealed a heightened burden of coronary artery disease.² The incidence was twice as high compared with other racial groups, and there was a greater occurrence of stroke compared with Black and White populations in the United States 2 decades ago.^2,3

“The high burden of cardiovascular disease in our cohort is not surprising given the high prevalence of risk factors for cardiovascular disease development in the cohort, including hypertension, diabetes, and hyperlipidemia,” the authors said.

While previous studies on hyperlipidemia among American Indian and Alaska Native populations have shown mixed results, the findings from the current study suggest a notable prevalence among older adults. The authors also noted that increasing racial disparities in key cardiovascular risk factors—such as diabetes and hypertension—underscore the urgency for immediate implementation of preventive strategies to address the growing burden of CVD among racially marginalized populations.

“It is important to acknowledge the sociopolitical, environmental, and economic inequities, rooted in racism, that drive the study findings,” the authors emphasized. “The burden of cardiovascular disease must be contextualized within a long racist history of settler colonialism, Indigenous genocide, governmental relocation policies, broken treaty obligations, intergenerational trauma, and intentional and sustained community disinvestment, all of which have fueled poverty and poor health in this population.”

According to the authors, addressing the challenges in cardiovascular health for these populations necessitates solutions that are designed and led by the community with a central focus on tribal sovereignty, and it is crucial to invest in community-level interventions to effectively tackle the significant burden posed by cardiovascular risk factors.

“Genuine engagement of Indigenous communities, with strategies that integrate traditional cultural teaching and healing into Western medicine, are essential to achieve optimal health,” the authors said.

Reference

1. Eberly LA, Shultz K, Merino M, et al. Cardiovascular disease burden and outcomes among American Indian and Alaska Native Medicare beneficiaries. JAMA Netw Open. Published online September 22, 2023. doi:10.1001/jamanetworkopen.2023.34923

2. Howard BV, Lee ET, Cowan LD, et al. Rising tide of cardiovascular disease in American Indians: the Strong Heart Study. Circulation. 1999;99(18):2389-2395. doi:10.1161/01.CIR.99.18.2389

3. Zhang Y, Galloway JM, Welty TK, et al. Incidence and risk factors for stroke in American Indians: the Strong Heart Study. Circulation. 2008;118(15):1577-1584. doi:10.1161/CIRCULATIONAHA.108.772285