Trends in Cardiovascular Disease Morbidity and Mortality in American Indians Over 25 Years: The Strong Heart Study

Trends in Premature Mortality from Acute Myocardial Infarction in American Indians/Alaska Natives in the United States from 1999 to 2020

Cardiovascular disease is the leading cause of mortality in American Indian and Alaska Native (AI/AN) groups. They are disproportionately found to have a higher rate of premature myocardial infarction (MI). The Centers for Disease Control and Prevention's Wide-ranging Online Data for Epidemiologic Research were queried to identify premature MI deaths (female <65 years and male <55 years) occurring within the United States between 1999 and 2020. We investigated proportionate mortality trends related to premature MI in AI/ANs stratified by gender. Deaths attributed to acute MI (AMI) were identified using the International Classification of Diseases, Tenth Revision, Clinical Modification codes I21 to I22. We compared the proportional mortality rate because of premature MI with that of a non-AI/AN racial group, which comprised all other races (Blacks, Whites, and Asian/Pacific Islander populations). In AI/ANs, we analyzed a total of 14,055 AMI deaths, of which 3,211 were premature MI deaths corresponding to a proportionate mortality rate of 22.8% (male 20.8%, female 26.2%). The non-AI/AN population had a lower proportionate mortality of 14.8% (male 13.7%, female 16%), p <0.01). On trend analysis, there was no significant improvement over time in the proportionate mortality of AI/ANs (19.8% in 1999 to 21.7% in 2020, p = 0.09). Upon comparison of gender, proportionate mortality of premature MI in women showed a statistically nonsignificant increase from 21.6% in 1999 to 27.3% in 2020 [average annual percent change of 0.7, p = 0.06)]. However, men had a statistically significant decrease in proportionate mortality of premature MI from 18.5% in 1999 to 18.2% in 2020 [average annual percent change of -0.8, p = 0.01)]. AI/ANs have an alarmingly higher rate of proportionate mortality of premature MI than that of other races, with no improvement in the proportionate mortality rates over 20 years, despite an overall downtrend in AMI mortality. Further research to address the reasons for the lack of improvement in premature MI is needed to improve outcomes in this patient population.

The Contribution of Declines in Blood Lead Levels to Reductions in Blood Pressure Levels: Longitudinal Evidence in the Strong Heart Family Study

BACKGROUND

Chronic lead exposure is associated with both subclinical and clinical cardiovascular disease. We evaluated whether declines in blood lead were associated with changes in systolic and diastolic blood pressure in adult American Indian participants from the SHFS (Strong Heart Family Study).

METHODS AND RESULTS

Lead in whole blood was measured in 285 SHFS participants in 1997 to 1999 and 2006 to 2009. Blood pressure and measures of cardiac geometry and function were obtained in 2001 to 2003 and 2006 to 2009. We used generalized estimating equations to evaluate the association of declines in blood lead with changes in blood pressure; cardiac function and geometry measures were considered secondary. Mean blood lead was 2.04 μg/dL at baseline. After ≈10 years, mean decline in blood lead was 0.67 μg/dL. In fully adjusted models, the mean difference in systolic blood pressure comparing the highest to lowest tertile of decline (>0.91 versus <0.27 μg/dL) in blood lead was -7.08 mm Hg (95% CI, -13.16 to -1.00). A significant nonlinear association between declines in blood lead and declines in systolic blood pressure was detected, with significant linear associations where blood lead decline was 0.1 μg/dL or higher. Declines in blood lead were nonsignificantly associated with declines in diastolic blood pressure and significantly associated with declines in interventricular septum thickness.

CONCLUSIONS

Declines in blood lead levels in American Indian adults, even when small (0.1-1.0 μg/dL), were associated with reductions in systolic blood pressure. These findings suggest the need to further study the cardiovascular impacts of reducing lead exposures and the importance of lead exposure prevention.

Heart Failure with Reduced Ejection Fraction and COVID-19, when the Sick Get Sicker: Unmasking Racial and Ethnic Inequities During a Pandemic

Minoritized racial and ethnic groups have the highest incidence, prevalence, and hospitalization rate for heart failure. Despite improvement in medical therapies and overall survival, the morbidity and mortality of these groups remain elevated. The reasons for this disparity are multifactorial, including social determinant of health (SDOH) such as access to care, bias, and structural racism. These same factors contributed to higher rates of COVID-19 infection among minoritized racial and ethnic groups. In this review, we aim to explore the lessons learned from the COVID-19 pandemic and its interconnection between heart failure and SDOH. The pandemic presents a window of opportunity for achieving greater equity in the health care of all vulnerable populations.

Contemporary Trends in Acute Myocardial Infarction in the American Indian/Alaska Native U.S. Population, 2000 to 2018

Coronary heart disease is disproportionately prevalent in the American Indian/Alaska Native (AI/AN) population. As care for acute myocardial infarction (AMI) continues to advance, equitable distribution and access for the AI/AN population is essential. Primary AMI hospitalizations for adults ≥18 years of age were identified from the Healthcare Cost and Utilization Project National Inpatient Sample from 2000 to 2018. Related co-morbidities, procedures of interest, and in-hospital mortality were also identified. These rates were stratified by race then trended over years using Poisson regression. Overall, 9,904,714 weighted hospitalizations for primary AMI were identified. From 2000 to 2018, AI/AN adults had relatively high rates of primary AMI hospitalization, second only to non-Hispanic (NH) White adults. The AMI rate increased from 14.0/1,000 to 16.1/1,000 among AI/AN adults, remaining higher than NH Black adults (12.1/1,000 to 13.0/1,000) and Hispanic adults (10.3/1,000 and 12.7/1,000) and becoming increasingly closer to NH White adults (25.1/1,000 to 20.0/1,000) (p <0.001 for each). AI/AN adults presented 5 years earlier than their NH White counterparts (64 vs 69 years old; p <0.001). In-hospital mortality was approximately 5% for all race categories and decreased in all groups but decreased at a much greater rate for NH White, NH Black and Hispanic adults (0.2% per year) compared with AI/AN adults (0.08% per year; p <0.001 for each comparison). Rates of coronary angiography and percutaneous coronary intervention increased in all groups, but coronary artery bypass graft utilization increased only in AI/AN adults (from 7% to 10%, p <0.001). In conclusion, from 2000 to 2018, AI/AN adults had a high rate of AMI hospitalizations (second only to NH White adults) that increased significantly over time. AI/AN adults were 5 years younger than their NH White counterparts at index AMI hospitalization. Care during these hospitalizations was similar among all racial groups, and in-hospital mortality decreased for all groups, albeit to a lesser degree among AI/AN adults. This study highlights the need for improved access to outpatient primary AMI prevention in the AI/AN population.

Epigenetic Biomarkers of Lead Exposure and Cardiovascular Disease: Prospective Evidence in the Strong Heart Study

Background Lead is a cardiotoxic metal with a variety of adverse health effects. In the absence of data on bone lead exposure, epigenetic biomarkers can serve as indicators of cumulative lead exposure and body burden. Herein, we leveraged novel epigenetic biomarkers of lead exposure to investigate their association with cardiovascular disease (CVD) incidence and mortality. Methods and Results Blood DNA methylation was measured using the Illumina MethylationEPIC BeadChip among 2231 participants of the Strong Heart Study (SHS) at baseline (1989-1991). Epigenetic biomarkers of lead levels in blood, patella, and tibia were estimated using previously identified cytosine-guanine dinucleotide (CpG) sites. CVD incidence and mortality data were available through 2017. Median concentrations of lead epigenetic biomarkers were 13.8 μg/g, 21.3 μg/g, and 2.9 μg/dL in tibia, patella, and blood, respectively. In adjusted models, the hazard ratio (HR) (95% CI) of CVD mortality per doubling increase in lead epigenetic biomarkers were 1.42 (1.07-1.87) for tibia lead, 1.22 (0.93-1.60) for patella lead, and 1.57 (1.16-2.11) for blood lead. The corresponding HRs for incident CVD were 0.99 (0.83-1.19), 1.07 (0.89-1.29), and 1.06 (0.87-1.30). The association between the tibia lead epigenetic biomarker and CVD mortality was modified by sex (interaction P value: 0.014), with men at increased risk (HR, 1.42 [95% CI, 1.17-1.72]) compared with women (HR, 1.04 [95% CI, 0.89-1.22]). Conclusions Tibia and blood epigenetic biomarkers were associated with increased risk of CVD mortality, potentially reflecting the cardiovascular impact of cumulative and recent lead exposures. These findings support that epigenetic biomarkers of lead exposure may capture some of the disease risk associated with lead exposure.

Unequitable Heart Failure Therapy for Black, Hispanic and American-Indian Patients

Despite the high prevalence of heart failure among Black and Hispanic populations, patients of colour are frequently under-prescribed guideline-directed medical therapy (GDMT) and American-Indian populations are not well characterised. Clinical inertia, financial toxicity, underrepresentation in trials, non-trustworthy medical systems, bias and structural racism are contributing factors. There is an urgent need to develop evidence-based strategies to increase the uptake of GDMT for heart failure in patients of colour. Postulated strategies include prescribing all GDMT upon first encounter, aggressive outpatient uptitration of GDMT, intervening upon social determinants of health, addressing bias and racism through changing processes or policies that unfairly disadvantage patients of colour, engagement of stakeholders and implementation of national quality improvement programmes.

Vascular Risk Factor Prevalence and Trends in Native Americans with Ischemic Stroke

INTRODUCTION

Native Americans have a higher incidence and prevalence of stroke and the highest stroke-related mortality among race-ethnic groups in the United States. We aimed to analyze trends in the ischemic stroke (IS) vascular risk factor prevalence in Native Americans along with a comparison to the other race-ethnic groups.

METHODS

National Inpatient Sample (NIS) database was used to explore the prevalence of risk factors among hospitalized IS patients during 2000 - 2016. Prevalence estimates were calculated for each risk factor within each race-ethnic group in 6 time periods. Linear trends were explored using linear regression models, with differences in trends between the Native American group and the other race-ethnic groups assessed using interaction terms. The analysis accounted for the complex sampling design, including hospital clusters, NIS stratum, and trend weights for analyzing multiple years of NIS data.

RESULTS

Native Americans constituted 5472 of the 1,278,784 IS patients. The age-and-sex-standardized prevalence of hypertension (slope = 2.24, p < 0.001), hyperlipidemia (slope = 6.29, p < 0.001), diabetes (slope = 2.04, p = 0.005), atrial fibrillation/flutter (trend slope = 0.80, p = 0.011), heart failure (trend slope = 0.73, p = 0.036) smoking (trend slope= 3.65, p < 0.001), and alcohol (slope = 0.60, p = 0.019) increased among Native Americans. They showed larger increases in hypertension prevalence compared to Blacks, Hispanics, and Asian/Pacific Islanders and in smoking prevalence compared to Hispanics and Asian/Pacific Islanders. By the year 2015-2016, Native Americans had the highest overall prevalence of diabetes, coronary artery disease, smoking, and alcohol among all race-ethnic groups.

CONCLUSION

The prevalence of most vascular risk factors among ischemic stroke patients has increased in Native Americans over the last two decades. Significantly larger increases in hypertension and smoking prevalence were seen in Native Americans compared to other groups along with them having the highest prevalence in multiple risk factors in recent years.

Moving Towards Equity With Digital Health Innovations for Stroke Care

Digital health has long been championed as a means to expanding access to health care. Now that the COVID-19 pandemic accelerated many health systems' integration of digital tools for care, digital health may provide a path towards more accessible stroke prevention and treatment, particularly for historically disadvantaged patient populations. Stroke management is composed of multiple time points where digital health innovations have the potential to augment health access and treatment: from primary prevention, to the time-sensitive detection of ischemic stroke, administration of thrombolytic agents and consideration for endovascular interventions, to appropriate post-acute care, rehabilitation, and lifelong secondary stroke prevention-stroke care relies on a multidisciplinary and standardized approach. However, as we discuss pointedly in this Focused Update, underrepresented individuals face multilevel digital health disparities that potentially diminish the benefits of these digital advances. As such, these multilevel needs must be discussed and accounted for as health systems seek to integrate innovative and equitable digital health solutions towards stroke care.

Spatial relationship between well water arsenic and uranium in Northern Plains native lands

Arsenic and uranium in unregulated private wells affect many rural populations across the US. The distribution of these contaminants in the private wells of most American Indian communities is poorly characterized, and seldom studied together. Here, we evaluate the association between drinking water arsenic and uranium levels in wells (n = 441) from three tribal regions in North Dakota and South Dakota participating in the Strong Heart Water Study. Groundwater contamination was extensive; 29% and 7% of wells exceeded maximum contaminant levels for arsenic and uranium respectively. 81% of wells had both arsenic and uranium concentrations at one-tenth of their human-health benchmark (arsenic, 1 μg/L; uranium 3 μg/L). Well arsenic and uranium concentrations were uncorrelated (rs = 0.06); however, there appeared to be a spatial correlation of wells co-contaminated by arsenic and uranium associated with flow along a geologic contact. These findings indicate the importance of measuring multiple metals in well water, and to understand underlying hydrogeological conditions. The underlying mechanisms for the prevalence of arsenic and uranium across Northern Plains Tribal Lands in the US, and in particular the occurrence of both elevated arsenic and uranium in drinking water wells in this region, demands further study.

All-Cause Mortality and Cardiovascular Death between Statins and Omega-3 Supplementation: A Meta-Analysis and Network Meta-Analysis from 55 Randomized Controlled Trials

Statins and omega-3 supplementation have shown potential benefits in preventing cardiovascular disease (CVD), but their comparative effects on mortality outcomes, in addition to primary and secondary prevention and mixed population, have not been investigated. This study aimed to examine the effect of statins and omega-3 supplementation and indirectly compare the effects of statin use and omega-3 fatty acids on all-cause mortality and CVD death. We included randomized controlled trials (RCTs) from meta-analyses published until December 2019. Pooled relative risks (RRs) and 95% confidence intervals (CIs) were calculated to indirectly compare the effect of statin use versus omega-3 supplementation in a frequentist network meta-analysis. In total, 55 RCTs were included in the final analysis. Compared with placebo, statins were significantly associated with a decreased the risk of all-cause mortality (RR = 0.90, 95% CI = 0.86–0.94) and CVD death (RR = 0.86, 95% CI = 0.80–0.92), while omega-3 supplementation showed a borderline effect on all-cause mortality (RR = 0.97, 95% CI = 0.94–1.01) but were significantly associated with a reduced risk of CVD death (RR = 0.92, 95% CI = 0.87–0.98) in the meta-analysis. The network meta-analysis found that all-cause mortality was significantly different between statin use and omega-3 supplementation for overall population (RR = 0.91, 95% CI = 0.85–0.98), but borderline for primary prevention and mixed population and nonsignificant for secondary prevention. Furthermore, there were borderline differences between statin use and omega-3 supplementation in CVD death in the total population (RR = 0.92, 95% CI = 0.82–1.04) and primary prevention (RR = 0.85, 95% CI = 0.68–1.05), but nonsignificant differences in secondary prevention (RR = 0.97, 95% CI = 0.66–1.43) and mixed population (RR = 0.92, 95% CI = 0.75–1.14). To summarize, statin use might be associated with a lower risk of all-cause mortality than omega-3 supplementation. Future direct comparisons between statin use and omega-3 supplementation are required to confirm the findings.

Trends in Cardiovascular Disease Morbidity and Mortality in American Indians Over 25 Years: The Strong Heart Study

Background American Indians experience high rates of cardiovascular disease. We evaluated whether cardiovascular disease incidence, mortality, and prevalence changed over 25 years among American Indians aged 30 to 85. Methods and Results The SHS (Strong Heart Study) and SHFS (Strong Heart Family Study) are prospective studies of cardiovascular disease in American Indians. Participants enrolled in 1989 to 1990 or 2000 to 2003 with birth years from 1915 to 1984 were followed for cardiovascular disease events through 2013. We used Poisson regression to analyze data for 5627 individuals aged 30 to 85 years during follow-up. Outcomes reflect change in age-specific cardiovascular disease incidence, mortality, and prevalence, stratified by sex. To illustrate generational change, 5-year relative risk compared most recent birth years for ages 45, 55, 65, and 75 to same-aged counterparts born 1 generation (23-25 years) earlier. At all ages, cardiovascular disease incidence was lower for people with more recent birth years. Cardiovascular disease mortality declined consistently among men, while prevalence declined among women. Generational comparisons were similar for women aged 45 to 75 (relative risk, 0.39-0.46), but among men magnitudes strengthened from age 45 to 75 (relative risk, 0.91-0.39). For cardiovascular disease mortality, risk was lower in the most recent versus the earliest birth years for women (relative risk, 0.56-0.83) and men (relative risk, 0.40-0.54), but results for women were inconclusive. Conclusions Cardiovascular disease incidence declined over a generation in an American Indian cohort. Mortality declined more for men, while prevalence declined more for women. These trends might reflect more improvement in case survival among men compared with women.