Low prevalence of atrial fibrillation in Amerindians: a population-based study in frequent fish consumers living in rural coastal Ecuador (The Atahualpa Project).

BACKGROUND: Information on the burden of atrial fibrillation (AF) in rural areas of developing countries is limited. Here, we aimed to assess AF prevalence in community-dwelling older adults living in rural Ecuador. METHODS: Atahualpa residents aged ≥60 years (mean age 70.5 ± 8.1 years) underwent 24-h Holter monitoring. Participants belong to the Amerindian ethnic group. The mean height in the study population was 147.9 ± 8.9 cm. Oily fish was a major source of food (mean intake: 8 ± 4 servings/week). RESULTS: Seven of 298 participants (2.3%) had AF. Persons with AF were older than those without (p = 0.051), but there were no differences in cardiovascular risk factors across groups. None of the seven AF cases had been detected in routine 12-lead ECGs taken at enrollment. CONCLUSIONS: Prevalence of AF in older Amerindians living in rural Ecuador is low. Both, racially-determined short stature and frequent dietary oily fish intake might explain the low prevalence of AF in this rural setting.

Hypertensive retinopathy and cerebral small vessel disease in Amerindians living in rural Ecuador: The Atahualpa Project.

BACKGROUND: Diagnosis of cerebral small vessel disease (SVD) is a challenge in remote areas where MRI is not available. Hypertensive retinopathy (HTRP) has shown to correlate with SVD in different ethnic groups, but there is no information from indigenous Latin American people. We assessed the usefulness of retinal photographs to detect cases with SVD among Amerindians living in rural Ecuador. METHODS: Atahualpa residents aged ≥60years with arterial hypertension or prehypertension were identified during a door-to-door survey. A confocal line scanning laser ophthalmoscope was used to identify and grade HTRP (according to the Keith-Wagener-Barker classification). MRIs were read with attention to the presence of white matter hyperintensities (WMH) of presumed vascular origin and lacunar infarcts. Using logistic regression models, we evaluated whether HTRP was independently associated with neuroimaging signatures of SVD. RESULTS: Of 323 eligible candidates, 241 (75%) were enrolled. MRI readings revealed moderate-to-severe WMH in 49 (20%) cases and lacunar infarcts in 29 (12%). HTRP Grade 1 was noticed in 90 (37%) individuals and Grade 2-3 in 42 (17%). After adjusting for demographics and cardiovascular risk factors, multivariate analyses showed a significant association between Grades 2-3 HTRP and moderate-to-severe WMH (OR: 3.87, 95% C.I.: 1.64-9.13) but not with lacunar infarcts (OR: 2.22, 95% C.I.: 0.83-5.92). CONCLUSION: Amerindians with HTRP Grades 2-3 are almost four times more likely to have SVD-related subcortical damage than those with no- or only Grade 1-HTRP. Retinal photographs might allow recognition of people who need further investigation and therapy.