RESUMO
The study aimed to establish a relationship of ethnicity to diastolic dysfunction in subjects of African-Caribbean and South Asian origins and the impact of diastolic dysfunction and ethnicity on all-cause and cardiovascular mortality. Hypertensive subjects with ejection fraction ≥55% and no history of ischaemic heart disease/valve pathology (n = 1546, 830 South Asians and 716 African-Caribbeans) were identified from the Ethnic-Echocardiographic Heart of England Screening Study (E-ECHOES). Diastolic function and cardiac remodelling were measured by echocardiography. African-Caribbean ethnicity was associated with lower prevalence of having diastolic dysfunction (odds ratio 0.67, 95% confidence interval 0.51-0.87, p = 0.003) and increased left ventricular filling pressure (odds ratio 0.48, 95% confidence interval 0.34-0.69, p < 0.001) as well as lower left atrial index (p < 0.001). This was the case despite the fact that African-Caribbean ethnicity was independently associated with higher left ventricular mass index (p < 0.001). Ninety-two deaths (6%) occurred during 68 ± 21 months follow-up. On Cox regression analysis, South Asian ethnicity (p = 0.024) was predictive of all-cause death before adjustment for parameters of diastolic dysfunction, but it was no longer predictive of death after accounting for these variables. South Asian ethnicity is independently associated with worse parameters of diastolic function in hypertension, despite African-Caribbeans having more prominent hypertrophy.
Assuntos
Insuficiência Cardíaca Diastólica/etnologia , Hipertensão/complicações , Adulto , Idoso , Ásia Ocidental/etnologia , População Negra/estatística & dados numéricos , Estudos Transversais , Ecocardiografia , Feminino , Insuficiência Cardíaca Diastólica/diagnóstico por imagem , Insuficiência Cardíaca Diastólica/etiologia , Insuficiência Cardíaca Diastólica/mortalidade , Humanos , Jamaica/etnologia , Masculino , Pessoa de Meia-Idade , Prevalência , Reino Unido/epidemiologiaRESUMO
BACKGROUND: Endothelial dysfunction is implicated in the pathophysiological features of heart failure (HF), and ethnic differences in the presentation of cardiovascular disease are evident, with an excess seen among South Asians (SAs). However, data on ethnic differences in endothelial function in HF are limited. METHODS AND RESULTS: In a cross-sectional study, we recruited 128 subjects with systolic HF: 50 SAs, 50 whites, and 28 African Caribbeans (ACs). In addition, SAs with systolic HF were compared with 40 SAs with coronary artery disease without HF ("disease controls") and 40 SA healthy controls. Macrovascular endothelial function was assessed by measurement of flow-mediated dilation (FMD) in response to hyperemia, arterial stiffness was assessed by the pulse-wave velocity, and microvascular endothelial function was assessed by forearm laser Doppler flowmetry. CD144-expressing endothelial microparticles were measured by flow cytometry. When compared with disease controls and healthy controls, SAs with HF had an impaired microvascular response to acetylcholine (P=0.001) and reduced FMD (P<0.001). In comparing ethnic groups, SAs with HF had an impaired response to acetylcholine (123±95.5%) compared with whites (258±156%) and ACs (286±173%, P<0.001 for both). Whites had a higher FMD (8.49±4.63%) than SAs (4.76±4.78%, P<0.001) and ACs (4.55±3.56%, P=0.01). No difference in endothelial-independent response was observed between study groups or in pulse-wave velocity. Ethnicity remained associated with microvascular endothelial function even after adjustment for age, presence of hypertension and diabetes mellitus, blood pressure, and glucose levels (P=0.003). There were no differences in numbers of endothelial microparticles. CONCLUSIONS: The SAs with HF have impaired microvascular and macrovascular endothelial function but preserved arterial elastic properties. Significant ethnic differences in endothelial function are evident in subjects with HF, with ethnicity being associated with microvascular endothelial dysfunction in this disorder.