Racial variation in cardiovascular morbidity and mortality in essential hypertension

Objectives-To perform a longitudinal comparison of morbidity and mortality among white, south Asian and Afro-Caribbean hypertensive patients in relati on to baseline demographic characteristics and clinic and ambulatory blood pressure variables. Design-Observational follow up study. Setting-District general hospital and community setting in Harrow, England. Patients-528 white, 106 south Asian, and 54 Afro-Caribbean subjects with es sential hypertension who had undergone 24 hour ambulatory intra-arterial bl ood pressure monitoring. Interventions-Follow up for assessment of all cause morbidity and mortality over a mean (SD) of 9.2 (4.1) years. Main outcome measures-Non-cardiovascular death, coronary death, cerebrovasc ular death, peripheral vascular death, non-fatal myocardial infarction, non -fatal stroke, coronary revascularisation. Results-South Asians had the highest all cause event rate of 3.46, compared with 2.50 (NS) and 0.90 (p = 0.002) events/100 patient-years for whites an d Afro-Caribbeans, respectively. This was because of an excess of coronary events (2.86 v 1.32 events/100 patient-years in south Asians v whites, resp ectively; p = 0.002). Age (p < 0.001), sex (p < 0.001), race (south Asians :whites, hazard ratio 1.79; p = 0.008), diabetes (p = 0.05), previous histo ry of cardiovascular disease (p < 0.001), and 24 hour ambulatory systolic b lood pressure (p = 0.006) were independent predictors of time to a first ev ent. Clinic blood pressure did not provide additional prognostic informatio n. Conclusions-South Asian origin was an independent predictor of all cause ev ents, mainly because of an excess of coronary events in this group. Ambulat ory but not clinic blood pressure was of additional value in predicting sub sequent morbidity and mortality.