Background and objectives
The added cardiovascular risk conferred by risk factors or diseases accompanying hypertension has been investigated in Caucasian patients, and much less is known in Chinese patients. Furthermore, the residual risk persisting in hypertensive patients, despite blood pressure (BP) reduction, due to accompanying conditions has never been explored in Chinese, and whether they differ from Caucasians under this respect is unknown.
Felodipine Event Reduction (FEVER) study randomized 9711 Chinese hypertensive patients to more or less intense antihypertensive treatment for 40 months, with outcome monitoring. The present analyses provide information on the role that baseline presence of individual risk factors has in increasing outcome probability despite BP control. Risk ratios were calculated using Cox proportional hazard models, adjusted for a large number of baseline variables, except the one under examination, and also adjusted for on-treatment systolic and diastolic BP.
Male sex, older age, diabetes and cardiovascular disease were accompanied by a significantly higher incidence of cardiovascular events (risk ratios 1.41–1.86 according to risk factor), stroke (risk ratios 1.42–1.72), cardiac events (risk ratios 1.40–2.70), all-cause death (risk ratios 1.51–2.16) and cardiovascular death (risk ratios 1.61–2.02). Higher baseline systolic BP and smoking conferred a significantly increased risk of cardiovascular events and strokes. Higher cholesterol was not found to increase any cardiovascular outcome. The same was the case for electrocardiographic left-ventricular hypertrophy and isolated systolic hypertension.
A number of additional risk factors increased the residual risk of Chinese hypertensive patients despite effective antihypertensive treatment as much as described in Caucasians. High serum cholesterol was an exception: whether this is a Chinese characteristic or a more general phenomenon remains to be investigated.