1Fu Wai Hospital, CAMS & PUMC, Beijing, China
2Clinical Trials and Research Center, Beijing Hypertension League Institute, Beijing, China
3Istituto Auxologico Italiano and Centro di Fisiologia Clinica e Ipertensione, University of Milan, Milan, Italy
Background and Objectives: The added cardiovascular risk conferred by risk factors or diseases accompanying hypertension has been investigated in Caucasian subjects, and much less is known in Chinese patients. Furthermore, the residual risk persisting in hypertensives, despite blood pressure (BP) reduction, due to accompanying conditions has never been explored in Chinese, and whether they differ from Caucasian under this respect is unknown.
Methods: FEVER randomized 9711 Chinese hypertensives to more or less intensive antihypertensives 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 (RR) 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 (SBP) and diastolic blood pressures (DBP).
Results: Male gender, older age, diabetes and cardiovascular disease were accompanied by a significantly higher incidence of cardiovascular events (RR 1.41 to 1.86 according to risk factor), stroke (RR 1.42 to 1.76), cardiac events (RR 1.34 C 2.70), cardiovascular death (RR 1.62 C 2.16) and all cause death (RR 1.61 C 2.02). Higher baseline SBP 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.
Conclusions: A number of additional risk factors increased the residual risk of Chinese hypertensives under effective antihypertensive treatment as much as described in Caucasian. High serum cholesterol was an exception: whether this is a Chinese characteristics or a more general phenomenon remains to be investigated. Absence of significant added risk in patients with isolated systolic hypertension defined as SBP > 140 and DBP < 90 mmHg, suggests this usual definition is inadequate to identify hypertensive patients complicated by significantly increased arterial stiffness.