Objectives To assess the estimated 10-year risk of stroke among hypertensive outpatients in China and to analyse the risk of stroke related to different combinations of risk factors.
Methods A multi-centre cross-sectional study was conducted from October 2011 to June 2012. Hypertensive outpatients were recruited from 36 tertiary hospitals in 23 provinces or municipalities of China. Subjects who were under the acute stage of a stroke event, or had a history of stroke, or refused to sign the inform consent were excluded. Data on age, gender, blood pressure (BP), current smoking status, and the history of diabetes, cardiovascular disease (CVD), atrial fibrillation (AF), left ventricular hypertrophy (LVH) and the medications of antihypertensive drugs were collected. The 10-year probability of stroke was determined by the Framingham stroke risk profile (FSRP). A total of 97185 outpatients were included in the final analysis.
Results (1) Of all hypertensive outpatients, the average BP was 140.0 ± 19.0 mmHg. Among them, 16.5% had diabetes, 6.0% atrial fibrillation, 8.7% left ventricular hypertrophy and 44.3% accompanying cardiovascular diseases. (2) The age-adjusted 10-year risk of stroke was 13.1%, and 15.7% in men, which was higher than that in women (10.6%). 62.4% of the male patients were categorised into the high risk group, compared with 34% of the females. (3) The risk of stroke increased with the number of risk factors. Among patients with only 1 risk factor, men with LVH and women with AF presented the highest risk of stroke (19.4%, 22.6% respectively). Among those with 2 risk factors, men with LVH and AF and women with AF and diabetes had significantly higher 10-year stroke risk (32.7%, 39.2% respectively). As for those with 23 risk factors, the combination of CVD history, LVH and AF was found to be associated with the highest risk both in men and women (48.2%, 51.4% respectively).
Conclusions The combination of risk factors besides BP significantly affects the 10-year risk of stroke in hypertensive outpatients. Beyond the control of BP, management of other risk factors also needs to be addressed for hypertensive outpatients, an important target population for the primary prevention of stroke. Effective managements aiming at these high risk patients will be helpful to reduce the incidence of stroke in the population.