Blood pressure and mortality among Chinese patients with cardiovascular disease

Objective To examine the association between blood pressure (BP) and mortality among patients with a history of cardiovascular disease (CVD) in China. Methods We conducted a prospective cohort study among 4195 CVD patients aged 40 years and older. Data on BP and covariables were obtained at a baseline examination in 1991 and follow- up evaluation was conducted in 1999 2000 using standard protocols. Results After adjustment for important covariables, a significant and linear relationship was observed between BP level and mortality from CVD and all-causes. For example, compared with those with a systolic BP less than 120 mmHg, patients with a systolic BP of 120 - 129, 130 139, 140 - 159, 160 - 179, and at least 180 mmHg had relative risks (95% confidence interval) of 1.28 (0.92, 1.78), 1.62 (1.19, 2.20), 2.09 (1.58, 2.77), 2.31 (1.73, 3.10), and 2.66 (2.01, 3.53) for CVD mortality, and 1.08 (0.84, 1.38), 1.26 (1.00, 1.60), 1.44 (1.17, 1.79), 1.57 (1.25, 1.96), and 1.86 (1.50, 2.30) for all- cause mortality (both P values < 0.0001 for linear trends), respectively. The relationship between BP and mortality was slightly stronger for systolic BP compared with diastolic BP or pulse pressure. Lowering BP to a normal level in hypertensive patients could prevent 55.5% of CVD mortality and 31.2% of all-cause mortality among individuals with a history of CVD. Conclusion These data indicate that there is a strong, independent, and positive association between BP and mortality among patients with a history of CVD. Furthermore, lowering of BP should be an important approach for preventing premature deaths in this population.