Incidence of cardiovascular events in white-coat, masked and sustained hypertension versus true normotension: a meta-analysis

Objective To perform a meta-analysis on the incidence of cardiovascular events in white-coat hypertension (WCHT), masked and sustained hypertension in comparison with true normotension. Methods We searched for individual studies, in which the adjusted relative risk of incident cardiovascular events was assessed in patients with WCHT, masked and sustained hypertension versus normotension in the same study population. For each type of hypertension, the weighted overall hazard ratio (HR) and 95% confidence intervals (CO were calculated. Results Seven studies were identified, involving a total of 11502 participants. Four studies were performed in the population, two in primary care and one in specialist care. Two studies were exclusively on treated hypertensive patients; individuals on anti hypertensive treatment were included in all the other studies except one. Cut-off blood pressure was 140/90 mmHg for off ice blood pressure in all studies and 135/85 mmHg (83 in one study) for out-of-office blood pressure. The average age of the study populations was 63 years; 53% were men. The endpoint consisted of cardiovascular death in one study and of various aggregates of fatal and non-fatal cardiovascular events in the others. During an average follow-up of 8.0 years, there were 912 first cardiovascular events. The overall adjusted H R versus normotension was 1.12 (95% Cl 0.84 -1.50) for WCHT (P = 0.59), 2.00 (1.58 - 2.52) for masked hypertension (P<0.001), and 2.28 (1-87-2.78) for sustained hypertension (P<0.001). Conclusion The meta-analysis indicates that the incidence of cardiovascular events is not significantly different between WCHT and true normotension, whereas the outcome is worse in patients with masked or sustained hypertension.