Blood Pressure Trajectories and the Risk of Intracerebral Hemorrhage and Cerebral Infarction: A Prospective Study.

The association between long-term blood pressure (BP) patterns in community-dwelling adults and risk of intracerebral hemorrhage and cerebral infarction is not well characterized. This prospective study included 79 385 participants, free of stroke, myocardial infarction, and cancer in or before 2010 (baseline). Systolic BP trajectories were identified using latent mixture modeling with data from 2006, 2008, and 2010. Incident cases of intracerebral hemorrhage and cerebral infarction occurred during 2010 to 2014, confirmed by review of medical records, by 3 physicians. We identified 5 distinct systolic BP trajectories during 2006 to 2010. Each of the trajectories was labeled according to their BP range and pattern over time: normotensive-stable (n=26 740), prehypertension-stable (n=35 674), stage 1 hypertension-increasing (n=8215), stage 1 hypertension-decreasing (n=6422), and stage 2 hypertension-stable (n=2334). We documented 1034 incident cases of cerebral infarction and 187 cases of intracerebral hemorrhage. Although the prehypertension-stable trajectory exhibited systolic BP range within the normal range (120-140 mm Hg) during 2006 to 2010, this group had higher stroke risk relative to the normotensive-stable group (<120 mm Hg) (adjusted hazard ratio was 3.11 for intracerebral hemorrhage and 1.99 for cerebral infarction; P<0.001 for both), after adjusting for possible confounders. Individuals in the stage 2 hypertension-stable systolic BP trajectory (175-179 mm Hg) had the highest risk of intracerebral hemorrhage (adjusted hazard ratio was 12.4) and cerebral infarction (adjusted hazard ratio was 5.07), relative to the normotensive-stable group (P<0.001 for both). BP trajectories were associated with the risk of stroke and increasing BP trajectories within the currently designated normal range may still increase the risk for stroke.