Relationship between blood pressure changes in acute phase of stroke and short-term prognosis in elderly patients

Objective To investigate the relationship between the blood pressure changes in acute phase of stroke in elderly patients and its prognosis at day 30.Methods A total of 275 consecutive elderly patients with stroke were documented from January 2008 to June 2010 using a retrospective cohort study.Among them,202 were cerebral infarction and 73 were intracerebral hemorrhage.Their blood pressures were continuously recorded at the first seven days.The prognosis of patients were evaluated at day 30 after onset of stroke.The patients were divided into 5 subgroups according to the mean systolic blood pressure (120-139,140-159,160-179,180-199,and 200 mm Hg) and the mean diastolic blood pressure ( 69,70-79,80-89,90-99,and 100 mm Hg) within 7 days in the acute phase of stroke.The modified Rankin scale ( mRS) scores and the National Institute of Health Stroke Scale (NIHSS) scores at admission and at day 30 were compared. Results ①Of the 275 patients,66 had poor prognosis,among them 22 were in the intracerebral hemorrhage group and 44 in the cerebral infarction group.There was no significant difference between the two groups (P = 0.200).As for the mean systolic blood pressure in the acute phase (within 7 days) for both groups and the different mean systolic blood pressures in 5 subgroups in patients with poor prognosis at day 30,there were significant differences for their prognosis( P 0.05).While the mean diastolic blood pressure within 7 days in the acute phase and the patients whose prognosis was poor,the prognostic comparison of the different mean diastolic blood pressures in all subgroups,except for 70 - 79 mm Hg and 80 - 89 mm Hg,there was no significant difference between the two groups (P 0.05),Comparing the prognosis,there were significant differences between all other groups (P 0.05).②When mean systolic blood pressure was 160-179 mm Hg,the mRS scores (median 2) and NIHSS scores ( median 7) were lower and prognosis was better at day 30 ( mRS median score 2, NIHSS median score 7) ;When mean diastolic blood pressure was above 100 mm Hg,the prognosis was poor.There were significant differences in mRS and NIHSS scores at day 30 among the groups with different mean diastolic blood pressure (P 0.05).The mean diastolic blood pressure between 70 and 90 mm Hg in the intracerebral hemorrhage group often indicated a better prognosis.The prognosis was even better when mean diastolic blood pressure under the 70 mm Hg in the cerebral infarction group.Conclusion The prognosis of the elderly patients with stroke is better at day 30 within 7 days after onset of stroke if their mean systolic blood pressure between 160 and 179 mm Hg.The mean diastolic blood pressure in acute phase of stroke may not predict the severity of disease,but it may reflect the outcome tendency of the patients at day 30.