The Significance Of Blood Pressure For The Development Of Hemorrhagic Transformation In Acute Middle Cerebral Artery Occlusion

[Objective]To investigate the relationship between blood pressure and the development of HT in massive cerebral infarction caused by cardioembolic middle cerebral artery occlusion (MCAO).[Methods]A retrospective investigation was conducted in146patients hospitalized within24h of the onset of acute massive cerebral infarction caused by unilateral cardioembolic MCAO and showed no HT on initial CT or MR scan. Patients were divided into two groups according to the follow-up CT or MR within7d of onset:HT group and no-HT group. Analysis was carried out to compare the relationship between the two groups of BP characteristic parameters. BP characteristic parameters of each patient were described using various summary parameters: maximum (max), minimum (min), range (max-min), average (mean), SD, average squared difference between successive measurements (sv), and maximum sv (svmax).[Results]Among all the427patients with acute massive cerebral infarction,389cases met the diagnosis of cardio-embolic MCAO. From these389patients,321cases were admitted within24hours of symptom onset. Then a number of patients were excluded because of the following causes:26who showed HT on an initial CT or MR scan,22who had previous stroke and left with sequelae,57who died or discharged within72hours of admission,19had no follow-up imagines,6who had inadequate BP (<9BP measurements during the first72hours), and45received thrombolysis or had other severe organic diseases. As a result,146patients enrolled our study. Follow-up images (CT or MR) revealed HT in52.7%(77/146).Among characteristic BP parameters categorized into quartiles, SBPmax, SBPmin, SBPmax-min, SBPsv, SBPsvmax, DBPinitial, DBPsd, DBPmax, DBPmin, DBPmax-min and DBPsv、DBPsvmax were associated with HT after acute massive cerebral infarction caused by cardioembolic MCAO independent of age, interval from onset to arrival, NIHSS score at admission, antiplatelet therapy, initial serum glucose, INR and PT (P<0.05on likelihood ratio test of trend). Most of the BP parameters showed a significant association with the development of HT except SBPinitial, SBPmean, SBPsd, DBPmean and DBPsvmax. Development of HT was more frequent in the high variability groups than the low variability groups consistently for most of variability parameters (SBPmax-min, SBPsd, SBPsvmax, DBPmax-min, DBPsd, DBPsv).[Conclusions]High BP level and Large BP fluctuations contribute to the development of HT after acute massive cerebral infarction caused by cardioembolic MCAO. For these patients, we should lower the blood pressure slowly and smoothly.