Background and purpose: The prevalence of hypertension (HT) does not explain the relatively high incidence of hemorrhagic stroke in Korea and other Asian countries, and whether HT has a greater impact on development of the intracerebral hemorrhage (ICH) than cerebral infarction (CI) remains unclear. It may be speculated that the adequacy of HT control is related to the subtype differences. The present study was aimed to elucidate (1) whether various risk factors exert a different impact on stroke subtypes and (2) whether the adequacy of HT control in patients with a previous history of HT is related to different subtypes in stroke patients from southern Seoul, Korea.
Methods: We prospectively studied 602 consecutive patients with acute stroke (CI and ICH) admitted to the Asan Medical Center and analyzed their stroke subtypes and risk factors. The mode of HT treatment before the stroke onset was specifically asked. We examined whether various risk factors were related to subtype differences in these patients. We also attempted, in patients with a prior history of HT, to see whether the mode of HT control was related to the subtype differences.
Results: 75.8% of the patients had CI (large vessel infarction 33.8%, small vessel infarction 22.1%) and 24.2% had ICH; 75% of the patients had HT of whom the presence of HT was previously unidentified in 8%. Previous treatment of HT was considered adequate in 32.4% and inadequate in the others. On multiple logistic analysis, diabetes mellitus and alcohol drinking were independently related to CI (v ICH), whereas HT did not favor any stroke subtypes. However, in patients with a prior history of HT, previous mode of HT control was a significant factor related to subtype differences in a way that inadequate treatment favored ICH. There were no specific risk factors that independently discriminate large vessel infarction versus small vessel infarction.
Conclusions: Apparently, HT was not a risk factor that preferentially favors any specific stroke subtypes in patients from southern Seoul. However, in patients with HT, previous mode of HT control was an important factor influencing the subtypes. Inadequate treatment of HT may play a role, at least in part, on the relatively prevalent ICH and hence the greater significance of stroke as a cause of death in Korea compared with Western countries.