Hypertension and clusters of risk factors in different stroke subtypes (an analysis of Hungarian patients via Budapest Stroke Data Bank)

Our aim was to determine the frequency of hypertension in the Hungarian stroke population, and to compare it with the data of other stroke registries. We attempted to find characteristic cluster-like associations between hypertension and another nine risk factors in different stroke subtypes and to ascertain the role of hypertension in leukoaraiosis, in early mortality, in stroke recurrence and in the case fatality rate up to 10 years. Risk factor profile of 500 unselected acute stroke cases of the Budapest Stroke Data Bank were analysed. We compared data of hypertensive stroke patients to those of unaffected ones. LIFEREG procedure of the SAS software package, cluster analysis, logistic regression, Pearson's correlation coefficient and Student's t-test were used as statistical methods. Hypertension was documented in 75% of the patients. The largest clusters were formed by the following groups: atherosclerotic stroke, hypertension with ischaemic heart disease; lacunar stroke and haemorrhage, hypertension with elevated serum cholesterol, cardiogenic embolism, ischaemic heart disease with atrial fibrillation. The case fatality rate was significantly higher in the group of hypertensive patients with ischaemic heart disease relative to those without it during the 10 years follow-up period. In the leukoaraiosis-group, systolic blood pressure was significantly higher than in the non-leukoaraiosis group. The rate of hypertension was higher than in other stroke registries. Hypertension appears to be the most frequent risk factor in stroke patients but case fatality rate is determined by presence or absence of ischaemic heart disease.