ObjectiveTo establish a diagnostic system for heat toxin syndrome of acute cerebral infarction. Based on this toxin syndrome diagnostic system, the general principles of heat toxin development will be uncovered, and the critical turning point at which the heat toxin syndrome occurs will also be explored. MethodsIn this study, a total of 271 hypertension patients with cerebral infarction within 72 h were recruited from the Affiliated Dongfang Hospital of the Beijing University of Chinese Medicine, the Affiliated Dongzhimen Hospital of Beijing University of Chinese Medicine, the Affiliated Renmin Hospital of Peking University, the Second Affiliated Hospital of Tianjin University of Traditional Chinese Medicine, the Affiliated Hospital of Shandong University of Traditional Chinese Medicine, the Affiliated Hospital of Changchun University of Traditional Chinese Medicine, the Affiliated Hospital of Hebei University of Traditional Chinese Medicine and China Meitan General Hospital from August, 2008, to December, 2009. The patients' Chinese medical information was recorded on days 1, 3, 5, 7, and 14 during their hospitalizations. The medical records were recorded according to traditional Chinese medicine (TCM) theory and included the serum marker levels at the beginning and at the end of the trial. The time line was also analyzed. ResultsThe level of Hs-CRP, PAG, NSE, OX-LDL, and MMP-9 were abnormal and, were higher in CI patients compared to hypertension patients. In the study of the heat toxin diagnosis system, according to the entropy clustering results, 30 combinations of the medical information can be sorted into the traditional syndromes, but 13 combinations cannot be sorted. To obtain more precise symptoms related to the heat toxins, a logistic regression equation was set up with the variables from the unsorted medical information; the dependent variables were fever and BP fluctuation. Weighted variables were obtained. MLP analysis demonstrated that the diagnosis model was stable and precise. The accuracy reached 83.82%. The ROC test showed that seven points of the diagnosis system was the best cutting point, with a sensitivity of 0.857 and a specificity of 0.955. Progressing stroke was related to heat toxin syndrome. When the turning point appeared, the combination of symptoms, such as coma, aphasia, gummy eyes, and halitosis, predicted the deterioration or recovery of CI. The heat toxin syndrome existed in every subtype of CI; however, the observed heat toxin levels were highest in PACI and lowest in LACI. Meanwhile, blood and sputum stasis syndromes transformed into heat toxicity were one source of heat toxin syndrome. ConclusionHeat toxin syndrome, as well as qi/blood/sputum stasis, co-existed in the CI patients, and the transformation frequently appeared during the process. Three to five days after the onset of CI was the turning point, at which time several combinations of medical indicators make it possible to predict the development of CI.