long term use of chronic oral anticoagulants can be complicated by anticoagulation associated intracranial hemorrhage ( aaich ) , the most devastating complication of anticoagulant therapy . among patients who received anticoagulant for management of thromboembolic problems , intracranial hemorrhages led to approximately 90% of deaths and major disability in survivors5 ) . rapid reversal is essential for prevention of enlargement of the aaich , which could result in brain herniation . on the other hand , reversal and discontinuance of anticoagulant can result in development of several kinds of side effects , such as thromboembolic complication . the risk and incidence of thromboembolic complication after cessation of anticoagulation in korean society have not been accurately reported ; in addition , there is no consensus regarding the proper period for withholding anticoagulant in the case of these patients . based on results of other studies , discontinuation for seven to 10 days appears to be safe2 ) . however , this has limitation as a proper guideline because these data were reported from small western retrospective series3,6,11 ) . in this study , we discussed reasonable access for management of patients with aaich who are at a high thromboembolic risk in the view of using an anticoagulant . from january 2008 to december 2012 , 47 patients with warfarin associated intracranial hemorrhage were admitted to a single neurological institution . eleven patients ( 23.4% ) died due to an initial massive hematoma and were excluded from this study . of the remaining 36 patients , 19 patients were not restarted with anticoagulant due to high risk of rebleeding and 17 patients were restarted with anticoagulant at a different time depending on each patient 's condition . restarting of drug was decided after consultation with the doctor who treated the patients due to the underlying disease . however , they did not give a clear answer regarding when the drug should be restarted after hemorrhage . if the rebleeding risk was greater than the thromboembolic risk , anticoagulants were not restarted . for these reasons , underlying disease to get oral anticoagulant , presenting hemorrhage type , thromboembolic risk factors , event day international normalized ratio ( inr ) , prothrombin time ( pt ) , and thromboembolic complication after cessation of anticoagulation were investigated . data analysis was performed retrospectively using the statistical package for the social sciences ( spss ) version 20.0 ( spss inc . , descriptive statistics were performed for determination of the influence of clinical factors on development of thromboembolic events in the non - restarted anticoagulant group . the kaplan - meier method was used to assess the incidence and probability of thromboembolic events in patients with passage of time . we need to identify the exact degree of thromboembolic risk in the patients ' group in order to obtain objective validity when comparing the results with those of other authors . in this study the cha2ds2-vasc [ congestive heart failure / left ventricular dysfunction , hypertension , age 75 ( double ) , diabetes , stroke ( double)-vascular disease , age 65 - 74 , and sex category ( female ) ] has been used in multiple cohorts and is better at identifying patients with true risk . the score is inclusive of the most common risk factors for stroke in everyday clinical practice4,8 ) . from january 2008 to december 2012 , 47 patients with warfarin associated intracranial hemorrhage were admitted to a single neurological institution . eleven patients ( 23.4% ) died due to an initial massive hematoma and were excluded from this study . of the remaining 36 patients , 19 patients were not restarted with anticoagulant due to high risk of rebleeding and 17 patients were restarted with anticoagulant at a different time depending on each patient 's condition . restarting of drug was decided after consultation with the doctor who treated the patients due to the underlying disease . however , they did not give a clear answer regarding when the drug should be restarted after hemorrhage . if the rebleeding risk was greater than the thromboembolic risk , anticoagulants were not restarted . for these reasons , underlying disease to get oral anticoagulant , presenting hemorrhage type , thromboembolic risk factors , event day international normalized ratio ( inr ) , prothrombin time ( pt ) , and thromboembolic complication after cessation of anticoagulation were investigated . data analysis was performed retrospectively using the statistical package for the social sciences ( spss ) version 20.0 ( spss inc . , descriptive statistics were performed for determination of the influence of clinical factors on development of thromboembolic events in the non - restarted anticoagulant group . the kaplan - meier method was used to assess the incidence and probability of thromboembolic events in patients with passage of time . we need to identify the exact degree of thromboembolic risk in the patients ' group in order to obtain objective validity when comparing the results with those of other authors . in this study the cha2ds2-vasc [ congestive heart failure / left ventricular dysfunction , hypertension , age 75 ( double ) , diabetes , stroke ( double)-vascular disease , age 65 - 74 , and sex category ( female ) ] has been used in multiple cohorts and is better at identifying patients with true risk . the score is inclusive of the most common risk factors for stroke in everyday clinical practice4,8 ) . the demographic and clinical characteristics of 19 patients in whom anticoagulants were not started are shown in table 1 and 2 . the most common type of aaich was spontaneous hemorrhage , which presented in eight cases ( 42.1% ) . acute subdural hematoma was the next main type of aaich in five cases ( 21.1% ) . the mean discontinuance time of the anticoagulant was 475.79682.49 days ( range , 8 - 1813 days ) . there were eight cases ( 42.1% ) with thromboembolic complications , three of which ( 37.5% ) resulted in death . two deaths were caused by sudden cardiac arrest , which was suspected with acute myocardial infarction , and another patient died of pulmonary thromboembolism . among the survivors , deep venous thrombosis followed by intravenous filter insertion occurred in two cases and another two patients presented with angina pectoris . and non - fetal pulmonary embolism occurred in one case . mean time to occurrence of thromboembolic complication was 21.3814.89 days ( range , 8 - 56 days ) . the probabilities of having thromboembolic complications at 7 , 14 , and 30 days following cessation of warfarin therapy were 0.0% ( 95% confidence interval , 0.00 - 20.92% ) , 10.53% ( 95% confidence interval , 1.84 - 34.54% ) , and 38.49% ( 95% confidence interval , 18.42 - 62.85% ) , respectively ( fig . the inr showed a gradual decrease to the normal range , and then thromboembolic complications started to occur after a few days . from the result , we found that all thromboembolic complications and death occurred after seven days in all cases , and most of these thromboembolic complications tended to be concentrated between one and two weeks . this study provided the longest follow up data on discontinuance of anticoagulant in patients presenting with aaich who have been at high thromboembolic risk estimated by cha2ds2-vasc score in korean society . first , discontinuance of the anticoagulant is common in aaich patients in the actual clinical field . proper restart of warfarin treatment after aaich was not prescribed for almost half of patients ( 47.2% , 17/36 ) . aaich induced mortality is very high and survivors from initial neurological damage are faced with the decision of whether or not to restart anticoagulan3,5 ) . however , proper use of anticoagulant in patients with aaich has not yet been established , and guidelines could not be obtained from a limited number of previous retrospective series3,6,11 ) . according to american heart association recommendations , in patients with a very high risk of thromboembolism in whom restarting warfarin is considered , warfarin therapy may be restarted at seven to 10 days since onset of the original hemorrhage2 ) . in this study , the consensus of the resumption of anticoagulant in aaich patients is not clear in our institution . decisions regarding to the starting time of anticoagulant were differed significantly among physicians due to the fact . and available data for determination of the optimal timing and dosage for restarting anticoagulation following an episode of aaich are inadequate . second , in this study , short duration ( within 7 days ) discontinuance of anticoagulants was relatively safe , similar to the result of a previous study series . kawamata et al.7 ) found no cases of ischemic stroke when warfarin treatment was discontinued for three days in 27 patients with aaich . tinker et al.10 ) retrospectively reviewed the risk of discontinuing warfarin therapy in 159 patients with mechanical heart valves undergoing elective surgery ; none of the patients had in - hospital thromboembolic complications . ananthasubramaniam et al.1 ) also reported that no thromboembolic complications occurred in 24 patients with prosthetic heart valves after withholding anticoagulant for an average of 15 days . like these previous studies , in this study , there was also no occurrence of thromboembolic complications within seven days since aaich . although a temporary withdrawal of anticoagulants within seven days may be safe , prolonged cessation could lead to catastrophic results . we found that thromboembolic complications begin to occur after seven days and the incidence shows a rapid increase around 14 days later . however , additional events occurred after two weeks . overall occurrence of thromboembolic complications was 42.1% ( 8/19 ) , higher than that reported in previous series1 ) . first , the time for withdrawal of anticoagulant was long , compared to the previous reports . in previous studies1 ) , anticoagulant was restarted within at least two weeks after a hemorrhagic event . the inr in patients with thromboembolic complication showed a gradual reduction and it fell below the normal range on ictus days . because the thromboembolic risk was accumulated after cessation of anticoagulants , second , the patients belonged to a very high risk group for occurrence of thromboembolic events . the cha2ds2-vasc score has been used in multiple cohorts for measurement of severity and for better identification of patients with true risk4 ) . the score includes the most common risk factors related to stroke in everyday clinical practice . among patients with cha2ds2-vasc score=2 , the incidence of thromboembolic complication in one year is 2.69% and the rate increased by 3.20% at a score of 3 points . for prevention of thromboembolism , anticoagulants are recommended for patients with a score of more than 2 points9 ) . in this study , the cha2ds2-vasc score was more than 2 points for all patients ( 2 points in three cases , 3 points in five , and 4 and 5 points in one case each ) , indicating that the patient has a high underlying thromboembolic risk . otherwise , previous reports did not objectively demonstrate the patients ' underlying thromboembolic risk , causing difficulty in comparison and analysis of results between studies . the limitation of this study is the retrospective design with a very small number of cases . however , the incidence of patients who did not restart anticoagulation after aaich was very low . over the past five years discontinuance of anticoagulant within seven days presented a relatively low incidence of thromboembolic complications in patients with aaich at a high thromboembolic risk ( cha2ds2-vasc score > 2 ) , and withdrawal of more than seven days may increase the risk of devastating results . we think that short term discontinuance of anticoagulant limited within seven days appears to be safe in korean people . unfortunately , this study was conducted retrospectively in a small number of cases of aaich and has several limitations to understanding . for a more reasonable and acceptable guideline on the use of anticoagulant in patients with aaich , conduct of further studies will be required .