Database: thrombosis_prediction
Question: For the patients whose total cholesterol is higher than normal, how many of them have a negative measure of degree of coagulation?
SQL: SELECT COUNT(T1.ID) FROM Patient AS T1 INNER JOIN Laboratory AS T2 ON T1.ID = T2.ID INNER JOIN Examination AS T3 ON T1.ID = T3.ID WHERE T2.`T-CHO` >= 250 AND T3.KCT = '-'