Analysis Of Hemorrhagic Risk Factors Resulted From Warfarin Therapy Following Mechanical Heart Valve Replacement In Elderly Patients

Objective:Observing the occurrence of hemorrhagic complications and related Clinical characteristics in elderly patients who underwent artificial heart mechanical valve replacement surgery and keep a long-term anticoagulant therapy with warfarin.To find out the risk factors of hemorrhage resulted from anticoagulant.Finally we hope to provide some clinical experience for the elderly patients with making a better individualized anticoagulant therapy regimens of warfarin and improve medication safety and efficacy.Methods:A retrospective analysis of the medical records was conducted.From January 2009 to May 2016,we included 97 patients aged over 65 years old who had underwent artificial heart mechanical valve replacement surgery in the cardiothoracic surgery department in our hospital and keep a long-term anticoagulation therapy with warfarin.The patients were all followed up by telephone or in the outpatient department.We Collected the basic information such as age,sex,weight and the position of valve replaced,symptoms and signs of heart failure,atrial fibrillation,diabetes,hypertension or using of antihypertensive drugs and diabetes medicines,dose of oral warfarin,value of the INR range and other basic information.Record the occurrence of adverse events such as bleeding or thromboembolism and the value of the INR,weight,symptoms and signs of heart failure when it happens.According to whether bleeding occurred or not during follow-up,patients were divided into bleeding group and non-bleeding group.The differences in clinical characteristics between the two groups were compared.Logistic multiple regression analysis was used to explore the risk factors of hemorrhage.Results:A total of 89 patients were accomplished the followed up with a follow-up rate of 91.7%.The median follow-up time of was 16.4(10.5-22)months.A total of 563 cases were followed up.No thrombosis and cranial embolism event occurred during the follow-up period.A total of 21 patients with bleeding symptoms during the follow-up period.There are 20 cases of slight bleeding which contains 10 cases of repeated skin ecchymosis,2 cases of conjunctival hemorrhage,4 cases of gingival bleeding,4 cases of epistaxis.Only one patient suffered with severe bleeding complication.The dose of warfarin in the follow-up period is 2.77±0.49 mg per day and the value of actual controlled INR value was 2.36±0.21.At the first follow-up,there were 78 cases INR values within the ideal range with 9 cases exceeding the ideal range and 2 cases below the ideal range.During the follow-up,there were 30 patients with symptoms or signs of heart failure,15 patients with hypertension or taking antihypertensive drugs,13 patients with diabetes,and 5 patients with a history of stroke.Finally there were 21 patients in the bleeding group(including slight bleeding)and 68 patients in the non-bleeding group.There was no significant difference in age,gender,weight,position of the valve replaced,hypertension,atrial fibrillation and diabetes between the two groups.The value of INR was 2.67±0.34 in the bleeding group and was 2.26±0.23 in the non-bleeding group.The difference between the two groups was statistically significant(P<0.05).The proportion of patients with heart failure was 54.3%in the bleeding group and 31.5%in the non-bleeding group.The difference between the two groups was statistically significant(P<0.05).Logistic multiple regression analysis shows that only INR was positively correlated with the risk of bleeding(OR=3.248,95%CI:2.793-4.246,P<0.05)Conclusion:The investigation and research has found that the risk of hemorrhage is significantly higher than embolism during anticoagulant therapy after cardiac mechanical valve replacement in the elder patient when the INR was controlled within 1.8-2.5.Therefore,the hemorrhage is the major complication that threaten the patient's health.The increased intensity of anticoagulation is an independent risk factor of hemorrhage.The elderly patients should be strengthen in the monitoring of anticoagulant treatment.Heart failure may be an important cause of increasing the intensity of anticoagulant therapy with warfarin and eventually leading to bleeding.In order to reduce the occurrence of hemorrhage complication and improve the safety of medication,the ideal INR value for elderly patients should be adjusted under 2.5.