ABSTRACT
BACKGROUND: Patients with a mechanical prosthetic heart valve implantation need to be treated with a vitamin K antagonist (VKA) due to a substantially high risk of thromboembolism. In this study we report data on patients with mechanical heart valves (MV), with the aim of evaluating the thromboembolic risk in relation to the type and site of implantation, quality of anticoagulation and risk factors associated with thromboembolism. METHODS: Observational retrospective multicenter study among Centers affiliated to the Italian Federation of Anticoagulation Clinics (FCSA) on patients with MV implanted after 1990 and followed for the management of anticoagulation. RESULTS: We analyzed 2357 patients with mechanical heart valves (55.2% males), followed for 24,081â¯years. During the follow-up, 164 thromboembolic events (0.67/100â¯pt-yrs) and 243 major bleedings (1.0/100â¯pt-yrs) occurred. The median Time in Therapeutic Range (TTR), calculated in all intended INR classes, was 60% (IQR 47-74%). The rates of thrombotic events were significantly higher in patients intended to stay at therapeutic ranges >INR 2.0-3.0. The presence of atrial fibrillation, history of thromboembolism and of mitral prosthesis were independently associated with thromboembolism. However, a bad quality of anticoagulation (TTR <47%, 25°percentile of our population) was not correlated with thromboembolism. CONCLUSIONS: A low rate of bleeding and thromboembolic events in patients with mechanical heart valves were found, despite the sub-optimal anticoagulation control. The thromboembolic risk was not associated with the low TTR.
Subject(s)
Blood Coagulation/drug effects , Heart Valve Prosthesis Implantation , Hemorrhage , Postoperative Complications , Thromboembolism , Warfarin , Aged , Anticoagulants/administration & dosage , Anticoagulants/adverse effects , Drug Monitoring/methods , Female , Heart Valve Prosthesis , Heart Valve Prosthesis Implantation/adverse effects , Heart Valve Prosthesis Implantation/instrumentation , Heart Valve Prosthesis Implantation/methods , Hemorrhage/chemically induced , Hemorrhage/epidemiology , Hemorrhage/prevention & control , Humans , International Normalized Ratio , Italy/epidemiology , Male , Middle Aged , Outcome Assessment, Health Care , Platelet Aggregation Inhibitors/administration & dosage , Platelet Aggregation Inhibitors/adverse effects , Postoperative Complications/diagnosis , Postoperative Complications/etiology , Postoperative Complications/prevention & control , Retrospective Studies , Risk Factors , Thromboembolism/diagnosis , Thromboembolism/epidemiology , Thromboembolism/etiology , Thromboembolism/prevention & control , Warfarin/administration & dosage , Warfarin/adverse effectsABSTRACT
It is generally recommended that patients with splanchnic vein thrombosis (SVT) should receive a minimum of 3 months of anticoagulant treatment. However, little information is available on the long-term risk of recurrent thrombotic events. The aim of this study was to evaluate the risk of venous and arterial thrombosis after discontinuation of vitamin K antagonist (VKA) in SVT patients. Retrospective information from a cohort of SVT patients treated with VKA and followed by 37 Italian Anticoagulation Clinics, up to June 2013, was collected. Only patients who discontinued VKA and did not receive any other anticoagulant drug were enrolled in this study. Thrombotic events during follow-up were centrally adjudicated. Ninety patients were included: 33 unprovoked SVT, 27 SVT secondary to transient risk factors, and 30 with permanent risk factors. During a median follow-up of 1.6 years, 6 venous and 1 arterial thrombosis were documented, for an incidence of 3.3/100 patient-years (pt-y). The recurrence rate was highest in the first year after VKA discontinuation (8.2/100'pt-y) and in patients with permanent risk factors (10.2/100'pt-y). Liver cirrhosis significantly increased the risk of recurrence. In conclusion, the rate of recurrent vascular complications after SVT is not negligible, at least in some patient subgroups.
