Factor Xa Inhibitors for Patients after Mechanical Heart Valve Replacement?

Patients with a mechanical heart valve need a lifelong anticoagulation due to the increased risk of valve thrombosis and thrombo-embolism. Currently, vitamin K antagonists (VKA) are the only approved class of oral anticoagulants, but relevant interactions and side effects lead to a large number of patients not achieving the optimal therapeutic target international normalized ration (INR). Therefore, steady measurements of the INR are imperative to ensure potent anticoagulation within a distinctive range. Direct oral anticoagulants (DOACs) with newer agents could serve as a possible alternative to VKAs in this patient cohort. DOACs are approved for several indications, e.g., atrial fibrillation (AF). They only have a minor interaction potential, which is why monitoring is not needed. Thereby, DOACs improve the livability of patients in need of chronical anticoagulation compared with VKAs. In contrast to dual platelet inhibition using aspirin in combination with an ADP receptor antagonist and the direct thrombin inhibitor dabigatran, the oral factor Xa inhibitors apixaban and rivaroxaban show promising results according to current evidence. In small-scale studies, factor Xa inhibitors were able to prevent thrombosis and thrombo-embolic events in patients with mechanical heart valves. Finally, DOACs seem to represent a feasible treatment option in patients with mechanical heart valves, but further studies are needed to evaluate clinical safety. In addition to the ongoing PROACT Xa trial with apixaban in patients after aortic On-X valve implantation, studies in an all-comer collective with rivaroxaban could be promising.

Anticoagulation after Spontaneous Intraparenchymal Hemorrhage in Patients with Mechanical Heart Valves and Concomitant Atrial Fibrillation

Aim Patients with mechanical heart valves and coexisting atrial fibrillation (AFib-MHV) who suffer an intraparenchymal hemorrhage (IPH, defined as bleeding solely within the brain parenchyma and/or ventricle) are at a high risk of thromboembolism without anticoagulation. Data are lacking regarding the safety of early re-initiation of anticoagulation in these patients. Patients and Methods We performed a descriptive, single-institution retrospective analysis of patients with AFib-MHV who suffered a non-traumatic, supratentorial IPH between July 2013 and June 2017. We analyzed the patients and IPH characteristics, anticoagulation and antiplatelet use, the occurrence of thrombotic and hemorrhage complications, and discharge disposition. We described the timing of initiation of anticoagulation and outcomes after IPH while in-patient. Results Six patients with AFib-MHV suffered a spontaneous IPH. Four were initiated on anticoagulation prior to discharge, of whom two were initiated within 3 days post-hemorrhage. These patients suffered no bleeding complications and were discharged home with a modified Rankin Scale of 1. Conclusion Patients with AFib-MHV who suffer a spontaneous IPH are a rare population to study. Further studies to guide the management of restarting anticoagulation in this select population are warranted.

Outcomes of leadless pacemaker implantation in patients with mechanical heart valves

Introduction Device-related infections constitute a major complication of transvenous pacemaker implantation. Mechanical heart valves (MHV) increase the risk of infective endocarditis (IE) and pacemaker infection, worsening their outcomes.Leadless pacemakers (LP) have been associated with low infection rates and thus pose an attractive option in MHV patients requiring permanent pacing. Methods and results This is a multicenter, observational, retrospective study including all consecutive patients implanted with an LP at 5 tertiary referral centers between June 2015 and January 2020.Procedural outcomes, complications, performance during follow-up and episodes of bacteremia and IE were recorded and compared between patients with and without a MHV (MHV and non-MHV groups).Four hundred fifty-nine patients were included (74 in the MHV group, 16.1%, and 385 in the non-MHV group, 83.9%).Implantation success, procedural outcomes and acute electrical performance were comparable between groups.Vascular complications and cardiac perforation occurred in 2.7 vs. 2.3% (p=1) and 0% vs. 0.8% (p=1) in the MHV group and non-MHV group, respectively.During a median post-implant follow-up of 308 days for the MHV group and 416 days for non-MHV patients (p=0.029), one case of IE was reported in the MHV group and 2 in the non-MHV group. All three occurred in patients with abandoned transvenous leads. Conclusion LP implantation is feasible and safe in patients with MHV, with procedural outcomes and electrical performance comparable to the general LP population. Device-related infections, including IE, are rare in patients receiving an LP, including those with an MHV. LP implantation should be considered in MHV patients with an indication for pacing. Funding Acknowledgement Type of funding sources: None. Procedural outcomes and complicationsBaseline and follow-up parameters

Potentially inappropriate prescribing of DOACs to patients with mechanical heart valves: a federated analysis of 57.9 million patients' primary care records in situ using OpenSAFELY

National guidance was issued during the COVID-19 pandemic to switch patients on warfarin to direct oral anticoagulants (DOACs) where appropriate as these require less frequent blood testing. DOACs are not recommended for patients with mechanical heart valves. We conducted a retrospective cohort study of DOAC prescribing in people with a record of a mechanical heart valve between September 2019 and May 2021, and describe the characteristics of this population. We identified 15,457 individuals with a mechanical heart valve recorded in their records, of whom 1058 (6.8%) had been prescribed a DOAC during the study period. 767 individuals with a record of a mechanical heart valve were currently prescribed a DOAC as of May 31st 2020. This is suggestive of inappropriate prescribing of DOACs in individuals with mechanical heart valves. Direct alerts have been issued to clinicians through their EHR software informing the issue. We show that the OpenSAFELY platform can be used for rapid audit and feedback to mitigate the indirect health impacts of COVID-19 on the NHS. We will monitor changes in prescribing for this risk group over the following months.

Anticoagulation for patients with mechanical heart valves at the end of life: understanding clinician attitudes and improving decision making

Background Decisions regarding continuation or cessation of anticoagulation for patients with mechanical heart valves nearing the end of life represent a difficult balance of risks. The risk of suffering and disability that may result from thromboembolism must be weighed against the burden of continued anticoagulation therapy and the excess bleeding risk this confers. Data allowing quantification of the relative risks are scarce, and this translates to a lack of published guidance on the topic. Here we describe how this lack of guidance is impacting upon healthcare professionals and their patients through misconception of risk and under-confidence in decision-making. We also present local guidance we have developed that aims to improve objective risk assessment and promote individualised, patient-centred decision-making. Methods Our survey was developed by specialists in palliative care and cardiology. The survey explored respondents' conception of the risks of stopping anticoagulation for patients with mechanical heart valves at the end of life, as well as their ability to identify patient factors that modify this risk. Respondent decision-making, confidence, and readiness to accept further guidance were also explored. Healthcare professionals at two university teaching hospitals were invited to participate in the survey. The study population included hospital specialists, generalists, and trainees. Results Fifty-two healthcare professionals completed the survey, including 16 palliative care specialists. 47 (90%) of respondents felt poorly informed of the risks of stopping or continuing anticoagulation. 6 (12%) correctly identified risk of thromboembolism in patients with mechanical heart valves who are not anticoagulated. The remainder overestimated risk by a factor of two (18, 35%) or five (27, 52%). 49 (94%) would find further guidance on this issue helpful. Conclusions The healthcare professionals we surveyed felt poorly informed and ill-equipped to make decisions regarding anticoagulation for patients with mechanical heart valves at the end of life. They were objectively poor at estimating the risks involved. In the absence of robust data to support protocolisation of practice, we believe these decisions must be taken in conversation with the patient, taking account of individual circumstances and priorities. We have developed guidance for local use to support such individualised decision-making.

Apixaban use in an atrial fibrillation patient with double mechanical heart valves: a case report

Background Warfarin is the only approved oral anticoagulant for long-term prophylaxis against valve thrombosis and thromboembolism in patients with mechanical heart valves. To date, apixaban for patients with double (aortic and mitral) mechanical heart valves has not been reported in the literature. Case summary We report the case of a 50-year-old female who underwent double (aortic and mitral) mechanical valve replacement in February 2017. Warfarin was prescribed after mechanical valve replacement. However, she complained of side effects of warfarin, including tingling sensation and numbness of legs, urticaria, skin rash, and nausea and voluntarily stopped taking medication. In December 2018, she was admitted to the emergency room due to ongoing chest pain. Coronary angiogram revealed embolic myocardial infarction at the left circumflex coronary artery. Nevertheless, she continued to refuse to take warfarin after anticoagulant therapy for coronary artery embolism. Given the patient’s objection, we prescribed apixaban 5 mg b.i.d. since February 2019. When she was diagnosed with atrial fibrillation in April 2020, no intracardiac thrombosis was confirmed on computed tomography and electrical cardioversion was performed safely. While on apixaban, no evidence of prosthetic valve thrombosis or thrombo-embolic events was observed during a 24-month period. Conclusion We report the efficacy and safety of apixaban in a patient with atrial fibrillation and double mechanical heart valves for preventing prosthetic valve thrombus and systemic embolism.