Warfarin treatment quality and prognosis in patients with mechanical heart valve prosthesis

Long-Term Risk of Hospitalization and Death in Patients With Mechanical Prosthetic Heart Valves

Mechanical prosthetic heart valves (MPHVs) are commonly used for valvular heart disease in patients with a long life expectancy. Few longitudinal data on the specific causes of hospitalization in patients with MPHV are available. We investigated the risk of all-cause hospitalization and mortality in patients with MPHV. We performed a prospective, observational, ongoing study including consecutive patients with MPHVs who were referred to the atherothrombosis outpatient clinic of the Policlinico Umberto I of Rome for the vitamin K antagonist management. Study end points were all-cause, cardiovascular hospitalization, and overall mortality. We included 305 patients with MPHV (38.4% women, median age 60.2 years). The site of MPHV was aortic in 53.5%, mitral in 29.5%, and mitroaortic in 17%. During a median follow-up of 57.3 months, 142 hospitalizations occurred (8.16 per 100 person-years). The most common causes of hospitalization were cardiovascular disease (3.62 per 100 person-years), infections, surgery, and bleeding. The predictors of cardiovascular hospitalization were atrial fibrillation (hazard ratio [HR] 1.75, 95% confidence interval [CI] 1.04 to 2.95, p = 0.035), previous stroke/transient ischemic attack (HR 2.96, 95% CI 1.59 to 5.48, p = 0.001), and peripheral artery disease (HR 2.42, 95% CI 1.09 to 5.36, p = 0.030). During a median follow-up of 97.2 months, 61 deaths occurred (2.43 per 100 person-years). Age was directly associated with the risk of death (HR 1.088, 95% CI 1.054 to 1.122, p <0.001), whereas the time in therapeutic range higher than the median was inversely associated (HR 0.436, 95% CI 0.242 to 0.786, p = 0.006). In conclusion, patients with MPHV had a high incidence of hospitalizations, especially cardiovascular-related. The incidence of death is high; however, it may be decreased by maintaining a good quality of anticoagulation.

Outcomes of Patients with a Mechanical Heart Valve and Poor Anticoagulation Control on Warfarin

BACKGROUND

 Patients with a mechanical heart valve (MHV) require oral anticoagulation. Poor anticoagulation control is thought to be associated with adverse outcomes, but data are limited.

OBJECTIVE

 To assess the risks of clinical outcomes in patients with a MHV and poor anticoagulation control on warfarin.

METHODS

 We conducted a retrospective study of consecutive patients undergoing MHV implantation at a tertiary care center (2010-2019). Primary outcome was a composite of ischemic stroke, systemic embolism, or prosthetic valve thrombosis. Major bleeding and death were key secondary outcomes. We constructed multivariable regression models to assess the association between time in therapeutic range (TTR) on warfarin beyond 90 days after surgery with outcomes.

RESULTS

 We included 671 patients with a MHV (80.6% in aortic, 14.6% in mitral position; mean age 61 years, 30.3% female). Median follow-up was 4.9 years, mean TTR was 62.5% (14.5% TTR <40%, 24.6% TTR 40-60%, and 61.0% TTR >60%). Overall rates of the primary outcome, major bleeding, and death were 0.73, 1.41, and 1.44 per 100 patient-years. Corresponding rates for patients with TTR <40% were 1.31, 2.77, and 3.22 per 100 patient-years. In adjusted analyses, every 10% decrement in TTR was associated with a 31% increase in hazard for the primary outcome (hazard ratio [HR]: 1.31, 95% confidence interval [CI]: 1.13-1.52), 34% increase in major bleeding (HR: 1.34, 95% CI: 1.17-1.52), and 32% increase in death (HR: 1.32, 95% CI: 1.11-1.57).

CONCLUSION

 In contemporary patients with a MHV, poor anticoagulation control on warfarin was associated with increased risks of thrombotic events, bleeding, and death.

Frequency of prothrombin time-international normalized ratio monitoring and the long-term prognosis in patients with mechanical valve replacement

BACKGROUND

The study aimed to assess the correlation between the monitoring frequency of PT-INR and the long-term prognosis in patients with mechanical heart valve (MHV) replacement after discharge.

METHODS

This single-center, observational study enrolled patients who underwent MHV replacement and discharged from June 2015 to May 2018. Patients or their corresponding family members were followed with a telephone questionnaire survey in July-October 2020. Based on monitoring intervals, patients were divided into frequent monitoring (FM) group (≤ 1 month) and less frequent monitoring (LFM) group (> 1 month). The primary endpoint was the composite of thromboembolic event, major bleeding or all-cause death. The secondary endpoints were thromboembolic event, major bleeding or all-cause death, respectively.

RESULTS

A total of 188 patients were included in the final analysis. The median follow-up duration was 3.6 years (Interquartile range: 2.6 to 4.4 years). 104 (55.3%) patients and 84 (44.7%) patients were classified into the FM group and the LFM group, respectively. The FM group had a significantly lower incidence of the primary endpoint than the LFM group (3.74 vs. 1.16 per 100 patient-years, adjusted HR: 3.31 [95% CI 1.05-10.42, P = 0.041]). Secondary analysis revealed that the risk of thromboembolic events and all-cause death were also reduced in the FM group.

CONCLUSIONS

The management of warfarin treatment in patients after MHV replacement remains challenging. Patients with less frequent monitoring of PT-INR might have worse clinical prognosis than those with frequent PT-INR monitoring.

Anticoagulation Control and Major Adverse Clinical Events in Patients with Operated Valvular Heart Disease with and without Atrial Fibrillation Receiving Vitamin K Antagonists

BACKGROUND

Good quality anticoagulation among patients with operated valvular heart disease is needed to reduce ischaemic and thromboembolic complications. There is limited evidence regarding factors that affect anticoagulation control in patients implanted with mechanical or tissue prosthetic valve(s).

AIM

To examine the quality of and factors that affect anticoagulation control, major adverse clinical events and all-cause death in operated valvular heart disease patients with and without atrial fibrillation who are receiving a vitamin K antagonist.

METHODS

Quality of anticoagulation were retrospectively assessed among 456 operated valvular heart disease patients [164 (36%) with AF and 290 (64%) without AF] via time in therapeutic range (TTR) (Rosendaal method) and percentage of INRs in range (PINRR) over a median of 6.2 (3.3-8.5) years. VHD was defined by the presence of a mechanical or tissue prosthetic valve at the mitral, aortic, or both sites.

RESULTS

Mean age 51 (14.7), 64.5% men. Most (96.1%) had a mechanical prosthesis and 64% had aortic valve replacement. Overall, mean TTR was 58.5% (14.6) and PINRR was 50.1% (13.8). Operated valvular heart disease patients with AF had significantly lower mean TTR and PINRR (TTR: 55.7% (14.2) vs. 60.1% (14.6); p = 0.002, respectively, PINRR: 47.4% (13.5) vs. 51.6% (13.7); p = 0.002, respectively), and a lower proportion of TTR ≥ 70%, despite a similar number of INR tests compared to those without AF. Predictors of TTR < 70% were female sex, AF and anaemia/bleeding history. Significantly higher proportions of operated valvular heart disease patients with AF died (20.7% vs. 5.8%; p < 0.001), but ≥1 MACE rates were similar between the two groups.

CONCLUSIONS

Operated valvular heart disease patients with AF at baseline have poorer anticoagulation control compared to those without AF. The presence of concomitant AF, anaemia/bleeding history and female sex independently predicted poor TTR. Stringent INR monitoring is needed to improve anticoagulation control and prevent major adverse clinical events in patients with operated valvular heart disease.

Social App to Improve Warfarin Therapy in Post-MHVR Chinese Patients: A Randomized Controlled Trial

Background

Poor anticoagulation quality was a major problem among warfarin-treated patients, which called for innovative and effective methods to improve it.

Objective

To investigate whether social app could be used to reduce warfarin-associated adverse events among post-MHVR Chinese patients.

Method

735 warfarin-treated patients (aged 50.8 ± 9.6 years, 59.9% female) were enrolled and randomized to a social app care group (warfarin therapy was guided by experienced clinicians via a social app) or a routine care group (warfarin therapy was managed through traditional in-office visits) at a 1 : 1 ratio. Ending points (bleeding and thrombotic events) were recorded during an 18-month follow-up period.

Results

A total of 718 patients were included in analysis. 57 of them suffered warfarin-associated adverse events, including 30 major bleedings and 27 thrombotic events. The time in the therapeutic range (TTR, Rosendaal method) in the social app group was 71.5%, which was significantly better than 52.6% in the routine care group (difference: 18.8%, 95% CI: 16.8-20.8). Compared with the patients from the social app group, patients under routine care experienced more bleeding (hazard ratio (HR): 2.31, 95% CI: 1.13-4.72). The social app care group had lower variation (0.55 vs. 0.70) in the international normalized ratio (INR) values and fewer incidents of extremely high INR (e.g., INR > 5.0, 0.87% vs. 3.42%) than the routine care group.

Conclusions

Social app management could significantly improve warfarin control and was associated with a reduction in bleeding risk. This trial was registered with NCT03264937.

Safety and efficacy of using portable coagulation monitor for INR examination after left-sided mechanical prosthetic valve replacement

BACKGROUND

Time in therapeutic range (TTR) is an index to assess the effectiveness of anticoagulation and is important to predict the risk of bleeding and thrombosis in patients taking warfarin. In recent years, the portable coagulation monitor, a point-of-care testing device for patients to perform self-management international normalized ratio (INR) examination, has provided an opportunity to improve the quality of oral warfarin treatment. In this study, we applied TTR to evaluate the safety and efficacy of the portable coagulation monitor for patients with oral anticoagulant warfarin after left-sided mechanical prosthetic valve (MPV) replacement.

METHODS

It is a single-centre cohort study. From September 2019 to June 2021, a total of 243 patients who returned to our institution for outpatient clinic revisit at 3 months after left-sided MPV replacement, met the inclusion criteria and agreed to be followed up were included. Self-management group used portable coagulation monitor for INR examination, and patients in the conventional group had their INR monitored in routine outpatient visits. Clinical data of the patients would be recorded for the next 12 months, and results were compared between the two groups to assess the effect of the coagulation monitor on TTR and complications related to bleeding and thrombosis in patients with left-sided MPV replacement.

RESULTS

A total of 212 individuals provided complete and validated INR data spanning of 1 year. Those who applied the portable coagulation monitor had higher TTR values and larger number of tests for INR. No significant differences were seen between the two groups in postoperative bleeding and thromboembolic complications, but portable coagulation monitor showed a trend toward fewer bleeding events.

CONCLUSION

Portable devices for coagulation monitoring are safe and can achieve a higher TTR. Patients who use the portable coagulation monitor for home INR self-management can achieve a safe and effective warfarin therapy.

Care of the patient after valve intervention

This review aims to outline the current evidence base and guidance for care of patients post-valve intervention. Careful follow-up, optimisation of medical therapy, antithrombotics, reduction of cardiovascular risk factors and patient education can help improve patient outcomes and quality of life. Those with mechanical valves should receive lifelong anticoagulation with a vitamin K antagonist but in certain circumstances may benefit from additional antiplatelet therapy. Patients with surgical bioprosthetic valves, valve repairs and transcatheter aortic valve implantation also benefit from antithrombotic therapy. Additionally, guideline-directed medical therapy for coexistent heart failure should be optimised. Cardiovascular risk factors such as hyperlipidaemia, hypertension and diabetes should be treated in the same way as those without valve intervention. Patients should also be encouraged to exercise regularly, eat healthily and maintain a healthy weight. Currently, there is not enough evidence to support routine cardiac rehabilitation in individuals post-valve surgery or intervention but this may be considered on a case-by-case basis. Women of childbearing age should be counselled regarding future pregnancy and the optimal management of their valve disease in this context. Patients should be educated regarding meticulous oral health, be encouraged to see their dentist regularly and antibiotics should be considered for high-risk dental procedures. Evidence shows that patients post-valve intervention or surgery are best treated in a dedicated valve clinic where they can undergo clinical review and surveillance echocardiography, be provided with heart valve education and have access to the multidisciplinary valve team if needed.

New Internet-Based Warfarin Anticoagulation Management Approach After Mechanical Heart Valve Replacement: Prospective, Multicenter, Randomized Controlled Trial

BACKGROUND

Mechanical heart valve replacement (MHVR) is an effective method for the treatment of severe heart valve disease; however, it subjects patient to lifelong warfarin therapy after MHVR with the attendant risk of bleeding and thrombosis. Whether internet-based warfarin management reduces complications and improves patient quality of life remains unknown.

OBJECTIVE

This study aimed to compare the effects of internet-based warfarin management and the conventional approach in patients who received MHVR in order to provide evidence regarding alternative strategies for long-term anticoagulation.

METHODS

This was a prospective, multicenter, randomized, open-label, controlled clinical trial with a 1-year follow-up. Patients who needed long-term warfarin anticoagulation after MHVR were enrolled and then randomly divided into conventional and internet-based management groups. The percentage of time in the therapeutic range (TTR) was used as the primary outcome, while bleeding, thrombosis, and other events were the secondary outcomes.

RESULTS

A total of 721 patients were enrolled. The baseline characteristics did not reach statistical differences between the 2 groups, suggesting the random assignment was successful. As a result, the internet-based group showed a significantly higher TTR (mean 0.53, SD 0.24 vs mean 0.46, SD 0.21; P<.001) and fraction of time in the therapeutic range (mean 0.48, SD 0.22 vs mean 0.42, SD 0.19; P<.001) than did those in the conventional group. Furthermore, as expected, the anticoagulation complications, including the bleeding and embolic events had a lower frequency in the internet-based group than in the conventional group (6.94% vs 12.74%; P=.01). Logistic regression showed that internet-based management increased the TTR by 7% (odds ratio [OR] 1.07, 95% CI 1.05-1.09; P<.001) and reduced the bleeding and embolic risk by 6% (OR 0.94, 95% CI 0.92-0.96; P=.01). Moreover, low TTR was found to be a risk factor for bleeding and embolic events (OR 0.87, 95% CI 0.83-0.91; P=.005).

CONCLUSIONS

The internet-based warfarin management is superior to the conventional method, as it can reduce the anticoagulation complications in patients who receive long-term warfarin anticoagulation after MHVR.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR1800016204; http://www.chictr.org.cn/showproj.aspx?proj=27518.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1136/bmjopen-2019-032949.

Antithrombotic Treatment After Surgical and Transcatheter Heart Valve Repair and Replacement

New antithrombotic drugs have been developed, new valve types have been designed and minimally invasive transcatheter techniques have emerged, making the choice of antithrombotic therapy after surgical or transcatheter heart valve repair and replacement increasingly complex. Moreover, due to a lack of large randomized controlled trials many recommendations for antithrombotic therapy are based on expert opinion, reflected by divergent recommendations in current guidelines. Therefore, decision-making in clinical practice regarding antithrombotic therapy for prosthetic heart valves is difficult, potentially resulting in sub-optimal patient treatment. This article compares the 2017 ESC/EACTS and 2020 ACC/AHA guidelines on the management of valvular heart disease and summarizes the available evidence. Finally, we established a convenient consensus on antithrombotic therapy after valve interventions based on over 800 annual cases of surgical and transcatheter heart valve repair and replacement and a multidisciplinary team discussion between the department of cardiovascular diseases and cardiac surgery of the University Hospitals Leuven, Belgium.

Sex-influence on the time in therapeutic range (TTR) during oral anticoagulation with coumarin derivatives: Systematic review and meta-analysis

AIMS

We sought to investigate the association between sex and oral anticoagulation control employing coumarin derivatives.

METHODS

Electronic sources were MEDLINE, Biblioteca Virtual em Saúde (BVS), The Cumulative Index to Nursing and Allied Health Literature (CINAHL), EMBASE, Cochrane Central and Web of Science. Inclusion criteria were: observational and experimental studies; age ≥18 years; both sexes; treatment with any coumarin derivative for ≥3 months; any indication of long-term use; quality of oral anticoagulation measured by time in therapeutic range (TTR). The meta-analysis was developed with odds ratios (OR) for binary variables and mean differences (MD) for continuous variables, using random-effects models (DerSimonian and Laird) with 95% confidence intervals (CI).

RESULTS

Overall, 22 articles were selected, comprising 16 cohort studies, four cross-sectional studies and two clinical trials. The number of participants ranged from 110 to 104 505 (183 612; women: 45%). The main indication of oral anticoagulation was atrial fibrillation. Most studies reported the use of warfarin. In the meta-analysis, 15 studies were analysed using TTR as a binary variable (OR = 0.87; 95% CI = 0.78, 0.96; z = -2.75; P = .006.; I²  = 67%) and seven studies as a continuous variable (MD = -2.97; 95% CI = -4.80, -1.14; z = -3.19; P = .0014; I²  = 75%). The pooled estimates indicated that women were associated with lower TTR than men.

CONCLUSIONS

Our findings revealed an association between female sex and worse oral anticoagulation control. Further studies are needed with primary design to investigate sex-related factors influencing oral anticoagulation control with coumarin derivatives. Innovative strategies focused on women's health may be useful to improve patient-centred care.

Impact of an oral anticoagulation self-monitoring and self-management program in patients with mechanical heart valve prosthesis

Objective: To analyze impact of implementation of an oral anticoagulation self-monitoring and self-management program among patients with mechanical valve prosthesis. Materials & methods: Observational and retrospective study performed in Hospital Moises Broggi, Barcelona, Spain. The program started on June 2019. The study compared 6-month period before and after the implementation of the program. Results: The study included 44 patients. There was a numerical increase of time in therapeutic range from 53.6 ± 21.3% to 57.1 ± 15.7% (p = 0.30). Proportion of patients with international normalized ratio (INR) >5 significantly decreased from 3.9 to 2.0% (p = 0.04). No significant differences were observed in thromboembolic or bleeding complications. Visits to emergency department decreased from (29.5 to 22.7%; p = 0.41). Conclusion: Oral anticoagulation self-monitoring and self-management program seems an appropriate approach that could provide additional benefits in selected patients with mechanical valve prosthesis.

Safety of low intensity oral anticoagulant therapy in patients with bileaflet mechanical aortic valve prosthesis: A propensity weighted study

BACKGROUND

Scarce data are available on the long-term outcomes of different regimens of oral anticoagulation in an all comer population of patients undergoing aortic valve replacement with a bileaflet mechanical heart valve.

METHODS

Outcomes of 88 patients discharged with a target INR of 2.0 (LOW-INR) were compared to 147 contemporary patients who have been recommended a target INR of 2.5 (CONV). Primary outcome was the composite of any thromboembolic or haemorrhagic events. Secondary outcomes were the individual components of the primary outcome, cardiovascular mortality and stroke. To reduce selection bias, a propensity weighted analysis was performed.

RESULTS

After inverse probability of treatment weighting, the primary endpoint occurred in 0.7% of patient in the LOW-INR group and in 7.0% in the CONV group (p = .0255). Linearized event rate were significantly lower in the LOW-INR group (primary endpoint: rate difference - 12.0 per 1000 patient/years, p = .0052; haemorrhage: -5.8 per 1000 patient/years, p = .0330; neurological events: -7.6 per 1000 patient/years, p = .0140). Conventional target INR was associated with an increased hazard of the composite endpoint (HR 11.193, 95% CI 1.424-88.003, p = .0217).

CONCLUSIONS

Lowering the intensity of oral anticoagulation resulted in a relevant clinical benefit of reduced rates of haemorrhagic and neurological adverse events in the mid-term follow-up. This report confirms the safety profile of the low INR regimen in an all comer population undergoing aortic valve replacement with an Abbott mechanical valve.

Surgical left atrial appendage occlusion in patients with atrial fibrillation undergoing mechanical heart valve replacement

BACKGROUND

Surgical left atrial appendage occlusion (SLAAO) may be associated with a lower risk of thromboembolism in patients with atrial fibrillation undergoing cardiac surgery. However, evidence regarding the effectiveness of SLAAO in patients undergoing mechanical heart valve replacement (MHVR) is lacking. Therefore, we aimed to evaluate the association between SLAAO and the cardiovascular outcomes in patients with atrial fibrillation undergoing MHVR.

METHODS

We retrospectively analyzed data for 497 patients with atrial fibrillation; 27.6% of the patients underwent SLAAO, and the remainder of the patients did not (No-SLAAO group). The primary outcome was a composite of ischemic stroke, systemic embolism, and all-cause mortality. Cumulative event-free survival rates were estimated using Kaplan-Meier curves, and we performed multivariate Cox analyses to evaluate the association between SLAAO and outcomes. We used one-to-one propensity score matching to balance patients' baseline characteristics, and analyzed 120 matching pairs.

RESULTS

Five patients died within 30 days postoperatively, and there were no significant differences between the two groups regarding in-hospital complications (all P > 0.05). After a median follow-up of 14 months, 14 primary events occurred. Kaplan-Meier curves showed no difference in the cumulative incidence of freedom from the primary outcome (log-rank P = 0.830), hemorrhagic events (log-rank P = 0.870), and the secondary outcome (log-rank P = 0.730), between the two groups. Multivariable Cox proportional hazards regression analysis showed no association between SLAAO and any outcome (all P > 0.05). After propensity score matching, cardiopulmonary bypass time and aortic cross-clamp time, and the postoperative length of stay were significantly longer in the SLAAO group (all P < 0.05); results were similar to the unadjusted analyses.

CONCLUSIONS

Concomitant SLAAO and MHVR was associated with longer length of stay, and cardiopulmonary bypass time and aortic cross-clamp time, but was not associated with additional protective effects against thromboembolic events and mortality during the 14-month follow-up.

Patient self-management of oral anticoagulation with vitamin K antagonists in everyday practice: clinical outcomes in a single centre cohort after long-term follow-up

Background

Patient self-management (PSM) of vitamin K antagonists (VKA) seems a very promising model of care for oral anticoagulation in terms of efficacy and safety. In comparison with other management models of VKA therapy, the number of scientific publications supporting the advantages of PSM is more limited. Currently, most of the scarce information comes from randomized clinical trials. Moreover, a small number of studies have assessed PSM of VKA therapy in real life conditions.

Methods

We analyzed clinical outcomes of 927 patients in a single center (6018.6 patient-years of follow-up). Recruitment took place between 2002 and 2017. All patients followed a structured training program, conducted by specialized nurses.

Results

Fifty percent of individuals had a mechanical heart valve (MHV), 23% suffered from recurrent venous thromboembolism (VTE) or high-risk thrombophilia, and 13% received VKA therapy because of atrial fibrillation (AF). Median follow-up was 6.5 years (range 0.1–15.97 years), median age was 58.1 years (IQR 48–65.9) and 46.5% were women. The incidence of major complications (either hemorrhagic or thromboembolic) was 1.87% patient-years (pt-ys) with a 95% CI of 1.54–2.27. The incidence of major thromboembolic events was 0.86% pt-ys (95% CI 0.64–1.13) and that of major hemorrhagic events was 1.01% pt-ys (95% CI 0.77–1.31). The incidence of intracranial bleeding was 0.22% pt-ys (95% CI 0.12–0.38). In terms of clinical indication for VKA therapy, the incidence of total major complications was 2.4% pt-ys, 2.0% pt-ys, 0.9% pt-ys and 1.34% pt-ys for MHV, AF, VTE and other (including valvulopathies and myocardiopathies), respectively. Clinical outcomes were worse in patients with multiple comorbidities, previous major complications during conventional VKA therapy, and in older individuals. The percentage of time in therapeutic range (TTR) was available in 861 (93%) patients. Overall, the mean (SD) of TTR was 63.6 ± 13.4%, being higher in men (66.2 ± 13.1%) than women (60.6 ± 13.2%), p < 0.05.

Conclusions

In terms of clinically relevant outcomes (incidence of major complications and mortality), PSM in real life setting seems to be a very good alternative in properly trained patients.

Time in therapeutic range and risk of thromboembolism and bleeding in patients with a mechanical heart valve prosthesis

OBJECTIVE

Oral anticoagulation with vitamin K antagonists is recommended after mechanical heart valve replacement. However, data regarding the association between the quality of vitamin K antagonist treatment and the risk of complications are sparse.

METHODS

Patients undergoing mechanical heart valve replacement (1997-2012) with available data on international normalized ratio values were identified in Danish registries. The quality of vitamin K antagonist treatment between discharge after valve replacement and 6 months postdischarge (ie, index) was assessed as time in therapeutic range (TTR) ≥70% or <70% reflecting the percentage of time in therapeutic international normalized ratio interval. Patients were followed from index until occurrence of an outcome of interest (ie, thromboembolism and bleeding), death, or end of study (December 31, 2012), whichever came first. The risk of outcomes according to quality of vitamin K antagonist treatment was estimated with multivariable Cox regression.

RESULTS

In total, 659 patients undergoing mechanical heart valve replacement were included in the study. Median number of international normalized ratio measurements in the 6-month period after surgery was 13 (interquartile range, 8-19). Median TTR was 54.9% (interquartile range, 39.0%-72.9%) and 29.1% of patients had a TTR ≥70%. Median follow-up was 6.1 years. The risk of thromboembolism was significantly lower in the group with TTR ≥70% compared with TTR <70% (hazard ratio, 0.44; 95% confidence interval, 0.22-0.85), whereas no significant difference concerning risk of bleeding among groups was found (hazard ratio, 0.63; 95% confidence interval 0.36-1.08).

CONCLUSIONS

In patients undergoing mechanical heart valve replacement, TTR <70% in the 6-month period after surgery was associated with an increased risk of thromboembolic events but not bleeding compared with TTR ≥70%.

New warfarin anticoagulation management model after heart valve surgery: rationale and design of a prospective, multicentre, randomised trial to compare an internet-based warfarin anticoagulation management model with the traditional warfarin management model

INTRODUCTION

Warfarin is an effective anticoagulant and the only oral anticoagulant available for patients with mechanical heart valves. The prothrombin time and the associated international normalised ratio (INR) are routinely tested to monitor the response to anticoagulation therapy in patients. Patients who undergo mechanical heart valve replacement need lifelong anticoagulation therapy, and their INR is regularly measured to adjust the anticoagulation strength and the dose of anticoagulation drugs. Appropriate warfarin anticoagulation management can reduce patient complications, such as bleeding and thrombosis, and improve the long-term survival rate. We propose modern internet technology as a platform to build a warfarin anticoagulation follow-up system after valve replacement surgery. This system will provide doctors and patients with more standardised and safer follow-up methods as well as a method to further reduce the risk of warfarin anticoagulation-related complications and improve its therapeutic effects.

METHODS AND ANALYSIS

A prospective, multicentre, randomised, controlled trial will be conducted. A total of 700 patients who require long-term warfarin anticoagulation monitoring after heart valve replacement will be enrolled and randomly divided at a 1:1 ratio into a traditional outpatient anticoagulation management group and a group undergoing a new method of management based on the internet technology with follow-up for 1 year. Differences in the percentage of time in the therapeutic range (TTR), drug dose adjustments, bleeding/thrombosis and other related complications will be observed. The primary endpoint is the difference in the TTR between the two groups. The purpose of this study is to explore a safer and more effective mode of doctor-patient interaction and communication in the internet era. As of 13 July 2019, 534 patients had been enrolled.

ETHICS AND DISSEMINATION

This study protocol was approved by the Ethics Committee of Beijing Anzhen Hospital, Capital Medical University. The results will be published in a peer-reviewed medical journal.

TRIAL REGISTRATION NUMBER

ChiCTR1800016204.

APOB gene polymorphisms may affect the risk of minor or minimal bleeding complications in patients on warfarin maintaining therapeutic INR

The purpose of this study was to investigate influence of gene polymorphisms of APOB and APOE on risk of bleeding complications at therapeutic INR, during warfarin treatment in Korean patients with mechanical cardiac valves. The study included 142 patients from the EwhA-Severance Treatment Group (EAST) of Warfarin. A total of 12 SNPs was investigated. Five SNPs of APOB (c.13013G>A, c.1853C>T, c.1594C>T, c.293C>T, and c.7545C>T) and five SNPs of APOE (g.4798T>G, g.6406G>A, g.10413T>C, c.388T>C, and c.526C>T) were selected. In addition to selected SNPs, VKORC1 g.6399C>T, and CYP2C9 c.1075A>C, which were known to have significant effects on warfarin stable doses, were also included in the study. Two SNPs of APOB (c.293C>T and c.1853C>T) were associated with bleeding complications. T allele carriers of c.293C>T had 8.6 times (95% CI 2.9-25.5, p < 0.001) increased risk of bleeding, and attributable risk was 88.3%. C allele carriers of c.1853C>T had 6.4 times (95% CI 2.3-17.9, p < 0.001) increased risk of bleeding after adjusting for covariates (attributable risk of 84.3%). AUROC values of models that included c.1853C>T and c.293C>T were 0.771 and 0.802, respectively. Among demographic characteristics, age was the only significant factor. This study revealed that APOB was associated with bleeding complications in patients with warfarin treatment after mechanical cardiac valves.

Triple therapy after PCI - Warfarin treatment quality and bleeding risk

Background

A combination of warfarin, aspirin and clopidogrel is indicated after percutaneous coronary intervention (PCI) in some patients, despite the higher risk of bleeding inferred by this triple therapy.

Objectives

Whether the treatment quality of warfarin measured by iTTR (individual time within therapeutic INR range) is associated with bleeding complications during triple therapy after PCI.

Methods

A retrospective register study consisting of 601 triple treated PCI patients from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR). The cohort was cross-matched with the Swedish Patient Registry for background characteristics and bleeding complications up to 6 months after PCI using ICD10 codes, the Prescribed Drug Registry for ongoing medications, and the national oral anticoagulation registry Auricula for warfarin treatment quality. The patients were grouped into four iTTR groups: <50%, 50–69.9%, 70–84.9% and >85% as well as iTTR above or below 70%.

Results

Of 601 patients, 39 (6.5%) had a bleeding complication (type 2 according to BARC). Bleeding was more common for iTTR<70% compared to iTTR>70%, 28 (9.3%) vs. 11 (3.7%) (p = 0.005). The bleeding frequency increased gradually from the best group, iTTR>85% with four bleeders (3.3%) up to 17 bleeders (13.3%) in the worst group with iTTR<50% (p = 0.003), with a corresponding bleeding rate per 100 treatment years of 8.0 and 44.9, respectively. In multivariate analysis low BMI, HR 1.11 (95% CI 1.01–1.22), a medical history of anemia HR 3.17 (1.16–8.69) and iTTR < 70% HR 2.86 (1.25–6.53) increased the risk of bleeding.

Conclusion

Triple therapy after PCI confers a high risk of bleeding events. Warfarin treatment quality measured by iTTR as well as a medical history of anemia are strong independent predictors of bleeding in these patients. Physicians should pay more attention to iTTR after PCI.

Use of D-dimer in oral anticoagulation therapy

Individualized anticoagulation management and improvement of the safety and effectiveness of oral anticoagulant have always been the focus of clinicians' attention. D-dimer, a sensitive marker of thrombosis and coagulation activation, is not only traditionally used in the diagnosis of venous thromboembolism, acute aortic dissection, and disseminated intravascular coagulation but can also be used as a helpful marker in the management of oral anticoagulant, including evaluating the anticoagulation quality, predicting clinical outcomes, and determining the optimal duration and intensity of anticoagulation.

Clinical manifestations and outcomes of severe warfarin overanticoagulation: from the EWA study

INTRODUCTION

Severe warfarin overanticoagulation is a risk factor for bleeding, but there is little information on its manifestations, prognosis and factors affecting the outcome. We describe the manifestations and clinical outcomes of severe warfarin overanticoagulation in a large group of patients with atrial fibrillation (AF).

MATERIAL AND METHODS

All international normalized ratio (INR) samples (n = 961,431) in the Turku University Hospital region between 2003 and 2015 were screened. A total of 412 AF patients with INR ≥9 were compared to 405 patients with stable warfarin anticoagulation for AF. Electronic patient records were manually reviewed to collect comprehensive data.

RESULTS

Of the 412 patients with INR ≥9, bleeding was the primary manifestation in 105 (25.5%). Non-bleeding symptoms were recorded in 165 (40.0%) patients and 142 (34.5%) had no symptoms. A total of 17 (16.2%) patients with a bleed and 67 (21.8%) without bleeding died within 30 days after the event. Intracranial haemorrhage strongly predicted death within 30 days. Other significant predictors were non-bleeding symptoms, active malignancies, recent bleed, history of myocardial infarction, older age, renal dysfunction and a recent treatment episode.

CONCLUSIONS

Bleeds are not the major determinant of the poor prognosis in severe overanticoagulation, as coincidental INR ≥9 findings also associate with high mortality. KEY MESSAGES Only a quarter of AF patients with INR ≥9 suffered a bleeding event and the clinical manifestation of INR ≥9 had a significant impact on patient outcome. The 30-day mortality rate in patients with INR ≥9 was high ranging from 9.2 to 32.7%. Several significant predictors of 30-day mortality after INR ≥9 were identified.

Incidence and predictors of excessive warfarin anticoagulation in patients with atrial fibrillation-The EWA study

Vitamin K antagonist warfarin is widely used in clinical practice and excessive anticoagulation is a well-known complication of this therapy. Little is known about permanent and temporary predictors for severe overanticoagulation. The aim of this study was to investigate the occurrence and predicting factors for episodes with very high (≥9) international normalized ratio (INR) values in warfarin treated patients with atrial fibrillation (AF). Excessive Warfarin Anticoagulation (EWA) study screened all patients (n = 13618) in the Turku University Hospital region with an INR ≥2 between years 2003–2015. Patients using warfarin anticoagulation for AF with very high (≥9) INR values (EWA Group) were identified (n = 412 patients) and their characteristics were compared to a control group (n = 405) of AF patients with stable INR during long-term follow-up. Over 20% (n = 92) of the EWA patients had more than one event of very high INR and in 105 (25.5%) patients EWA led to a bleeding event. Of the several temporary and permanent EWA risk factors observed, strongest were excessive alcohol consumption in 9.6% of patients (OR 24.4, 95% CI 9.9–50.4, p<0.0001) and reduced renal function (OR 15.2, 95% CI 5.67–40.7, p<0.0001). Recent antibiotic or antifungal medication, recent hospitalization or outpatient clinic visit and the first 6 months of warfarin use were the most significant temporary risk factors for EWA. Excessive warfarin anticoagulation can be predicted with several permanent and temporary clinical risk factors, many of which are modifiable.