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

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.

Thirty-year outcomes of low-intensity anticoagulation for mechanical aortic valve

The long-term safety, efficacy, and outcomes of low-intensity anticoagulation for mechanical heart valves remain unclear. This study aimed to evaluate the long-term outcomes of low-intensity anticoagulation therapy after aortic valve replacement (AVR) with a mechanical prosthesis. This retrospective cohort study consulted medical records and conducted a questionnaire to investigate 519 patients who underwent single AVR with the St. Jude Medical bileaflet valve and were in sinus rhythm. All patients were followed up with an international normalized ratio (INR) target of 1.6-2.5, and their INR values were checked throughout the follow-up period. The survival rate, incidence of major adverse cardiac and cerebrovascular events (MACCE), and risk factors for cardiac death and MACCE were investigated. The total follow-up was 9793 patient-years, and the follow-up periods were 19.9 (standard deviation [SD]: 7.9) years. The mean INR was 2.03 (SD: 0.54). Survival rates from cardiac death were 93.6% in 20 years and 85.2% in 30 years. Advanced age ≥ 70 years was the only significant risk factor for cardiac death and MACCE, and the INR < 2.0 was not significant risk factor for MACCE including thromboembolism or bleeding events. Low-intensity anticoagulation with an INR of 1.6-2.5 for patients with sinus rhythm after AVR with a bileaflet mechanical valve is safe and effective, even over 30 years.

Oral Anticoagulation Use in Individuals With Atrial Fibrillation and Chronic Kidney Disease: A Review

Atrial fibrillation (AF) is highly prevalent in patients with chronic kidney disease (CKD). It is associated with an increased risk of stroke, which increases as kidney function declines. In the general population and in those with a moderate degree of CKD (creatinine clearance 30-50 mL/min), the use of oral anticoagulation to decrease the risk of stroke has been the standard of care based on a favorable risk-benefit profile that had been established in seminal randomized controlled trials. However, evidence regarding the use of oral anticoagulants for stroke prevention is less clear in patients with severe CKD (creatinine clearance <30 mL/min) and those receiving maintenance dialysis, as these individuals were excluded from such large randomized controlled trials. Nevertheless, the direct oral anticoagulants have invariably usurped vitamin K antagonists as the preferred choice for oral anticoagulation among patients with AF across all strata of CKD based on their well-defined safety and efficacy and multiple pharmacokinetic benefits (e.g., less drug-drug interactions). This review summarizes the current literature on the role of oral anticoagulation in the management of AF among patients with CKD and highlights current deficiencies in the evidence base and how to overcome them.

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.

Clinical Outcomes of Different Warfarin Self-Care Strategies: A Systematic Review and Network Meta-Analysis

AIM

To compare the effects of different strategies for warfarin self-care.

METHODS

PubMed, EMBASE, CENTRAL, CINAHL, ProQuest Dissertations & Theses, and OpenGrey were searched from inception to August 2021. Randomized controlled trials (RCTs) of warfarin self-care, either patient self-testing (PST) or patient self-management (PSM), were included. Self-care approaches were classified based on the TIP framework (theme, intensity, provider): (1) PST ≥1/week via e-Health (PST/High/e-Health); (2) PST ≥1/week by health care practitioner (PST/High/HCP); (3) PST <1/week via e-Health (PST/Low/e-Health); (4) PSM ≥1/week by e-Health (PSM/High/e-Health); (5) PSM ≥1/week by patient (PSM/High/Pt); (6) PSM <1/week by patient (PSM/Low/Pt); and (7) PSM with flexible frequency by patient (PSM/Flex/Pt). Mean differences (MDs) and risk ratios (RRs) with 95% confidence interval (CI) were estimated using frequentist network meta-analyses with a random-effects model. The certainty of evidence was evaluated using CINeMA (Confidence in Network Meta-Analysis).

RESULTS

Sixteen RCTs involving 5,895 participants were included. When compared with usual care, time in therapeutic range was higher in PSM/High/Pt and PST/High/e-Health with MD [95% CI] of 7.67% [0.26-15.08] and 5.65% [0.04-11.26], respectively. The certainty of evidence was rated as moderate for these findings. The risk of thromboembolic events was lower in the PSM/Flex/Pt group when compared with PST/High/e-Health (RR: 0.39 [0.20-0.77]) and usual care (RR: 0.38 [0.17-0.88]) with low and very low level of evidence, respectively. There was no significant difference in the proportion of international normalized ratio (INR) values in range, major bleeding, and all-cause mortality among different self-care features.

CONCLUSION

Patient self-care (either PST or PSM) by measuring INR values at least once weekly is more effective in controlling the INR level.

Case report: Mechanical mitral prosthetic valve thrombosis in the context of COVID-19 despite effective anticoagulation

Background

The SARS-CoV2 virus has been an emerging virus since December 2019 and is the cause of a global pandemic whose clinical manifestations extend far beyond respiratory disease.

Case summary

A patient with severe coronavirus disease 2019 respiratory infection, carrying a mechanical mitral valve and under anticoagulation, was admitted to our cardiology department because of a new atrial fibrillation, which turned out to be related to thrombosis of the mitral mechanical valve.

Conclusion

The pro-coagulant effect of the SARS-CoV2 virus does not spare patients at risk of thrombosis, even under effective anticoagulation. In patients with mechanical valves under vitamin K antagonist treatment, there is a high risk of thrombus formation. The treatment is based on thrombolysis by therapeutic anticoagulation, fibrinolysis, or surgery depending on the size, composition of thrombus, and clinical manifestation.

Outcomes related to anticoagulation management for mechanical valve replacements

Background

This study evaluates anticoagulation management and its impact on longitudinal clinical outcomes in patients undergoing mechanical valve replacement.

Methods

Patients undergoing mechanical mitral valve replacement (MVR) or aortic valve replacement (AVR) from 2010–2018 at a single center were included. Patients were stratified into therapeutic and non-therapeutic anticoagulation groups based on the median percentage of international normalized ratio (INR) values within the reference range (2.0–3.0 for AVR, 2.5–3.5 for MVR) during the first post-operative year. Using Cox regression analysis, comorbidity-adjusted survival and freedom from adverse events were compared.

Results

Six hundred and fifty-one patients underwent mechanical valve replacement (166 MVR, 485 AVR). Comorbidity-adjusted survival was similar in the MVR and AVR cohorts (P=0.23). There was a median of 27 [interquartile range (IQR): 14–42] INRs drawn per patient in the first post-operative year. The median percentage of INRs within the reference values during the first post-operative year was 42.85% (IQR: 30.77–53.95%), with the majority of non-therapeutic INRs being subtherapeutic (34.51%; n=6,864). There were no significant differences in adjusted survival between the therapeutic and non-therapeutic groups [hazard ratio (HR): 1.12, P=0.73]. Within the first post-operative year, there were no significant differences in stroke, major bleeding, peripheral non-stroke arterial thromboembolism, and readmission for intravenous heparin in the therapeutic and non-therapeutic groups.

Conclusions

Taking into account relevant comorbidities and valve type, patients with a larger proportion of non-therapeutic INRs during the first post-operative year demonstrated no difference in longitudinal clinical outcomes. Further research into more standardized INR monitoring and potentially expanded INR target ranges for patients undergoing mechanical valve replacement is warranted.

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.

Long-term Outcomes Following Mechanical or Bioprosthetic Aortic Valve Replacement in Young Women

Background

Studies performed to date reporting outcomes after mechanical or bioprosthetic aortic valve replacement (AVR) have largely neglected the young female population. This study compares long-term outcomes in female patients aged < 50 years undergoing AVR with either a mechanical or bioprosthetic valve.

Methods

In this propensity-matched study, we compared outcomes after mechanical AVR (n = 57) and bioprosthetic AVR (n = 57) between 2004 and 2018. The primary outcome of this study is survival. Secondary outcomes include the rate of reoperation, stroke, myocardial infarction, rehospitalization for heart failure, and incidence of serious adverse events. Outcomes were measured over 15 years, with a median follow-up of 7.8 years.

Results

In patients receiving a mechanical AVR vs a bioprosthetic AVR, overall survival at median follow-up was equivalent, at 93%. There is a lower rate of reoperation in patients receiving a mechanical AVR vs a bioprosthetic AVR (1.8% vs 8.8%). The rate of new-onset atrial fibrillation was significantly higher in the mechanical AVR group vs the bioprosthetic AVR group (18.2% vs 7.3%). No significant difference was seen in the rate of serious adverse events.

Conclusions

These results provide contemporary data demonstrating equivalent long-term survival between mechanical and bioprosthetic AVR, with higher rates of new atrial fibrillation after mechanical AVR, and higher rates of reoperation after bioprosthetic AVR. These results suggest that either valve type is safe, and that preoperative assessment and counselling, as well as the follow-up, medical treatment and indications for intervention, must be a collaborative decision-making process between the clinician and the patient.