Security and cost comparison of INR self-testing and conventional hospital INR testing in patients with mechanical heart valve replacement

Late dysfunction of a mechanical aortic valve after long-term low molecular weight heparin therapy: a case report

Background

To date, vitamin K anticoagulants are the only recommended long-term therapy for mechanical heart valves. Bleeding episodes, thromboembolic events, and international normalized ratio monitoring are difficult and prevalent complications for these patients. This report reflects the late mechanical aortic valve dysfunction after long-term low molecular weight heparin therapy.

Case summary

A 66-year-old male patient underwent mechanical aortic valve replacement in 2007. He was administered therapeutic doses of enoxaparin for nearly 12 years due to warfarin-related bleeding complications and labile international normalized ratios. However, he experienced multiple cardiovascular and cerebrovascular thromboembolic events, including an anterolateral ST-elevation myocardial infarction with left anterior descending artery thrombus, treated with thrombus aspiration and stenting. The patient was eventually admitted with symptoms and signs of acute heart failure, and echocardiography, fluoroscopy, and a cardiac computed tomography detected mechanical aortic valve prosthesis dysfunction, with an immobile leaflet and pannus. The patient demonstrated no improvement despite switching to unfractionated heparin, and he ultimately underwent redo aortic bioprosthetic valve surgery with a favourable outcome.

Discussion

Low molecular weight heparin is prescribed for patients with aortic mechanical valves who are intolerant to vitamin K antagonists or as bridging in certain situations. Anti-Xa factor monitoring should be considered for long-term prescriptions.

Role of Electrode Configuration and Morphology in Printed Prothrombin Time Sensors

Patients on long-term anticoagulation therapy require frequent testing of prothrombin time/international normalized ratio (PT/INR) to ensure therapeutic efficacy. Point-of-care (POC) PT tests for at-home monitoring eliminate the burden of visiting the clinic, but realizing a cost-effective and robust at-home POC test for PT has remained elusive. Recent demonstrations of printed PT sensors show promise for addressing the cost concerns; however, the printed sensors have lacked quality control to ensure reliability between tests. In this work, on-chip redundancy is introduced with fully printed impedimetric PT sensors by incorporating simultaneous testing with a single fingerstick volume of blood (8 μL). The influence of electrode dimensions and composition were studied, revealing an optimal electrode spacing of 200 μm and an unexpected dependence on the morphology of the electrodes. Three distinct silver morphologies were studied: aerosol jet printed silver nanoparticles (AgNPs), aerosol jet printed silver nanowires (AgNWs), and evaporated silver (Ag). In general, AgNPs exhibited the best PT sensor performance, due to relatively low conductance and high porosity. Overall, the printed impedimetric PT sensor functionalization was improved by incorporating simultaneous testing and, when combined with a handheld control device, shows promise for leading to a system that overcomes the challenges of commercial PT/INR coagulometers.

Lead management in patients undergoing percutaneous tricuspid valve replacement or repair: a 'heart team' approach

Clinically significant tricuspid regurgitation (TR) has historically been managed with either medical therapy or surgical interventions. More recently, percutaneous trans-catheter tricuspid valve (TV) replacement and tricuspid trans-catheter edge-to-edge repair have emerged as alternative treatment modalities. Patients with cardiac implantable electronic devices (CIEDs) have an increased incidence of TR. Severe TR in this population can occur for multiple reasons but most often results from the interactions between the CIED lead and the TV apparatus. Management decisions in patients with CIED leads and clinically significant TR, who are undergoing evaluation for a percutaneous TV intervention, need careful consideration as a trans-venous lead extraction (TLE) may both worsen and improve TR severity. Furthermore, given the potential risks of 'jailing' a CIED lead at the time of a percutaneous TV intervention (lead fracture and risk of subsequent infections), consideration should be given to performing a TLE prior to a percutaneous TV intervention. The purpose of this 'state-of-the-art' review is to provide an overview of the causes of TR in patients with CIEDs, discuss the available therapeutic options for patients with TR and CIED leads, and advocate for including a lead management specialist as a member of the 'heart team' when making treatment decisions in patients TR and CIED leads.

Readmissions After Surgical Aortic Valve Replacement: Influence of Prosthesis Type

INTRODUCTION

Prosthesis choice during aortic valve replacement (AVR) weighs lifelong anticoagulation with mechanical valves (M-AVR) against structural valve degeneration in bioprosthetic valves (B-AVR).

METHODS

The Nationwide Readmissions Database was queried to identify patients who underwent isolated surgical AVR between January 1, 2016 and December 31, 2018, stratifying by prothesis type. Propensity score matching was used to compare risk-adjusted outcomes. Readmission at 1 y was estimated with Kaplan-Meier (KM) analysis.

RESULTS

Patients (n = 109,744) who underwent AVR (90,574 B-AVR and 19,170 M-AVR) were included. B-AVR patients were older (median 68 versus 57 y; P < 0.001) and had more comorbidities (mean Elixhauser score: 11.8 versus 10.7; P < 0.001) compared to M-AVR patients. After matching (n = 36,951), there was no difference in age (58 versus 57 y; P = 0.6) and Elixhauser score (11.0 versus 10.8; P = 0.3). B-AVR patients had similar in-hospital mortality (2.3% versus 2.3%; P = 0.9) and cost (mean: $50,958 versus $51,200; P = 0.4) compared with M-AVR patients. However, B-AVR patients had shorter length of stay (8.3 versus 8.7 d; P < 0.001) and fewer readmissions at 30 d (10.3% versus 12.6%; P < 0.001) and 90 d (14.8% versus 17.8%; P < 0.001), and 1 y (P < 0.001, KM analysis). Patients undergoing B-AVR were less likely to be readmitted for bleeding or coagulopathy (5.7% versus 9.9%; P < 0.001) and effusions (9.1% versus 11.9%; P < 0.001).

CONCLUSIONS

B-AVR patients had similar early outcomes compared to M-AVR patients, but lower rates of readmission. Bleeding, coagulopathy, and effusions are drivers of excess readmissions in M-AVR patients. Readmission reduction strategies targeting bleeding and improved anticoagulation management are warranted in the first year following AVR.

Estimating the Potential Economic Impact of Tissue Valve Replacement for Heart Valve Disease in China: Patient-Level and Population-Level Cost-Benefit Simulation Analyses

OBJECTIVES

This study seeks to estimate the potential societal economic impact of treating patients with heart valve disease (HVD) in China with surgical tissue valve replacement versus mechanical valves.

METHODS

This societal economic cost-benefit evaluation is based on an individual simulation model for subgroups of patients with HVD that is also aggregated to a macrosocietal model. The individual simulation model was developed to estimate the likely economic impact of surgical aortic valve replacement (SAVR) with tissue versus mechanical valves for different subgroups among all eligible patients with HVD over their remaining lifetimes. Clinical inputs were informed by health claims database analysis, expert clinical opinion, and published literature. Epidemiological inputs and demographic inputs were sourced from the published literature and the China Statistical Yearbook 2020. Health gains were valued at 3 times the average national income.

RESULTS

Projected total lifetime economic gains were greater for patients receiving tissue valves. Costs were reported in 2021 US dollars. The average lifetime net economic gain for tissue valve patients was $51 736 (20.0% more than for mechanical valve patients). Increasing the use of tissue valves to 50% among all eligible patients with HVD would provide aggregate long-term economic gains of $167 billion during their remaining lifetimes. The economic gains from greater tissue valve use were due to avoiding anticoagulation monitoring costs, improved quality of life, and greater post-SAVR labor force participation.

CONCLUSION

Increased use of tissue valves versus mechanical values in SAVR procedures in China would be likely to generate a substantial societal economic gain.

Combining portable coagulometers with the Internet: A new model of warfarin anticoagulation in patients following mechanical heart valve replacement

Heart valve replacement, as a safe and effective treatment for severe valvular heart disease, can significantly improve hemodynamics in patients. However, such patients then require lifelong anticoagulant therapy. Warfarin, a cheap and highly effective vitamin K antagonist, remains the major anticoagulant recommended for lifelong use following mechanical heart valve replacement. However, the effect of warfarin anticoagulant therapy is complicated by physiological differences among patients and non-compliance with treatment at different degrees. Effective management of warfarin therapy after heart valve replacement is currently an important issue. Portable coagulometers and the emergence of the Internet have provided new opportunities for long-term management of anticoagulation therapy, but the safety and affordability of this approach remain to be fully evaluated. This paper reviews recent progress on the use of portable coagulometers and the Internet in the management of warfarin anticoagulation therapy following mechanical heart valve replacement, which offers opportunities for reducing complications during postoperative anticoagulation and for facilitating patient compliance during follow-up.

Relationship Between Family Functioning and Medication Adherence in Chinese Patients With Mechanical Heart Valve Replacement: A Moderated Mediation Model

Background: Medication adherence is crucial for patients with mechanical heart valve replacement. Although families functioning is positively associated with medication adherence, little is known about the underlying mechanisms. Objective: To test whether family functioning affects medication adherence through illness perceptions and whether this mediating effect was moderated by medication literacy. Methods: 319 patients after mechanical heart valve replacement were included in this cross-sectional study from June 2021 to October 2021. Data regarding family functioning, illness perceptions, medication adherence, and medication literacy were collected through questionnaires. The moderated mediation model was examined by Hayes's PROCESS macro, based on the bootstrapping method. Results: The results revealed illness perceptions partially mediated the association of family functioning on medication adherence [β = 0.08, 95% confidence intervals: (0.04, 0.12)], and this effect was stronger for patients with low medication literacy than those with high literacy [β = -0.36, 95% CI: (-0.50, -0.22)]. Furthermore, the relationship between family functioning and medication adherence was only significant in patients with low medication literacy [β = 0.36, 95% CI: (0.23, 0.50)]. Conclusion: The mediating effect of illness perceptions between family functioning and medication adherence was moderated by medication literacy. Efforts to improve medication adherence by targeting at improving family functioning may be more effective when considering illness perceptions, especially for patients with limited medication literacy.

Self-management of patients with heart valve replacement and its clinical outcomes: a systematic review

Introduction

For patients with heart valve replacement, self-management can play an essential role in the management of their condition.

Aim

This review aimed to identify the aspects of self-management and its clinical outcomes in patients with heart valve replacement.

Material and methods

In this systematic review, the peer-reviewed research literature on self-management of patients with heart valve replacement was assessed. Since May 2020, the PubMed, Scopus, and web of science databases were searched regardless of time and language limitations. The eligibility of the articles was assessed by title or abstract according to the search strategy. Article selection was applied regarding to inclusion and exclusion criteria. Also, article screening was conducted by 2 independent authors.

Results

Twenty-five studies were considered in this systematic review. For inclusion, the self-management of patients had to have prerequisites, appropriate training, and be applicable in the aspects of anticoagulation therapy self-management, international normalized ratio (INR) self-testing, low-dose INR self-management, and heart valve function self-monitoring. In this method, through proper management of INR levels and anticoagulation therapy, the complications rate could be reduced and the patients would be able to diagnose functional disorders in the early stages by monitoring the valve function. This procedure was able to prevent the progression of complications.

Conclusions

Self-management is an applicable protocol in the field of anticoagulation therapy, INR control, low-dose INR management, and the monitoring of cardiac valve function. This protocol could improve the quality of treatment for these patients through upgrading the care standards.

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.

Coagulation testing: Comparison of portable (CoaguChek® XS) and automated coagulation analyzer in healthy cats

Background and Aim:

The CoaguChek^® XS (CCX) is a portable coagulation analyzer that is widely used to monitor prothrombin time (PT) in human patients taking oral anticoagulants. It can also be reliably used for screening dogs when PT is in the normal range. Efficacy of the portable CCX coagulation analyzer was evaluated for testing PT in healthy cats and the normal range was established.

Materials and Methods:

Blood samples of 82 cats were collected from the jugular vein and PT was measured using both the CCX and an automated coagulation analyzer (ACA). Spearman’s correlation was used to measure the strength and direction of association between the two analyzers, while limits of agreement were assessed utilizing Bland-Altman analysis.

Results:

Range of PT using the CCX was 10.1-14.1 s. Correlation between the two analyzers was moderate but significant (r=0.3465, p=0.0014). Mean difference between CCX-PT and ACA-PT was 1.624 s and standard deviation was 0.890 with 95.1% of the samples falling within the limits of agreement.

Conclusion:

The CCX is a portable, easy to use coagulation analyzer that requires a small volume of blood and gives results within 1 min. Results showed moderate correlation and good agreement with a standard automated laboratory analyzer. The CCX can be used for screening coagulation testing when PT is in the normal range for cats. However, testing accuracy of the CCX in abnormal PT cats should be further investigated before diagnostic coagulopathy applications.

The patients' perspective of international normalized ratio self-testing, remote communication of test results and confidence to move to self-management

AIMS AND OBJECTIVES

To elicit the perceptions of patients, who self-tested their international normalized ratio and communicated their results via a text or phone messaging system, to determine their satisfaction with the education and support that they received and to establish their confidence to move to self-management.

BACKGROUND

Self-testing of international normalized ratio has been shown to be reliable and is fast becoming common practice. As innovations are introduced to point of care testing, more research is needed to elicit patients' perceptions of the self-testing process.

DESIGN

This three site study used a cross-sectional prospective descriptive survey.

METHODS

Three hundred and thirty patients who were prescribed warfarin and using international normalized ratio self-testing were invited to take part in the study. The anonymous survey examined patient profile, patients' usage, issues, perceptions, confidence and satisfaction with using the self-testing system and their preparedness for self-management of warfarin dosage.

RESULTS

The response rate was 57% (n = 178). Patients' confidence in self-testing was high (90%). Patients expressed a high level of satisfaction with the support received, but expressed the need for more information on support groups, side effects of warfarin, dietary information and how to dispose of needles. When asked if they felt confident to adjust their own warfarin levels 73% agreed. Chi-squared tests for independence revealed that none of the patient profile factors examined influenced this confidence. The patients cited the greatest advantages of the service were reduced burden, more autonomy, convenience and ease of use. The main disadvantages cited were cost and communication issues.

CONCLUSION

Patients were satisfied with self-testing. The majority felt they were ready to move to self-management.

RELEVANCE TO CLINICAL PRACTICE

The introduction of innovations to remote point of care testing, such as warfarin self-testing, needs to have support at least equal to that provided in a hospital setting.