Comorbidities against quality control of VKA therapy in non-valvular atrial fibrillation: a French national cross-sectional study

Patients' and clinicians' perceptions of oral anticoagulants in atrial fibrillation: a systematic narrative review and meta-analysis

Background

Atrial fibrillation (AF) increases the risk of developing a stroke by 20%. AF related strokes are associated with greater morbidity. Historically, warfarin was the anticoagulant of choice for stroke prevention in patients with AF but lately patients are being switched or started on direct oral anticoagulants (DOACs). DOACs are promoted as safer alternatives to warfarin and it is expected that they will be associated with fewer challenges both for patients and healthcare professionals. This systematic narrative review aimed to explore perspectives of patients and professionals on medicines optimisation of oral anticoagulation with vitamin K antagonists and DOACs in atrial fibrillation.

Methods

Prospero registration CRD42018091591. Systematic searches undertaken of research studies (qualitative and quantitative), published February 2018 to November 2020 from several databases (Web of Science, Scopus, Medline Via Ovid, CINHAL via Ebsco, and PubMED via NCBI) following PRISMA methodology. Data were organised using Covidence software. Two reviewers independently assessed the quality of the included studies and synthesized the findings (thematic analysis approach).

Results

Thirty-four studies were included. Studies were critically appraised using established critical appraisal tools (Qualsyst) and a risk of bias was assigned. Clinicians considered old age and the associated complexities such as co-morbidities and the increased potential for bleeding as potential barriers to optimising anticoagulation. Whereas patients’ health and medication beliefs influenced adherence. Notably, structured patient support was important in enhancing safety and effective anticoagulation. For both patients and clinicians, confidence and experience of safe anticoagulation was influenced by the presence of co-morbidities,  poor knowledge and understanding of AF and the purpose of anticoagulation.

Conclusion

Age, complex multimorbidity and polypharmacy influence prescribing, with DOACs being perceived to be safer than warfarin. This systematic narrative review suggests that interventions are needed to support patient self-management. There are residual anxieties associated with long term anticoagulation in the context of complexities.

Trial registration

Not applicable.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-021-01590-x.

Patient-related factors associated with oral anticoagulation control: a population-based cohort study

OBJECTIVES

Time in therapeutic range (TTR) of ≥70% is a commonly used indicator of optimal anticoagulation control. This study aimed to determine the patterns and predictors of anticoagulation control in a population-based cohort of new users of warfarin.

METHODS

This was a retrospective cohort study. All adults (age ≥18 years) who had been newly initiated on warfarin therapy between January 2006 and March 2011were selected from administrative health databases. TTR was calculated using the Rosendaal method. Multivariable logistic regression models were used to identify patient-related factors associated with optimal TTR. Predictors of patients spending >30% of time above and below the therapeutic international normalised ratio (INR) range were also examined.

KEY FINDINGS

A total of 6032 patients were included in this study. The mean TTR was 54.1 ± 18.8%, and 82.3% of patients had subthreshold TTR (<70%). Compared with New Zealand Europeans, Māori and Pacific people had decreased odds of achieving optimal TTR and increased odds of spending >30% of time below the therapeutic INR range. Patients aged 65-74 years and 75 years or older had increased odds of achieving optimal TTR but decreased odds of spending >30% of time below the therapeutic INR range than those <65 years. Compared with those living in the least socioeconomically deprived areas, those living in the most deprived areas had decreased odds of achieving optimal TTR.

CONCLUSIONS

Anticoagulation control with warfarin is suboptimal in routine care in New Zealand. Age, ethnicity and deprivation index were significant predictors of TTR. It is important to ensure equitable access to appropriate, high-quality care for those living in deprived areas and those from ethnic minority groups.

Real-Life International Normalized Ratio Profile in Patients with Non-Valvular Atrial Fibrillation Prescribed Vitamin K Antagonist

Coagulation status with vitamin K antagonists (VKAs) needs to be monitored carefully to ensure maximal efficacy with minimal complication rates.

Aim. To study the international normalized ratio (INR) values in patients on VKAs in selected area, find out which patient characteristics that is associated with good INR control and calculation of the time in the therapeutic range (TTR) according to the number of INR/Patient.

Material and methods. A total of 200 patients with non-valvular atrial fibrillation prescribed vitamin K antagonist as anticoagulant were evaluated. They were divided into two groups: group I with TTR≥65% (n=93) and group II with TTR<65% (n=107). Stroke and hemorrhagic risks were calculated by means of the CHA2DS2-VASc score and HAS-BLED score, respectively. Presence of comorbid diseases was assessed by the Charlson index. TTR was calculated using Rosendaal method.

Results. Patients in group I (TTR≥65%) were younger (p<0.001), more often men (p<0.074) with a high level of education (p<0.001), had lower stroke and hemorrhagic risks (mean CHA2DS2-VASc score was 1.0 and HAS-BLED score – 0.0), and also had fewer comorbidities (mean Charlson index was 0.0; p<0.001) compared to patients in group II (TTR<65%). The rate of inadequate control with VKAs (TTR<65) was 52%. Multivariate logistic regression analysis was done to see the significant independent predictors for a good INR control i.e. TTR≥65%. It was found that high level of education compared to lower levels is the only significant independent predictor for obtaining good INR control (odds ratio=133, 95% confidence interval 34.24-514.44, p<0.001).

Conclusion. It was found that high level of education compared to lower levels is the only significant independent predictor for obtaining good INR control.

National survey on the management of heart failure in individuals over 80 years of age in French geriatric care units

BACKGROUND

To evaluate the prevalence and management of heart failure (HF) in very old patients in geriatric settings.

METHODS

Members of the French Society of Geriatrics and Gerontology throughout France were invited to participate in a point prevalence survey and to include all patients ≥80 years old, hospitalized in geriatric settings, with HF (stable or decompensated) on June 18, 2012. General characteristics, presence of comorbidities, blood tests and medications were recorded.

RESULTS

Among 7,197 patients in geriatric institution, prevalence of HF was 20.5% (n = 1,478): (27% in acute care, 24.2% in rehabilitation care and 18% in nursing home). Mean age was 88.2 (SD = 5.2) and Charlson co morbidity score was high (8.49 (SD = 2.21)). Left ventricular ejection fraction (LVEF) was available in 770 (52%) patients: 536 (69.6%) had a preserved LVEF (≥ 50%), 120 (15.6%) a reduced LVEF (< 40%), and 114 (14.8%) a midrange LVEF (40-49%). Prescription of recommended HF drugs was low: 42.6% (629) used Angiotensin Converting Enzyme Inhibitors (ACEI) or Angiotensin Receptor Blockers (ARBs), 48.0% (709) β-blockers, and 21.9% (324) ACEI or ARB with β-blockers, even in reduced LVEF. In multivariate analysis ACEI or ARBs were more often used in patients with myocardial infarction (1.36 (1.04-1.78)), stroke (1.42 (1.06-1.91)), and diabetes (1.54 (1.14-2.06)). β blockers were more likely used in patients with myocardial infarction (2.06 (1.54-2.76)) and atrial fibrillation (1.70 (1.28-2.28)).

CONCLUSION

In this large very old population, prevalence of HF was high. Recommended HF drugs were underused even in reduced LVEF. These results indicate that management of HF in geriatric settings can still be improved.

Anticoagulation quality and clinical outcomes in multimorbid elderly patients with acute venous thromboembolism

BACKGROUND

Multimorbid patients with acute venous thromboembolism (VTE) are often excluded from clinical trials and little is known about their prognosis.

OBJECTIVES

To examine whether multimorbidity is associated with adverse clinical outcomes and lower anticoagulation quality in older patients with VTE.

PATIENTS/METHODS

We studied 991 patients aged ≥65 years with acute VTE in a Swiss prospective multicenter cohort study. A modified Charlson Comorbidity Index was used to measure multimorbidity, which was defined as the presence ≥2 of 17 predefined comorbid conditions. We examined the association between multimorbidity and recurrent VTE and major bleeding, adjusting for confounders and periods of anticoagulation. We assessed whether the percentage of time spent in the therapeutic international normalized ratio (INR) range varied by the number of comorbidities present.

RESULTS

Overall, 708 (71%) patients were multimorbid. Multimorbid patients had a higher 3-year cumulative incidence of recurrent VTE (16.8 vs. 10.8%; P = 0.056) and major bleeding (18.7 vs. 9.0%; P = 0.001) than non-multimorbid patients. After adjustment, multimorbid patients had a significantly higher risk of recurrent VTE (sub-hazard ratio [SHR] 1.66, 95% confidence interval [CI] 1.08-2.57) and a higher risk of major bleeding (SHR 1.55, 95% CI 0.96-2.50), although the latter failed to achieve statistical significance. With increasing numbers of comorbid conditions, patients spent less time in and more time above and below the therapeutic INR range.

CONCLUSIONS

Multimorbid patients with acute VTE have not only a lower anticoagulation quality but also more complications. Clinical trials should explicitly enroll multimorbid patients to determine the optimal anticoagulation strategy in such patients.

Follow-up and management of valvular heart disease patients with prosthetic valve: a clinical practice guideline for Indian scenario

PURPOSE

Valvular heart disease (VHD) patients after prosthetic valve implantation are at risk of thromboembolic events. Follow-up care of patients with prosthetic valve has a paramount role in reducing the morbidity and mortality. Currently, in India, there is quintessential need to stream line the follow-up care of prosthetic valve patients. This mandates the development of a consensus guideline for the antithrombotic therapy in VHD patients post prosthetic valve implantation.

METHODS

A national level panel was constituted comprising 13 leading cardio care experts in India who thoroughly reviewed the up to date literature, formulated the recommendations, and developed the consensus document. Later on, extensive discussions were held on this draft and the recommendations in 8 regional meetings involving 79 additional experts from the cardio care in India, to arrive at a consensus. The final consensus document is developed relying on the available evidence and/or majority consensus from all the meetings.

RESULTS

The panel recommended vitamin K antagonist (VKA) therapy with individualized target international normalized ratio (INR) in VHD patients after prosthetic valve implantation. The panel opined that management of prosthetic valve complications should be personalized on the basis of type of complications. In addition, the panel recommends to distinguish individuals with various co-morbidities and attend them appropriately.

CONCLUSIONS

Anticoagulant therapy with VKA seems to be an effective option post prosthetic valve implantation in VHD patients. However, the role for non-VKA oral therapy in prosthetic valve patients and the safety and efficacy of novel oral anticoagulants in patients with bioprosthetic valve need to be studied extensively.

Characteristics of patients with thromboembolic disorders on warfarin therapy in resource limited settings

Background

Warfarin is a drug with narrow therapeutic index used in the management of thromboembolic disorders. Several factors affect its plasma concentrations with a resultant risk of toxicity. We examined the database of patients on warfarin therapy in order to establish the factors that affect the stability of INR and correlated them to clinical outcomes in resource limited settings.

Methods

We analysed retrospective data of patients admitted to adult medical wards at Moi Teaching and Referral Hospital (MTRH) in 2015. Inclusion criteria were patients with thromboembolic and related disorders and on warfarin treatment. Derived data included demographics, indications for warfarin use, co-prescribed drugs, co-morbidities, INR measurements, duration of hospital stay and clinical outcomes. Descriptive statistics were used to summarize the data. Pearson’s correlation coefficient was used to assess relationships between duration of hospitalization and number of INR tests. Regression splines were used to capture INR trends during the follow up period. Data was analysed using R v. 3.3.1.

Results

A total of 310 patients had thromboembolic disorders, out of which 63 met the study criteria.

The median age was 48 years, while the mean number of INR measurements was once every four days. Majority of patients did not achieve stable INR values, with only two having consecutive INR values within therapeutic goal. Patients who died had high INR levels. The median duration of hospital stay was 9 days (IQR: 7.0, 16.5). There was a significant correlation between length of stay in hospital and the number of times that INR were measured (Corr = 0.667, p < 0.001). The two most common indications for warfarin were DVT (64.4%) and atrial fibrillation (24.7%). All the patients had one or more comorbid conditions except for 11 with DVT alone, with cardiovascular diseases and infections being the most frequent, and on concomitant medications, majority of which are known to interact with warfarin.

Conclusions

It was difficult to achieve stable INR under the prevailing conditions despite the frequent tests.

The potential factors that may have contributed to the fluctuations include drug-drug interactions, frequency of INR tests, comorbidities and the short duration of hospital stay.

Long-Term Statin Administration Does Not Affect Warfarin Time in Therapeutic Range in Australia or Singapore

BACKGROUND

Warfarin requires ongoing monitoring of the International Normalised Ratio (INR). This is because numerous factors influence the response, including drug interactions with commonly-prescribed medications, such as statins. The administration of statins with warfarin may change INR; however, there is limited information regarding the effects on warfarin control as measured by time in therapeutic range (TTR). Statins may also alter bleeds with warfarin, but there are conflicting reports demonstrating both increased and decreased bleeds, and limited data on diverse ethnic populations. Therefore, the aim of this study was to determine the effect of statin administration on warfarin control and bleeds in patients in Australia and Singapore.

METHODS

Retrospective data were collected for patients on warfarin between January and June 2014 in Australia and Singapore. Patient data were used to calculate TTR and bleed events. Concurrent statin therapy was assessed and comparisons of TTR and bleed incidence were made across patient subgroups.

RESULTS

Warfarin control in Australia and Singapore was not significantly affected by statins, as measured by TTR (83% and 58%, respectively), frequency of testing, and warfarin doses. In Australia, statin use did not significantly affect bleeds, whilst in Singapore the bleed incidence was significantly lower for patients on statins.

CONCLUSIONS

Chronic concurrent administration of statins with warfarin does not adversely affect warfarin TTR in Australia or Singapore. In Singapore, patients on statins, compared to no statins, had a lower bleed incidence and this requires further investigation, especially given the potential genetic influences of ethnicity on both statin and warfarin metabolism.

Direct oral anticoagulants in the treatment of pulmonary embolism

OBJECTIVE

The objective of this review is to examine the management strategies for pulmonary embolism (PE) with an emphasis of the role of direct oral anticoagulants (DOACs).

METHODS

PubMed was searched to identify relevant journal articles published through April 2017. Additional references were obtained from articles discovered during the database search.

RESULTS

Initial heparinization followed by long-term anticoagulation with vitamin K antagonists has been considered the mainstay for the treatment of PE. However, DOACs now offer comparably effective and potentially safer alternatives for both acute and long-term treatment of PE using a monotherapy approach without the need for initial heparinization for rivaroxaban or apixaban. Advantages to using DOACs include oral availability, rapid onset of action, minimal drug and food interactions, predictable pharmacokinetics, and lack of need for routine monitoring. Limitations of using these agents include a limited availability of assays to quickly and efficiently measure their anticoagulant effects and the lack of widely available reversal agents for the direct oral factor Xa inhibitors; although idarucizumab has recently been approved for the reversal of dabigatran's anticoagulant effects.

CONCLUSIONS

Advantages to using DOACs render them an attractive alternative to conventional therapy in PE treatment that may simplify acute and long-term treatment paradigms, improve patient outcomes, and increase patient compliance. However, questions remain pertaining to the use of DOACs in PE patients with high-risk features and in cancer patients and fragile populations. Clinical studies are under way to address many of these issues.

A High HASBLED Score Identifies Poor Warfarin Control in Patients Treated for Non-Valvular Atrial Fibrillation in Australia and Singapore

Warfarin reduces stroke risk in atrial fibrillation (AF) patients. The quality of warfarin control, measured by time in therapeutic range (TTR), impacts outcome and adverse events. One tool evaluating risk of adverse events and potential warfarin control would simplify risk-benefit assessment of warfarin. Recently, HASBLED was demonstrated effective for this purpose, but this was in well-controlled patients with deep vein thrombosis. HASBLED as a predictor of warfarin control has not been validated in other populations including differing indications, warfarin control levels and ethnicities. The aim of this study was to determine whether HASBLED can predict warfarin control in patients with AF in Australia and Singapore. Retrospective data were collected for patients receiving warfarin between January and June 2014 in Australia and Singapore. Patient data were used to calculate HASBLED at the start and end of the study period. TTR was calculated for each patient, and mean TTR used for analysis to stratified HASBLED scores. Of the 4370 patients, there were 3199 in Australia and 1171 in Singapore with mean TTRs of 82% and 58%, respectively. At the start of the study, a HASBLED score ≥3 predicted significantly lower TTR in Singapore, whilst at the end of the study, this score identified patients with poor control in both Australia and Singapore. A HASBLED score ≥3 in patients treated with warfarin can differentiate significantly lower TTRs in Australian and Singapore patients with AF. HASBLED may assess bleed risk and warfarin control, identifying patients at high risk of poor warfarin outcome requiring additional INR monitoring or alternative anticoagulation.

Antithrombotic treatment and characteristics of elderly patients with non-valvular atrial fibrillation hospitalized at Internal Medicine departments. NONAVASC registry

BACKGROUND AND OBJETIVES

The prevalence of non-valvular atrial fibrillation (NVAF) increases with the patient's age and is associated with high morbi-mortality rates. The main goal of this study was to describe the characteristics of hospitalized elderly patients with NVAF and to identify the clinical and functional factors which determine the use of different antithrombotic strategies.

PATIENTS AND METHODS

Observational, prospective, multicentre study carried out on patients with NVAF over the age of 75, who had been admitted for any medical condition to Internal Medicine departments.

RESULTS

We evaluated 804 patients with a mean age of 85 years (range 75-101), of which 53.9% were females. The prevalence of risk factors and cardiovascular disease was high: hypertension (87.6%), heart failure (65.4%), ischemic cardiomyopathy (24.4%), cerebrovascular disease (22.4%) and chronic kidney disease (45%). Among those cases with previous diagnoses of NVAF, antithrombotic treatment was prescribed in 86.2% of patients: anticoagulants (59.7%), antiplatelet medication (17.8%) and double therapy (8.7%). The factors associated with the use of antithrombotic treatment were history of acute coronary syndrome and atrial fibrillation progression longer than one year. Older age, atrial fibrillation for less than one year, higher HAS-BLED scores and severe cognitive impairment were associated with the use of anti-platelet drugs. Permanent atrial fibrillation favoured the use of anticoagulants.

CONCLUSIONS

Hospitalized patients older than 75 years old with NVAF showed numerous comorbidities. The percentage of anticoagulation was small and 18% received only anti-platelet therapy. The patient's age, atrial fibrillation's progression time and the severity of the cognitive impairment influenced this therapy choice.

Identifying Drug-Drug Interactions by Data Mining: A Pilot Study of Warfarin-Associated Drug Interactions

BACKGROUND

Knowledge about drug-drug interactions commonly arises from preclinical trials, from adverse drug reports, or based on knowledge of mechanisms of action. Our aim was to investigate whether drug-drug interactions were discoverable without prior hypotheses using data mining. We focused on warfarin-drug interactions as the prototype.

METHODS AND RESULTS

We analyzed altered prothrombin time (measured as international normalized ratio [INR]) after initiation of a novel prescription in previously INR-stable warfarin-treated patients with nonvalvular atrial fibrillation. Data sets were retrieved from clinical work. Random forest (a machine-learning method) was set up to predict altered INR levels after novel prescriptions. The most important drug groups from the analysis were further investigated using logistic regression in a new data set. Two hundred and twenty drug groups were analyzed in 61 190 novel prescriptions. We rediscovered 2 drug groups having known interactions (β-lactamase-resistant penicillins [dicloxacillin] and carboxamide derivatives) and 3 antithrombotic/anticoagulant agents (platelet aggregation inhibitors excluding heparin, direct thrombin inhibitors [dabigatran etexilate], and heparins) causing decreasing INR. Six drug groups with known interactions were rediscovered causing increasing INR (antiarrhythmics class III [amiodarone], other opioids [tramadol], glucocorticoids, triazole derivatives, and combinations of penicillins, including β-lactamase inhibitors) and two had a known interaction in a closely related drug group (oripavine derivatives [buprenorphine] and natural opium alkaloids). Antipropulsives had an unknown signal of increasing INR.

CONCLUSIONS

We were able to identify known warfarin-drug interactions without a prior hypothesis using clinical registries. Additionally, we discovered a few potentially novel interactions. This opens up for the use of data mining to discover unknown drug-drug interactions in cardiovascular medicine.

A multi-factorial analysis of response to warfarin in a UK prospective cohort

Background

Warfarin is the most widely used oral anticoagulant worldwide, but it has a narrow therapeutic index which necessitates constant monitoring of anticoagulation response. Previous genome-wide studies have focused on identifying factors explaining variance in stable dose, but have not explored the initial patient response to warfarin, and a wider range of clinical and biochemical factors affecting both initial and stable dosing with warfarin.

Methods

A prospective cohort of 711 patients starting warfarin was followed up for 6 months with analyses focusing on both non-genetic and genetic factors. The outcome measures used were mean weekly warfarin dose (MWD), stable mean weekly dose (SMWD) and international normalised ratio (INR) > 4 during the first week. Samples were genotyped on the Illumina Human610-Quad chip. Statistical analyses were performed using Plink and R.

Results

VKORC1 and CYP2C9 were the major genetic determinants of warfarin MWD and SMWD, with CYP4F2 having a smaller effect. Age, height, weight, cigarette smoking and interacting medications accounted for less than 20 % of the variance. Our multifactorial analysis explained 57.89 % and 56.97 % of the variation for MWD and SMWD, respectively. Genotypes for VKORC1 and CYP2C9*3, age, height and weight, as well as other clinical factors such as alcohol consumption, loading dose and concomitant drugs were important for the initial INR response to warfarin. In a small subset of patients for whom data were available, levels of the coagulation factors VII and IX (highly correlated) also played a role.

Conclusion

Our multifactorial analysis in a prospectively recruited cohort has shown that multiple factors, genetic and clinical, are important in determining the response to warfarin. VKORC1 and CYP2C9 genetic polymorphisms are the most important determinants of warfarin dosing, and it is highly unlikely that other common variants of clinical importance influencing warfarin dosage will be found. Both VKORC1 and CYP2C9*3 are important determinants of the initial INR response to warfarin. Other novel variants, which did not reach genome-wide significance, were identified for the different outcome measures, but need replication.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-015-0255-y) contains supplementary material, which is available to authorized users.