The quality of warfarin therapy and CHA2DS2-VASc score associate with the incidence of myocardial infarction and cardiovascular outcome in patients with atrial fibrillation: data from the nationwide FinWAF Registry

Associations of anaemia with bleeding and thrombotic complications in patients with atrial fibrillation treated with warfarin: a registry-based nested case-control study

OBJECTIVES

We studied association of laboratory testing beyond the international normalised ratio (INR) with bleeding and stroke/transient ischaemic attack (TIA) outcomes in patients with atrial fibrillation treated with warfarin.

DESIGN

This was a retrospective nested case-control study from the Finnish Warfarin in Atrial Fibrillation (FinWAF) registry (n=54 568), reporting the management and outcome in warfarin-anticoagulated patients. Associations of blood count test frequency and results were assessed together with risk of bleeding or stroke/TIA during 5-year follow-up.

SETTING

National FinWAF registry, with data from all six hospital districts. Follow-up period for complications was 1 January 2007-31 December 2011.

PARTICIPANTS

A total of 54 568 warfarin-anticoagulated patients.

RESULTS

The number of patients with bleeding was 4681 (9%) and stroke/TIA episodes, 4692 (9%). In patients with bleeds, lower haemoglobin (within 3 months) preceded the event compared with the controls (median 126 vs 135 g/L; IQR 111-141 g/L vs 123-147 g/L, p<0.001), while patients with stroke/TIA had only modestly lower INR (median 2.2 vs 2.3; 1.8-2.6 vs 2.1-2.7, p<0.001). When the last measured haemoglobin was below the reference value (130 g/L for men, 120 g/L for women), the OR for a bleeding complication was 2.9 and stroke/TIA, 1.5. If the haemoglobin level was below 100 g/L, the complication risk increased further by 10-fold. If haemoglobin values were repeatedly (more than five times) low during the preceding 3 months, future OR was for bleeds 2.3 and for stroke/TIA 2.4.

CONCLUSIONS

The deeper the anaemia, the higher the risk of bleeding and stroke/TIA. However, INR remained mainly at its target and only occasionally deviated, failing to detect the complication risk. Repeated low haemoglobin results, compatible with persistent anaemia, refer to suboptimal management and increased the complication risk in anticoagulated patients.

Comparative analysis of left atrial appendage closure efficacy and outcomes by CHA2DS2-VASc score group in patients with non-valvular atrial fibrillation

Background

Higher CHA₂DS₂-VASc score is associated with an increased risk of adverse cardio-cerebrovascular events in patients with non-valvular atrial fibrillation (NVAF), regardless of oral anticoagulation (OAC) status. However, whether this association still exists in patients undergoing left atrial appendage closure (LAAC) is unknown. We evaluated the impact of CHA₂DS₂-VASc score on LAAC efficacy and outcomes.

Methods

A total of 401 consecutive patients undergoing LAAC were included and divided into 3 groups based on CHA₂DS₂-VASc score (0–2, 3–4, and ≥5). Baseline characteristics, periprocedural complications, and long-term outcomes were collected and compared across all groups.

Results

There were no significant differences in implantation success, periprocedural complications, and long-term outcomes across all score groups. Kaplan-Meier estimation showed that the cumulative ratio of freedom from all-cause mortality (P = 0.146), cardiovascular mortality (P = 0.519), and non-cardiovascular mortality (P = 0.168) did not differ significantly by CHA₂DS₂-VASc score group. LAAC decreased the risks of thromboembolism and major bleeding, resulting in a relative risk reduction (RRR) of 82.4% (P < 0.001) and 66.7% (P < 0.001) compared with expected risks in the overall cohort, respectively. Subgroup analysis indicated that observed risks of thromboembolism and major bleeding were significantly lower than the expected risks in score 3–4 and score ≥5 groups, respectively. The level of RRR increased with CHA₂DS₂-VASc score (P < 0.001 for trend) for thromboembolism but not for major bleeding (P = 0.2729 for trend).

Conclusion

Patients with higher CHA₂DS₂-VASc score did not experience worse outcomes, which may be partly attributed to more benefits provided by LAAC intervention in such patients compared to those with a low score.

Cost-Effectiveness of Apixaban versus Other Direct Oral Anticoagulants and Warfarin in the Prevention of Thromboembolic Complications Among Finnish Patients with Non-Valvular Atrial Fibrillation

Purpose

Direct oral anticoagulant (DOAC) use for the prevention of thromboembolic complications in patients with non-valvular atrial fibrillation (AF) has increased steadily in Finland. DOACs have been shown to be cost-effective in comparison to warfarin, but published evidence of relative cost-effectiveness between DOACs is still scarce and mostly based on indirect comparisons of clinical trial evidence. The aim of this study was to compare the cost-effectiveness of apixaban to dabigatran, rivaroxaban and warfarin in a Finnish setting using real-life evidence where available.

Patients and Methods

A lifetime Markov simulation model used previously in a published Finnish assessment comparing apixaban and warfarin was modified and updated with the relative effectiveness and safety data available from the real-world NAXOS-study and representative Finnish input data for patient characteristics, event risks, mortality, resource use, costs, and quality of life. Apixaban’s cost-effectiveness was assessed from health care payer perspective (using 3% per year discount rate) based on incremental cost-effectiveness ratio (ICER, cost per quality-adjusted life year [QALY] gained), probability of cost-effectiveness (at willingness-to-pay [WTP] of 35,000 euros/QALY), and net monetary benefit (NMB).

Results

Apixaban increased the average modelled quality-adjusted life-expectancy and reduced the average total health care costs of AF patients when compared to warfarin (+0.14 QALYs, −3691 euros), dabigatran (+0.11 QALYs, −404 euros), and rivaroxaban (+0.03 QALYs, −43 euros). The resulting NMB of apixaban versus warfarin, dabigatran and rivaroxaban was 8723, 4168, and 1129 euros, respectively. The respective probabilities of apixaban being cost-effective against each comparator were 100%, 92.7%, and 64.0%.

Conclusion

In this modelling study, apixaban dominated other anticoagulants in the Finnish real-life setting.

Coronary heart disease and atrial fibrillation: a vicious cycle

The population suffering from coronary heart disease (CHD) complicated by atrial fibrillation (AF) is rising rapidly. A strong correlation between the two diseases has been reported, and the many common risk factors they share may play prominent roles in their development. In addition, CHD can directly promote the progression of AF by affecting reentry formation, focal ectopic activity, and neural remodeling. At the same time, AF also affects CHD through three aspects: 1) atherosclerosis, 2) the mismatch of blood supply and oxygen consumption, and 3) thrombosis. In conclusion, CHD and AF can aggravate each other and seem to form a vicious cycle. For patients with CHD complicated by AF, principal studies and guidelines have focused on antithrombotic treatment and rhythm control, which are paramount for these patients. Of note, our review sheds light on the strategies to break the cycle of the two diseases, which may be fundamental to treat these patients and optimize the benefit.

Who approves/pays for additional monitoring?

Major considerations in the provision of healthcare are availability, affordability, accessibility, and appropriateness, especially in the setting of heart failure where disease burden is growing, developments have been rapid and newer biomarkers, diagnostic and imaging techniques, monitoring systems, devices, procedures, and drugs have all been developed in a relatively short period of time. Many monitoring and diagnostic systems have been developed but the disproportionate cost of conducting trials of their effectiveness has limited their uptake. There are added complexities, in that the utilization of doctors for the supervision of the monitoring results may be optimal in one setting and not in another because of differences in the characteristics of organization of healthcare provision, making even interpretation of the trials we have had, still difficult to interpret. New technologies are continuously changing the approach to healthcare and will reshape the structure of the healthcare systems in the future. Mobile technologies can empower patients and carers by giving them more control over their health and social care needs and reducing their dependence on healthcare professionals for monitoring their health, but a significant problem is the integration of the multitude of monitored parameters with clinical data and the recognition of intervention thresholds. Digital technology can help, but we need to prove its cost/efficacy and how it will be paid for. Governments in many European countries and worldwide are trying to establish frameworks that promote the convergence of standards and regulations for telemedicine solutions and yet simultaneously health authorities are closely scrutinizing healthcare spending, with the objective of reducing and optimizing expenditure in the provision of health services. There are multiple factors to be considered for the reimbursement models associated with the implementation of physiological monitoring yet it remains a challenge in cash-strapped health systems.