Elsevier

The American Journal of Cardiology

Volume 159, 15 November 2021, Pages 87-93
The American Journal of Cardiology

Comparison of Low and Full Dose Apixaban Versus Warfarin in Patients With Atrial Fibrillation and Renal Dysfunction (from a National Registry)

https://doi.org/10.1016/j.amjcard.2021.08.022Get rights and content

The use of direct oral anticoagulants for stroke prevention in patients with non-valvular atrial fibrillation (NVAF) is robust. However, the efficacy and safety of different dosage in patients with renal dysfunction is still a clinical challenge. We aimed to evaluate the clinical characteristics and outcomes of patients treated with apixaban in its different doses. A multicenter prospective cohort study, where consecutive eligible apixaban or warfarin treated patients with NVAF and renal impairment, were registered. Patients were followed-up for clinical events over a mean period of 1 year. Analyses were performed according to the dose of apixaban given, with consideration to the standard indications for dose reduction. Primary outcome was a composite of 1-year mortality, stroke or systemic embolism, major bleeding and myocardial infarction, while secondary outcomes included those components separated. Among the study population (n = 2,140), risk of composite outcome was significantly lower in the high dose apixaban group (10%, n = 491) than the low dose group (18%, n = 673) and the warfarin group (18%, n = 976) p <0.001. Results of 1-year mortality were similar. Apixaban dosing analysis revealed 65% of patients were appropriately dosed, while 31% were under-dosed and 4% were over-dosed. Furthermore, 53% of patients treated with low dose apixaban were under-dosed. Propensity score analysis revealed that patients who were appropriately treated with low-dose apixaban had a trend towards better composite outcome and mortality than 1:1 matched warfarin treated patients (18% vs 24%, p = 0.09 and 16% vs 23%, p = 0.06, respectively). Overall, appropriately dosed apixaban treated patients at any dose had significantly better outcomes than matched warfarin treated patients (composite outcome probability of 13.1% vs 18.6%, p = 0.007). In conclusion, apixaban at any dose is a reasonable alternative to warfarin in patients with renal impairment, possibly associated with improved outcomes.

Section snippets

Methods

This is a multicenter prospective cohort study where consecutive eligible patients with NVAF and renal impairment were registered between March 2014 and August 2017 in ten medical centers across Israel. Inclusion criteria were recent apixaban or warfarin prescription (within 3 months), according to treating physician discretion, renal impairment defined as eGFR MDRD below 60 ml/min/BSA, and signing a consent form. Patients were excluded if they had valvular atrial fibrillation or presence of

Results

A total of 2,232 patients were enrolled at 10 Israeli sites from November 2015 to August 2017. The current analysis includes 2,140 patients with full data who have completed the follow-up. The warfarin group included 976 (45.6%) patients, whereas the apixaban group included 1164 (54.4%) patients (5 mg [high dose] 491 and 2.5 mg [low dose] 673).

Table 1 provides the patient's characteristics and outcomes according to the 3 treatment regimens. The apixaban groups' subjects had high mean

Discussion

In this multicenter prospective cohort study we have compared between patients with NVAF and renal dysfunction treated by warfarin with those treated by high or low dose apixaban.

This study revealed several findings:

  • Overall, the high dose apixaban group had a better prognosis than the low dose apixaban group and the warfarin group.

  • In propensity score analysis demonstrated the appropriately low dose apixaban group had a trend towards better outcomes than the warfarin group.

  • Appropriately dosed

Disclosures

Ilan Goldenberg reports financial support was provided by Pfizer Inc. Ilan Goldenberg reports a relationship with Pfizer Inc that includes: funding grants.

Alon Barsheshet and Robert Klempfner have received speaker honoraria from Boehringer Ingelheim, Pfizer, and Bayer.

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These authors contributed equally to this work.

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