Table 2.
Meta-analyses comparing outcomes in atrial fibrillation patients prescribed different types of antithrombotic medications.
| Study | Number of Patients (n) | Study Design | Treatment(s) | Outcomes (Primarily Regarding the Incidence of Stroke) | Haemorrhagic Adverse Events |
|---|---|---|---|---|---|
| Carnicelli et al. [59] | 71,683 | Meta-analysis | Standard-dose DOACs vs. lower-dose DOACs vs. warfarin | Relative to warfarin, standard-dose DOACs were linked to significant decreases in the risk of stroke or systemic embolism (HR 0.81 [95% CI 0.74–0.89]) and mortality (HR 0.92 [95% CI 0.87–0.97]). When compared to warfarin, lower-dose DOACs were not associated with a significant difference in the risk of stroke or systemic embolism (HR 1.06 [95% CI 0.95–1.19]). However, there was a significant decrease in mortality (HR 0.90, [95% CI 0.83–0.97]. |
Relative to warfarin, standard-dose DOACs were linked to a significant decrease in the risk of intracranial bleeding (HR 0.45 [95% CI 0.37–0.56]) but not in the risk of major bleeding (HR 0.86, 95% CI [0.74–1.01]). On the other hand, when compared to warfarin, lower dose DOACs were associated with a lower risk of both intracranial bleeding (HR 0.28 [95% CI 0.21–0.37]) and major bleeding (HR 0.63 [95% CI 0.45–0.88]). |
| Erdem et al. [60] | 73,122 | Meta-analysis | DOACs vs. warfarin | Compared to warfarin, there was a decreased risk of stroke or systemic embolism when taking DOACs in patients ≥ 75 years old (RR 0.57 [95% CI 0.42–0.76]) and patients < 75 years old (RR 0.74, 95% CI [0.43, 1.27]). This was statistically significant for ages ≥75 years but not ages <75 years. | Compared to warfarin, there was a significantly lower risk of major bleeding in patients taking DOACs who were ≥75 years old (RR 0.74 [95% CI 0.63–0.87]) as well as in those <75 years old (RR 0.64 [95% CI 0.44–0.93]). |
| Zeng et al. [61] | 835,520 | Meta-analysis | DOACs vs. warfarin | Relative to warfarin, DOACs were associated with a significantly lower risk of ischemic stroke (HR 0.79 [95% CI 0.71–0.87]) and mortality (HR 0.90 [95% CI 0.84–0.96]). | Relative to warfarin, DOACs were associated with a significantly lower risk of intracranial bleeding (HR 0.58 [95% CI 0.52–0.65]) and major bleeding (HR 0.79 [95% CI 0.64–0.97]) but no significant decrease in the risk of gastrointestinal bleeding (HR 0.97 [95% CI 0.73–1.29]). |
| Tereshchenko et al. [62] | 96,017 | Meta-analysis | Aspirin vs. VKAs vs. DOACs vs. placebo | After adjusting for other variables, treatment with VKAs and DOACs led to significantly lower rates of stroke or systemic embolism compared to placebo. However, the odds were not significantly lower for patients taking aspirin compared to placebo (aOR 0.77 [95% CI 0.53–1.11]). | After adjusting for other variables, there was no significant difference in the rates of major bleeding between treatments with aspirin, VKAs, and DOACs. |
Abbreviations: AF = atrial fibrillation, DOAC = direct-acting oral anticoagulant, RR = relative risk, CI = confidence interval, HR = hazard ratio, OR = odds ratio, aOR = adjusted odds ratio, VKA = vitamin K-antagonists.