Risk of Cardiovascular Events and Incident Atrial Fibrillation in Patients without Prior Atrial Fibrillation: Implications for Expanding the Indications for Anticoagulation

5 years ago

Risk of Cardiovascular Events and Incident Atrial Fibrillation in Patients without Prior Atrial Fibrillation: Implications for Expanding the Indications for Anticoagulation

There is growing interest in the role for non-vitamin K antagonist oral anticoagulants (NOACs) in patients without atrial fibrillation (AF). We aimed to provide a comprehensive assessment of the risks of ischemic stroke, myocardial infarction (MI), AF, and major bleeding in patients without previously diagnosed AF.

Methods

Using a large U.S. administrative database, we identified 6,495,875 patients ≥50 years between 1/1/2011–9/30/2016, who were not diagnosed with AF and were not treated with oral anticoagulants or non-aspirin antiplatelet agents. We assessed the risks by age, sex, the number of risk factors, and the combination of risk factors. We also calculated the number needed to treat (NNT) or harm (NNH) based on the untreated risks in our dataset and relative risks of NOAC treatment derived from a recent clinical trial.

Results

The event rates were 0.67%/year for ischemic stroke or MI, 0.96%/year for AF, and 0.52%/year for major bleeding. Among patients who had a stroke during follow up, 84% were not diagnosed with AF at any time, and only 5% were diagnosed with AF before the stroke. Patients who had low NNT for cardiovascular risk reduction (i.e., potentially benefiting the most from the addition of NOACs) also had low NNH for major bleeding (i.e., facing serious harm).

Conclusions

Patients without diagnosed AF but with certain risk factors were at a particularly high cardiovascular risk and may require new prevention approaches. In addition to the ongoing trials, future trials in other high-risk populations, e.g., diabetes and chronic kidney disease may be warranted.

Publisher URL: www.sciencedirect.com/science

DOI: S0002870318300474