AF appears to worsen outcomes in patients with MI

In a new study, atrial fibrillation, regardless of type, was associated with increased risk for death, reinfarction and ischemic stroke in patients with MI.

Researchers analyzed 155,071 survivors of MI between 2000 and 2009 from Swedish registries to determine whether the different types of AF had any effect on death and CV outcomes in this population.

The outcomes of interest were a composite of all-cause mortality, MI and ischemic stroke, and individual components of that composite. Follow-up was 90 days.

Gorav Batra, MD, and colleagues found that 15.5% of the cohort had AF (new-onset AF with sinus rhythm at discharge, 3.7%; new-onset AF with AF at discharge, 3.9%; paroxysmal AF, 4.9%; chronic AF, 3%).

Those with AF had an event rate of the composite outcome of 90.9 per 100 person-years vs. 45.2 per 100 person-years in those without AF (HR = 1.28; 95% CI, 1.19-1.37), according to the researchers.

There were no differences in the composite outcome between the subtypes of AF, Batra, from Uppsala Clinical Research and Department of Medical Sciences, Cardiology, Uppsala University, Sweden, and colleagues found.

Compared with no AF, presence of AF was associated with elevated risk for mortality (HR = 1.59; 95% CI, 1.41-1.8), reinfarction (HR = 1.14; 95% CI, 1.05-1.24) and ischemic stroke (HR = 2.29; 95% CI, 1.92-2.74).

AF conferred higher risk for the composite outcome regardless of whether a patient had STEMI (HR = 1.34; 95% CI, 1.21-1.48) or non-STEMI (HR = 1.24; 95% CI, 1.13-1.36; P for interaction = .23), Batra and colleagues wrote.

“Possible explanations supporting the increased risk of MI in patients with AF might be that both conditions share similar pathophysiological pathways and that AF might be a marker for illness, inflammation and structural heart disease,” they wrote.

They added that the mortality results “might reflect on AF as a marker for illness and structural heart disease” and the stroke results imply that “a careful evaluation of antithrombotic medication at discharge must be considered for all patients with AF, including those with sinus rhythm at discharge. Despite the known benefit of oral anticoagulants in patients with AF, less than a quarter of the patients in our study received oral anticoagulants at discharge.” – by Erik Swain

Source: www.healio.com