Atrial fibrillation ups in-hospital mortality in patients with acute aortic syndromes

In-hospital mortality, but not stroke, is greater among patients presenting with acute aortic syndromes and atrial fibrillation (AF) than those without AF, a study has shown.

“The presence of AF appears be an adverse prognostic event in patients with acute aortic syndromes,” the researchers said. “However, further study is needed to determine the mechanism for early mortality and identify interventions to improve survival.”

The study included 309 consecutive patients with acute aortic syndromes admitted to a single tertiary care centre from January 2015 to March 2020. The researchers then identified AF patients on the presenting electrocardiogram (ECG).

Of the participants, 148 (48 percent) presented with Stanford type A and 161 (52 percent) with Stanford type B acute aortic syndromes. Twenty-seven (8.7 percent) patients had AF on the presenting ECG, of whom 12 (44 percent) had type A and 15 (56 percent) had type B acute aortic syndromes. [Am J Med 2021;134:1419-1423]

Patients with AF were older, more likely to be White, and to have a history of cancer, peripheral artery disease (PAD), cerebrovascular disease, and heart failure with preserved ejection fraction (HFpEF) compared to those without AF.

The frequency of in-hospital mortality was higher among acute aortic syndromes patients with AF than those without AF (40.7 percent vs 12.4 percent; p<0.0001). On the other hand, stroke frequency did not differ significantly between the two cohorts.

“This observation may be explained, at least in part, by the older age and higher prevalence of comorbidities, including a prior diagnosis of AF, history of cancer, PAD, stroke/transient ischaemic attack, and HFpEF, observed in the AF group,” the researchers said. [J Thorac Cardiovasc Surg 2005;129:112-122; Circulation 2014;130:S45-S50]

“In support of this hypothesis, an analysis of the International Registry of Acute Aortic Dissection data identified age ≥70 years as an independent predictor of in-hospital mortality in patients with type A dissection,” they added. [J Am Coll Cardiol 2002;40:685-692]

These findings suggest that AF may be used as a surrogate marker of risk for in-hospital mortality instead of being a causal factor, according to the researchers.

Of note, the absence of a difference in the frequency of stroke between acute aortic syndromes patients with and without AF could be explained by the intervening presence of multiple cardiovascular risk rather than by AF in isolation. In addition, more than 60 percent of the AF patients were on anticoagulation at presentation, which might have reduced their risk of stroke.

“Our study is unique in the inclusion of a cohort of patients with a wide spectrum of acute aortic syndrome, which was managed either surgically or with medical therapy alone at a single tertiary academic medical centre,” the researchers said.

“The multidisciplinary care approach from diagnosis throughout admission lends strength to the ascertainment of endpoints and entry criteria,” they added. [J Am Coll Cardiol 2019;73:2477-2486]