Mortality after stroke in patients with paroxysmal and chronic atrial fibrillation - The FibStroke study

Background: Recent studies have reported that patients with paroxysmal atrial fibrillation (AF) have lower risk of thromboembolism and better prognosis than patients with chronic AF. We sought to address the differences in ischaemic events in patients with paroxysmal AF and chronic AF.

Methods: The FibStroke study is a cross-sectional observational multicenter registry that included AF patients with an ischaemic stroke, TIA (transient ischaemic attack) or intracranial bleed during 2003-2012 identified from discharge registries of four Finnish hospitals. Altogether 1448 patients with paroxysmal and 1808 patients with chronic atrial fibrillation suffered a total of 707 TIA-episodes and 2549 ischaemic strokes.

Results: Mortality within 30days after the index event was significantly lower in patients with paroxysmal AF than with chronic AF (7.6% vs 16.9%, p<0.01). At the onset of event, 62.8% of the patients with paroxysmal AF were in sinus rhythm, and these patients had better prognosis after the event compared to patients with other rhythm than sinus rhythm (mortality 5.2% vs 15.7%, p<0.01). In the propensity score matched analysis mortality after stroke was significantly lower in patients with paroxysmal AF than in patients with chronic AF (11.6% vs 17.8%, p<0.01), while mortality after TIA was also lower, but did not reach statistical significance (0.4% vs 1.7%, p=0.31).

Conclusions: A significant proportion of strokes in AF patients occur in patients with paroxysmal AF, but they have better prognosis than patients with chronic AF. The prognosis is also significantly better in patients who are in sinus rhythm at the onset of event.