Antti Palomäki

Underuse of anticoagulation in stroke patients with atrial fibrillation – the FibStroke Study

Current guidelines recommend oral anticoagulation (OAC) for patients with atrial fibrillation (AF) and increased risk of thromboembolic events. The reasons for not using OAC in AF patients suffering stroke or transient ischaemic attack (TIA) were assessed.

Strokes after cardioversion of atrial fibrillation--The FibStroke study.

BACKGROUND Cardioversion of atrial fibrillation (AF) is associated with an increased risk for stroke. We identified all cardioversions during the 30 days preceding stroke or transient ischemic attack (TIA) in patients with a previously diagnosed AF, and sought to assess the characteristics of cardioversions leading to stroke or TIA. METHODS FibStroke is a cross-sectional observational multicenter registry that included AF patients with an ischemic stroke or intracranial bleed identified from a discharge registry of four Finnish hospitals. In total 3677 consecutive AF patients suffered 3252 strokes and 956 TIA episodes during 2003–2012. This pre-specified analysis focused on the 1644 events that occurred to patients with paroxysmal or persistent AF at the time of stroke/TIA. RESULTS A total of 78 strokes and 22 TIA episodes were preceded by a cardioversion. Post-cardioversion strokes accounted for 6.4% of strokes in patients with paroxysmal/persistent AF. Of the 100 cardioversions leading to an ischemic event, 77 were acute and 23 were elective, 63 events occurred in patients not using anticoagulation, and 5 patients had periprocedural INR < 2. Importantly, 21 patients were in low risk of stroke, i.e. CHA2DS2-VASc score < 2. The median delay from cardioversion to event was 2 days. All nine patients who after an unsuccessful cardioversion developed a stroke had a spontaneous cardioversion prior to stroke. CONCLUSIONS Every sixteenth stroke of patients with paroxysmal/persistent AF is preceded by a cardioversion. Most post-cardioversion strokes occur in patients not using oral anticoagulation before cardioversion of acute AF.

Stroke as the First Manifestation of Atrial Fibrillation

Atrial fibrillation may remain undiagnosed until an ischemic stroke occurs. In this retrospective cohort study we assessed the prevalence of ischemic stroke or transient ischemic attack as the first manifestation of atrial fibrillation in 3,623 patients treated for their first ever stroke or transient ischemic attack during 2003–2012. Two groups were formed: patients with a history of atrial fibrillation and patients with new atrial fibrillation diagnosed during hospitalization for stroke or transient ischemic attack. A control group of 781 patients with intracranial hemorrhage was compiled similarly to explore causality between new atrial fibrillation and stroke. The median age of the patients was 78.3 [13.0] years and 2,009 (55.5%) were women. New atrial fibrillation was diagnosed in 753 (20.8%) patients with stroke or transient ischemic attack, compared to 15 (1.9%) with intracranial hemorrhage. Younger age and no history of coronary artery disease or other vascular diseases, heart failure, or hypertension were the independent predictors of new atrial fibrillation detected concomitantly with an ischemic event. Thus, ischemic stroke was the first clinical manifestation of atrial fibrillation in 37% of younger (<75 years) patients with no history of cardiovascular diseases. In conclusion, atrial fibrillation is too often diagnosed only after an ischemic stroke has occurred, especially in middle-aged healthy individuals. New atrial fibrillation seems to be predominantly the cause of the ischemic stroke and not triggered by the acute cerebrovascular event.

Stroke recurrence in patients with atrial fibrillation: concomitant carotid artery stenosis doubles the risk

Atrial fibrillation (AF) and significant carotid artery stenosis (CAS) often coexist in patients with acute stroke but whether CAS affects the stroke recurrence rate in anticoagulated AF patients is largely unknown. The effect of concomitant CAS on both short‐ and long‐term prognosis after stroke in patients with AF was evaluated.

Postoperative Strokes and Intracranial Bleeds in Patients With Atrial Fibrillation: The FibStroke Study

Patients with atrial fibrillation (AF) frequently undergo invasive procedures. Optimal perioperative use of oral anticoagulation (OAC) and heparin bridging is not well defined.

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.

Traumatic and spontaneous intracranial hemorrhage in atrial fibrillation patients on warfarin

Background Intracranial hemorrhage is the most devastating complication in patients with atrial fibrillation (AF) receiving oral anticoagulation (OAC). It can be either spontaneous or caused by head trauma. We sought to address the prevalence, clinical characteristics, and prognosis of traumatic and spontaneous intracranial hemorrhages in AF patients on OAC. Methods Multicenter FibStroke registry of 5,629 patients identified 592 intracranial hemorrhages during warfarin treatment between 2003 and 2012. Results A large proportion (40%) of intracranial hemorrhages were traumatic. Of these, 64% were subdural hemorrhages (SDHs) and 20% intracerebral hemorrhages (ICHs). With respect to the spontaneous hemorrhages, 25% were SDHs and 67% ICHs. Patients with traumatic hemorrhage were older (81 vs 78 years, p = 0.01) and more often had congestive heart failure (30% vs 16%, p < 0.01) and anemia (7% vs 3%, p = 0.03) compared to patients with spontaneous hemorrhage. Admission international normalized ratio (INR) values (2.7 vs 2.7, p = 0.79), as well as CHA2DS2-VASc (median 4 vs 4, p = 0.08) and HAS-BLED (median 2 vs 2, p = 0.05) scores, were similar between the groups. The 30-day mortality after traumatic hemorrhage was significantly lower than after spontaneous hemorrhage (25% vs 36%, p < 0.01). Conclusions A significant proportion of intracranial hemorrhages in anticoagulated AF patients were traumatic. Traumatic hemorrhages were predominantly SDHs and less often fatal when compared to spontaneous hemorrhages, which were mainly ICHs. Admission INR values as well as CHA2DS2-VASc and HAS-BLED scores were similar in patients with spontaneous and traumatic intracranial hemorrhage. Clinicaltrials.gov identifier NCT02146040.

How do anticoagulated atrial fibrillation patients who suffer ischemic stroke or spontaneous intracerebral hemorrhage differ

Atrial fibrillation (AF) increases risk of ischemic stroke, and oral anticoagulation (OAC) increases risk of intracerebral hemorrhage (ICH). This study aimed to compare OAC‐treated AF patients with an ischemic stroke/transient ischemic attack (TIA) or spontaneous ICH as their first lifetime cerebrovascular event, especially focusing on patients with therapeutic international normalized ratio (INR).

Usefulness of the CHA 2 DS 2 -VASc and HAS-BLED Scores in Predicting the Risk of Stroke Versus Intracranial Bleeding in Patients with Atrial Fibrillation (From the FibStroke Study)

CHA2DS2-VASc and HAS-BLED scores stratify the risk of thromboembolic and bleeding events respectively in patients with atrial fibrillation. There is only little information on how they differentiate which of the 2 clinically most important complications (ischemic stroke [IS] or an intracranial bleeding [IB]) the patient is more prone to suffer. We evaluated both scores in patients with either of these major complications. The FibStroke Study collected data on all patients with atrial fibrillation with either an IS or an IB event between 2003 and 2012 in 4 Finnish hospital districts. Individual electronic patient records were manually reviewed to collect the study data. To assess the relative risk of IS and IB, an IS/IB-ratio was calculated by dividing the absolute number of ISs with the absolute number of IBs within each score category. A total of 3,816 (82.7%) ISs and 798 (17.3%) IBs were detected in 3,909 patients. In general, ISs occurred more often than IBs in patients on oral anticoagulation in each score category (ratio 1.6 to 5.1). The ratio decreased below 1, however, only with very high HAS-BLED scores (>4). Moreover, 221 ISs and 53 IBs occurred in patients with HAS-BLED > CHA2DS2-VASc, of whom only 19.7% were on anticoagulation. In conclusion, IS was the predominant intracranial event irrespective of CHA2DS2-VASc score, HAS-BLED score ≤4, or use of oral anticoagulation, also in patients with low estimated thromboembolic risk (CHA2DS2-VASc 0 to 1). Furthermore, the HAS-BLED score predicted the excess of IBs over ISs only at very high-risk levels.

INTRACRANIAL BLEEDINGS AND ISCHEMIC STROKES DURING WARFARIN TREATMENT IN PATIENTS WITH ATRIAL FIBRILLATION: THE FIBSTROKE STUDY

Anticoagulation therapy with warfarin is effective in the prevention of ischemic strokes in patients with atrial fibrillation (AF) but predisposes to intracranial bleedings. In this retrospective study data from 1,867 patients with a history of AF and ischemic stroke, transient ischemic attack (TIA