Home » Posts tagged 'atrial fibrillation'
Tag Archives: atrial fibrillation
BRIDGE Trial Summary: Douketis JD et al. randomized 1,884 patients on warfarin (INR 2-3 for ≥3m) with AF or A-flutter and CHADS2 Score ≥1 to LMWH: dalteparin (100 IU/kg BID) or placebo. The objective was to assess if bridging anticoagulation reduce rates of arterial thromboembolism compared to no bridging in patients with atrial fibrillation undergoing an invasive procedure. The results showed noninferiority (P=0.01) of the primary outcome (TIA or stroke or arterial embolism) in patients with no bridging as compared with bridging. The authors of the BRIDGE trial concluded that among patients with low- and intermediate-risk atrial fibrillation receiving anticoagulation and undergoing an invasive procedure, periprocedural bridging anticoagulation with LMWH did not reduce the incidence of arterial thromboembolism when compared to no bridging, but did increase the risk of major bleeding.
AF-CHF Trial Summary: Roy D et al. randomized 1,376 patients with nonvalvular atrial fibrillation and HFrEF (LVEF ≤35% and NYHA II-IV symptoms) were randomized to rhythm control (pharmacologic or electrical approach) or rate control (target <80 bpm at rest). The objective was to assess if rhythm-control reduce CV mortality in patients with AF and HFrEF as compared to rate control. The results showed no difference in terms of CV mortality in both groups. (P=0.59) The authors of the AF CHF trial concluded that among patients with AF and HFrEF, rhythm-control did not reduce cardiovascular mortality but did reduce AF related hospitalizations, as compared to rate control.
2018, Catheter Ablation for AF with Heart Failure, NEJM
2011, Apixaban vs. warfarin in atrial fibrillation, NEJM
2011, Rivaroxaban vs. warfarin in atrial fibrillation, NEJM
2010, Heart Rate Control in patients with Atrial Fibrillation in Preventing CV events, NEJM
RACE II Visual Summary
RACE II was a randomized, prospective, open label, multicenter (33 centers in Netherlands), parallel-group,non-industry sponsored, controlled noninferiority trial investigatingthe role of lenient ratecontrol (HR<110 bpm) versus strict rate control (HR<80 bpm) in preventing cardiovascular events in patients with permanent atrial fibrillation (AF).
614 patients randomized [lenient rate control (n=311) vs. strict rate control (n=303)]. Enrollment was between 2005 & 2007 with follow up for 2-3 years.Patient <= 80 years, with permanent AF for up to 12 months, having mean resting HR > 80 bpm, and on oral anticoagulation therapy or aspirin (if no risk factors for thromboembolic complication present) were included. Those with paroxysmal AF, known contraindications to either strict or lenient rate control, NYHA class IV or HF admission <3 months, cardiac surgery <3 months, stroke, current or planned PPM, ICD or CRT, SSS or AV conduction disturbance, untreated hyperthyroidism, or inability to walk/bike were excluded.
AV nodal blocking agents (beta-blockers, non-dihydropyridine CCBs, or digoxin; alone or in combination) were administered and dose adjusted to achieve target heart rate. More patients in the lenient control arm achieved the target heart rate than in the strict control arm (97.7% vs 75.2%; P<0.001). The mean heart rate in the lenient and strict control arms were 93 & 76 bpm respectively at the end of dose adjustment phase and 85 & 76 bpm respectively at the end of the study follow up period. INR was similar in the two arms.
Primary outcome was the composite of cardiovascular death, HF hospitalization, stroke, systemic embolism, major bleeding and arrhythmic events (syncope, sustained VT, cardiac arrest, life-threatening adverse effect of rate control agents, and implantation of PPM or ICD). Primary outcome was met in 12.9% in the lenient control arm vs 14.9% in the strict control arm [absolute difference of 2% (90% CI -7.6 to 3.5%; P < 0.001); HR 0.84 (90% CI 0.58 to 1.21)].
Individual components of the primary outcome were similar in the two arms. All-cause death, symptoms from AF, number of patients in each NYHA class I to III, frequency of hospitalization and adverse events were similar in the two arms as well. Authors (Van Gelder IC et al) concluded that “in patients with permanent atrial fibrillation, lenient rate control is as effective as strict rate control and is easier to achieve”.
2014, 30 Days AF monitoring in patients with Cryptogenic Stroke, NEJM
CRYSTAL AF Trial Summary
The Cryptogenic Stroke and Underlying Atrial Fibrillation (CRYSTAL AF) trial randomized 441 patients ,who were 40 years or older and with a diagnosis of cryptogenic stroke or transient ischemic attack within 90 days, in a 1:1 ratio to Insertable Cardiac Monitor (ICM) implantation or routine monitoring at the investigator’s discretion. Prior to randomization, all patients underwent at least 24 hours of ECG monitoring and had no evidence of atrial fibrillation at baseline. Patients were enrolled in 55 centers in Canada, Europe, and the United States. The primary endpoint was the time to first detection of atrial fibrillation, lasting >30 seconds, within 6 months. Approximately, 8.9% of patients in the ICM group were diagnosed with AF, compared with 1.4% in the control group (HR: 6.4; 95%CI: 1.9 to 21.7; p<0.001). Results were consistent through 12 months and 36 months. Atrial fibrillation diagnosed in the ICM group was more frequently asymptomatic than in the control group. Prescription of oral anticoagulants was more than doubled in the ICM group, as compared with the control group, at both 6 and 12 months.
2002, Rate-control and Rhythm-Control in Patients in patients with AF, NEJM
We currently lack significant data or clear cut guidelines for closing left atrial appendage in patients with LAA for prevention of stroke. The current ACC/AHA/HRS guidelines recommends anticoagulation in patients with atrial fibrillation and CHA2DS2-VASc >2 (Grade Ia) irrespective of presence or absence of LAA.
The PROTECT AF trial was a randomized non-inferior trial that studied the usefulness of WATCHMAN device in closing LAA and prevention of stroke. The trial did show non-inferiority of the device closure vs warfarin anticoagulation but it was associated with higher side effects which were mostly periprocedural.
Based on this trial, the 2012 Focus European Society of Cardiology Guidelines called for “LAA closure/occlusion/excision” using percutaneous device in patients who are at high stroke risk and have contraindications for long-term oral anticoagulation (Class IIb; Level of Evidence B). The current AHA/ACC/HRS, however, does not include recommendations of LAA closure devices due to lack of enough robust evidence. However, both ESC and AHA/ACC guidelines suggest that surgical excision of the LAA may be considered in patients undergoing cardiac surgery or thoracoscopic atrial fibrillation surgery (Grade IIB)
Sources: Lancet, 2015 ACC/HRS/SCAI LAA Occlusion Device Societal Overview
Summarized by: Usama bin Nasir, MD
Contribution To Literature:
Atrial fibrillation (AF) was noted to be a risk marker for stroke in the Framingham cohort in 1978. Since then anticoagulation is an important part of managing AF. Use of aspirin in patients with AF is a common practice based on this notion that it might add to prevention of MI or stroke in such patients. The ORBIT-AF study tackled this question by determining the risk factors associated with concomitant use of aspirin and oral anticoagulation (OAC) in patients with AF.
The present study was a retrospective review of ORBIT-AF prospective registry that enrolled 7.347 patients with AF on OAC. The ORBIT-AF registry enrolled patients from 174 US sites. Follow up period of this review was of 6 months and the primary outcomes that were studied were: bleeding, hospitalization, CV events, and mortality.
- Age ≥ 18 years
- Atrial fibrillation on EKG
- Anticipated life expectancy <6 months
- Atrial flutter only
- Patients not taking oral anticoagulant
- Patients taking antiplatelet therapies other than ASA
- Transient AF secondary to a reversible condition
- Current enrollment in a randomized clinical trial of antithrombotic therapy for AF
Among 7347 patients, 4804 were on OAC alone and 2543 patients were on both OAC plus aspirin.
|Overall (n=7347)||OAC Alone (n=4804)||OAC+ASA (n=2543)|
|AF type, %|
- After adjustment for baseline characteristics the primary outcomes for OAC vs OAC + ASA were as follows:
Risk of major bleeding: HR 1.53 (1.20–1.96), p = 0.0006
(note, the risk for bleed is almost 1.5 times for OAC + ASA compared to OAC alone)
All-Cause Hospitalization: HR 1.08 (1.00–1.17), p = 0.06
Mortality: HR 1.26 (0.98–1.63), p = 0.08
The present study indicates worse outcomes in terms of major bleeding and also indicates towards higher mortality and hospitalizations but the latter results are not significant. Based on the real-world National Cardiovascular Data Registry (NCDR) Practice Innovation and Clinical Excellence (PINNACLE) registry more than one-third of 210,380 patients who had CHA2DS2-VASc scores ≥2 were treated with aspirin alone, and not with oral anticoagulants as per ACC/AHA/HRS guidelines. (2) Using OAC is important for prevention of stroke in patients with AF and this has been presented in a number of studies. However, the use of aspirin in addition to OAC in AF has always been questioned. The current study tackled this very question. The results suggest that we should avoid combination therapy in patients who do not have history of CAD. While in patients with history of CAD, using combination therapy outweighs the risks. Note The 2011 ACC/AHA/HRS guidelines recommend using ASA + OAC in patients with history of MI. However, 2014 guidelines have not commented on combination therapy.
- Wolf PA, et al. “Epidemiologic assessment of chronic atrial fibrillation and risk of stroke: The Framingham study.” Neurology.1978;28(10):973-977.
- Hsu J.C., Maddox T.M., Kennedy K., et al. (2016) Aspirin instead of oral anticoagulant prescription in atrial fibrillation patients at risk for stroke. J Am Coll Cardiol 67:2913–2923.