Paroxysmal AF associated with worse clinical outcomes than persistent AF
Paroxysmal atrial fibrillation is associated with worse clinical outcomes than persistent/ permanent atrial fibrillation in patients with heart failure and reduced ejection fraction
Presented at ACC.17 by JJV McMurrayNews - Mar. 23, 2017
Whether AF is an independent prognostic factor in HFrEF is disputed. In relevant clinical studies, AF was inconsistently defined, with some using medical history and others using the baseline ECG to identify AF. Moreover, the outcomes have not been related to the type of AF at baseline (paroxysmal vs. persistent/permanent), and the relationship between incident AF and outcomes has barely been assessed. Also, adjustment of outcomes has varied between studies. On top of that, the most powerful independent predictor of outcomes, the measurement of natriuretic peptides, has not been included in chronic HFrEF studies.
In this study, the association between AF and the risk of CV events was evaluated according to AF status at randomisation, in a pooled analysis of the PARADIGM-HF and the ATMOSPHERE databases, the 2 largest global multicentre, randomised trials in HFrEF patients. The trials had an almost identical design and detailed clinical data, plasma NTproBNP and a 12 lead ECG were recorded/measured at baseline. Investigators asked about history of AF (and if yes, whether the AF was paroxysmal or persistent/permanent), and whether or not the baseline ECG showed AF. The primary outcome of both trials was a composite of CV death or HF hospitalisation.
- Out of 15415 patients randomised in both trials, 35.6% had a history of AF, and 68.8% of these had persistent/permanent AF, while 30.0% had paroxysmal AF.
- After adjustment for randomised treatment and baseline characteristics (age, gender, region, race, NYHA class, LVEF, HR, SBP, eGFR, DM, BMI, time since HF diagnosis, history of HF hospitalisation, stroke, MI, and log NT-proBNP), the baseline-AF-associated risk of primary endpoint compared with patients without AF was: HR for permanent AF: 0.93; 95% CI: 0.86-1.01; HR for paroxysmal AF: 1.20; 95% CI: 1.09-1.32; P<0.001; HR for new-onset AF: 2.25; 95% CI: 1.84-2.74; P<0.001.
- Compared with patients without AF, the adjusted risk of CV death was: HR for permanent AF: 0.97; 95% CI: 0.88-1.06; HR for paroxysmal AF: 1.09; 95% CI: 0.96-1.23; P=0.08.
- Compared with patients without AF, the adjusted risk of HF hospitalisation was: HR for permanent AF: 0.93; 95% CI: 0.84-1.03; HR for paroxysmal AF: 1.33; 95% CI: 1.18-1.50; P<0.001.
- Compared with patients without AF, the adjusted risk of all-cause mortality was: HR for permanent AF: 0.95; 95% CI: 0.87-1.04; HR for paroxysmal AF: 1.08; 95% CI: 0.96-1.21; HR for new-onset AF: 2.30; 95% CI: 1.91-2.77; P<0.01.
- Compared with patients without AF, the adjusted risk of stroke was: HR for permanent AF: 1.04; 95% CI: 0.82-1.31; HR for paroxysmal AF: 1.33; 95% CI: 1.01-1.75; HR for new-onset AF: 2.10; 95% CI: 1.19-3.69; P=0.010.
Paroxysmal, but not persistent/permanent AF, was associated with a higher risk of the composite outcome of HF hospitalisation or CV death, even after adjustment for other prognostic variables, including NT proBNP. This finding was driven by an elevated risk of HF hospitalisation. Paroxysmal AF was also associated with a higher adjusted risk of stroke, but persistent/permanent AF was not. New-onset AF conferred the greatest risk of all, since it was associated with a higher risk of HF hospitalisation, death and stroke. These data suggest that new-onset AF should prompt immediate consideration of anticoagulant therapy.
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