Left atrial dysfunction in bicuspid aortic valve patients with severe aortic stenosis is associated with post-operative atrial fibrillation following aortic valve replacement.

Abstract

To investigate (i) the association between pre-operative left atrial (LA) reservoir strain and post-operative atrial fibrillation (AF) and (ii) the incidence of post-operative ischaemic stroke events separately in bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) patients after surgical aortic valve replacement for isolated severe aortic stenosis (AS). We prospectively enrolled 227 patients (n = 133 BAV and n = 94 TAV) with isolated severe AS scheduled for aortic valve replacement. A comprehensive intra- and inter-observer validated pre-operative echocardiogram with an analysis of LA reservoir strain was performed. Post-operative AF was defined as a sustained (>30 s) episode of AF or atrial flutter. The timing of neurological events was defined in accordance with the Valve Academic Research Consortium-3 criteria for stroke. Post-operative AF occurred in 114 of 227 patients (50.2%), with no difference between BAV and TAV patients (48.1 vs. 53.1%, P = 0.452). Persisting post-operative AF at discharge was more frequent in BAV patients (29.7 vs. 8.0%, P = 0.005). Pre-operative LA reservoir strain was independently associated with post-operative AF (odds ratio = 1.064, 95% confidence interval 1.032-1.095, P < 0.001), with a significant interaction between LA reservoir strain and aortic valve morphology (Pinteraction = 0.002). The cumulative transient ischemic attack (TIA)/stroke incidence during follow-up was significantly higher in BAV patients (19.1 vs. 5.8% at 5 years). Pre-operative LA function was associated with post-operative AF after aortic valve replacement in BAV AS patients, while post-operative AF in TAV AS patients likely depends on transient post-operative alterations and traditional cardiovascular risk factors. TIA/stroke during follow-up was more common in BAV AS patients.