P435Reproducibility and predictive value of a simple novel method to measure pulmonary vein activity in persistent atrial fibrillation FARS AF CL study

Funding Acknowledgements

No disclosure

Introduction. Pulmonary vein (PV) firing can trigger or act as a rapid driver to maintain atrial fibrillation (AF). Automated 1-minute measurement of fragmented and non-fragmented PV activity cycle length (CL) showed contradictory results to predict ablation outcome in persistent AF. 

Purpose. This study investigated the reproducibility of a novel non-automated simple method to measure non-fragmented fastest discrete consecutive AF signal cycle length and the value of this measurement in the PVs to predict long-term success after pulmonary vein isolation (PVI) only ablation in persistent AF. 

Methods. Consecutive 75 patients with persistent AF undergoing first-time PVI between 2015 and 2018 were included. The mean of 10 FAstest Repetitive Similar morphology discrete signal cycle lengths (FARS-AF CL) were measured twice with > 2 minutes between in the coronary sinus (CS), superior vena cava (SVC), left and right atrial appendage (LAA, RAA) and PVs. FARS discrete AF signals were defined as (I) signal duration ≤80 msec; (II) repetitive similar morphological characteristics; (III) fastest consecutive 10 intervals during 1-minute observation. The reproducibility of the FARS–AF CL measurement was compared to traditional 10 consecutive interval measurements of fragmented CS signals. The CL gradient between the PV and the LA was quantified by the computing the ratio of the PV and LAA or CS CL. 

Results.  Good correlation was found between two FARS CL measurements in the CS, PVs, LAA and RAA (Correlation Kendall area: 0.882, 0.675-0.941, 0.859, 0.944, respectively). The correlation between two traditional CL measurements of fragmented CS signals was low (Correlation Kendall area:-0.006). After a mean follow-up of 20 months, freedom from atrial arrhythmias was achieved in 50 (66%) patients after the single PVI procedure with or without the use of AADs. Patient without recurrence were more likely to have FARS CL ≤140 msec (8 vs. 42%, p= 0.002), higher FARS PV CL/LAA CL and FARS PV CL/CS CL ratio (96 ± 13% vs. 86 ± 23 %, p= 0.04; 95 ± 13% vs. 82 ± 22%, p= 0.036). Patients with recurrence at follow-up had more dilated left atria (LAVI: 44 ± 12 vs. 38 ± 9 ml/m2, p= 0.02; LA diameter: 49 ± 6 vs. 45 ± 6 mm, p= 0.01), less AF termination during the procedure (16 vs. 37%, p= 0.049) and less first pass isolation (44 vs. 68%, p= 0.04). Multivariable Cox regression analysis showed that LAVI (p = 0.035) and FARS-PV CL (0.011) were significant predictors of arrhythmia free survival. After adjusting for LAVI, FARS-PV CL remained a significant predictor of AF recurrence (p = 0.028).

Conclusions. Traditional non-automated AF CL measurement of fragmented CS signals is poorly reproducible.  FARS-AF CL measurements in the PVs, RA and LA structures are highly reproducible. FARS-AF CL measurement in the PVs could predict the success of PVI-only procedure in persistent AF independent of left atrial size.

P1525 Residual functional mitral regurgitation post-MitraClip is associated with worse hemodynamics and predicts poor outcome at 2-year follow-up

Background

Percutaneous mitral valve repair using MitraClip offers symptomatic benefit and improves rest and exercise hemodynamics in patients with severe functional mitral regurgitation (MR). Recent randomized trials have shown contradictory results regarding the impact of MitraClip on mid-term survival in functional MR. It is unknown whether improved hemodynamics are related to patients" outcome.

Purpose

To assess whether residual MR and altered resting and exercise hemodynamics are predictors of outcome in patients with functional MR treated with MitraClip.

Methods

Consecutive patients (n = 45, 72 ± 10years, left ventricular ejection fraction (LVEF) 34 ± 9%) with symptomatic severe functional MR were prospectively evaluated by Doppler echocardiography at rest and during symptom-limited exercise on a semi-supine bicycle pre- and 6 months post-MitraClip procedure. LVEF, MR severity, cardiac output (CO), systolic pulmonary artery pressure (SPAP) and a flow-corrected SPAP/CO ratio were assessed at rest and peak exercise. 2-year follow-up clinical data were collected from patient records.

Results

During 2-year follow-up post-MitraClip, 15 patients (33%) experienced major cardiac events (hospitalization for heart failure (n = 14) and/or cardiac death (n = 5)). Age, gender, a history of coronary artery disease, diabetes, baseline MR severity and baseline SPAP/CO ratio at rest and during exercise were not related to a worse event-free survival. In contrast, patients with events at 2-year follow up had more often a history of hospitalization for heart failure (73 vs. 37%, p = 0.029), lower baseline LVEF (30 ± 8 vs. 36 ± 10%, p = 0.041), more residual MR at 6 months post-MitraClip (MR jet area/left atrial area 27 ± 14 vs. 15 ± 10%, p = 0.004) and higher SPAP/CO ratios at rest and during exercise 6 months post-MitraClip (13.9 ± 5.3 vs. 9.9 ± 3.4mmHg/L/min, p = 0.007 and 13.6 ± 4.9 vs. 9.4 ± 4.6mmHg/L/min, p = 0.009, respectively). When corrected for baseline LVEF, residual MR 6 months post-MitraClip remained an independent predictor for worse 2-year outcome. Residual MR was moderately correlated to a worse SPAP/CO ratio 6 months post-MitraClip (Pearson Rho 0.518, p < 0.001).

Conclusions

In patients with functional MR treated with MitraClip, residual MR at 6-month follow-up is associated with impaired hemodynamics, and is an independent predictor of cardiac events at 2-year follow-up.

P1364 Contractile reserve predicts reverse remodelling after successful percutaneous mitral valve repair in patients with functional mitral regurgitation

Background

Recent randomised trials have shown conflicting results regarding the usefulness of percutaneous mitral valve repair using MitraClip in patients with severe functional mitral regurgitation (FMR). At present, it remains unclear whether patients with FMR and advanced heart failure might benefit from MitraClip therapy. Moreover, it has been shown that left ventricular reverse remodelling (LVRR) post-MitraClip is associated with a favourable outcome.

Purpose

We sought to assess whether baseline contractile reserve (CR) can predict LVRR and improvement of LV ejection fraction (EF) in FMR patients undergoing MitraClip therapy.

Methods

Consecutive patients with symptomatic severe FMR referred for MitraClip were recruited in two tertiary centres. All patients were scheduled for a semi-supine bicycle exercise echocardiography before and 6 months after the intervention. Patients who were not able to perform an exercise test and who did not complete 6 month follow up were excluded from further analysis. Baseline CR was obtained by subtracting peak exercise LVEF from LVEF at rest. LVRR was defined as a 10% decrease in LV end systolic volume (ESV) at follow-up.

Results

34 patients completed 6 month follow up (61% male, age 71 ± 10 years, LVEF 32 ± 8%). LVRR was observed in 15 patients (44%). We found a trend towards a moderate correlation between baseline CR and relative decrease in LVESV at 6 months (Pearson Rho -0.321, p = 0.064). This correlation became significant in a sub-analysis considering only patients with post-procedural FMR grade ≤2 (n = 27; Pearson Rho -0.444, p = 0.020). In contrast, LVRR was not related to baseline LVEF, LV dimensions or volumes. Furthermore, baseline CR was strongly correlated with an increase of LVEF at 6 months post-MitraClip in these patients (Pearson Rho 0.653, p < 0.001).

Conclusion

CR predicts LVRR and improvement of LVEF in patients with FMR after successful MitraClip therapy (reduction of FMR towards grade ≤2), in contrast to resting indices of LV dysfunction and dilatation. More studies with outcome data are needed to determine whether CR is a useful parameter to identify patients with FMR who might benefit from MitraClip therapy.