What is the clinical evidence from this study?

Study design: Observational. Population: Atrial fibrillation (n=173). Intervention: Left atrial pressure ≥ 21 mmHg vs. Left atrial pressure < 21 mmHg. Primary outcome: Extensive left atrial late gadolinium enhancement (≥ 20%) (OR 2.218, 95% CI 1.138-4.324, p=0.019).

October 5, 2020Open Access

Association of left atrial pressure with late gadolinium enhancement extent in patient who underwent catheter ablation for atrial fibrillation

Q: What are the key findings of this study?

Elevated left atrial pressure ≥ 21 mmHg was an independent predictor of extensive left atrial late gadolinium enhancement (OR 2.218), which predicted worse ablation outcomes in non-paroxysmal AF.

Key Result

Elevated left atrial pressure ≥ 21 mmHg was an independent predictor of extensive left atrial late gadolinium enhancement (OR 2.218), which predicted worse ablation outcomes in non-paroxysmal AF.

Study Design

Type

Observational (n=173)

Multicenter

Structured PICO

Does extensive left atrial late gadolinium enhancement on CMR predict recurrence of atrial arrhythmia after catheter ablation in patients with atrial fibrillation?

Population

173 patients (mean age 57, 19% female) with drug-refractory atrial fibrillation referred for first-time catheter ablation.

Exposure

Extensive left atrial late gadolinium enhancement (E-LGE, defined as LGE extent ≥ 20% of the LA wall volume) on CMR imaging.

Comparator

Small left atrial late gadolinium enhancement (S-LGE, defined as LGE extent < 20% of the LA wall volume) on CMR imaging.

Outcome

Recurrence of atrial arrhythmia (defined as any episode of AF/AT lasting more than 30 seconds after a blanking period of 3 months) over 1 year of follow-up.hard clinical

Extensive left atrial late gadolinium enhancement on CMR is associated with elevated left atrial pressure and predicts worse outcomes after catheter ablation specifically in patients with non-paroxysmal atrial fibrillation.

Main Result

Odds Ratio: 2.218 (95% CI 1.138–4.324)

p-value: p=0.019

Limitations

Single-center, observational design
Routine performance of quality 3D LGE-CMR requires high expertise and support
Processing of CMR images is laborious and requires experienced observers
Accurate quantitative analysis of LA-LGE remains a challenge due to thin LA walls and partial volume effects
LA pressure is not a fixed parameter and is sensitive to patient volume and heart rate
Image quality of LGE image is often confused by arrhythmia

Abstract

Atrial remodeling with fibrosis has been well-described in patients with atrial fibrillation (AF). We hypothesized that the left atrial (LA)-late gadolinium enhancement (LGE) extent on cardiac magnetic resonance (CMR) imaging is associated with LA pressure and can be a marker for suitable candidates for non-paroxysmal AF ablation. A total of 173 AF patients with an LA-LGE area on CMR imaging were enrolled. The clinical parameters, including invasively measured LA pressure, were compared between the patients with extensive LA-LGE (E-LGE, LGE extent ≥ 20%, n = 78) and those with small LA-LGE (S-LGE, LGE extent < 20%, n = 95). The E-LGE group had higher peak LA pressures than the S-LGE group (23 versus 19 mmHg, p < 0.001). The E-LGE group had more patients with non-paroxysmal AF (non-PAF) (51% vs. 34%), heart failure (9% vs. 0%), and higher NT pro-B-type natriuretic peptide (472 vs. 265 pg/ml) (all p < 0.05). LA pressure ≥ 21 mmHg was an independent predictor of E-LGE (OR = 2.218; p = 0.019). In the paroxysmal AF (PAF) subgroup, freedom from atrial arrhythmia after catheter ablation was not different (81% vs 86%, log-rank p = 0.529). However, in the non-PAF subgroup, it was significantly higher in the S-LGE group than in the E-LGE group (81% vs 55%, log-rank p = 0.014). Increased LA pressure was related to the LA-LGE extent. LA-LGE was a good predictor of outcome after catheter ablation, but only in patients with non-PAF.

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