Long-term reverse remodeling and prognostic value of myocardial fibrosis after rhythm control in atrial tachyarrhythmia–related LV dysfunction
T Koertl, L Unger, J Pangratz, O Hamer, L S Maier, R Wachter, S Sossalla, D Lavall, C SchachAbstract
Background
Atrial tachyarrhythmia is a common and potentially reversible cause of left ventricular systolic dysfunction (LVSD). While short-term improvement of left ventricular (LV) function after rhythm control has been demonstrated, data on long-term recovery, late gadolinium enhancement (LGE) change over time as well as on the prognostic value of LGE are limited (1, 2).
Purpose
To evaluate long-term reverse remodeling after rhythm control therapy and to assess the prognostic value of LGE in patients with LVSD and atrial arrhythmia.
Methods
Fifty patients with atrial tachyarrhythmia (atrial fibrillation/flutter + heart rate >100 bpm) and newly diagnosed, otherwise unexplained LVSD (mean age 68.1±11.2 years, baseline LV ejection fraction (LVEF) 35.7±8.6%) were prospectively enrolled following successful rhythm control. Long-term survival was assessed after a mean follow-up of 4.1 years. Serial cardiac magnetic resonance imaging (cMRI) at baseline and long-term follow-up was available in 22 patients (mean interval between cMRIs 3.4 years). LV function, chamber volumes and myocardial fibrosis quantified by LGE were evaluated. Complete LV reverse remodeling (CRR) was defined as an absolute LVEF increase ≥15% and an LV end-diastolic volume index (LVEDVi) decrease ≥10%, adapted from prior reverse-remodeling definitions (3), whereas patients meeting only one of these criteria were classified as having partial reverse remodeling (PRR).
Results
During long-term follow-up, 11 of the 50 patients (22%) died. Non-survivors were older (77.5±9.3 years vs. 65.4±10.3 years, p=0.001), presented with higher initial heart rates (137.6±17.9 bpm vs. 122.6±13.8 bpm, p=0.005) and had a greater amount of LGE in the first cMRI (12.0±5.8% vs. 7.4±4.6%, p=0.036). ROC analysis suggested an LGE threshold of 12% for mortality prediction. Kaplan–Meier analysis demonstrated lower survival in patients with LGE ≥12% compared to those with lower LGE (p=0.014, Figure 1). Baseline age was comparable between LGE groups, supporting the relevance of LGE independent of age. In patients with paired cMRIs, LVEF improved from 36.1±12.7% to 46.8±11.3% (p=0.005). LV dimensions and volumes decreased significantly, including LV end-diastolic diameter (from 61.0±6.7 mm to 55.2±9.2 mm, p=0.0003) and LVEDVi (from 104.1±30.8 mL/m2 to 92.2±30.3 mL/m2, p=0.02). LGE extent remained unchanged (6.5±4.3% vs 6.4±4.5%, p=0.329). Six of 22 patients (27%) showed CRR, while 11 showed PRR (50%) and 5 patients (23%) did not fulfill any remodeling criteria. CRR and PRR status correlated with left atrial end-diastolic/systolic volume index (LAEDVi/LAESVi) (Figure 2).
Conclusion
In arrhythmia-associated LV dysfunction, rhythm control was associated with sustained functional and structural reverse remodeling, although complete recovery only occurred in 27%. Baseline LGE burden was associated with long-term mortality, supporting cMRI-based LGE assessment for risk stratification.