The hallmark of arrhythmia-induced cardiomyopathy (AIC) is reversibility of left ventricular systolic dysfunction (LVSD) following rhythm restoration. We aimed (a) to determine the prevalence of AIC in patients with newly diagnosed LVSD and concomitant tachyarrhythmia, (b) to estimate the time to recovery (TTR) of patients with AIC and (c) to identify potential predictors of AIC.
Method:
Patients hospitalized for newly diagnosed and otherwise unexplainable LVSD (i.e. left ventricular ejection fraction (LVEF) <50%) and coexisting tachyarrhythmia (atrial fibrillation/flutter + heart rate >100/min) were prospectively screened. Other causes of LVSD had to be excluded. Sixty-eight consecutive patients were prospectively enrolled, received effective rhythm restoration, and were followed up after 2, 4, and 6 months including clinical characteristics, biomarker assessment and imaging. Left ventricular scar was quantified by late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging. According to the protocol, 18 Patients were excluded, mostly because of recurrent arrhythmia. AIC was diagnosed ex juvantibus at the end of follow-up when LVEF increased either by ≥15% or by ≥10% and above 50%.
Results: Forty-one of 50 patients (LVEF 35.4±8.2%) were diagnosed with AIC, corresponding to a prevalence of 82%. The majority of recovery took place in the first 2 months: LVEF increased to 52.7±8.0% (p < 0.001); after 4 (6) months to 54.4±6.1% (57.2±6.1%, fig. 1). The ΔLVEF (baseline vs. month 2) correlated negatively (fig. 2) and the TTR correlated positively (fig. 3) with the percentage of LGE in patients with LGE ≥1%. Remarkably, there was no difference in distribution of LGE positive and negative patients between the groups (p = 0.682) and there was no difference in absolute LV LGE content between the groups (5.8±6.3% in AIC vs. 5.1±5.6% in non-AIC, p = 0.776). Left ventricular end diastolic diameter at baseline (LVEDD) was predictive for an AIC in a multivariate regression model (odds ratio (95% confidence interval) = 0.71 (0.48 – 0.95), p-value = 0.042, c-index = 0.82) with smaller values favoring AIC; the optimal cut-off was a LVEDD of 56.5mm.
Conclusion:
In this relevant patient population with newly, otherwise unexplainable LVSD and tachyarrhythmia, the prevalence of AIC was 82%. Most of the recovery from LVSD occurred in the first few months after rhythm control. TTR correlated positively with left ventricular fibrosis and the diagnosis of AIC was likely when the LVEDD was <56.5 mm. These results may help to accelerate the diagnosis of AIC and thereby optimize the therapeutic strategy.
https://dgk.org/kongress_programme/ht2022/aP758.html