Invasive Coronary Physiology Assessment in Patients With Arrhythmia-Induced Cardiomyopathy

Area of Science:

• Cardiology
• Cardiovascular Research
• Internal Medicine

Background:

• Arrhythmia-induced cardiomyopathy (AIC) results from impaired left ventricular function caused by cardiac arrhythmias.
• Atrial fibrillation (AF) is a common arrhythmia that can lead to AIC.
• Coronary microvascular dysfunction (CMD) is a potential contributor to AIC, but its association with AF requires further investigation.

Purpose of the Study:

• To investigate the association between coronary microvascular dysfunction (CMD) and arrhythmia-induced cardiomyopathy (AIC) in patients with atrial fibrillation (AF).
• To determine if CMD is an independent predictor of impaired left ventricular function in patients with AF.

Main Methods:

• A multicenter observational study enrolled patients with recent AF diagnosis (<6 months).
• Invasive coronary physiology assessment using bolus thermodilution was performed.
• Patients were categorized by left ventricular ejection fraction (LVEF): AIC group (LVEF < 50%) and preserved LVEF group (LVEF ≥ 50%). A control group with dilated cardiomyopathy (DCM) without AF was also included.
• CMD was defined by abnormal coronary flow reserve (CFR < 2.5) and/or abnormal index of microcirculatory resistance (IMR ≥ 25).

Main Results:

• Among 84 patients, CMD was more prevalent in the AIC group (79%) compared to the preserved LVEF (38%) and DCM (33%) groups.
• Significant correlations were observed between CFR and LVEF, and IMR and LVEF in AF patients.
• Multivariable analysis revealed CMD as an independent predictor of AIC (adjusted odds ratio: 6.2).

Conclusions:

• Coronary microvascular dysfunction (CMD) is strongly and independently associated with left ventricular dysfunction in patients with atrial fibrillation (AF).
• CMD may play a significant role in the development of arrhythmia-induced cardiomyopathy (AIC) in the context of AF.