The study assessed patients who underwent cardiac magnetic resonance imaging (CMR) due to reduced left ventricular ejection fraction (LVEF) and a history of atrial or ventricular arrhythmia. AIC was diagnosed retrospectively in patients who showed improvement in LVEF by more than 15% within six months of rhythm control without any other specific heart disease identified. The researchers compared the clinical, laboratory, and imaging characteristics of 86 patients with AIC to those of 463 patients with other non-ischaemic cardiomyopathies (NICM).
The results demonstrated that patients with AIC were generally younger and more often male. They exhibited fewer cardiovascular risk factors, better kidney function, and significantly lower levels of natriuretic peptides compared to the NICM group. Importantly, CMR imaging revealed that AIC patients had smaller left ventricular volumes, thinner myocardial walls, and preserved longitudinal strain. Notably, late gadolinium enhancement (LGE), an indicator of myocardial scarring, was rare in AIC, found in only 8% of patients compared to 65% in other NICM types. The absence of LGE was strongly associated with AIC diagnosis, highlighting the potential of CMR in differentiating AIC from other cardiomyopathies.
Furthermore, the study emphasizes the reversibility of AIC upon rhythm normalization and suggests that early identification through CMR can influence management and prognosis. Since AIC can mimic dilated cardiomyopathy, especially in patients presenting with heart failure symptoms and arrhythmia, distinguishing the two is crucial. This research contributes valuable insights by establishing a phenotype of AIC characterized by low fibrosis burden, preserved myocardial function, and good response to rhythm control.
In conclusion, this study underscores the utility of CMR in identifying AIC and supports its role in guiding treatment strategies. The findings advocate for increased awareness of AIC and integration of imaging biomarkers in clinical decision-making to ensure timely and accurate diagnosis, which may ultimately lead to improved patient outcomes.
Source: https://onlinelibrary.wiley.com/doi/full/10.1002/ejhf.3684
