G N de Medeiros, G G Berton, L M Visentini, A D Alves E Gomes, C P A Costa, L de Almeida Paiva, T P Fagundes
LGE is present in approximately one-fifth of patients with MM, with a suggested predilection for the inferolateral myocardium. These findings should be interpreted in light of the limited number of studies, small sample sizes, and high heterogeneity. Nevertheless, they support the role of CMR in detecting subclinical cardiac involvement in MM and provide a basis for future prospective studies to clarify the prognostic significance of LGE in this population.
AIM: Mitochondrial myopathy (MM) encompasses a heterogeneous group of genetic disorders characterized by impaired oxidative phosphorylation and multisystemic involvement, particularly affecting the myocardium. Cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) is a validated method for detecting myocardial fibrosis and has demonstrated prognostic value across cardiomyopathies. However, the prevalence and distribution of LGE in MM remain uncertain.
MATERIALS AND METHODS: We conducted a systematic review and meta-analysis of observational studies evaluating LGE on CMR in patients diagnosed with MM. PubMed, Embase, and Cochrane Library were searched up to October 2025 without language restriction. The primary end point was the pooled prevalence of LGE. The secondary end points included LGE regional distribution (inferolateral, septal, or other segments). Pooled proportions were calculated using a random effects model with double-arcsine transformation, and heterogeneity was quantified with I2 statistics. Sensitivity and influence analyses were performed using leave-one-out and Baujat plots.
RESULTS: Five studies involving 133 patients with MM were included. The pooled LGE prevalence was 20.72% (95% CI: 5.63%-41.00%), with high heterogeneity (I2 = 81.1%). The inferolateral region was most commonly affected (8.47%, 95% CI: 0.60%-21.65%), followed by other locations (4.93%, 95% CI: 0.00%-17.67%), and septal LGE was least frequent (2.76%, 95% CI: 0.13%-7.37%).
CONCLUSION: LGE is present in approximately one-fifth of patients with MM, with a suggested predilection for the inferolateral myocardium. These findings should be interpreted in light of the limited number of studies, small sample sizes, and high heterogeneity. Nevertheless, they support the role of CMR in detecting subclinical cardiac involvement in MM and provide a basis for future prospective studies to clarify the prognostic significance of LGE in this population.