Concentric hypertrophic remodelling and subendocardial dysfunction in mitochondrial DNA point mutation carriers

Area of Science:

• Cardiology
• Genetics
• Biochemistry

Background:

• Mitochondrial disease is linked to heart problems, impacting morbidity and mortality.
• Current cardiac screening strategies for these patients are not well-defined.

Purpose of the Study:

• To identify subclinical myocardial abnormalities in mitochondrial DNA mutation carriers.
• To investigate cardiac changes in patients with the m.3243A>G mutation who have no known cardiac involvement.

Main Methods:

• Cardiac MRI including spectroscopy, cine, tagging, and late gadolinium enhancement (LGE) was used.
• 22 patients with the m.3243A>G mutation and 22 controls were studied.
• Disease burden was assessed using the Newcastle Mitochondrial Disease Adult Scale (NMDAS) and mutation load.

Main Results:

• Patients exhibited increased left ventricular mass index (LVMI), wall thickness, and torsion compared to controls.
• Longitudinal shortening was reduced in patients, correlating with increased LVMI.
• No differences in diastolic function or focal LGE were observed; phosphocreatine/adenosine triphosphate ratio was decreased.

Conclusions:

• Concentric remodelling and subendocardial dysfunction are present in m.3243A>G mutation carriers without clinical cardiac disease.
• Higher mutation loads and NMDAS scores are associated with increased LVMI, indicating a higher risk of cardiac involvement.