Aortic distensibility alterations in adults with m.3243A>G MELAS gene mutation.

PRINCIPLES: MELAS, or mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes is a new distinctive clinical entity. The current study was designed to assess ascending aortic elasticity in adult patients with MELAS syndrome and in gene carriers, and to compare the results with age- and gender-matched healthy controls.

METHODS: The study comprised eight patients with MELAS syndrome and four asymptomatic gene carriers. All subjects underwent complete 2-dimensional transthoracic echocardiography, and systolic and diastolic ascending aortic diameters (SD and DD respectively) were recorded in M-mode 3 cm above the aortic valve from a parasternal long-axis view. Aortic elastic properties were calculated using aortic data and forearm blood pressure values.

RESULTS: SD and DD of MELAS patients and gene carriers were enlarged compared with controls. Aortic stiffness index was increased (16.4+/-3.7 vs 3.6+/-1.1, p=0.00001), while aortic strain (0.035+/-0.012% vs 0.146+/-0.050%, p=0.00002) and aortic distensibility (1.03+/-0.30 cm2/dynes 10(-6) vs 4.70+/-1.69 cm2/dynes 10(-6), p=0.0002) were decreased in MELAS patients compared with controls. Aortic elastic properties of gene carriers were between MELAS patients and controls.

CONCLUSIONS: Increased ascending aortic stiffness and enlarged aortic dimensions suggesting vascular remodelling were found in MELAS patients as compared with controls.