Inclusion Criteria all participants:  Written informed consent Age: 18+ Sex: male/female Carriers of a heteroplasmic mtDNA mutation load >20% in skeletal muscle or >1% in blood  Exclusion Criteria all participants:  No informed consent Use of anti-coagulants, anti-thrombotics and other medication influencing coagulation Have a weekly alcohol intake of ≥ 35 units (men) or ≥ 24 units (women) Current history of drug abuse A history of strokes Significant concurrent illness Ongoing participation in other clinical trials that contain an intervention Major surgery within 4 weeks of the visit Pregnant or lactating women Patients unable and/or unwilling to comply with treatment and study instructions