Inclusion Criteria:  Definite left-sided infective endocarditis defined by the ESC (European Society of Cardiology) modified Duke Criteria  AND  Valve vegetation =>10mm AND <=30mm with 1 or no previous embolic event during current IE case  Exclusion Criteria:  Unwilling to sign informed consent At least one clear class I recommendation for surgery because of heart failure or uncontrolled local infection (abscess, false aneurysm, fistula) Unavailable for follow-up (e.g. tourist)  OR  At least one of the following criteria (unsuitable for surgery)  Intracranial hemorrhage <1 month Life expectancy <1 year Age ≥85 years BMI below 15 or above 45 Possible severe liver cirrhosis (Child-Pugh Class B or worse) Clinical frailty score of 6 or above EUROSCORE II > 50% Severe pulmonary disease (FEV1 (Forced expiratory volume in 1 second) or DLCO (Diffusing capacity for carbon monoxide) <30% of expected) Left ventricular ejection fraction (<20%) Technically inoperable (e.g. extracorporeal circulation deemed impossible)