If a patient has diastolic heart failure, his left ventricle becomes stiffer than normal. Because of that, his heart can't relax the way it should. When it pumps, it can't fill up with blood as it's supposed to. Because there's less blood in the ventricle, less blood is pumped out to the body. This disfunction has very negative influence on the quality of life. It causes shortness of breath, tiredness, weakness, swelling of feet, ankles, legs, or abdomen, lasting cough or wheezing, fast or irregular heartbeat, dizziness, confusion, nausea, lack of appetite. It may lead to many complications including anemia, impaired kidney function or stroke. With diastolic heart failure, currently, there is no available treatment for the condition. The current practice involves only identifying and treating comorbidities (i.e. conditions such as hypertension, diabetes, etc.) associated with heart failure and symptomatic relief medications like use of diuretics. CORolla® - an elastic "spring-like" metallic device (Figure 1) which is implanted inside the Left Ventricle (LV) of the heart in a minimally invasive procedure. It is innovative device-based treatment for HFpEF (Heart failure with preserved ejection fraction) aimed at providing diastolic heart failure treatment. The overall objective is to clinically validate the medical device and reach market readiness.