This is a pilot clinical study of CCM in addition to optimal medical therapy (OMT) over a 24 week period. The primary endpoint shall be a mean change in KCCQ score. To further improve the accuracy and objectivity of measurements, assessments of peak VO2 (oxygen uptake) will also be performed. Tests can be performed using upright and semi-supine bicycle ergometer or using treadmill. In sites where more than one option is available, bicycle ergometer is the preferred option. Treadmill is only allowed in case no bicycle is available at the site. Each subject shall be consistently tested using the same method throughout the study.