Age above 18 years and consentable;

Persistent angina symptoms despite optimal medical therapy and/or evidence of inducible ischemia;

Angiographically-proven coronary artery disease;

De novo lesion in a native coronary artery;

Target reference vessel diameter between 2.25 and 4.00 mm by visual estimation;

Calcification of the target lesion as determined by angiography (grade 3);

Unsuccessful lesion preparation (\<30% reduction of baseline diameter stenosis) with conventional NC balloon angioplasty

Written informed consent.

A ComparIson of Strategies to PrepAre SeveRely CALCified Coronary Lesions