Extracorporeal Shockwave Myocardial Revascularization in Refractory Angina

Inclusion Criteria: * history of coronary artery disease; * refractory angina pectoris, defined as the persistence of a angina pectoris (Canadian Cardiovascular Society class ≥ 2) for more than 3 months, despite the use of optimal medical therapy (which included β blockers, calcium channel blockers, long-acting nitrates, ivabradine, ranolazine and trimetazidine, up-titrated to the maximal tolerated dose) and coronary disease not amenable for further revascularization (as determined by an interventional cardiologist and cardiac surgeon); * stable maximal medical therapy for at least 6 weeks; * stress-induced ischemia at baseline SPECT; * left ventricular ejection fraction higher than 40%; * age higher than 18 years. Exclusion Criteria: * myocardial infarction or unstable angina in the previous 3 months, * acute myocarditis, pericarditis, left ventricular thrombus, cardiac malignancies, chronic pulmonary disease (including emphysema and pulmonary fibrosis), endocarditis * pregnancy