Results of percutaneous transluminal coronary angioplasty by multiple relatively low frequency operators.
D000800:Angioplasty, Balloon / Q000592:standards / Q000706:statistics & numerical data; D002983:Clinical Competence; D003327:Coronary Disease / Q000628:therapy; D006801:Humans; D010820:Physicians / Q000592:standards; D014481:United States