Angina Pectoris, VariantAngina PectorisAngina, UnstableErgonovineCoronary VasospasmAngina, StableIsosorbide DinitrateCoronary AngiographyElectrocardiographyMyocardial InfarctionMyocardial IschemiaSpasmCoronary DiseaseCoronary VesselsNicorandilCoronary Artery DiseaseThiobarbituratesHyperventilationElectrocardiography, AmbulatoryAngioplasty, Balloon, CoronaryCopper SulfateNitroglycerinVasodilator AgentsPlatelet Aggregation InhibitorsCalcium Channel BlockersExercise TestTreatment OutcomeRisk FactorsMicrovascular AnginaProspective StudiesRegistriesBiological MarkersRisk AssessmentCoronary Circulation