Table 1. Definitions of selected cardiovascular events in Medicare Inpatient (MedPar) files based on Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) Codes.

Clinical event	Diagnostic and procedure codes used to define events in Medicare
Acute myocardial infarction	Hospital discharge codes: 410.×0, 410.×1
Coronary revascularization	Procedures codes for coronary artery bypass graft (36.1×, 36.2) or percutaneous coronary intervention (00.66, 36.0, 36.00, 36.01, 36.02, 36.05, 36.97)
Abdominal aortic aneurysm	Diagnosis codes (441.3-441.5, 441.9) or procedure codes (38.34,38.44,39.25,39.52,39.71) or CPT codes (35081, 35082, 35102, 35103, 35091, 0001T, 0002T, 35800, 34802-34805, 34830-34832)
Left Extremity peripheral artery disease	Diagnosis codes (440.20-440.24, 440.0, 443.0,444.22,444.81, 447.1,443.81 or 250.70), Procedure codes (39.50, 39.90, 00.55, 17.56, 99.10, 38.08,38.14, 38.16, 38.18, 39.25, 39.29, 84.11, 84.12, 84.15, 84.17) or CPT codes (35583,35556,35585,35571,35587,35621,35654,35646,35651,35656,35661, 35351,35355,35371,35302,35303,35306,34201,34203,35666,35665,35681, 27590,27880,27882,27884,28805,28810,28820,28825,37205,35471-35474,37226-37231,35470,35491,-35495,35606,37220,37221,37224,04 37225
Coronary artery Stenosis treatment	Diagnosis codes (433.10,433.30, 447.1, 433.11), procedure codes (38.42,38.12,39.90, 00.63) or CPT codes (35301,35390,37215,37216,0005T,0075T,0076T)