VARIABLES USED TO ADJUST FOR PATIENTS RISK

Peripheral vascular disease(PVD): PVD a) cerebrovascular disease: prior CVA, prior TIA, prior carotid surgery, carotid stenosis by history or radiographic studies, or carotid bruit; as b) lower extremity (LE) disease: claudication, amputation, prior lower extremity bypass, absent pedal pulses or lower extremity ulcers.
Diabetes: Documented in medical record or patient history. Diabetes with no sequelae: Diabetes without sequelae described as follows. Diabetes with sequelae: Diabetes with renal disease, retinopathy, peripheral neuropathy, gastroparesis, or peripheral circulatory disease.
Renal failure prior to surgery: On peritoneal or hemo-dialysis.
Pre-op creatinine: Last pre-operative creatinine measurement taken before procedure. Documented in medical record or patient history.
Chronic obstructive pulmonary disease: COPD, or asthma requiring inhalers, theophyllines/aminophyllines, or steroids.
White blood cell (WBC): Last pre-operative measurement of WBC taken before procedure.
Priority at Surgery: Emergent: Medical factors relating to the patient's cardiac disease dictate that surgery should be performed within hours to avoid unnecessary morbidity or death. Examples: failed PTCA with acute coronary insufficiency and/or hemodynamic instability, similar situation in absence of PTCA. This case should take precedence in time over an elective case, open a new room, or be done at night, if necessary. Urgent: Medical factors require patient to stay in hospital to have operation before discharge. The risk of immediate morbidity and death are not present. Examples: threatening pathologic anatomy such as high grade Left Main Coronary Disease, particularly with moderately severe symptoms or history of life threatening arrhythmia (VF) related to ischemia. May have intra-aortic balloon pump (IABP) or intravenous (IV) nitroglycerin (NTG) as part of treatment program. This case might be done in the next available surgical slot but would not necessarily take precedence over an elective case and could possibly wait for several days. Non-urgent: Medical factors indicate the need for operation but the clinical picture allows discharge from the hospital with readmission at a later date for more elective surgery. Little risk of incurring morbidity or death outside of the hospital with good medical management and restricted physical activities.
Preoperative ejection fraction: Most recent prior to CABG, including during the current hospitalization.
Recent MI (≤7 days): The development of a) new Q waves on EKG, or b) new ST-T changes with a significant rise (defined locally) in CPK with positive (defined locally) isoenzymes.
Left main artery stenosis: If a range is specified on angiography report give an integer midpoint of the range.

IN-HOSPITAL OUTCOMES

Mortality: Death during index hospitalization.
Cerebrovascular Accident:Diagnosis documented by MD and defined by the following: new focal neurological deficit which appears and is still at least partially evident more than 24 hours after its onset, occurring during or following the CABG procedure and established prior to discharge.
Return or Operating Room for Bleeding: Performance of a median sternotomy to assess bleeding after initial departure from O.R..
Mediastinitis/sternal Dehiscence: Mediastinitis [two of the following with no other recognized cause: (a) Organisms and white blood cells seen on gram stain aspirated fluid; (b) Positive deep culture; (c) Radiographic evidence of infection] or sternal dehiscence requiring re-operation.
Post-operative Renal Failure or Insufficiency: A new peritoneal or hemo-dialysis that occurred after the procedure or an increase in serum creatinine to >2.0 and two times the most recent pre-operative creatinine level.

Logistic regression is used to calculate the predicted risk of mortality associated with the procedure for each patient in the registry. Using this risk information from the model, a risk profile for the entire NNE region can be created. Direct standardization (or adjustment) methods allow us to approximate what the center outcome rates would be if all centers operated on patients with the same risk profile as the entire region. This method uses a center's actual mortality rates within categories of risk but applies them to a standardized risk profile. In this way, institution rates can be compared without the confounding effects of varying case mix.