Author + information
- Eric Garth Johnson,
- Donald Lappe,
- Jeffrey Anderson,
- J. Muhlestein,
- Heidi May,
- Tami Bair and
- Benjamin Horne
The Intermountain Risk Score (IMRS) is calculated from components of the complete blood count (CBC) and basic metabolic profile (BMP) and predicts mortality in the general population, general medical patients, heart failure patients, cardiac transplant, ICD recipients, and general cath lab patients. IMRS has not been tested in a coronary artery bypass graft (CABG) subpopulation. We used IMRS to assess mortality risk and risk of myocardial infarction (MI), stroke, and repeat revascularization in CABG patients.
IMRS values were calculated among CABG patients enrolled in the Intermountain Heart Collaborative Study. A maximum 18.4 years of follow–up was available, with a median follow up of 10.5 years. Survival analysis utilized Cox regression adjusting for 20 co–variables. Mortality data were gathered from Social Security records, hospital records, and Utah death certificates. Electronic medical records were queried for MI, stroke, and revascularization outcome data.
IMRS strongly predicted death in both females (adjusted, moderate–risk vs. low–risk: HR=1.91, 95% CI=1.40, 2.61, p<0.0001; high–risk vs. low–risk: HR=4.27, CI=2.85, 6.40, p<0.0001) and males (adjusted, moderate–risk: HR=1.55, CI=1.32, 1.81, p<0.0001; high–risk: HR=2.36, CI=1.79, 3.12, p<0.0001), with areas under the curve of 0.667 and 0.655, respectively. IMRS also predicted MI in females (adjusted, moderate–risk: HR=1.41, CI=0.87, 2.28, p=0.17; high–risk: HR=2.36, CI=1.79, 3.12, p=0.018) but not in males (p=0.25). Although IMRS did not significantly predict stroke in either sex (p=0.63 in females), a trend was seen in males (high–risk: HR=1.92, CI=0.99, 3.73, p=0.053). IMRS did not predict repeat revascularization in either sex (p=0.76, 0.43).
IMRS is an effective tool for mortality risk stratification among both sexes undergoing CABG. Risk of MI and stroke may also be predicted by IMRS, which deserves further study. Because of the very low incremental cost of CBC and BMP labs, IMRS may provide a substantial increase in medical benefit with almost no increase in resource utilization. These data suggest that IMRS should be further studied as a prognostic tool in clinical care.
Poster Sessions, Expo North
Monday, March 11, 2013, 9:45 a.m.–10:30 a.m.
Session Title: Cardiac Surgical Outcomes and Quality of Care
Abstract Category: 28. Quality of Care and Outcomes Assessment
Presentation Number: 1289–114
- 2013 American College of Cardiology Foundation