Exercise EKG for Cardiac Risk Assessment for Noncardiac Surgery

Electrocardiographic Exercise Stress Testing for Cardiac Risk Assessment in Patients Undergoing Noncardiac Surgery

Anesth 2001; 94(1):38-46

Reviewed by: R. Prasad, MD

Comments:

Nice, prospective study demonstrating utility of exercise stress testing.
Small sample size, few actual complications studied.
Could have missed events POD 6-30 (not studied in as much detail as first 5 days)
Direct comparison with other tools (e.g., stress echo/thal) will be nice to see.
Click here for the MathPad formula (will go into your MemoPad).

Methods:

204 pts, 2-yr period, intermediate risk for cardiac complications, noncardiac surgery. 19pts excluded = 185 in study.
Exercise EKG on supine bicycle ergometer. Abnl = new horizontal or down-sloping ST >= 0.1mV in 3 consecutive beats.
Resting 12-lead EKG. Abnl = abnl Q's or ST depression >= 0.1 mV.
EKG's: 2 independent evaluators; 3rd to break ties in interpretation.
Holter from evening before surgery to morning POD #2.
Surface echo by one cardiologist done before surgery.
Surgery classification:

Class	Examples
Major Vascular	Aortic repair, aortoiliac or iliac endarterectomy
Minor Vascular	CEA, peripheral vascular
Major Intraabd	Gastric, liver, pancreatic, small bowel, colonic, rectal
Minor Intraabd	Cholecystectomy, laparotom, herniotomy

Outcomes analyzed: cardiac mortality and morbidity during first 30 POD's. Cardiac death, perioperative MI or minor cell injury (elevated troponin-T), CHF.

Results:

ST depression >=0.1mV during exercise testing (even if could not reach 85% of maximal predicted HR) was an independent risk factor. Helps stratify risk further.