100 QUESTIONS IN CARDIOLOGY

100 Which patients should undergo preoperative

non-invasive investigations or coronary

angiography?

Matthew Barnard

Non-invasive testing refers to investigations other than angio-

graphy such as dipyridamole thallium scanning or dobutamine

stress echocardiography. The literature on this question is over-

whelming. It is best approached by nine simple steps. These are

based on the recommendations of the joint consensus conference of

the American College of Cardiology and the American Heart

Association.^1 Clinical predictors, functional capacity and magnitude

of surgical risk can be assessed from Tables 101.3, 101.4 and 101.5 in

the next question.

Step 1What is the urgency of surgery?

If absolute emergency proceed to surgery, otherwise proceed to

step 2.

Step 2Has the patient undergone coronary revascularisation in

the last five years?

If so and symptoms are stable, proceed to surgery. If not, or

symptoms are unstable go to step 3.

Step 3Has there been a coronary evaluation in the past two

years?

If so and there are no changes or new symptoms proceed to surgery.

If not, or there have been changes go to step 4.

Step 4Is there an unstable coronary syndrome or major clinical

predictor of risk?

If so proceed direct to angiography. If not go to step 5.

Step 5Are there intermediate clinical predictors of risk?

If so go to step 6. If not go to step 7.