Perioperative Cardiac Risk Assessment

Question 1

Summary flow diagram

Answer 1

Question 2

Timing of surgery:
Emergency
Urgent
Elective

Answer 2

Timing of Surgery
Emergency surgery (acute life- or limb-threatening condition)
Recommend against delaying surgery for risk assessment
Urgent (e.g. acute bowel obstruction, hip #) or semiurgent surgery (e.g. surgery for cancer w/ potential to metastasize)
Preop risk assessment if pt’s history/physical exam suggests potential undiagnosed severe obstructive intracardiac abnormality, severe pHTN, or unstable cardiovascular condition (e.g. unstable angina, acute stroke)
Elective surgery
Preop risk assessment if ≥45 yrs or 18-44 yrs w/ known significant CVS disease

     Significant CVS Disease CAD

CVD

PVD

CHF

Severe pHTN

Severe obstructive intracardiac abnormality (aortic stenosis, mitral stenosis, HOCM)

Question 3

Risk Assessment

Answer 3

Risk Assessment: Revised Cardiac Risk Index (RCRI)

1 point for each of:

CAD/IHD (Hx MI, +exercise test, ischemic CP or nitrate use, ECG w/ pathological Q waves; pts w/ prev CABG or angioplasty meet criteria if they have these findings post-procedure)
CVD (CVA or TIA)
CHF (Hx heart failure, pulm edema, PND, S3 gallop or bilat rales on exam, CXR showing pulm vasc resistance)
Preop Insulin Use
Preop creatinine >177 µmol/L
High risk surgery (intraperitoneal, intrathoracic, suprainguinal vascular)

*Recommend communicating risk to pts on basis of expected event rate among 100 pts or range of risk consistent w/ 95% confidence interval of risk estimate

Answer 4

Preop Investigations
Measure preop brain natriuretic peptide (BNP) or NT-proBNP to enhance periop cardiac risk estimation in:
≥65 yrs
45-64 yrs w/ sig CVS dz
RCRI ≥1
BNP ≥92 mg/L or NT-proBNP ≥300 ng/L a/w ↑ risk of death or MI 30 days post-noncardiac sx

No routine echo, coronary CTA, exercise or cardiopulmonary exercise testing, or pharmacological stress echo or radionuclide imaging
Urgent echo if suspected undiagnosed severe obstructive intracardiac abnormality or severe pHTN
Consider echo if suspect cardiomyopathy (may be reasonable to do postop)

No preop prophylactic coronary revascularization for pts w/ stable CAD undergoing noncardiac sx

Question 5

Perioperative medication management

Answer 5

Perioperative medication management
No initiation or continuation of ASA for prevention of periop cardiac events
D/C chronic ASA ≥3 days preop to ↓ bleeding risk
Restart when risk of surgical bleeding has passed (ex 8-10 days after major noncardiac sx)
Exceptions:
Recent coronary artery stent
CEA
+/- certain surgical interventions (ex free flap, acute limb ischemia)

No α2 agonist or β-blocker initiation w/in 24 hrs of surgery
Continue chronic β-blockers perioperatively
If preop hTN, consider ↓ing or holding preop β-blocker dose

Withhold ACEI and ARBs 24 hrs preop
Consider restarting POD2 if hemodynamically stable

Continue chronic statin tx periop

Facilitate smoking cessation preop (Ideally ≥4 wks preop)
Smoking cessation counselling, nicotine replacement therapy

Question 6

Postoperative Management

Answer 6

Postoperative Management
Daily troponin for 48-72 hrs postop in pts w/ ↑ NT-proBNP/BNP preop
If no preop BNP, measure in at risk patients (>5% risk CVS death or nonfatal MI @ 30 days)
Myocardial injury after noncardiac surgery (MINS) = peak troponin T ≥0.03 ng/mL believed to be d/t myocardial ischemia
Often asymptomatic
a/w ↑ 30 day mortality

Postop ECG in PACU for same group of pts monitored w/ postop troponin

Suggest shared-care mgt (ex anesthesiologist, cardiologist, geriatrician, internist) of pts w/ ↑ NT-proBNP/BNP preop and “@ risk” pts

Initiate long-term ASA & statin tx in pts who suffer myocardial injury/infarction postop