AHA/ACC Guidelines (2007) – Perioperative Cardiovascular Evaluation of the
Patient undergoing Non-cardiac Surgery
Take Home Message = if assessment and evaluation not indicated irrespective of
perioperative context then just crack on.
3 factors involved in risk stratification:
1. Patient risk factors (high, intermediate and low risk)
2. Functional capacity (>4 METS = low, <4 METS = high)
3. Surgery (high, intermediate and low risk)
Clinical Assessment
ACTIVE MEDICAL PROBLEMS/MAJOR RISK FACTORS
- unstable angina
- recent MI (< 1 month)
- uncontrolled heart failure
- significant arrhythmias (high grade AV block, symptomatic arrhythmias, supraventricular
arrhythmias with a rapid ventricular rate)
- severe valvular disease
- recent CABG or PCI (<6 weeks)
CLINICAL PREDICTORS (LEE’S CRITERIA)/INTERMEDIATE RISK FACTORS
-
previous MI (>1 month)
stable mild angina
compensated heart failure
renal impairment (Cr > 170)
DM (on insulin)
Risk of Perioperative Cardiac Events (AMI, APO, CVA, arrhythmia, death)
0 factors = 0.4%
1 = 1%
2 = 6.6%
3-5 = 11%
MINOR RISK FACTORS
-
advanced age
abnormal ECG
arrhythmia
low functional capacity
previous CVA
uncontrolled HT
Functional Capacity
1 MET = personal cares
Jeremy Fernando (2011)
2 METS = walk indoors
3 METS = walk a block on level ground, dusting and washing dishes
4 METS = climb a flight of stairs or walk up hill
5 METS = run a short distance
6 METS = scrubbing floors or lifting heavy objects
7-9 METS = golf, bowling, dancing, doubles tennis, throwing rugby ball
>10 METS = swimming, singles tennis, basketball, skiing
Surgery
HIGH RISK (>5%)
- major emergency surgery
- aortic or major open vascular surgery
INTERMEDIATE RISK (1-5%)
-
intraperitoneal and intrathoracic surgery
carotid endarterectomy
head and neck surgery
orthopaedic surgery
prostate surgery
LOW RISK (<1%)
-
endoscopic procedures
superficial procedure
cataract surgery
breast surgery
ambulatory surgery
Investigations
- FBC; anaemia
- ECG; conduction abnormalities, arrhythmia, Q waves, ischaemic change
- U+E; renal function
- LV function; echo, ventriculography, radionucleotide angiography (not predictive of
intraoperative ischaemia)
- 12 lead ECG;
- ETT;
- Dobutamine stress ECHO;
- Radionucleotide stress testing; can quantify the areas of myocardium that is @ risk
- Angio: anatomical nature of lesion and ability to revascularise
Management
PREOPERATIVE
Preoperative CABG
- if symptoms are stable, CABG doesn’t change risk of MI of death (CARP study & DECREASE
study)
Jeremy Fernando (2011)
Preoperative PCI
- again, unless intervention is indicated in and of itself it doesn’t change risk
- balloon angioplasty -> delay surgery 2-4 weeks and keep anti-platelet agents going
- bare metal stent -> delay surgery 4-6 weeks (will be on clopidogrel for this time too)
- drug eluting stents -> delay surgery for 12 months (will be on dual platelet therapy), if
patients must undergo therapy keep aspirin going and restart clopidogrel as soon as possible
Perioperative management of patients with prior PCI
-
see above time frames (4 weeks, 6 weeks & 12 months)
try and keep dual anti-platelet therapy going
if can’t keep aspirin going and reinstitute clopidogrel as soon as possible
there is no evidence that other agents decrease risk of stent thrombosis
Perioperative management of patients who have received intracoronary
brachytherapy
- gamma or beta brachytherapy used to treat recurrent in-stent restenosis
- continue anti-platelet agents if possible
Perioperative management of the patient who requires PCI and surgery soon after
-
use same time lines based on when surgery indicated
4 weeks -> balloon
6 weeks -> bare metal stent
12 months -> drug eluting stent
can put stents in and then deal with restenosis if it takes place
also CABG + non-cardiac surgery an option
Perioperative Beta-blockers
-
aim = to decrease perioperative MI and death
should start weeks prior to surgery
use longer acting agents
aim for a HR <65
continue perioperatively
see below
Perioperative Statins
- keep going
- decreased risk of MI and death
Alpha 2 Agonists
- reduction in perioperative MI and mortality
Perioperative Calcium channel blockers
- reduced SVT and ischaemia
- trend towards decreased MI and death
Jeremy Fernando (2011)
INTRAOPERATIVE
Electomagnetic Interference + ICD’s and Pacemakers
- recent evaluation (within 3-6 months)
- reprogram to an asynchronous mode (D00 or V00)
- ICD -> turn off their tachyarrhythmia treatment algorithms, place defibrillation paddles far
away from device (AP ideal)
Otherwise standard care
POSTOPERATIVE
- monitor clinically for MI
- if develops PCI needs to considered in context of bleeding risk
- manage acutely with early consultation with cardiology
Jeremy Fernando (2011)