3. INCIDENCE
5.8% overall risk of postoperative major cardiac
complications in patients undergoing
major noncardiac surgical procedures.
Defining PMI, is often difficult :
Most PMIs occur without symptoms in anesthetized or
sedated patients.
The creatine kinase-MB isoenzyme has limited
sensitivity and specificity because of coexisting skeletal
muscle injury.
Consequently, PMI was often recognized late
(postoperative day 3 to 5), resulting in high (30% to
70%) mortality.
4. Two distinct mechanisms may lead to PMI:
Acute coronary syndrome.
Prolonged myocardial oxygen supply-
demand imbalance in the presence of stable
coronary artery disease (CAD).
5. Acute coronary syndrome occurs when an
unstable or vulnerable plaque undergoes
spontaneous rupture, fissuring, or erosion,
leading to acute coronary thrombosis,
ischemia, and infarction.
External stressors ,those occurring
postoperatively are believed to contribute.
6. The sympathetic induced Tachycardia and
Hypertension, common in the perioperative
period, may exert shear stress, leading to rupture
of plaques.
Increased postoperative procoagulants
(fibrinogen, factor VIII coagulant, von Willebrand
factor, α1-antitrypsin), increased platelet
reactivity, decreased endogenous anticoagulants
(protein C, antithrombin III), and decreased
fibrinolysis have been reported.
7. Tachycardia is the most common cause of
postoperative oxygen supply-demand
imbalance.
Heart rates >80 bpm in patients with
significant CAD can lead to prolonged
ischemia and PMI.
8. Postoperative hypotension
(hypovolemia, bleeding, or systemic
vasodilatation), hypertension (elevated stress
hormones, vasoconstriction), anemia, hypoxe
mia, and hypercarbia aggravate ischemia.
Stress-induced and ischemia-induced
coronary vasoconstriction impairs coronary
perfusion.
9. The 2007 ACC/AHA guidelines on cardiovascular
evaluation for noncardiac surgery concluded that
three elements must be assessed to determine the
risk of cardiac events :
Patient specific clinical variables.
Exercise capacity.
Surgery-specific risk.
10. Major predictors that require intensive management
and may lead to delay in or cancellation of the
operative procedure.
Unstable coronary syndromes including unstable
angina or recent MI.
Decompensated heart failure including NYHA
functional class IV or worsening or new-onset HF
Significant arrhythmias
Valvular heart disease-severe AS/ severe MS
11. Other clinical predictors that warrant careful
assessment of current status.
History of ischemic heart disease
History of cerebrovascular disease
History of compensated heart failure or prior
heart failure
Diabetes mellitus
Renal insufficiency
12. The 2007 ACC/AHA guidelines on cardiovascular
evaluation for noncardiac surgery concluded that
three elements must be assessed to determine the
risk of cardiac events :
Patient specific clinical variables.
Exercise capacity.
Surgery-specific risk.
13. Patients with good functional status have a lower
risk of complications.
Functional status can be expressed in metabolic
equivalents (MET).
1 MET is defined as the oxygen uptake in a sitting
position (3.5 mL O2 uptake/kg per min).
Perioperative cardiac risk is increased in patients
unable to meet a 4-MET demand during most
normal daily activities.
14. Indicators of functional status :
Can walk up a flight of steps = 4 METs
Can do heavy work around the house such as
scrubbing floors or lifting or moving heavy
furniture = between 4 and 10 METs
Can participate in strenuous sports such as
swimming, singles tennis, football, basketball
= = >10 METs
15. The 2007 ACC/AHA guidelines on cardiovascular
evaluation for noncardiac surgery concluded that
three elements must be assessed to determine the
risk of cardiac events :
Patient specific clinical variables.
Exercise capacity.
Surgery-specific risk.
16. The type and timing of surgery significantly
affects the patient's risk of perioperative cardiac
complications.
High-risk procedures - Rate of cardiac death
or nonfatal MI is > 5%
Intermediate-risk procedures – 1% - 5%
Low-risk procedures - < 1%
17.
18. Institutional and/or individual surgeon
experience with the procedure may increase
or lower the risk.
Emergency surgery is associated with
particularly high risk (5 times) than with
elective procedures.
19. Multivariable analyses, identified combinations of
factors, based upon routine clinical information
and laboratory tests, that used to estimate the risk
of cardiac complications.
It was developed by Goldman, Detsky, and Eagle
20. High-risk type of surgery ( vascular surgery and
open intraperitoneal or intrathoracic procedures)
History of ischemic heart disease.
History of HF.
History of cerebrovascular disease.
Diabetes mellitus requiring treatment with insulin.
Preoperative serum creatinine >2.0 mg/dL (177
µmol/L).
21. Rate of cardiac death, nonfatal myocardial
infarction, and nonfatal cardiac arrest according to
the number of predictors.
No risk factors - 0.4 %
One risk factor - 1.0 %
Two risk factors - 2.4 %
Three or more risk factors - 5.4 %
22. RECOMMENDATIONS CLASS LEVEL
For patients with cardiac risk factor (s)
undergoing inter meadiate or high – risk
surgery
I B
For patients with cardiac risk factor (s)
undergoing low - risk surgery
IIa B
For patients with no cardiac risk factors
undergoing high / intermediate risk surgery
IIb B
23. RECOMMENDATIONS CLASS LEVEL
For patients with severe valvular heart
disease.
I C
In patients undergoing high-risk
surgery for LV assessment.
IIa C
24. RECOMMENDATION CLASS LEVEL
For patients with > 2 cardiac risk factors
undergoing high risk surgery
I B
For patients with < 3 cardiac risk factors
undergoing high risk surgery
IIb B
For patients undergoing intermediate risk
surgery
IIb C
25. RECOMMENDATION CLASS LEVEL
Acute STEMI / NON-STEMI /Unstable angina
Angina unresponsive to medical treatment
I A
Cardiac stable patients undergoing high risk surgery IIb B
Cardiac stable patients undergoing intermediate risk
surgery
IIb C
26. Diagnosis complicated by lack of symptomatic
presentation in about half of patients with perioperative
MI.
Deveraux et al, proposed the following diagnostic criteria:
Rise in troponin (or fall after an elevated value) plus one or
more of following.
Ischemic signs or symptoms (e.g., SOB)
New pathologic Q waves on ECG.
New wall motion abnormality or fixed defect on echo.
27. BETA BLOCKERS
Beta blockers have been used in patients undergoing
noncardiac sx, in those at high risk.
Possible mechanisms for such a benefit include
Reduction in myocardial oxygen demand
Increase in myocardial oxygen delivery due to
prolongation of coronary diastolic filling time.
Prevention of fatal ventricular arrhythmias,
protection against plaque rupture in the setting of
increased sympathetic activity .
28. The large Perioperative Ischemic Evaluation (POISE)
trial reported increased mortality and, mostly in
association with hypotension in patients treated
with metoprolol.
The evidence does not support the initiation of
prophylactic perioperative beta blocker therapy in
most patients undergoing noncardiac surgery (RCRI
≤2).
POISE does not exclude benefit in high risk patients
(RCRI ≥3)
29. If beta blockers are used
Beta-1 selective agent, begin as an outpatient up
to 30 days prior to operation, titrating to HR 50-60
BPM.
Longer-acting agent (atenolol or bisoprolol) may
be more effective than shorter-acting agent
(metoprolol).
Benefit was demonstrated when therapy was
begun one month before surgery.
30. Statins
Recommend in those already being treated or with
other indications for treatment.
There is no convincing evidence of benefit of
starting therapy in those patients who otherwise do
not meet accepted criteria for initiation of statin
therapy.
31. Aspirin
The accepted practice is to discontinue aspirin 5 to
7 days before a surgical procedure to prevent
bleeding.
Recent analyses suggest that there is only a mild
increase in the frequency of bleeding with aspirin
and no increase in mortality.
Possible exceptions are intracranial and prostate
surgery.
32. Two recent prospective randomized trials
(Coronary Artery Revascularization Prophylaxis
[CARP] and Dutch Echographic Cardiac Risk
Evaluation Applying Stress Echo [DECREASE] failed
to show such benefit.
Revascularization prior to noncardiac surgery
should only be performed in patients who have
high-risk coronary anatomy that fulfill current
criteria applicable to all patients with coronary
disease.
33.
34. European Heart Journal (2009)
British journal of Anaesthesia 107; 83-96 (2011)
Up Todate 2011 (19.3)
Medscape