Title: Perioperative myocardial infarction after noncardiac surgery
1Perioperative myocardial infarction after
noncardiac surgery
- INCIDENCE
- 5.8 overall risk of postoperative cardiac death
or major cardiac complications in patients
undergoing major noncardiac surgical procedures
Goldman et al. NEJM 1977. - 3 risk of perioperative MI in patients
undergoing nonoperative surgery Deveraux et al.,
CMAJ 2005 - Risk of 1.4, 3.2, to 6.9 in successive
surgical patients Mangano et al., NEJM 1995. - 1.8 incidence of perioperative MI in men over
the age of 40, but ranging from 0 to 0.8 to
4.1 Ashton et al., Ann Intern Med 1993. - High risk patients experienced perioperative MI
3.0 of the time Mangano et al. NEJM 1990 - 4.7-5.6 incidence in patients with known
coronary disease Shah et al. Anesth Analg 1990
Badner et al. Anesthesiology 1998.
2- DIAGNOSIS
- 14 patients have chest pain
- 53 have a sign or symptom that triggers
consideration for perioperative MI - Cardiac biomarkers
3Revised Goldman Cardiac Risk Index (RCRI)
- Independent predictors of major cardiac
complications - High-risk operation (intraperitoneal,
intrathoracic, suprainguinal vascular procedures) - Hx of ischemic heart disease
- Hx of heart failure
- Hx of cerebrovascular disease
- DM requiring insulin
- Preoperative serum creatinine gt 2.0 mg/dL
4Revised Goldman Cardiac Risk Index (RCRI)
- Deveraux et al., CMAJ 2005
- Rate of cardiac death MI, and cardiac arrest
- 0 RF 0.4 0.1-0.8
- 1 RF 1.0 0.5-1.4
- 2 RF 2.4 1.3-3.5
- 3RF 5.4 2.8-7.9
5Revised Goldman Cardiac Risk Index (RCRI)
- Auerbach et al. Circulation 2006
- Rate of cardiac death, MI, cardiac arrest or VF,
pulmonary edema, complete heart block, without or
with perioperative beta-blocker treatment - 0 RF 0.4-1.0 vs. lt1.0
- 1-2 RF 2.2-6.6 vs. 0.8-1.6
- 3 RF gt9 vs. gt3
6Diagnosis of perioperative MI after noncardiac
surgery
- No standard diagnostic criteria. Diagnosis
complicated by lack of symptomatic presentation
in about half of patients with perioperative MI. - Deveraux et al, CMAJ 2005 proposed the following
diagnostic criteria - 1) rise in troponin (or fall after an elevated
value) plus one or more of - Ischemic signs or symptoms (e.g., SOB)
- New pathologic Q waves on ECG
- Coronary artery intervention
- New wall motion abnormality or fixed defect on
echo or myocardial perfusion imaging - 2) new pathologic Q waves on ECG in patients
without troponin measurements
7Diagnosis of perioperative MI after noncardiac
surgery
- Study 108 patients (96 vascular and 12 spinal
procedures) - Blood samples q6h for 36h post-surgery
- Daily ECG
- Baseline and day 3 echocardiogram
- Of 8 patients with new wall motion abnormalities,
8 had elevated troponin I 6 had elevated CK-MB.
False positives included 1 with elevated troponin
I and 19 with elevated CK-MB
8Prognosis of perioperative MI after noncardiac
surgery
- 15-25 in-hospital mortality, of which
perioperative MI accounts for 2/3 - Nonfatal perioperative MI predisposes to death,
ACS, or progressive angina - Post-op troponin I gt 1.5 mcg/L increased 6-mo
mortality (OR 5.9) - Post-op troponin I gt 0.6 mcg/L increased 32-mo
mortality (OR 2.15)
9Role of perioperative beta-blockers in mortality
risk
- 2006 retrospective study of 663,665 adults
undergoing major noncardiac surgery. 18
received beta-blockers (14 RCRI-0, 44 RCRI-4). - RCRI 0 1.4 mortality, OR 1.36 1.27-1.45
- RCRI 1 2.2 mortality, OR 1.09 1.01-1.19
- RCRI 2 3.9 mortality, OR 0.88 0.80-0.98
- RCRI 3 5.8 mortality, OR 0.71 0.63-0.80
- RCRI 4 7.4 mortality, OR 0.58 0.50-0.67
10Choice of beta-blocker agent for perioperative
administration
- Cardiovascular benefit of perioperative
beta-blockers has only been demonstrated for
beta-adrenergic receptor 1-selective antagonists,
such as atenolol or metoprolol. - Retrospective cohort analysis (Redelmeier BMJ
2005) of treatment with atenolol vs. metoprolol
in elderly indicated a decreased rate of death or
MI after treatment with atenolol relative to
metoprolol (2.5 vs 3.2 mortality). - Although nonselective agents such as propanolol
are not initiated for perioperative therapy due
to adverse pulmonary and peripheral arterial
effects, patients on long-term propanolol use do
not need to switch agent perioperatively.
11Timing of beta-blocker administration
- Auerbach JAMA 2002 meta-analysis of timing of
administration (from 1 mo prior to while in the
PACU) - beta-blocker therapy should begin before surgery
and should be continued at least through
hospitalization. - Rapid cessation should be avoided.
12Adverse effects of perioperative beta-blocker
administration
- Bradycardia requiring atropine treatment is
reported in gt20 patients receiving perioperative
beta-blockers. - Withdrawal may lead to adrenergic
hypersensitivity, associated with accelerated
angina, MI, or cardiovascular mortality. - Beta-adrenergic receptor 1 antagonist agents are
generally safe and can be tolerated by patients
with severe COPD or or reactive airway disease.
13Recommendations for perioperative beta-blocker
therapy
- For RCRIgt2, Beta-1 selective agent, begin as an
outpatient up to 30 d prior to operation,
titrating to HR 50-60 BPM. - Longer-acting agent (atenolol or bisoprolol) may
be more effective than shorter-acting agent
(metoprolol). - No data for duration of therapysuggest
continuing for 1 month after surgery.