Perioperative myocardial infarction after noncardiac surgery

1
Perioperative 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

3
Revised 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

4
Revised 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

5
Revised 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

6
Diagnosis 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

7
Diagnosis 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

8
Prognosis 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)

9
Role 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

10
Choice 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.

11
Timing 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.

12
Adverse 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.

13
Recommendations 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.