© 2018 Kurt Pfeifer.

Ischemic Disease (CAD)

ASSESSMENT

Data Gathering

History

Symptoms

Exam

  • Previous cardiovascular disease

  • Previous cardiac testing (stress tests, cardiac catheterization, echocardiography, CT coronary angiography)

  • Previous coronary interventions (including vessel, stent/bypass type)

  • Chest pain

  • Exertional dyspnea or lightheadedness

  • Palpitations

  • Diaphoresis

  • Fatigue

  • Syncope

  • S4/S3

  • Pulmonary crackles

  • Edema

  • Elevated JVP

  • Cardiac murmurs

Risk Stratification

Diagnostic Studies

 
  • ECG indications - within 1-3 months (ACC/AHA guideline; italicized are author recommendations) if any of following:

    • high-risk surgery (e.g., >3 hours, intraoperative blood loss >1000 cc, vascular, thoracic)

    • cardiovascular disease

    • CAD equivalents (DM, CVA/TIA, CHF, CKD, PAD)

    • use of medications which alter cardiac conduction (e.g., amiodarone, quetiapine)

  • Echocardiogram indications: none except as indicated for non-ischemic cardiac disease

  • Stress testing - see Risk Stratification Algorithm below

Risk Stratification Algorithm

The following algorithm represents the author's synthesis of the ACC/AHA, ESC/ESA, and CCS perioperative guidelines in addition to other guidelines and high-quality evidence published since the release of those guidelines. This algorithm has not been prospectively validated. Click here for rationale behind this algorithm.

If you prefer to use any of the published perioperative guidelines, please click the links above. 

Emergency surgery?
Yes
N
O
Symptoms of myocardial ischemia which have never been evaluated or are new/progressed since last evaluation?
Yes

Further coronary evaluation adapted as needed for surgical timeframe

N
O

Revised Cardiac Risk Index (RCRI) score = 0 & age <65 yrs?

Yes
N
O

Coronary event or intervention in past yr?

Yes
N
O
Normal coronary evaluation in
past yr?
Yes
N
O
Estimated risk of major adverse cardiac events (MACE) <1%
Yes
N
O

Functional (exercise) capacity >4 METs on Duke Activity Status Index (DASI)?

Yes
N
O
Surgery time-sensitive (required in <6 weeks)?
Yes
N
O
Will further coronary evaluation alter management?
Yes
N
O
Perform stress test (or if anesthesiology/cardiology at your institution support its use for preop risk stratification, order NT-proBNP)
abnormal
ACS/PCI Algorithm
YES
Symptoms of myocardial ischemia which are new/progressed since last evaluation?
N
O

Further coronary evaluation adapted as needed for surgical timeframe

Further coronary evaluation adapted as needed for surgical timeframe

Percutaneous intervention (PCI) with bare metal stent (BMS) within 30 days?

YES

Delay surgery for at least  30 days unless urgent (consider longer delay if placed in setting of MI)

N
O

MI within 60 days?

YES

Delay surgery for at least  60 days unless urgent (consider longer delay if PCI performed for MI)

N
O

Delay surgery for at least 3 months unless urgent (consider longer delay if PCI performed for MI)

YES

PCI with drug-eluting stent (DES) within 3 months?

N
O

​*Stent Thrombosis Risk Factors

  • Multiple stents

  • Overlapping stents

  • Stents close to artery bifurcations

  • Stent placement for MI

PCI with drug-eluting stent (DES) within 6 months?

YES

If surgical delay risk > stent thrombosis risk*, proceed to surgery; otherwise, delay for at least 6 months (consider longer delay if PCI performed for MI)

N
O

Proceed to surgery unless PCI for MI within past 12 months, then discuss with cardiology/surgery benefits/risks of further delay

MANAGEMENT

Indications for Surgical Delay

 
  • New or worsened symptoms of cardiac disease

  • PCI with BMS within 30 days, CABG within 6-8 weeks, or PCI with DES within 3 months (ACC/AHA Guideline)

  • MI within 60 days (ACC/AHA Guideline)

Medication Management

Antiplatelet Therapy (ACC/AHA Guideline)

  • If surgical bleeding risk low, continue all antiplatelet therapy uninterrupted

  • If surgical bleeding risk is not low - 

    • History of coronary stenting​: continue all antiplatelet therapy uninterrupted if possible (discuss with surgeon); if not possible, continue low-dose aspirin (<100 mg daily) uninterrupted unless bleeding risk high (eg, craniotomy) or patient has aspirin allergy (Graham MM et al)

    • No history of coronary stenting but previous vascular disease (eg, PAD), vascular interventions (eg, coronary bypass grafting), or ischemic events (eg, stroke): continue low-dose aspirin (with caveats above) only if ischemic risk definitely outweighs bleeding risk (discuss with surgeon)

Beta-Blocker Therapy (ACC/AHA Guideline)

  • Chronic beta-blocker therapy: continue uninterrupted but reasonable to temporarily hold as needed for hypotension/bradycardia​

  • Beta-blocker initiation: consider for these indications and in the absence of these contraindications - 

    • INDICATIONS (ACC/AHA class of recommendation/level of evidence):

      • Intermediate- or high-risk ischemia on stress testing (IIb/C)

      • ≥3 RCRI criteria (IIb/B)

    • CONTRAINDICATIONS:

      • ≤24 hours before surgery​

      • Decompensated heart failure

      • Hypotension/bradycardia

      • History of CVA/TIA (based on elevated stroke risk in POISE-1 trial - POISE)

    • Start as far in advance of surgery as possible to assure titration to safe/effective dose (>1 week & likely at least 1 month based on trial evidence - Flu WJ et alChen RJ et al)

Statin Therapy (ACC/AHA Guideline)

  • Chronic statin therapy: continue uninterrupted

  • Statin initiation: consider for these indications and in the absence of these contraindications - 

    • INDICATIONS (ACC/AHA class of recommendation/level of evidence):

      • Vascular surgery (IIa/B)

      • Meet ACC/AHA hyperlipidemia guideline indications for long-term therapy (IIb/C)

    • CONTRAINDICATIONS:

      • Risk for acute kidney injury (AKI) - based on data suggesting increased AKI risk with perioperative statin use - London MJ et al & Zheng Z et al)

    • Start with dose that is appropriate per ACC/AHA hyperlipidemia guidelines

Postoperative Surveillance

  • CONFLICTING GUIDELINES: ACC/AHA does not recommend postoperative ECG or troponin monitoring except for symptoms of cardiac dysfunction. ESC/ESA recommends postop troponins for 48-72 hrs after major surgery in high-risk patients. CCS recommends ECG in PACU & postop troponins for 48-72 hrs for patients ≥65 or 18-64 with cardiovascular disease undergoing urgent/emergent non-outpatient surgery and for patients with preop NT-proBNP ≥300 mg/L or BNP ≥90 mg/L undergoing elective non-outpatient surgery

  • Evidence for association of myocardial injury after noncardiac surgery (MINS; includes troponin elevations without ischemic symptoms or ECG changes) & mortality remains compelling. Most MINS and postop MIs are asymptomatic. Recent MANAGE trial demonstrated potential benefit from treating such patients with dabigatran.

  • Based on this information, the author recommends this approach:

    • At your institution, develop protocols with anesthesiology, surgery, cardiology, and hospital medicine for who should undergo postop surveillance and what will be done for abnormal results​

    • Consider daily postoperative troponin and ECG for 48-72 hours after non-low-risk surgery requiring postoperative admission if following criteria met:

      • Preop estimated MACE risk >1%​

      • Poor functional capacity

      • Clear plan for how results will alter management (eg, ICU care and/or cardiology consultation)

COUNSELING & COMMUNICATION

  • Collaborate with patients' cardiologists

  • When conveying to patients their risk of cardiovascular complications, avoid the use of subjective terms such as low or high risk.

  • Provide estimate of percentage risk in terms of how many patients out of 100 like them would be expected to have a heart attack or die (eg, 4% = 4 out of 100) (CCS guideline).

  • When ordering preoperative coronary evaluation in asymptomatic individuals for risk stratification, clearly communicate to the patient that the purpose is for risk stratification - even abnormal findings may not help with actual reduction of risk.