When referring a patient to cardiology for pre-operative cardiac clearance, should I order an electrocardiogram and chemical stress test or let the cardiologist order them?

Preoperative Cardiac Testing for Cardiology Referrals

When referring a patient to cardiology for pre-operative cardiac clearance, you should let the cardiologist order the EKG and chemical stress test rather than ordering these tests yourself. 1

Rationale for Letting Cardiologists Order Tests

The decision to order preoperative cardiac testing should follow a systematic approach based on the 2014 ACC/AHA guidelines on perioperative cardiovascular evaluation:

• Cardiologists are better positioned to determine which specific tests are needed based on their comprehensive evaluation of the patient's cardiac risk factors and the planned surgery
• Allowing cardiologists to order tests prevents unnecessary duplication and ensures appropriate test selection and timing
• The cardiologist can integrate test results directly into their clearance assessment

Algorithm for Pre-Operative Cardiac Testing Referrals

Step 1: Assess the Surgical Risk

• Low-risk procedures (<1% risk of MACE): Cataract surgery, endoscopy, superficial procedures
• Intermediate-risk procedures (1-5% risk of MACE): Intraperitoneal/intrathoracic surgery, carotid endarterectomy
• High-risk procedures (>5% risk of MACE): Major vascular surgery, prolonged procedures with large fluid shifts

Step 2: Determine When to Refer to Cardiology

Refer to cardiology if:

• Active cardiac conditions (unstable coronary syndromes, decompensated heart failure, significant arrhythmias, severe valvular disease) 1
• Poor functional capacity (<4 METs) with multiple cardiac risk factors undergoing intermediate or high-risk surgery 1
• Unknown functional capacity with ≥3 cardiac risk factors undergoing vascular surgery 1

Step 3: What to Include in Your Referral

• Provide comprehensive clinical information including:
  • Patient's cardiac history and risk factors
  • Type and urgency of planned surgery
  • Functional capacity assessment (if known)
  • Most recent relevant laboratory results
  • Previous cardiac testing results (if available)

Evidence-Based Recommendations

For EKG Testing:

• Do not routinely order preoperative EKGs for asymptomatic patients undergoing low-risk procedures 1
• A preoperative resting 12-lead ECG is reasonable for patients with known coronary heart disease or other significant structural heart disease undergoing intermediate or high-risk surgery 1
• The optimal timing for preoperative ECG is within 1-3 months of surgery for stable patients 1

For Stress Testing:

• Do not routinely order stress tests for patients undergoing low-risk procedures 1
• For patients with elevated risk and poor functional capacity (<4 METs), it is reasonable to let the cardiologist determine if pharmacological stress testing (DSE or MPI) is needed 1
• The cardiologist should decide if stress testing will change management before ordering it 1

Common Pitfalls to Avoid

• Unnecessary testing: Routine preoperative cardiac testing in low-risk patients or procedures does not improve outcomes and may lead to unnecessary interventions 2
• Delayed surgery: Preoperative cardiology consultation delays surgery by an average of two weeks 3, so only refer when truly indicated
• Unclear referral questions: Vague referral requests like "cleared for surgery" without specific questions lead to inefficient consultations 1
• Duplicate testing: Ordering tests before cardiology consultation can result in unnecessary repetition if the cardiologist determines different tests are needed

Quality of Evidence

The recommendations are primarily based on the 2014 ACC/AHA guidelines 1, which provide Class I-III recommendations with levels of evidence. These guidelines represent the most comprehensive and authoritative source for perioperative cardiac evaluation. Earlier guidelines from 2007 1 and 2002 1 provide consistent recommendations, emphasizing that the cardiologist should determine which tests are necessary based on their evaluation.

By following this approach, you can ensure efficient use of resources, prevent unnecessary testing, and optimize the value of cardiology consultation for perioperative risk assessment.