Can a patient with mild mixed plaque disease in the proximal segment of the Left Anterior Descending (LAD) artery be cleared for knee surgery?

Preoperative Clearance for Knee Surgery with Mild Proximal LAD Plaque

Yes, this patient can be cleared for knee surgery. The coronary CT angiography demonstrates only mild mixed plaque in the proximal LAD without significant stenosis, and all coronary arteries show no significant disease, making this patient appropriate for elective orthopedic surgery with standard perioperative cardiac risk management.

Risk Stratification for Non-Cardiac Surgery

Knee surgery is classified as intermediate-risk surgery (reported cardiac risk generally 1-5%), which is substantially lower risk than major vascular surgery 1. The patient's coronary anatomy shows:

• No significant stenosis in any coronary territory (left main, LAD, diagonal, circumflex, obtuse marginal, RCA, PDA, or PL branches)
• Mild mixed plaque only in the proximal LAD segment, which does not meet criteria for hemodynamically significant disease
• Normal coronary origins and proximal course with a right-dominant system

Functional Significance of Mild Plaque

The mild plaque described does not constitute significant coronary artery disease requiring intervention or surgical delay 2:

• Lesions <50% stenosis are managed medically, not with revascularization 2
• Only stenoses >90% reliably predict hemodynamic relevance (96% correct classification), while intermediate stenoses (40-70%) require functional assessment 2
• Mild plaque without significant stenosis does not change perioperative risk stratification or warrant delay of necessary surgery 2

Perioperative Cardiac Management

The patient should proceed to surgery with optimal medical therapy 1:

• Continue all cardiovascular medications perioperatively, including any antiplatelet therapy, statins, beta-blockers, and ACE inhibitors if prescribed 1
• Initiate statin therapy if not already prescribed, as any detectable coronary atherosclerosis warrants statin treatment 3
• Low-dose aspirin should be continued unless bleeding risk from the specific surgical procedure outweighs cardiovascular benefit 1
• Beta-blocker therapy should be continued if already prescribed, with low-dose titration before surgery 1

When Preoperative Coronary Evaluation Would Be Indicated

Additional cardiac testing is NOT indicated in this patient because 1:

• Preoperative coronary angiography is recommended only for patients with three or more cardiac risk factors (angina, prior MI, stroke/TIA, renal dysfunction with creatinine >2 mg/dL, heart failure, diabetes) undergoing high-risk surgery 1
• Knee surgery is intermediate-risk, not high-risk surgery 1
• The patient already has anatomic documentation showing no significant coronary stenosis

Functional cardiac testing would only be warranted if the patient had unstable cardiac conditions (acute coronary syndrome, decompensated heart failure, severe arrhythmias, severe valvular disease) requiring immediate treatment before elective surgery 1.

Common Pitfalls to Avoid

Do not delay surgery for insignificant coronary findings 2:

• The presence of mild plaque on CT angiography without stenosis does not require further invasive evaluation
• Unnecessary coronary intervention on non-significant lesions carries procedural risks (complications, need for dual antiplatelet therapy, in-stent restenosis risk, stent thrombosis) without benefit 2

Do not confuse plaque presence with hemodynamic significance 2:

• Visual assessment of coronary stenosis correlates poorly with functional significance 2
• The target of revascularization is myocardial ischemia, not epicardial coronary disease itself 1

Surgical Clearance Recommendation

The patient should be cleared for knee surgery with the following perioperative plan:

• Proceed with surgery without delay for additional cardiac testing 1
• Optimize medical therapy with statin, aspirin (unless contraindicated by surgical bleeding risk), and continuation of any existing cardiac medications 1, 3
• Standard perioperative monitoring appropriate for intermediate-risk surgery 1
• Postoperative surveillance for cardiac events with continuation of medical therapy 1

Long-term management after surgery should include aggressive risk factor modification (smoking cessation, blood pressure control <130/80 mmHg, diabetes management if present, LDL-C reduction of at least 30-50% from baseline) and lifestyle modifications (regular physical activity, heart-healthy diet, weight management) 3.