What is the best approach for preoperative risk stratification in a patient with Left Ventricular (LV) dysfunction and an Ejection Fraction (EF) of 35%?

From the Guidelines

The best approach for preoperative risk stratification in a patient with Left Ventricular (LV) dysfunction and an Ejection Fraction (EF) of 35% involves a comprehensive cardiac evaluation, including a thorough clinical assessment, transthoracic echocardiogram, laboratory tests, and consideration of stress testing for moderate to high-risk surgeries, as recommended by the 2014 ACC/AHA guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery 1.

Key Components of Preoperative Risk Stratification

• Begin with a thorough clinical assessment including history, physical examination, and baseline electrocardiogram
• Obtain a transthoracic echocardiogram to confirm the EF and assess for valvular disease, wall motion abnormalities, and diastolic function
• Laboratory tests should include complete blood count, comprehensive metabolic panel, and cardiac biomarkers
• For moderate to high-risk surgeries, consider stress testing such as dobutamine stress echocardiography or nuclear perfusion imaging to evaluate for inducible ischemia

Medical Therapy Optimization

• Cardiology consultation is recommended to optimize medical therapy preoperatively, which typically includes beta-blockers (such as metoprolol 25-100 mg twice daily), ACE inhibitors (like lisinopril 5-40 mg daily), and statins (such as atorvastatin 20-80 mg daily) 1
• Continue these medications perioperatively when possible

Emergency Surgeries

• For emergency surgeries, proceed with surgery while implementing appropriate monitoring and management strategies This comprehensive approach helps quantify perioperative cardiac risk, guides appropriate interventions, and improves outcomes in patients with significant LV dysfunction by addressing both the hemodynamic challenges and potential for ischemic complications during surgery, as supported by the 2014 ACC/AHA guideline 1 and other studies 1.

From the Research

Preoperative Risk Stratification for Patients with LV Dysfunction and EF of 35%

The approach to preoperative risk stratification in patients with left ventricular (LV) dysfunction and an ejection fraction (EF) of 35% involves several key considerations:

• Optimization of End-Organ Dysfunction: Preoperative optimization of end-organ dysfunction, such as renal function and volume status, is crucial 2.
• Medication Adjustments: Adjusting medications, including withholding inhibitors of the renin-angiotensin-aldosterone system before surgery and continuing, but not starting, β-blockers, can help minimize risks 2.
• Risk Score Assessment: Using standard formulas such as the EuroSCORE-II or Society of Thoracic Surgeons risk scores can provide an objective assessment of a patient's risk 2.
• Hemodynamic Optimization: In high-risk patients, preoperative hemodynamic optimization might be achieved with the insertion of a pulmonary artery catheter and hemodynamic-based tailored therapy 2.
• Identification of Independent Risk Factors: Identifying independent risk factors such as preoperative hemodynamic instability and serum creatinine >166 µmol/L can help predict 30-day mortality in patients with low EF undergoing CABG 3.

Diagnostic Tools

Diagnostic tools such as:

• Transthoracic Echocardiography (TTE): Can identify cardiac disease, asymptomatic left ventricular dysfunction, and aberrations in central volume status, providing valuable hemodynamic information 4.
• Natriuretic Peptides: Measuring levels of natriuretic peptides (brain natriuretic peptide [BNP] and N-terminal proBNP) can provide additional prognostic value 2.

Prognostic Implications

Asymptomatic left ventricular dysfunction has prognostic implications for postoperative outcomes, including 30-day cardiovascular events and long-term cardiovascular mortality 5. The presence of 3-vessel angiographic coronary artery occlusive disease is an independent predictor of cardiac morbidity, while inducible ischemia by cardiac stress imaging is not 6.

Approach to Risk Stratification

A comprehensive approach to preoperative risk stratification should include:

• Clinical risk factors
• Results of noninvasive cardiac stress testing
• Coronary angiography with coronary revascularization performed when appropriate 6.