What are the indications for a biventricular implantable cardioverter-defibrillator (ICD) upgrade in a patient with left ventricular ejection fraction (LVEF) of 20% and left bundle branch block (LBBB) with a QRS duration greater than 140 milliseconds?

From the Guidelines

I strongly recommend upgrading to a biventricular implantable cardioverter-defibrillator (BiV ICD) for this patient with a left ventricular ejection fraction (LVEF) of 20% and left bundle branch block (LBBB) with a QRS duration greater than 140 milliseconds, as it can significantly improve their quality of life, reduce heart failure hospitalizations, and provide protection against life-threatening arrhythmias. The patient's clinical profile, including their severely reduced LVEF and LBBB with prolonged QRS duration, indicates significant electrical dyssynchrony, which can be addressed by cardiac resynchronization therapy (CRT) provided by the BiV ICD. According to the 2013 ACCF/AHA guideline for the management of heart failure 1, CRT is indicated for patients with LVEF ≤35%, sinus rhythm, LBBB with a QRS ≥150 ms, and NYHA class II, III, or ambulatory IV symptoms on guideline-directed medical therapy (GDMT), which aligns with the benefits this patient can derive from the upgrade. Key points to discuss with the patient include:

• The procedure involves adding an additional lead to stimulate the left ventricle, which can resynchronize ventricular contraction and improve heart function.
• Clinical trials have shown that patients with similar characteristics (LVEF ≤35%, LBBB with QRS ≥150ms) benefit significantly from CRT, with improvements in survival, reduced heart failure hospitalizations, and enhanced quality of life 1.
• Potential risks such as infection, lead dislodgement, and procedure-related complications exist but are generally outweighed by the potential benefits in this specific case.
• The importance of shared decision-making, considering the patient's preferences, values, and individual circumstances, especially regarding the potential for sudden death and nonsudden death from heart failure or noncardiac conditions, as emphasized in the guidelines 1.

From the Research

Indications for Biventricular ICD Upgrade

The indications for a biventricular implantable cardioverter-defibrillator (ICD) upgrade in a patient with left ventricular ejection fraction (LVEF) of 20% and left bundle branch block (LBBB) with a QRS duration greater than 140 milliseconds are:

• Heart failure with reduced ejection fraction (HFrEF) and LBBB, as cardiac resynchronization therapy (CRT) has been shown to reduce heart failure hospitalization and all-cause mortality in these patients 2, 3, 4, 5
• Presence of LBBB with QRS duration greater than 140 milliseconds, as this indicates significant electrical dyssynchrony that can be improved with CRT 2, 3, 4, 5
• LVEF of 20%, which is below the normal range and indicates significant left ventricular dysfunction, making the patient a potential candidate for CRT 2, 3, 4, 5

Comparison of Left Bundle Branch Pacing and Biventricular Pacing

Studies have compared left bundle branch pacing (LBBP) and biventricular pacing (BVP) for CRT in patients with HFrEF and LBBB, and found that:

• LBBP-CRT is superior to BVP-CRT in reducing heart failure hospitalization and improving LVEF, QRS duration, and pacing thresholds 2, 4, 5
• LBBP-CRT has a higher response rate and super-response rate compared to BVP-CRT 2, 4, 5
• LBBP-CRT is associated with improved electromechanical resynchronization and higher clinical and echocardiographic response rates compared to BVP-CRT 4, 5

Clinical Implications

The findings of these studies suggest that:

• Patients with HFrEF and LBBB may benefit from CRT with LBBP, particularly those with significant electrical dyssynchrony and reduced LVEF 2, 3, 4, 5
• LBBP-CRT may be a preferred option over BVP-CRT in these patients, due to its superior efficacy in reducing heart failure hospitalization and improving LVEF and QRS duration 2, 4, 5