From the Guidelines
The patient with ischemic cardiomyopathy, LVEF of 25%, and a history of acute myocardial infarction 2 months ago, with an ECG showing right bundle branch block (RBBB) and a QRS duration of 150 milliseconds, in sinus rhythm, should be considered for Implantable Cardioverter-Defibrillator (ICD) therapy for primary prevention of sudden cardiac death (SCD) as the patient meets the criteria of LVEF ≤35% and is at least 40 days post-MI 1.
Key Considerations
- The patient's LVEF of 25% and history of MI put them at high risk for SCD, making ICD therapy a recommended option for primary prevention 1.
- The presence of RBBB with a QRS duration of 150 milliseconds may not be an ideal candidate for Cardiac Resynchronization Therapy (CRT) as the guidelines primarily recommend CRT for patients with Left Bundle Branch Block (LBBB) 1.
- However, CRT can be useful for patients with a non-LBBB pattern and a QRS duration ≥150 ms, and NYHA class III or ambulatory class IV symptoms on guideline-directed medical therapy (GDMT) 1.
- The patient's NYHA class is not specified, but if they have NYHA class II or III symptoms, ICD therapy is recommended, and if they have NYHA class III or ambulatory class IV symptoms, CRT can be considered 1.
Management
- The patient should be on GDMT for heart failure, including medications such as ACE inhibitors, beta-blockers, and diuretics, as tolerated.
- ICD therapy should be considered for primary prevention of SCD, given the patient's LVEF and history of MI.
- If the patient has NYHA class III or ambulatory class IV symptoms, CRT can be considered, despite the presence of RBBB, as it may still provide benefits in reducing hospitalizations and improving symptoms.
From the Research
Management of Ischemic Cardiomyopathy
The management of a patient with ischemic cardiomyopathy, left ventricular ejection fraction (LVEF) of 25%, who had an acute myocardial infarction (MI) 2 months ago, involves several considerations.
- The patient's LVEF is significantly reduced, indicating severe left ventricular dysfunction.
- The presence of right bundle branch block (RBBB) and a QRS duration of 150 milliseconds on the electrocardiogram (ECG) suggests abnormal ventricular conduction.
Implantable Cardioverter Defibrillator (ICD) Therapy
- Guidelines recommend primary prevention implantable cardioverter defibrillator (PPICD) for LVEF <35% only after 3 months of optimal medical therapy (OMT) or 6 weeks after acute MI with persistent LVEF dysfunction 2.
- However, some high-risk patients may not receive a potentially life-saving PPICD if guidelines are stringently adhered to, highlighting the need for a more personalized approach to ICD prescription 2.
- The risk of sudden cardiac death is highest in the first month after AMI, but there is no survival benefit of early ICD implantation, and the optimal time frame has yet to be established 3.
Cardiac Resynchronization Therapy (CRT)
- CRT is the therapy of choice for patients with symptomatic systolic heart failure (HF) and left bundle branch block (LBBB), despite optimal medical therapy (OMT) 4.
- However, the patient in question has RBBB, not LBBB, which may affect the consideration for CRT.
- Alternative pacing sites and strategies are available if CRT is not feasible and effective in patients 4.
Left Ventricular Assist Device (LVAD) as Destination Therapy
- Patients with severe ischemic cardiomyopathy (LVEF <25%) and severe ischemic mitral regurgitation have a poor survival with medical therapy alone 5.
- LVAD as destination therapy is reserved for patients who are too high risk for conventional surgery, and may be considered as an alternative therapy for these patients 5.