What is the management strategy for a patient with hypertrophic cardiomyopathy (HCM) and a 2 mm thick wall apical cardiac fibrotic aneurysm, considering the risk of rupture?

Management of Apical Cardiac Fibrotic Aneurysm in Hypertrophic Cardiomyopathy

Patients with hypertrophic cardiomyopathy (HCM) and left ventricular apical aneurysms are at high risk for sudden cardiac death, ventricular arrhythmias, and thromboembolic events, requiring aggressive intervention with ICD placement and anticoagulation therapy.

Risk Assessment for Apical Aneurysms in HCM

• LV apical aneurysm in HCM is identified as a major risk factor for sudden cardiac death (SCD) according to the 2024 AHA/ACC guidelines 1
• Apical aneurysms, defined as discrete thin-walled dyskinetic or akinetic segments with transmural scar or late gadolinium enhancement (LGE) of the most distal portion of the LV chamber, are independent risk factors for adverse outcomes regardless of size 1
• The annual rate of sudden death events in patients with HCM and apical aneurysms is approximately 4.7%, which is significantly higher than in HCM patients without aneurysms 2
• The combined rate of HCM-related deaths and life-saving aborted events in patients with apical aneurysms is 6.4% per year, which is three times higher than the 2.0% per year event rate in HCM patients without aneurysms 2

Diagnostic Approach

• Cardiovascular magnetic resonance (CMR) imaging is superior to echocardiography for detecting apical aneurysms, particularly when they are small 1
• CMR with late gadolinium enhancement (LGE) is essential to characterize the aneurysm and identify areas of myocardial fibrosis, which may represent a substrate for ventricular arrhythmias 1
• If CMR is not available or contraindicated, echocardiography with LV cavity opacification using intravenous ultrasound-enhancing agents should be considered 3
• Continuous ambulatory electrocardiographic monitoring (24-48 hours) is recommended to detect nonsustained ventricular tachycardia, which is common in patients with apical aneurysms 1

Management Strategy

Primary Prevention of Sudden Cardiac Death

• ICD implantation is strongly recommended for patients with HCM and apical aneurysm due to the high risk of sudden cardiac death and ventricular arrhythmias 1, 2
• The presence of an apical aneurysm should be considered a major risk factor for SCD when making decisions about ICD placement, even if other conventional risk factors are absent 1, 2
• Recurrent monomorphic ventricular tachycardia may occur in patients with apical aneurysms, and radiofrequency ablation of the arrhythmic focus should be considered in cases of frequent ICD shocks 2

Anticoagulation Therapy

• Patients with HCM and apical aneurysms have a significant risk of thromboembolic events (approximately 1.1% per year) 2
• Anticoagulation therapy is recommended for all patients with HCM and apical aneurysms, even in the absence of visible thrombus 2
• CMR imaging should be performed to assess for the presence of thrombus within the aneurysm 1, 2
• Studies have shown that non-anticoagulated patients with apical aneurysms experienced thromboembolic events, whereas those with anticoagulation did not 2

Surgical Considerations

• Surgical aneurysmectomy may be considered in selected patients, particularly those with large aneurysms or recurrent ventricular arrhythmias despite medical therapy 4
• Limited data suggest that patients who undergo aneurysmectomy may have better outcomes compared to those managed medically 4
• Heart transplantation may be necessary in cases of progressive heart failure associated with apical aneurysms 2

Follow-up and Monitoring

• Regular follow-up with cardiac imaging (preferably CMR) is recommended to monitor aneurysm size, ventricular function, and the presence of thrombus 1
• Routine follow-up with serial imaging every 1-2 years is recommended for patients with HCM and apical aneurysms 3
• More frequent monitoring may be warranted in patients with symptoms or evidence of progressive disease 1

Specific Considerations for 2mm Thick Wall Apical Aneurysm

• A 2mm thick wall apical aneurysm represents a significantly thinned myocardium compared to normal wall thickness, indicating advanced disease 1
• The long-standing nature (15 years) of the aneurysm suggests chronic fibrotic changes, which may provide some stability against acute rupture but increases risk of arrhythmias 1, 2
• The presence of fibrosis within the aneurysm, as indicated by LGE on CMR, significantly increases the risk of ventricular arrhythmias and SCD 1
• While the risk of spontaneous rupture of chronic fibrotic aneurysms is relatively low compared to acute aneurysms, the overall mortality and morbidity risk remains high due to arrhythmias and thromboembolism 2, 4

Clinical Pitfalls and Caveats

• Apical aneurysms may be missed on standard echocardiography; CMR is the preferred imaging modality 1
• The size of the aneurysm does not consistently correlate with adverse outcomes; even small aneurysms carry significant risk 2
• Patients may remain asymptomatic despite high-risk features, emphasizing the importance of imaging and risk stratification 2
• The combination of HCM and apical aneurysm represents a unique phenotype with substantially higher risk than either condition alone 2, 4
• Anticoagulation therapy should be considered even in the absence of atrial fibrillation due to the high risk of thrombus formation within the aneurysm 2