Arrhythmic risk stratification in patients with left ventricular ring-like scar

Area of Science:

• Cardiology
• Cardiac Imaging
• Electrophysiology

Background:

• Left ventricular (LV) ring-like scar on cardiac magnetic resonance (CMR) is associated with malignant arrhythmias in non-ischemic cardiomyopathy.
• Identifying risk factors for life-threatening arrhythmic events (LAEs) is crucial for patient management.

Purpose of the Study:

• To comprehensively evaluate the LV ring-like scar phenotype.
• To identify risk factors for LAEs, including sudden cardiac death (SCD), aborted SCD, and sustained ventricular tachycardia.

Main Methods:

• Retrospective analysis of 115 patients with LV ring-like scar across 6 centers.
• Inclusion criteria: ring-like LV scar (≥3 contiguous segments, subepicardial/midwall LGE) plus genetic variant, family history, or arrhythmogenic cardiomyopathy diagnosis.
• Multivariable analysis to identify predictors of LAEs, with risk stratification based on ECG and predictive variables.

Main Results:

• The study included 115 patients (42% female, median age 39).
• During follow-up (median 4.6 years), 84% survived free from LAEs (3.8 events/100 patient-years).
• Independent predictors of LAEs included anterior Q waves (HR 1.030), QRS width (HR 4.642), and LV end-diastolic volume index (LVEDVi) (HR 1.011).
• Three risk categories showed decreasing survival: normal ECG (100%), abnormal ECG without predictors (65%), and abnormal ECG with predictors (49%).

Conclusions:

• The LV ring-like scar phenotype is associated with high rates of malignant arrhythmias.
• Anterior Q waves, QRS prolongation, and increased LVEDVi are independent risk factors for LAEs.
• A normal ECG identifies a low-risk subgroup within this patient population.