Risk Assessment for Arrhythmias in Patients with Left Ventricular Ring-Like Scarring

Overview

This multicentre study evaluated 115 patients with left ventricular (LV) ring-like scar detected by cardiac magnetic resonance (CMR) and identified key predictors of life-threatening arrhythmic events (LAEs). Anterior Q waves, QRS prolongation, and increased LV end-diastolic volume index (LVEDVi) were independently associated with higher arrhythmic risk, while a normal ECG indicated lower risk.

Background

Left ventricular ring-like scar, characterized by contiguous sub-epicardial/midwall late gadolinium enhancement on CMR, is a distinctive phenotype linked to arrhythmogenic cardiomyopathy and increased risk of malignant ventricular arrhythmias. This scar pattern is associated with various genetic substrates, including desmoplakin and filamin C mutations, and is recognized as a major diagnostic criterion in inherited cardiomyopathies. Despite its prognostic importance, risk stratification within this phenotype remains unclear. This study aimed to identify clinical and instrumental predictors of life-threatening arrhythmic events in patients with LV ring-like scar.

Data Highlights

Survival free from LAEs at median 4.6 years follow-up: 84%; overall survival free from LAEs: 60% (3.8 events/100 patients/year).

Key Findings

• LV ring-like scar phenotype is associated with a high incidence of malignant ventricular arrhythmias in non-ischaemic cardiomyopathy patients.
• Anterior Q waves on ECG independently predict life-threatening arrhythmic events (HR 1.030, P < 0.001).
• Prolonged QRS duration significantly increases arrhythmic risk (HR 4.642, P = 0.018).
• Increased LV end-diastolic volume index (LVEDVi) is independently associated with higher risk of LAEs (HR 1.011 per mL/m2, P = 0.040).
• Patients with normal ECG findings have a substantially lower risk of LAEs, with 100% survival free from events in this subgroup.
• Commonly used predictors such as left ventricular ejection fraction did not add significant prognostic value in this cohort.

Clinical Implications

In patients with LV ring-like scar, routine ECG evaluation focusing on anterior Q waves and QRS duration, combined with assessment of LV volumes, can improve risk stratification for life-threatening arrhythmias. Identifying patients with normal ECG may help define a lower-risk subgroup, potentially guiding management decisions and device implantation strategies. Traditional reliance on LV systolic function alone may be insufficient in this population.

Conclusion

LV ring-like scarring detected by CMR identifies a high-risk arrhythmogenic phenotype in non-ischaemic cardiomyopathy, with anterior Q waves, QRS prolongation, and increased LVEDVi serving as key independent predictors of malignant arrhythmias. ECG remains a valuable tool for risk stratification in this setting.

References

1. European Heart Journal Cardiovascular Imaging 2024 -- Risk Assessment for Arrhythmias in Patients with Left Ventricular Ring-Like Scarring
2. D. Penela et al. 2024 -- Ring-like patterns on imaging and sudden cardiac death: can ECG help stratify risk?