Myocardial infarct heterogeneity assessment by late gadolinium enhancement cardiovascular magnetic resonance imaging shows predictive value for ventricular arrhythmia development after acute myocardial infarction

The aim of this study was to assess the association between the proportions of penumbra-visualized by late gadolinium enhanced cardiovascular magnetic resonance imaging (LGE-CMR)-after acute myocardial infarction (AMI) and the prevalence of ventricular tachycardia (VT). One-hundred and sixty-two AMI patients, successfully, treated by primary percutaneous coronary intervention (PCI) underwent LGE-CMR after a median of 3 days (3-4) and 24-h Holter monitoring after 1 month. With LGE-CMR, the total amount of enhanced myocardium was quantified and divided into an infarct core (>50% of maximal signal intensity) and penumbra (25-50% of maximal signal intensity). With Holter monitoring, the number of VTs (≥4 successive PVCs) per 24 h was measured. The mean total enhanced myocardium was 31 ± 11% of the left ventricular mass. The % penumbra accounted for 39 ± 11% of the total enhanced area. In 29 (18%) patients, Holter monitoring showed VT, with a median of 1 episode (1-3) in 24 h. A larger proportion of penumbra within the enhanced area increased the risk of VTs [OR: 1.06 (95% CI: 1.02-1.10), P = 0.003]. After multivariate logistic regression analysis, the presence of ventricular fibrillation before primary PCI [OR: 5.60 (95% CI: 1.54-20.29), P = 0.01] and the proportional amount of penumbra within the enhanced myocardium [OR: 1.06 (95% CI: 1.02-1.10), P = 0.04] were independently associated with VT on Holter monitoring. Larger proportions of penumbra in the subacute phase after AMI are associated with increased risk of developing VTs. Quantification of penumbra size may become a useful future tool for risk stratification and ultimately for the prevention of ventricular arrhythmias.