Overview

Fibrotic tissue is known to be the substrate for the appearance of scar-related reentrant ventricular arrhythmias (VA) in chronic ischemic cardiomyopathy (ICM). Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) has proven to be a useful technique in the non-invasive characterization of the scarred tissue and the underlying arrhythmogenic substrate. Previous studies identified the presence of significant scarring (> 5% of the left ventricular -LV- mass) is an independent predictor of adverse outcome (all-cause mortality or appropriate ICD discharge for ventricular tachycardia or fibrillation) in patients being considered for implantable cardioverter-defibrillator (ICD) placement. Parallelly, the presence of heterogeneous tissue channels, which correlate with voltage channels after endocardial voltage mapping of the scar, can be more frequently observed in patients suffering from sustained monomorphic ventricular tachycardias (SMVT) than in matched controls for age, sex, infarct location, and left ventricular ejection fraction (LVEF). However, the lack of solid evidence and randomized trials make LVEF still the main decision parameter when assessing suitability for ICD implantation in primary prevention of sudden cardiac death (SCD). In a recent, case-control study, we identified the border zone channel (BZC) mass as the only independent predictor for VT occurrence, after matching for age, sex, LVEF and total scar mass. This BZC mass can be automatically calculated using a commercially available, post-processing imaging platform named ADAS 3D LV (ADAS3D Medical, Barcelona, Spain), with FDA 510(k) Clearance and European Community Mark approval. Thus, CMR-derived BZC mass might be used as an automatically reproducible criterium to reclassify those patients with chronic ICM at highest risk for developing VA/SCD in a relatively short period of approx. 2 years.

In the present cohort study, we sought to evaluate the usefulness of the BZC mass measurement to predict the occurrence of VT events in a prospective, multicenter, unselected series of consecutive chronic ischemic patients without previous arrhythmia evidence, irrespectively of their LVEF.

Eligibility

Inclusion Criteria:

• Age > 18 years.
• Chronic (> 3 months after the index coronary event), stable ischemic heart disease, irrespectively of the LVEF.
• Life expectancy of > 1 year with a good functional status.
• Signed informed consent.

Exclusion Criteria:

• Age < 18 years.
• Pregnancy.
• Life expectancy of < 1 year, or bad functional status (NYHA IV functional class).
• Other concomitant structural heart diseases (e.g. congenital, non-ischemic, etc.)
• Previously documented sustained ventricular arrhythmias.
• Impossibility or contraindications to undergo a contrast-enhanced CMR study.
• Concomitant investigation treatments.
• Medical, geographical and social factors that make study participation impractical, and inability to give written informed consent. Patient's refusal to participate in the study.