# Evaluating the predictive value of late gadolinium enhancement assessed by cardiac magnetic resonance on sudden cardiac death in patients selected for implantable cardioverter defibrillator and cardiac resynchronization therapy implantation: a systematic review and meta-analysis

## TL;DR

This study finds that late gadolinium enhancement (LGE) on cardiac MRI is linked to higher sudden cardiac death risk in patients considered for heart devices, especially in non-ischemic cases.

## Contribution

The study provides a meta-analysis showing LGE-CMR's predictive value for sudden cardiac death in CRT candidates, highlighting its importance in non-ischemic patients.

## Key findings

- LGE-positive patients had a 72% higher risk of sudden cardiac death compared to LGE-negative patients.
- Non-ischemic patients with LGE positivity had a significantly higher SCD risk (HR 2.42).
- CRT-only patients showed no significant difference in SCD risk between LGE-positive and LGE-negative groups.

## Abstract

Late gadolinium enhancement (LGE) assessed by cardiovascular magnetic resonance (CMR) can evaluate myocardial scar associated with a higher risk of sudden cardiac death (SCD), which can guide the selection between cardiac resynchronization therapy with or without a defibrillator (CRT-P/CRT-D). Our aim was to investigate the association between LGE and SCD risk in patients with CRT using the LGE-CMR technique.

We performed a systematic literature search using four databases. The target population was CRT candidates. The primary endpoint was SCD. The risk of bias was assessed using the QUIPS tool.

Fifteen eligible articles were included with a total of 2494 patients, of whom 27%, 56%, and 19% had an implantable cardioverter defibrillator (ICD), CRT-D, and CRT-P, respectively. Altogether, 54.71% of the cohort was LGE positive, who had a 72% higher risk for SCD (HR 1.72; 95% CI 1.18–2.50) compared to LGE negatives. In non-ischemic patients, the proportion of LGE positivity was 46.6%, with a significantly higher risk for SCD as compared to LGE negatives (HR 2.42; 95% CI 1.99–2.94). The subgroup of CRT-only patients showed no difference between the LGE-positive vs. negative candidates (HR 1.17; 95% CI 0.82–1.68). Comparable SCD risk was observed between articles with short- (OR 7.47; 95% CI 0.54–103.12) vs. long-term (OR 6.15; 95% CI 0.96–39.45) follow-up time.

LGE-CMR positivity was associated with an increased SCD risk; however, in CRT candidates, the difference in risk reduction between LGE positive vs. negative patients was statistically not significant, suggesting a role of reverse remodeling. LGE-CMR before device implantation could be crucial in identifying high-risk patients even in non-ischemic etiology.

The online version contains supplementary material available at 10.1007/s00392-024-02441-2.