Key result
Myocardial scarring >5% of LV mass detected by CMR was associated with a 5.2-fold increased risk of death or appropriate ICD discharge compared to minimal or no scarring (≤5%).
Why the study?
Current SCD risk stratification relies on LVEF, but many patients with preserved LVEF suffer SCD and many with poor LVEF do not benefit from ICD prophylaxis, necessitating improved risk stratification methods.
Does an assessment of myocardial scarring by DE-CMR improve risk stratification for adverse outcomes in patients evaluated for ICD implantation?
Cohort (n=137)
No
Does an assessment of myocardial scarring by DE-CMR improve risk stratification for adverse outcomes in patients evaluated for ICD implantation?
Myocardial scar size >5% detected by CMR provides independent prognostic value beyond LVEF, potentially improving the selection of patients for primary and secondary ICD implantation.
Answers are grounded in this paper and cite their sources.
May support CMR scar assessment to refine ICD selection beyond LVEF; leaves open validation in larger prospective trials before practice change.
Objectives We tested whether an assessment of myocardial scarring by cardiac magnetic resonance (CMR) would improve risk stratification in patients evaluated for implantable cardioverter-defibrillator implantation. Background Current SCD risk stratification emphasizes left-ventricular ejection fraction (LVEF), however the majority of patients suffering SCD have a preserved LVEF and many with poor LVEF do not benefit from ICD prophylaxis. Methods One hundred thirty-seven patients undergoing evaluation for possible ICD placement were prospectively enrolled and underwent CMR assessment of LVEF and scar. The prespecified primary endpoint was death or appropriate ICD discharge for sustained ventricular tachyarrhythmia. Results During a median follow-up of 24 months the primary endpoint occurred in 39 patients. Whereas the rate of adverse events steadily increased with decreasing LVEF, a sharp step-up was observed for scar size >5% of LV mass (HR=5.2 [95% CI, 2.0-13.3]). On multivariable Cox proportional hazards analysis, including LVEF and electrophysiological-study results, scar size (as a continuous variable or dichotomized at 5%) was an independent predictor of adverse outcome. Among patients with LVEF >30%, those with significant scarring (>5%) had higher risk than those with minimal-or-no (≤5%) scarring (HR=6.3 [1.4-28.0]). Those with LVEF >30% and significant scarring had similar risk to patients with LVEF ≤30% (p=0.56). Among patients with LVEF ≤30%, those with significant scarring again had higher risk than those with minimal-or-no scarring (HR=3.9 [1.2-13.1]). Those with LVEF ≤30% and minimal scarring had similar risk to patients with LVEF >30% (p=0.71). Conclusions Myocardial scarring detected by CMR is an independent predictor of adverse outcome in patients being considered for ICD placement. In patients with LVEF >30%, significant scarring (>5% LV) identifies a high-risk cohort similar in risk to those with LVEF ≤30%. Conversely, in patients with LVEF ≤30%, minimal-or-no scarring identifies a low-risk cohort similar to those with LVEF >30%.
No takes yet. Share an insight, caveat, or question.
Klem et al. (2012) conducted a cohort in Patients evaluated for implantable cardioverter-defibrillator (ICD) implantation (n=137). Myocardial scar size >5% of LV mass by CMR vs. Myocardial scar size ≤5% of LV mass by CMR was evaluated on Death or appropriate ICD discharge for sustained ventricular tachyarrhythmia (HR 5.2, 95% CI 2.0-13.3, p=0.0006). Myocardial scarring >5% of LV mass detected by CMR was associated with a 5.2-fold increased risk of death or appropriate ICD discharge compared to minimal or no scarring (≤5%).
Synapse has enriched 10 related papers. Consider them for comparative context: