CMR Quantification of Myocardial Scar Provides Additive Prognostic Information in Nonischemic Cardiomyopathy

Abstract

OBJECTIVES This study sought to determine whether the extent of late gadolinium enhancement (LGE) can provide additive prognostic information in patients with a nonischemic dilated cardiomyopathy (NIDC) with an indication for implantable cardioverter-defibrillator (ICD) therapy for the primary prevention of sudden cardiac death (SCD). BACKGROUND Data suggest that the presence of LGE is a strong discriminator of events in patients with NIDC. Limited data exist on the role of LGE quantification. METHODS The extent of LGE and clinical follow-up were assessed in 162 patients with NIDC prior to ICD insertion for primary prevention of SCD. LGE extent was quantified using both the standard deviation–based (2-SD) method and the full-width half-maximum (FWHM) method. RESULTS We studied 162 patients with NIDC (65% male; mean age: 55 years; left ventricular ejection fraction [LVEF]: 26 ± 8%) and followed up for major adverse cardiac events (MACE), including cardiovascular death and appropriate ICD therapy, for a mean of 29 ± 18 months. Annual MACE rates were substantially higher in patients with LGE (24%) than in those without LGE (2%). By univariate association, the presence and the extent of LGE demonstrated the strongest associations with MACE (LGE presence, hazard ratio [HR]: 14.5 [95% confidence interval (CI): 6.1 to 32.6; p < 0.001]; LGE extent, HR: 1.15 per 1% increase in volume of LGE [95% CI: 1.12 to 1.18; p < 0.0001]). Multivariate analyses showed that LGE extent was the strongest predictor in the best overall model for MACE, and a 7-fold hazard was observed per 10% LGE extent after adjustments for patient age, sex, and LVEF (adjusted HR: 7.61; p < 0.0001). LGE quantitation by 2-SD and FWHM both demonstrated robust prognostic association, with the highest MACE rate observed in patients with LGE involving >6.1% of LV myocardium. CONCLUSIONS LGE extent may provide further risk stratification in patients with NIDC with a current indication for ICD implantation for the primary prevention of SCD. Strategic guidance on ICD therapy by cardiac magnetic resonance in patients with NIDC warrants further study.

Late Gadolinium Enhancement and the Risk for Ventricular Arrhythmias or Sudden Death in Dilated Cardiomyopathy

“…The majority of studies evaluated the presence or absence of LGE by visual analysis. 4,6,7,10,[13][14][15][16][17][18][19][20]22,[24][25][26][27][28][29]30,32 Duration of follow-up ranged from 1 year to 5.3 years; mean follow up was 3 years. The majority of reports considered a composite arrhythmic end-point formed by sudden cardiac death and/or aborted cardiac arrest, sustained ventricular arrhythmias and/or appropriate ICD therapies.…”

“…The majority of reports considered a composite arrhythmic end-point formed by sudden cardiac death and/or aborted cardiac arrest, sustained ventricular arrhythmias and/or appropriate ICD therapies. 4,5,7,8,10,13,14,[16][17][18]20,22,25,[28][29][30][31] In two reports history of arrhythmic events was the end-point analyzed. 9,32 These data were not used to calculate annual event rates, but were included in the evaluation of pooled OR.…”

“…4,17,25,30 The pooled adjusted hazard ratio (HR 6.7, 95% CI 3.6-12.5) indicates that LGE is an independent predictor of the arrhythmic endpoint (table 5, supplementary material).…”

“…However, very few studies evaluated the association between LGE pattern 25,30 or extension 4,9,17,25,31 and arrhythmic events specifically in DCM. The limited data available and the differences in methods used not only to measure but also to report the quantification of LGE make these factors less suitable to be the target of a metaanalysis at present.…”

Incidence, Predictors, and Outcomes of Implantable Cardioverter‐Defibrillator Discharge Among People Living With HIV

“…The mechanisms involved in the increase in ICD discharge among PHIV have not been fully elucidated. Myocardial fibrosis may play a key role; it is a key pathophysiological driver for the development of cardiac arrhythmias, and both the presence and the extent of myocardial fibrosis are predictors of ventricular arrhythmias 15, 18, 19, 20. At baseline, PHIV without HF have both an increase in the presence and extent of myocardial fibrosis 21, 22.…”