Cardiac MRI Risk Stratification for Dilated Cardiomyopathy with Left Ventricular Ejection Fraction of 35% or Higher

Background: Studies over the past 15 years have demonstrated that a considerable number of patients with dilated cardiomyopathy (DCM) who died from sudden cardiac death (SCD) had a left ventricular (LV) ejection fraction (LVEF) of 35% or higher.Purpose: To identify clinical and cardiac MRI risk factors for adverse events in patients with DCM and LVEF of 35% or higher.Materials and Methods: In this retrospective study, consecutive patients with DCM and LVEF of 35% or higher who underwent cardiac MRI between January 2010 and December 2017 were included. The primary end point was a composite of SCD or aborted SCD. The secondary end point was a composite of all-cause mortality, heart transplant, or hospitalization for heart failure. The risk factors for the primary and secondary end points were identified with multivariable Cox analysis.Results: A total of 466 patients with DCM and LVEF of 35% or higher (mean age, 44 years +/- 14 [SD]; 358 men) were included. During a mean follow-up of 79 months +/- 30 (SD) (range, 7-143 months), 40 patients reached the primary end point and 61 reached the secondary end point. In the adjusted analysis, age (hazard ratio [HR], 1.03 per year [95% CI: 1.00, 1.05]; P = .04), family history of SCD (HR, 3.4 [95% CI: 1.3, 8.8]; P = .01), New York Heart Association (NYHA) class III or IV (HR vs NYHA class I or II, 2.1 [95% CI: 1.1, 3.9]; P = .02), and myocardial scar at late gadolinium enhancement (LGE) MRI greater than or equal to 7.1% of the LV mass (HR, 4.4 [95% CI: 2.4, 8.3]; P < .001) were associated with SCD or aborted SCD. For the composite secondary end point, LGE greater than or equal to 7.1% of the LV mass (HR vs LGE <7.1%, 2.0 [95% CI: 1.2, 3.4]; P = .01), left atrial maximum volume index, and reduced global longitudinal strain were independent predictors.Conclusion: For patients with dilated cardiomyopathy and left ventricular (LV) ejection fraction of 35% or higher, cardiac MRI-defined myocardial scar greater than or equal to 7.1% of the LV mass was associated with sudden cardiac death (SCD) or aborted SCD.(c) RSNA, 2022

Automated summary

This retrospective study aimed to identify clinical and cardiac MRI risk factors for adverse events in patients with dilated cardiomyopathy (DCM) and left ventricular ejection fraction (LVEF) of 35% or higher. The results showed that myocardial scar at late gadolinium enhancement (LGE) MRI equal to or greater than 7.1% of the LV mass was associated with sudden cardiac death (SCD) or aborted SCD.