Prognostic impact of combined late gadolinium enhancement on cardiovascular magnetic resonance and peak oxygen consumption in ambulatory patients with nonischemic dilated cardiomyopathy

Abstract

Background: Peak oxygen consumption (peak VO₂) and late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) are prognostic in heart failure. We investigated whether LGE-CMR and peak VO₂combined had additive value in risk stratifying patients with nonischemic dilated cardiomyopathy (DCM).

Methods and results: Fifty-seven DCM patients underwent CMR and cardiopulmonary exercise testing. Cardiac events were cardiac death, hospitalization for decompensated heart failure, or lethal arrhythmia. Twenty-five (44%) were LGE-positive. The median peak VO₂was 18.5 mL·kg(-1)·min(-1). On multivariate analysis, positive LGE (P = .048) and peak VO₂(P = .003) were independent cardiac event predictors. Cardiac event risk was significantly higher with positive LGE and peak VO₂< 18.5 mL ·kg⁻¹ ·min⁻¹ than with negative LGE and peak VO₂≥ 18.5 mL · kg⁻¹ · min⁻¹ (hazard ratio 12.5; 95% CI 1.57-100; P = .017). In 3 patient groups (group A: no LGE, peak VO₂≥ 18.5 mL · kg⁻¹ · min⁻¹, n = 18; group B: positive LGE or peak VO₂< 18.5 mL · kg⁻¹ · min⁻¹, n = 24; group C: positive LGE and peak VO₂< 18.5 mL · kg⁻¹ · min⁻¹, n = 15) during follow-up (71 ± 32 months), group C had higher cardiac event rates than the others.

Conclusions: Combined assessment of LGE-CMR and peak VO₂provides additive prognostic information in ambulatory DCM.

Keywords: Exercise tolerance; magnetic resonance imaging; prognosis.