Objective: Late gadolinium enhancement (LGE) is not necessarily ideal for detecting diffuse myocardial fibrosis in idiopathic dilated cardiomyopathy (DCM). Since systolic blood pressure response (SBPR) during exercise has been proposed to reflect cardiac pump reserve in patients with heart failure, we wished to determine whether LGE plus SBPR is a better prognostic factor in patients with DCM.
Methods: LGE and cardiopulmonary exercise testing results in consecutive 207 patients with DCM were examined. Patients were divided into four groups according to the presence or absence of LGE and the SBPR cut-off value of +40 mm Hg according to receiver operating characteristic curve analysis: LGE-positive+SBPR <40 mm Hg (n=65), LGE-positive+SBPR ≥40 mm Hg (n=40), LGE-negative+SBPR <40 mm Hg (n=33) and LGE-negative+SBPR ≥40 mm Hg (n=69). The composite end point was cardiac death, cardiac transplantation, LV assist device implantation, life-threatening arrhythmia or heart failure.
Results: Forty-two (20%) patients developed the composite end point, with rates of 35%, 20%, 21% and 6% in patients with LGE-positive+SBPR <40 mm Hg, LGE-positive+SBPR ≥40 mm Hg, LGE-negative+SBPR <40 mm Hg and LGE-negative+SBPR ≥40 mm Hg status, respectively. Multivariable Cox regression analysis identified LGE-positive and SBPR <40 mm Hg as a significant independent predictor of cardiac events (HR 2.08, 95% CI 1.06 to 4.11, p=0.034). Of note, there was no significant difference in the cardiac event-free survival rate between the LGE-positive+SBPR ≥40 mm Hg and LGE-negative+SBPR <40 mm Hg groups (p=0.736).
Conclusions: The combination of LGE and SBPR provides more clinically relevant information for assessing the risk of cardiac events in patients with DCM than LGE status alone.
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