In patients with non-ischemic cardiomyopathy, mid-wall fibrosis was associated with reduced global circumferential strain (-6.6% vs -9.4%, p=0.004) and increased rigid left ventricular body rotation.
Cross-Sectional (n=116)
Blinded observers
Yes
Does the presence of left ventricular mid-wall fibrosis impair LV myocardial mechanics in patients with non-ischemic cardiomyopathy?
In patients with non-ischemic cardiomyopathy, mid-wall fibrosis is associated with significant impairments in systolic and diastolic myocardial mechanics despite similar ejection fractions, providing a mechanistic explanation for their higher risk of pump failure.
Absolute Event Rate: -6.6% vs -9.4%
p-value: p=0.004
BACKGROUND: Left ventricular (LV) mid-wall fibrosis (MWF), which occurs in about a quarter of patients with non-ischemic cardiomyopathy (NICM), is associated with high risk of pump failure. The mid LV wall is the site of circumferential myocardial fibers. We sought to determine the effect of MWF on LV myocardial mechanics. METHODS: Patients with NICM (n = 116; age: 62.8 ± 13.2 years; 67% male) underwent late gadolinium enhancement cardiovascular magnetic resonance (CMR) and were categorized according to the presence (+) or absence (-) of MWF. Feature tracking (FT) CMR was used to assess myocardial deformation. RESULTS: Despite a similar LVEF (24.3 vs. 27.5%, p = 0.20), patients with MWF (32 24%) had lower global circumferential strain (Ɛcc: -6.6% vs. -9.4 %, P = 0.004), but similar longitudinal (Ɛll: -7.6 % vs. -9.4 %, p = 0.053) and radial (Ɛrr: 14.6% vs. 17.8% p = 0.18) strain. Compared with - MWF, + MWF was associated with reduced LV systolic, circumferential strain rate (-0.38 ± 0.1 vs. -0.56 ± 0.3 s(-1), p = 0.005) and peak LV twist (4.65 vs. 6.31°, p = 0.004), as well as rigid LV body rotation (64 % vs. 28 %, P <0.001). In addition, +MWF was associated with reduced LV diastolic strain rates (DSRcc: 0.34 vs. 0.46 s(-1); DSRll: 0.38 vs. 0.50s(-1); DSRrr: -0.55 vs. -0.75 s(-1); all p <0.05). CONCLUSIONS: MWF is associated with reduced LV global circumferential strain, strain rate and torsion. In addition, MWF is associated with rigid LV body rotation and reduced diastolic strain rates. These systolic and diastolic disturbances may be related to the increased risk of pump failure observed in patients with NICM and MWF.
Taylor et al. (Fri,) conducted a cross-sectional in Non-ischemic cardiomyopathy (n=116). Left ventricular mid-wall fibrosis vs. Absence of mid-wall fibrosis was evaluated on Global circumferential strain (p=0.004). In patients with non-ischemic cardiomyopathy, mid-wall fibrosis was associated with reduced global circumferential strain (-6.6% vs -9.4%, p=0.004) and increased rigid left ventricular body rotation.
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