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Scar heterogeneity on cardiovascular magnetic resonance as a predictor of appropriate implantable cardioverter defibrillator therapy.

Rayatzadeh H, Tan A, Chan RH, Patel SJ, Hauser TH, Ngo L, Shaw JL, Hong SN, Zimetbaum P, Buxton AE, Josephson ME, Manning WJ, Nezafat R - J Cardiovasc Magn Reson (2013)

Bottom Line: However, HSA2-4SD and HSA4-6SD were significantly larger in the ICD therapy group (P = 0.001 and P = 0.03, respectively).In multivariable model HSA2-4SD was the only significant independent predictor of ICD therapy (HR = 1.08, 95%CI: 1.00-1.16, P = 0.04).Kaplan-Meier analysis showed that patients with greater HSA2-4SD had a lower survival free of appropriate ICD therapy (P = 0.026).

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Background: Despite the survival benefit of implantable-cardioverter-defibrillators (ICDs), the vast majority of patients receiving an ICD for primary prevention do not receive ICD therapy. We sought to assess the role of heterogeneous scar area (HSA) identified by late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) in predicting appropriate ICD therapy for primary prevention of sudden cardiac death (SCD).

Methods: From September 2003 to March 2011, all patients who underwent primary prevention ICD implantation and had a pre-implantation LGE-CMR were identified. Scar size was determined using thresholds of 4 and 6 standard deviations (SD) above remote normal myocardium; HSA was defined using 3 different criteria; as the region between 2 SD and 4 SD (HSA2-4SD), between 2SD and 6SD (HSA2-6SD), and between 4SD and 6SD (HSA4-6SD). The end-point was appropriate ICD therapy.

Results: Out of 40 total patients followed for 25 ± 24 months, 7 had appropriate ICD therapy. Scar size measured by different thresholds was similar in ICD therapy and non-ICD therapy groups (P = NS for all). However, HSA2-4SD and HSA4-6SD were significantly larger in the ICD therapy group (P = 0.001 and P = 0.03, respectively). In multivariable model HSA2-4SD was the only significant independent predictor of ICD therapy (HR = 1.08, 95%CI: 1.00-1.16, P = 0.04). Kaplan-Meier analysis showed that patients with greater HSA2-4SD had a lower survival free of appropriate ICD therapy (P = 0.026).

Conclusions: In primary prevention ICD implantation, LGE-CMR HSA identifies patients with appropriate ICD therapy. If confirmed in larger series, HSA can be used for risk stratification in primary prevention of SCD.

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Assessment of heterogeneous scar area (HSA). A) Mid-ventricular short axis LGE image of a patient with considerable LGE (red arrow) in ventricular septum and anterior wall, and a region of interest in normal myocardium in the inferior wall (ROI; orange box) used to define thresholds for LGE. RV indicates right ventricle; LV, left ventricle. B) Endocardial (red) and epicardial (green) borders were outlined manually. Grayscale threshold 2SDs above the mean signal intensity of the ROI (red shading) was outlined. C) Grayscale threshold 4SDs above the mean signal intensity of the ROI (red shading) were considered as scar core and is shown in red shading. D) HSA2-4SD defined as the signal intensity between ≥2SD and <4SD is shown in yellow shading, superimposed on scar core (>4SD) in red shading.
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Figure 1: Assessment of heterogeneous scar area (HSA). A) Mid-ventricular short axis LGE image of a patient with considerable LGE (red arrow) in ventricular septum and anterior wall, and a region of interest in normal myocardium in the inferior wall (ROI; orange box) used to define thresholds for LGE. RV indicates right ventricle; LV, left ventricle. B) Endocardial (red) and epicardial (green) borders were outlined manually. Grayscale threshold 2SDs above the mean signal intensity of the ROI (red shading) was outlined. C) Grayscale threshold 4SDs above the mean signal intensity of the ROI (red shading) were considered as scar core and is shown in red shading. D) HSA2-4SD defined as the signal intensity between ≥2SD and <4SD is shown in yellow shading, superimposed on scar core (>4SD) in red shading.

Mentions: In order to identify the best SI threshold of scar detection as well as HSA, scar size was determined using a threshold of 4 or 6 SD above the mean of the remote normal myocardium and by manual tracing (Figure 1); HSA was defined as the difference between 2 SD and 4 SD (HSA2-4SD), between 2SD and 6SD (HSA2-6SD) and between 4SD and 6SD (HSA4-6SD). The amount of LGE for each group was expressed in grams.


Scar heterogeneity on cardiovascular magnetic resonance as a predictor of appropriate implantable cardioverter defibrillator therapy.

Rayatzadeh H, Tan A, Chan RH, Patel SJ, Hauser TH, Ngo L, Shaw JL, Hong SN, Zimetbaum P, Buxton AE, Josephson ME, Manning WJ, Nezafat R - J Cardiovasc Magn Reson (2013)

Assessment of heterogeneous scar area (HSA). A) Mid-ventricular short axis LGE image of a patient with considerable LGE (red arrow) in ventricular septum and anterior wall, and a region of interest in normal myocardium in the inferior wall (ROI; orange box) used to define thresholds for LGE. RV indicates right ventricle; LV, left ventricle. B) Endocardial (red) and epicardial (green) borders were outlined manually. Grayscale threshold 2SDs above the mean signal intensity of the ROI (red shading) was outlined. C) Grayscale threshold 4SDs above the mean signal intensity of the ROI (red shading) were considered as scar core and is shown in red shading. D) HSA2-4SD defined as the signal intensity between ≥2SD and <4SD is shown in yellow shading, superimposed on scar core (>4SD) in red shading.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3750752&req=5

Figure 1: Assessment of heterogeneous scar area (HSA). A) Mid-ventricular short axis LGE image of a patient with considerable LGE (red arrow) in ventricular septum and anterior wall, and a region of interest in normal myocardium in the inferior wall (ROI; orange box) used to define thresholds for LGE. RV indicates right ventricle; LV, left ventricle. B) Endocardial (red) and epicardial (green) borders were outlined manually. Grayscale threshold 2SDs above the mean signal intensity of the ROI (red shading) was outlined. C) Grayscale threshold 4SDs above the mean signal intensity of the ROI (red shading) were considered as scar core and is shown in red shading. D) HSA2-4SD defined as the signal intensity between ≥2SD and <4SD is shown in yellow shading, superimposed on scar core (>4SD) in red shading.
Mentions: In order to identify the best SI threshold of scar detection as well as HSA, scar size was determined using a threshold of 4 or 6 SD above the mean of the remote normal myocardium and by manual tracing (Figure 1); HSA was defined as the difference between 2 SD and 4 SD (HSA2-4SD), between 2SD and 6SD (HSA2-6SD) and between 4SD and 6SD (HSA4-6SD). The amount of LGE for each group was expressed in grams.

Bottom Line: However, HSA2-4SD and HSA4-6SD were significantly larger in the ICD therapy group (P = 0.001 and P = 0.03, respectively).In multivariable model HSA2-4SD was the only significant independent predictor of ICD therapy (HR = 1.08, 95%CI: 1.00-1.16, P = 0.04).Kaplan-Meier analysis showed that patients with greater HSA2-4SD had a lower survival free of appropriate ICD therapy (P = 0.026).

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Background: Despite the survival benefit of implantable-cardioverter-defibrillators (ICDs), the vast majority of patients receiving an ICD for primary prevention do not receive ICD therapy. We sought to assess the role of heterogeneous scar area (HSA) identified by late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) in predicting appropriate ICD therapy for primary prevention of sudden cardiac death (SCD).

Methods: From September 2003 to March 2011, all patients who underwent primary prevention ICD implantation and had a pre-implantation LGE-CMR were identified. Scar size was determined using thresholds of 4 and 6 standard deviations (SD) above remote normal myocardium; HSA was defined using 3 different criteria; as the region between 2 SD and 4 SD (HSA2-4SD), between 2SD and 6SD (HSA2-6SD), and between 4SD and 6SD (HSA4-6SD). The end-point was appropriate ICD therapy.

Results: Out of 40 total patients followed for 25 ± 24 months, 7 had appropriate ICD therapy. Scar size measured by different thresholds was similar in ICD therapy and non-ICD therapy groups (P = NS for all). However, HSA2-4SD and HSA4-6SD were significantly larger in the ICD therapy group (P = 0.001 and P = 0.03, respectively). In multivariable model HSA2-4SD was the only significant independent predictor of ICD therapy (HR = 1.08, 95%CI: 1.00-1.16, P = 0.04). Kaplan-Meier analysis showed that patients with greater HSA2-4SD had a lower survival free of appropriate ICD therapy (P = 0.026).

Conclusions: In primary prevention ICD implantation, LGE-CMR HSA identifies patients with appropriate ICD therapy. If confirmed in larger series, HSA can be used for risk stratification in primary prevention of SCD.

Show MeSH
Related in: MedlinePlus