Abstract
Background: Current guidelines provide left ventricular ejection fraction (LVEF) criterion for the use of implantable cardioverter defibrillators (ICD) but do not specify which modality to use for LVEF measurement. There are limited data comparing conventional planar radionuclide ventriculography (RNV) and cardiac MRI (cMRI) for LVEF measurement in this patient population.
Methods: This single-centre study included 124 consecutive patients referred for ICD implantation who underwent both RNV and cMRI within 30 days. LVEF was measured by both techniques with 2 independent readers each. The short axis stack of cine images was used for LVEF quantification by cMRI and the left anterior oblique projection for RNV. Bland-Altman analysis was used to assess agreement of LVEF measurement and kappa to assess the impact on clinical decision making regarding ICD implant.
Results: Among 124 patients (age 64±11 years, 77% male, 60% had known ischemic heart disease; 45% subsequently received ICD), the median interval between the cMRI and RNV studies was 1 day (interquartile range of 1-10 days), the mean LVEF was 32±12% by cMRI and 33±11% by RNV (p=0.60). LVEF by cMRI and RNV showed good correlation with an intraclass correlation coefficient (ICC) of 0.859 (p<0.001), but Bland-Altman analysis showed relatively wide limits of agreement (-12.1 to 11.4) (Figure 1). The kappa value was 0.628. LVEF by cMRI reclassified 29 (24%) patients being considered for ICD when compared to LVEF by RNV (Table 1). There was no significant correlation between the absolute difference in LVEF measurements by the two modalities and QRS interval or heart rate. LVEF quantification by both modalities showed good interobserver reproducibility (ICC 0.96 and 0.94, respectively) (limits of agreement -7.27 to 5.75 and -8.63 to 6.34, respectively).
Conclusion: Although LVEF measurements by cMRI and RNV show substantial agreement, there is frequent reclassification of patients for ICD placement based on LVEF between the two modalities. Future studies should determine if a particular imaging modality for LVEF measurement may enhance ICD decision making and treatment benefit, thereby improve patient outcomes.
Methods: This single-centre study included 124 consecutive patients referred for ICD implantation who underwent both RNV and cMRI within 30 days. LVEF was measured by both techniques with 2 independent readers each. The short axis stack of cine images was used for LVEF quantification by cMRI and the left anterior oblique projection for RNV. Bland-Altman analysis was used to assess agreement of LVEF measurement and kappa to assess the impact on clinical decision making regarding ICD implant.
Results: Among 124 patients (age 64±11 years, 77% male, 60% had known ischemic heart disease; 45% subsequently received ICD), the median interval between the cMRI and RNV studies was 1 day (interquartile range of 1-10 days), the mean LVEF was 32±12% by cMRI and 33±11% by RNV (p=0.60). LVEF by cMRI and RNV showed good correlation with an intraclass correlation coefficient (ICC) of 0.859 (p<0.001), but Bland-Altman analysis showed relatively wide limits of agreement (-12.1 to 11.4) (Figure 1). The kappa value was 0.628. LVEF by cMRI reclassified 29 (24%) patients being considered for ICD when compared to LVEF by RNV (Table 1). There was no significant correlation between the absolute difference in LVEF measurements by the two modalities and QRS interval or heart rate. LVEF quantification by both modalities showed good interobserver reproducibility (ICC 0.96 and 0.94, respectively) (limits of agreement -7.27 to 5.75 and -8.63 to 6.34, respectively).
Conclusion: Although LVEF measurements by cMRI and RNV show substantial agreement, there is frequent reclassification of patients for ICD placement based on LVEF between the two modalities. Future studies should determine if a particular imaging modality for LVEF measurement may enhance ICD decision making and treatment benefit, thereby improve patient outcomes.
| Original language | English |
|---|---|
| Article number | 141 |
| Pages (from-to) | S71-S72 |
| Number of pages | 2 |
| Journal | Canadian Journal of Cardiology |
| Volume | 31 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - Oct 2015 |