Feature-tracking cardiac magnetic resonance and 2D speckle-tracking echocardiography showed a strong global longitudinal strain correlation (r = 0.793), but limits of agreement spanned 8.3 percentage points, sufficient to misclassify individual patients.
Reanalysis of segmental strain data confirms statistical robustness of intermodality differences, but wide limits of agreement between FT-CMR and 2D-STE mean the modalities are not interchangeable for individual patient tracking.
Effect estimate: r = 0.793
p-value: p=<0.001
Abstract Khidr and colleagues recently reported an intermodality comparison of left ventricular longitudinal strain by feature-tracking cardiac magnetic resonance (FT-CMR) and 2D speckle-tracking echocardiography (2D-STE) in 55 stable patients with chronic ischemic heart disease and reduced ejection fraction. Their analysis showed a strong global longitudinal strain (GLS) correlation (r = 0.793, P < 0.001) and explicitly cautioned against treating the two modalities as interchangeable for individual or longitudinal assessment. We support these conclusions and write to extend two methodological points. First, the 17 segment-level paired comparisons in Table 4 are reported without explicit multiplicity adjustment. On recomputation against a Bonferroni threshold of α/17≈0.00294, 11 of 17 segmental differences remain statistically significant, indicating that the original segmental signal is more statistically robust than an unadjusted reader might assume; we therefore recommend explicit reporting of adjusted P-values together with a unified mixed-effects formulation that accommodates within-patient segment-to-segment correlation. Second, the GLS limits of agreement span 8.3 percentage points (− 3.2% to + 5.1%), a width sufficient to misclassify individual patients across established GLS thresholds. A worked example is provided, and the recommendation to confine longitudinal follow-up to a single platform is argued to deserve more prominent placement in the Abstract and Conclusions.
Malik et al. (Fri,) conducted a letter in Chronic ischemic heart disease with reduced ejection fraction (n=55). Feature-tracking cardiac magnetic resonance (FT-CMR) vs. 2D speckle-tracking echocardiography (2D-STE) was evaluated on Global longitudinal strain (GLS) correlation (r = 0.793, p=<0.001). Feature-tracking cardiac magnetic resonance and 2D speckle-tracking echocardiography showed a strong global longitudinal strain correlation (r = 0.793), but limits of agreement spanned 8.3 percentage points, sufficient to misclassify individual patients.