Cardiac MRI Versus Echocardiography for Left Ventricular Ejection Fraction Assessment: a Prospective Comparative...

Accurate assessment of left ventricular ejection fraction (LVEF) is fundamental to the diagnosis, risk stratification and management of cardiovascular diseases. Cardiac magnetic resonance imaging (CMR) is the established reference standard, while echocardiography and global longitudinal strain (GLS) provide widely accessible alternatives. This study compared LVEF by CMR, two-dimensional echocardiography (2D Echo), three-dimensional echocardiography (3D Echo) and GLS in patients with cardiovascular diseases at a Northeast Indian tertiary care centre.

A hospital-based prospective observational comparative study enrolled 50 patients with confirmed cardiovascular pathology at Assam Medical College and Hospital (AMCH), Dibrugarh. Cardiac magnetic resonance imaging was performed on a Siemens Magnetom Avanto 1.5 T scanner; echocardiography employed the Philips Affiniti CVx system. Agreement was assessed by Bland-Altman analysis and intraclass correlation coefficient (ICC).

The mean CMR-LVEF was 48.5 ± 12.3%. 2D Echo showed a mean positive bias of +2.7 percentage points (95% limits of agreement [LoA]: -8.5% to +13.9%; ICC 0.89) and 3D Echo showed superior agreement (bias +1.3%; LoA -6.2% to +8.8%; ICC 0.93). Upward reclassification by 2D Echo occurred in 26% of patients. Global longitudinal strain strongly correlated with CMR-LVEF (r = -0.87, p < 0.001) and identified subclinical dysfunction in 35% of patients with preserved LVEF (≥50%).

Cardiac magnetic resonance remains the reference standard for LVEF quantification. 3D Echo shows significantly superior agreement with CMR versus 2D Echo. Global longitudinal strain provides incremental diagnostic value beyond LVEF. A tiered multimodality imaging strategy with selective CMR confirmation at clinical decision boundaries is recommended.