Cardiac magnetic resonance imaging for assessment of mitral stenosis before and after percutaneous balloon valvuloplasty in comparison to two- and three-dimensional echocardiography.

Abstract

The experience with cardiac magnetic resonance (CMR) in mitral stenosis (MS) is limited in contrast to mitral regurgitation. To compare CMR versus 2D and 3D transthoracic (TTE) and 3D transesophgeal (TEE) echocardiography in assessment of rheumatic MS before and after percutaneous balloon mitral valvuloplasty (PBMV). Twenty consecutive symptomatic patients with MS were evaluated prospectively and independently by CMR, TTE, and TEE pre-PBMV, and by CMR and TTE post-PBMV. Mitral valve area (MVA) was assessed by CMR planimetry, TTE and TEE planimetry, and pressure half time (PHT). Further assessment included trans-mitral velocity, mitral regurgitation (MR), and left atrial (LA) volume. PBMV was successful in 18 patients and failed in two patients (one with MVA <1.5 cm2, one developed severe MR). Pre-PBMV and MVA by CMR, 2D TTE, biplane, 3D TTE, 3D TEE, and PHT were 1.16, 1.16, 1.10, 1.02, 1.05, and 0.99 cm2, respectively. Post-PBMV, a significant increase in MVA was observed (2.15, 2.06, 2.07, 2.04, and 2.03 cm2, respectively). High agreement was observed between CMR and echocardiography before and after PBMV, except for PHT method. CMR significantly underestimated trans-mitral velocity and gradients compared to echocardiography (P<0.001). Before PBMV, mild MR was observed in 11, 12, and 19 patients by 2D TTE, 3D TTE, and CMR. After PBMV, MR was observed in all patients (19 mild, one severe) by all modalities. Echocardiography significantly underestimated LA volume compared to CMR (P<0.001). LA volume decreased significantly after PBMV (P<0.001). CMR provides comprehensive assessment of several parameters in MS patients before and after intervention. Agreement with echocardiography is acceptable.