THE VALUE OF TRANSESOPHAGEAL ECHOCARDIOGRAPHY IN PREDICTING IMMEDIATEAND LONG-TERM OUTCOME OF BALLOON MITRAL VALVULOPLASTY - COMPARISON WITH TRANSTHORACIC ECHOCARDIOGRAPHY

The purpose of this study was to assess the role of transesophageal ec hocardiography in predicting the immediate and long-term outcome of ba lloon mitral valvuloplasty, and compare the results to transthoracic e chocardiography. Background: Transesophageal echocardiography accurate ly detects left atrial thrombi and allows better visualization of mitr al valve morphology; however, its value in predicting the immediate an d long-term outcome of balloon mitral valvuloplasty had not been asses sed as adequately as for transthoracic echocardiograph. Methods: In 56 patients referred for balloon mitral valvuloplasty, both transesophag eal and transthoracic echocardiography were performed (Group A). An ec ho score for both techniques was used to reflect mitral valve morpholo gy, and its predictive value for immediate and long-term outcome of th e valvuloplasty was assessed. The impact of transesophageal echocardio graphy in preventing procedural embolic events in those 56 patients wa s assessed by comparison to another group of 41 patients, who were exa mined only by transthoracic echocardiography prior to balloon mitral v alvuloplasty (Group B). Results: In Group A, transesophageal echocardi ography detected left atrial thrombus in seven, while transthoracic ec hocardiography detected left atrial thrombus in two patients. After 2 months of warfarin therapy, a repeat transesophageal echo examination in four patients showed resolution of thrombus in three who went on to have balloon mitral valvuloplasty. Among 52 patients who eventually h ad the procedure after thrombus was excluded by transesophageal echoca rdiography, there were no embolic events, compared to three embolic ev ents among the 41 patients in Group B (P = 0.08). The transthoracic ec hocardiography scores, while slightly higher, correlated well with tra nsesophageal echocardiography scores (r = 0.51, P < 0.001). The increa se in mitral valve area did not correlate well to total transthoracic or transesophageal echocardiography scores, while it correlated negati vely to valve calcification by transthoracic (r = 0.29, P < 0.05) and mobility by transesophageal echocardiography (r = -0.59, P < 0.02). At follow-up (7 +/- 4 months) nonsurvivors (7/56) had higher total score s by either transthoracic (P < 0.01) or transesophageal echocardiograp hy (P < 0.05) compared to survivors. The percent reduction in mitral v alve area was greater with age (r = 0.5, P < 0.02), time to follow-up (r - 0.67, P = 0.002), valve mobility by transthoracic echocardiograph y (r = 0.59, P < 0.01), and valve calcification by transthoracic echoc ardiography (r = 0.37, P = 0.09) and transesophageal echocardiography (r = 0.4, P = 0.07). Conclusions: Transesophageal echocardiography is superior to transthoracic echocardiography in detecting left atrial th rombi, and it may reduce the risk of embolic events following balloon mitral valvuloplasty. Assessment of mitral valve morphology by transes ophageal echocardiography is complementary and not superior to assessm ent by transthoracic echocardiography. Mitral valve calcification and mobility appear to be the best morphological predictors of immediate a nd long-term outcome following balloon mitral valvuloplasty.