VALUE OF QUANTIFICATION OF MITRAL-VALVE D ISEASE BY TRANSESOPHAGEAL ECHOCARDIOGRAPHY BEFORE PERCUTANEOUS MITRAL COMMISSUROTOMY

The aims of this study were to determine the value of quantifying mitr al valve disease by transoesophageal echocardiography before percutane ous mitral commissurotomy (PMC) and to analyse the incidence of emboli c complications during PMC since the introduction of transoesophageal echocardiography. From March 1987 to December 1991, 317 patients with pure or dominant mitral stenosis were selected by Doppler echocardiogr aphy to undergo PMC at the Montreal Institute of Cardiology. The clini cal features of the first 138 patients (Group I) were the same as thos e of the last 179 patients (Group 2) who also underwent routine transo esophageal echocardiography the day before the procedure. A thrombus i n the left atrial appendage was observed in 8 patients in Group 2 (4.4 %), No embolic complications have occurred since the protocol was cha nged to include routine transoesophageal echocardiography, whereas 4 e mbolic episodes, 3 of which were fatal, occurred in patients in group 1. The indication of PMC was turned down because of angiographically s evere mitral regurgitation which was underestimated by transthoracic e chocardiography in 2 patients in Group 1 (1.4 %) and in 3 patients in group 2 (1.6 %). The mobility, thickness and degree of calcification o f the valves were attributed a score from 0-4 at transthoracic and tra nsoesophageal echocardiography. No difference was observed in the scor es of mobility (2.3 +/- 0.5 versus 2.3 +/- 0.05, NS) or valve thicknes s (2.1 +/- 0.4 versus 2.1 +/- 0.4, NS). However, valvular calcificatio n appeared to be more pronounced at transthoracic than at transoesopha geal echocardiography (1.5 +/- 0.9 versus 1.3 +/- 1.0, p < 0.002), but the differences observed were not predictive of haemodynamic success or of aggravation of mitral regurgitation at PMC. These results show t hat no embolic complications have occurred since routine investigation of the presence of thrombosis of the left atrial appendage has been p erformed before PMC. On the other hand, the study of the mitral valvul ar apparatus by transoesophageal echocardiography prolongs the time of examination without providing any more information than that obtained by transthoracic echocardiography in echogenic subjects.