Predictors, Mechanisms and Outcome of Severe Mitral Regurgitation Complicating Percutaneous Mitral Valvotomy with the lnoue Balloon Rosa Hernandez, MD, Carlos Macaya, MD, Camino BaAuelos, MD, Fernando Alfonso, MD, Javier Goicolea, MD, And& biguez, MD, Antonio Fernandez-Ortiz, MD, Juan Castillo, MD, Paloma Aragoncillo, MD, Manuel Gil Aguado, MD, and Pedro Zarco, MD During 241 consecutive percutaneous mitral val- votomy (PMV) procedures performed with the In- oue balloon, 16 patients (6.6%) developed severe mitral regurgitation (MR). Baseline clinical, echo- cardiographic (Doppler mitral valve area and Wil- kins’ score) and hemodynamic data were not dif- ferent from those of patients without this compli- cation. Severe MR occurred during the first inflation in 7 patients and after several stepwise inflations In 9. Although maximal balloon size was similar in both groups, unusual indentatlons and subvalvular Inflations were more frequently ob- served in patients who developed severe MR. Ear- ly mitral valve replacement was required in 6 pa- tients. All of them had a leaflet rupture either along the midportion (2 patients), along a commis- sure (4 patlents), or both. Commlssural calcium was present in 5 valves and 5 also had severe sub- valvular Involvement that had been underestimat- ed by echocardiography. Df the 10 nonsurgically treated patients, 4 had chordal rupture by echo- cardlographic criteria, whereas in the remainlng 6 the precise mechanism of MR could not be deter- mined. During follow-up (11.4 f 4 months, range 1 to 30), 1 patient required surgery for symptoms and the remaining 9 were symptomatically im- proved and free of left ventricular dilatation. In conclusion, severe MR complicated 6.6% of PMV procedures with the lnoue balloon, and its mecha- nism was leaflet or chordal rupture. Although one third of the patients required early mitral surgery, most of the remaining obtained midterm sympto- matic benefit. (Am J Cardiol lSS2;70:116S-1174) From the Cardiopulmonary, Pathology and Cardiac Surgery Depart- ments, Hospital Universitario San Carlos, Madrid, Spain. Manuscript received April 27,1992; revised manuscript received and accepted June 23, 1992. Address for reprints: Carlos Macaya, MD, Departamento de Car- diopulmonar, Hospital Universitario San Car&, C/ Martin Lagos s/n, Madrid 28040, Spain. P ercutaneous mitral valvotomy (PMV) is a well-es- tablished procedure for the treatment of patients with symptomatic mitral stenosis.‘-I2The proce- dure produces a significant increase in mitral area-21 and provides clinical improvement in most patients, but the development of severe mitral regurgitation (MR),3*5J7 even if infrequent, is still a major limi- tation of the technique. Although some investigators have identified several anatomic6*7 and procedural fac- tors7J0J5J9+22 as predictors of MR after PMV, others failed to find any correlation between mitral anatomy and the developmentof this complication.3J9q22 Clinical tolerance to acutely produced severe MR is variable, and while some patients require emergency surgery, others do not need it,6g8-10 and even a few may have a decrease in the severity of MR over time.21v22 The pur- poseof this study was (1) to determine the incidence of severe MR after Inoue balloon PMV, (2) to identify factors potentially related to the development of this complication, (3) to analyze its mechanisms, and (4) to describethe outcome of patients with well-tolerated se- vere MR. METHODS Patlent populatiom From February 1989 to Novem- ber 1991, 246 consecutivesymptomatic patients (New York Heart Association functional class 211) with moderateto severe mitral stenosis underwent PMV with the Inoue balloon at our institution, after a previous ex- perience with the double-balloon technique (42 cases not included in this study). In 5 procedures,dilatation was not performed, either because of a complication (cardiac tamponade in 1 patient) or a technical failure (unable to cross the valve in 4 patients early in the se- ries). From the 241 patients who actually underwent PMV with the Inoue balloon, MR increasedby 1 grade in 75 (31%), by 12 gradesin 32 (13.8%), and was con- sidered severe (by left ventriculography) in 16 (6.6’S, group with severe MR). Thesepatients, who were even- ly distributed over the study period, were compared with the remaining 225 patients (group without severe MR). Percutaneous mitral valvotemy procedure: After standard left- and right-sided cardiac catheterization, PMV was performed through the right femoral vein us- ing the anterograde transseptal approach. The maximal diameter of the Inoue balloon was selectedtaking into account body surface area (26 mm for <1.5 m2, 28 mm for 1.5 to 1.7 m2, and 30 mm for >1.7 m2). After pa- REGURGITATION COMPLICATING MITRAL VALVOTOMY 1169