International Journal of Cardiology, W(lYY2) 237-242 0 1992 Elsevier Science Publishers B.V. All rights reserved
CARD10
237 0167-5273/92/$05.00
01545
Echocardiographic variables affecting surgical outcome in patients undergoing closed mitral commissurotomy K. Prasad
and S. Radhakrishnan
Department of Cardiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India (Received
17 February
1992; revision
accepted
14 June 1992)
Prasad K, Radhakrishnan S. Echocardiographic variables affecting surgical outcome in patients undergoing closed mitral commissurotomy. Int J Cardiol 1992;37:237-242. We studied, by transthoracic cross-sectional echocardiography, the influence of subvalvar pathology on the early hemodynamic result of closed mitral commissurotomy in 132 patients with severe rheumatic mitral stenosis (56 males, 76 females, mean age 25.2 yr, range 10-55) in our tertiary care hospital in North India from July 89 to December 91. The mitral subdistance ratio was calculated by dividing the distance between the papillary muscle tip and mitral valve in systole (apical 4-chamber view) by left ventricular diastolic length (apical long axis view). Nineteen patients with mild subvalvar pathology (mitral subdistance ratio > 0.18) and 71 patients with moderate, achieved a larger valve area (2.26 cm2 SD 0.54) than 42 patients with severe subvalvar pathology (mitral subdistance ratio < 0.12, postoperative valve area 2.09 cm2 SD 0.6, p < 0.05). In addition, 9 of these 42 patients (21%) developed significant mitral regurgitation (4 deaths), in contrast to l/19 with mild and 6/71 with moderate subvalvar pathology. We conclude that echocardiography identifies patients with severe subvalvar pathology who fare poorly after closed mitral commissurotomy. However, this procedure would still be practised in developing countries like ours due to financial constraints. Key words: Mitral stenosis; Echocardiography;
Valvotomy
Introduction Rheumatic mitral stenosis continues to be common in India and other developing countries.
Correspondence to: Dr. S. Radhakrishnan, ology, Sanjay Gandhi Postgraduate Institute ences, P.O. Box 375, Lucknow, India.
Dept. of Cardiof Medical Sci-
The disease affects the poor, and open commissurotomy is expensive. Closed mitral commissurotomy is still offered to many of these patients [l-4]. However, little information exists regarding postoperative transvalvar gradient, valve area and valvar regurgitation. We therefore studied echocardiographically the effects of preoperative variables on the postoperative results in patients undergoing closed mitral commissurotomy in our tertiary care hospital.
238
Materials and Methods One hundred and thirty two patients (56 males, 76 females) age lo-55 yr (mean 24.3) with symptomatic severe mitral stenosis who underwent closed mitral commissurotomy at this hospital between July 89 to December 91 formed the basis of this study. Detailed preoperative assessment included history, clinical examination, chest X-ray, electrocardiogram, and cross-sectional echocardiography and color Doppler study. Patients who died in the postoperative period and in whom repeat study was not possible have been excluded from the study. Echocardiography was carried out with Toshiba SSH 65-A or ATL Ultramark- machines both of which were equipped with a color Doppler system and phased array transducers of 2.5 and 3 MHz. The cross-sectional echocardiographic study included assessment of chamber size and function. All the valves were examined for any pathology and the mitral valve for the following features: valve mobility, commissural fusion, subvalvar fusion and calcification. Subvalvar pathology was graded according to the technique used by Akins et al, for angiographic grading of subvalvar pathology [5] and mitral subdistance ratio was calculated as shown in Fig. 1. The apical two- and four-chamber views were used to calculate the mitral subdistance ratio and for grading the severity of subvalvar pathology. The distance was calculated as the ratio of the distance between the papillary muscle tips and the mitral valve in systole to the left ventricular long axis in diastole (apex to aortic valve). We examined the validity of this method of grading in a group of patients (n = 22) who had undergone open mitral commissurotomy and found it to correlate very well with the surgeon’s assessment on the operation table [6] (Table 1). The presence of dense calcification was taken as a contraindication for closed mitral commissurotomy. Calcification, when suspected by echocardiography, was confirmed by fluoroscopy in each case (patients with mild calcification were offered closed commissurotomy if they could not afford an open procedure). The severity of mitral stenosis was assessed by
MSDR=__IN Y -IN
SYSTOLE DIASTOLE
Fig. 1. Calculation of mitral subdistance ratio (MSDR). X = distance between papillary muscle tip to mitral valve in systale; Y = left ventricular diastolic length in long axis view.
Doppler examination. The continuous wave cursor of the 2.5 MHz duplex transducer was aligned parallel to the mitral inflow signal. The mitral valve peak and mean gradients and the mitral valve area by pressure half-time method [7] were calculated from the spectral display. A mean of 3 values in patients with sinus rhythm and 5 values in those with atria1 fibrillation were obtained. Mitral regurgitation was looked for in each case and severity graded according to the method of Nanda et al. [8] with slight modification. Trivial mitral regurgitation was considered as a well-defined jet not extending more than 1 cm distal to TABLE 1 Operative correlation of subvalvar pathology @VP). Echo SVP
Mild Moderate Severe Total
Surgeon’s assessment
Total
Mild
Moderate
Severe
5 5
_ 5 1 6
_ 2 9 11
5 7 10 22
239
the mitral valve and not audible clinically. This modification was considered necessary in view of a large group of patients with such a signal. Patients having trivial to mild mitral regurgitation were considered for closed mitral commissurotomy. Patients with aortic regurgitation and normal left ventricular dimensions were considered for closed commissurotomy. The post operative study was repeated 7-14 days after surgery before discharge. The mitral valve area was again examined for gradients, valve area and the severity of mitral regurgitation. Based on the severity of the subvalvar pathology as judged by mitral subdistance ratio, the patients were divided into 3 groups: Group A: mild subvalvar pathology and mitral subdistance > 0.18; Group B: moderate subvalvar ratio pathology and mitral subdistance ratio 0.12-0.18; and Group C: severe subvalvar pathology and mitral subdistance ratio < 0.12. Statistical methods All values in the text are expressed as mean + standard deviation (SD). The results were analysed using the Student t-test, analysis of variance and multivariate regression analysis both stepwise and full model regression. Age, preoperative valve area and increase in valve area were compared in the 3 groups by the Student r-test and analysis of variance. Postoperative mitral valve area and postoperative mitral regurgitation and the increase in mitral valve area were the endpoints for the regression analysis. Correlation matrix was also calculated for age, subvalvar pathology, preoperative mitral valve area, mitral regurgitation and postoperative mitral valve area and mitral regurgitation, The chi-square test was used to compare the degree of postoperative mitral regurgitation in the 3 groups, individually and collectively. Results Patients In all, 132 patients were studied. There were 56 males (42%) and 76 (58%) females. Ages
TABLE
2
Preoperative characteristics tral commissurotomy. SVP
Mild (n = 19) Moderate (n = 71) Severe (n = 42)
of patients
undergoing
PG CmmHg)
MG
MVA
CmmHg)
(cm21
18.78 SD 5.8 20.93 SD 6.62 20.36 SD 4.8
12.94 SD 4.3 13.83 SD 5.92 13.86 SD 14.26
0.287 SD 0.21 0.795 SD 0.17 0.716 SD 0.20
closed mi-
MR Trivial
Mild
4
2
14
10
11
9
SVP = subvalvar pathology; PG = peak gradient; MG = mean gradient: MVA = mitral valve area; MR = mitral regurgitation.
ranged from lo-55 yr (mean 25.2 yr). Thirty six (27%) patients were in NYHA class I, 74 (56%) in class III, and 22 (17%) in class IV. Forty-eight patients had isolated mitral stenosis. Fifty-three patients had associated aortic regurgitation which was trivial in 20, mild in 23 and of moderate severity in 10. Twelve patients were pregnant and of these, 6 underwent commissurotomy during pregnancy. Mitral valves All patients had severe mitral stenosis. Sixteen patients had mild calcification of the mitral valve. The subvalvar pathology was mild in 19 (14%) patients, moderate in 71 (54%), and severe in 42 (32%) (Table 2). Fifty of the 132 patients (38%) had trivial or mild mitral regurgitation preoperatively. It was slightly more frequent in patients with severe subvalvar pathology (48%) than in those with mild or moderate subvalvar pathology (32% and 34%, respectively). Postoperative status There was a significant increase in valve area and decrease in peak and mean gradients, after surgery in all groups (Table 3). Patients with severe subvalvar pathology, however, achieved lesser valve areas (2.09 cm* SD 0.6) as compared to patients with mild or moderate subvalvar pathology (valve areas 2.27 cm* SD 0.4 and 2.25
240 TABLE 4
TABLE 3 Postoperative characteristics of patients mitral commissurotomy (n = 132). SVP Mild (n = 19) Moderate (?I = 71) Severe fn = 420)
PG
undergoing
MG
Comparison of patients with and without mitral valve calcification.
closed
9.07 SD 3.20
4.34 SD 1.54
2.27 SD 0.40
9.52 SD 3.51
4.50 SD 1.90
2.25 SD 0.58
9.89 SD 2.80
4.80 SD 2.10
2.09 SD 0.67
PG = peak gradient; MG = mean gradient; valve area; SVP = subvalvar pathology.
Mitral valve area (cm*)
Group
MVA
Calcific MS (n = 16) Noncalcific MS (n = 87) *
Preop.
Postop.
0.69 SD 0.23 0.78 SD 0.18
1.60 SD 0.30 2.23 SD 0.54
* Patients with mild and moderate subvalvar pathology only. MS = mitral stenosis.
MVA = mitral
Mitral regurgitation
cm2 SD 0.58 respectively, p < 0.05,Table 3). This difference was even more marked when the 10 patients who developed moderate or severe mitral regurgitation were excluded from the analysis, because abnormal opening of the valve may give falsely high values of valve area. Significant mitral regurgitation occurred mostly in patients with severe subvalvar pathology (see below).
Whenever present preoperatively, regurgitation persisted after operation (Table 5). The increase of trivial/mild regurgitation was 38% preoperatively and 52% post operatively. In addition, 16 (12.1%) patients had moderately severe regurgitation after commisurotomy (Table 5). Significant regurgitation occurred mostly in patients with severe subvalvar pathology. Thus, 9 of 42 patients (21.4%) with severe subvalvar pathology developed moderate or severe regurgitation, and 4 of these 9 died in the postoperative period. Six of 71 patients (8.7%) with moderate subvalvar pathology and 1 of 19 (5%) with mild subvalvar pathology developed moderate regurgitation. Three of 16 patients of calcific mitral stenosis
Calcification Twelve of the patients with mitral calcification had severe and 4 had moderate subvalvar pathology. The postoperative valve areas were less in patients with calcified valves (Table 4). TABLE 5
Effect of closed mitral commissurotomy on the postoperative outcome of mitral regurgitation (MR) in different subvalvar pathology (SVP) groups. Preop. MR
SVP
None
Trivial
Mild
Total
Postoperative MR None
Trivial
Mild
Moderate
Mild Moderate Severe
4 33 11
4
4 14 11
1 _
Mild Moderate Severe
_ _ 1
4 12 10
_ 2 _
2 6
_
Mild Moderate Severe
_ _
_
Mild Moderate Severe
4 33 11
4 1 _
Severe
Total
_
13 47 22
_
4 14 II
_
4 3
6
2 10 9
10 32 21
1 6 3
_ _ 6
19 71 42
241
developed significant regurgitation, and in one it caused death. The cause of mitral regurgitation was avulsion fo the anterior leaflet (3 patients), chordal rupture (2), prolapse of posterior leaflet (2), and tear of posterior leaflet (1 patient). In 8 other patients with significant regurgitation, no damage to the apparatus was detectable by echocardiography, Mitral regurgitation jets were single in 76 patients and multiple in 12. Single jets were most often directed posteriorly (32/76, 42%), though central (20/76) and anterior (22/76) were also common. Of the 12 patients with multiple jets 8 had severe subvalvar pathology and 4 moderate. Using regression analysis both subvalvar pathology grading (p < 0.013) and preoperative mitral valve area (p < 0.0005) were independent predictors for the postoperative mitral valve area achieved. Also, the presence of preoperative mitral regurgitation was an independent predictor of postoperative mitral regurgitation (p < 0.05). Discussion Although cross-sectional Doppler echocardiography has been available for many years, little information on the hemodynamic effects of closed mitral commissurotomy has been published [9111. In addition, present day equipment provides excellent visualization of the subvalvar structures and degree of fibrosis present. We therefore conducted this study to see the hemodynamic effects of closed valvotomy, and the influence of subvalvar pathology on operative results. We conducted the postoperative study 7-14 days after operation, to allow the left anterior thoracotomy site to heal, and also to allow time for postoperative changes in left atria1 compliance, which affect the pressure half time - valve area relationship [121. Our results show that patients with mild or moderate subvalvar pathology achieve excellent improvement in the valve area and transvalvar gradients. Patients with severe subvalvar pathology do less well, with a greater incidence of postoperative mitral regurgitation and smaller increases in valve areas. Although most patients tolerated mitral regurgitation in the early postop-
erative period, 4/14 died. Open valvotomy should therefore be preferred in this subgroup, and closed valvotomy should be offered to the patients only as the last resort. Similarly, the presence of even milk degrees of calcification adversely affects results. Our results are in agreement with those of others [3,4] who found that the presence of subvalvar fusion detected during commissurotomy was an important determinant of the final outcome after closed commissurotomy. In balloon valvotomy, which is similar to closed commissurotomy, the degree of subvalvar pathology also influences the final result [13-151. Our study did not take consecutive patients, as those who were advised to undergo open commissurotomy are not included. We have also not studied the long-term course of these patients, but this is currently being done by us. In conclusion, echocardiographic assessment of the submitral apparatus before operation identifies a group of patients who have severe subvalvar fusion. The group achieves smaller valve areas after closed valvotomy in comparison to patients with mild or moderate subvalvar pathology. These patients also have a three-fold (21%) higher chance of developing significant regurgitation after closed commissurotomy. Open commissurotomy should therefore be preferred in this subgroup. In spite of this, a significant number of patients with severe subvalvar pathology do undergo close commissurotomy at our institute because of financial constraints. References Sujoy R, Gopinath N. Mitral stenosis. Circulation 1988;37-38(suppl V):68-76. Cautam K, Goulshed N, Epstein EJ, Llewellyn MJ. Vargas E, Tallis K. Preoperative clinical predictors of longterm survivors in mitral stenosis - analysis of 200 cases followed up to 27 years after closed mitral valvotomy. Thorax 1986;41:401-406. John S, Bashi W, Jairaj PS et al. Closed mitral valvotomy - early results and long-term follow-up of 3724 consecutive patients. Circulation 1983;68:891-896. Farhat MB, Boussada H, Gandbaskch I et al. Closed versus open mitral commissurotomy in pure non-calcific mitral stenosis - hemodynamic studies before and after operation. J Thorac Cardiovasc Surg 1990,99:639-644.
242 5 Akins CW, Kirklin JW, Block PC et al. Preoperative evaluation fo subvalvar fibrosis in mitral stenosis. Circulation 1979;6O(suppl):171-176. 6 Ravikumar R, Mantri RR, Radhakrishnan S et al. Color Doppler assessment of patients undergoing open mitral commissurotomy (abstract). Indian Heart J 1990;42:221. 7 Hatle L, Angelson BAJ, Tromsdale A. Non-invasive assessment of atrio-ventricular pressure half time by ultrasound. Circulation 1979;60:1096-1104. 8 Nanda NC. In: Atlas of color Doppler echocardiography. Philadelphia: Lea and Febiger, 1989;46-50. 9 Pate1 JJ, Shama D, Mitha ASX et al. Balloon mitral valvuloplasty versus closed mitral commissurotomy - a randomized study (abstract). J Am Coll Cardiol 1990;152:5A. 10 Turi ZG, Reyes VP, Raju BS et al. Percutaneous balloon versus surgical closed commissurotomy for mitral stenosis - A prospective randomized trial. Circulation 1991;83: 1179-1185.
11 Nair M, Arora R, Mohan JC et al. Assessment of mitral subvalvar stenosis by echocardiography - utility of various methods before and after mitral valvotomy. Int J Cardiol 32;3:389-394. 12 Chambers J, Jackson G, Jewitt D. Limitations of Doppler ultrasound in the assessment of function of prosthetic valves. Br Heart J 1990,63:189-194. 13 Inoue K, Owaki T, Nakamura T et al. Clinical applications of transvenous mitral commissurotomy by a new balloon cathether. J Thorac Cardiovasc Surg 1984;87:394-402. 14 Herman HC, Wilkins GT, Abscal VM et al. Percutaneous balloon mitral valvotomy for patients with mitral stenosis - analysis of factors influencing early results. J Thorac Cardiovasc Surg 1988;96:33-38. 15 Wilkins GT, Weyman AE, Abscal VM et al. Percutaneous balloon dilatation of mitral valve - an analysis of echocardiographic variables related to the outcome and mechanism of dilataion. Br Heart J 1988:60:299-308.
CARD10
237 0167-5273/92/$05.00
01545
Echocardiographic variables affecting surgical outcome in patients undergoing closed mitral commissurotomy K. Prasad
and S. Radhakrishnan
Department of Cardiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India (Received
17 February
1992; revision
accepted
14 June 1992)
Prasad K, Radhakrishnan S. Echocardiographic variables affecting surgical outcome in patients undergoing closed mitral commissurotomy. Int J Cardiol 1992;37:237-242. We studied, by transthoracic cross-sectional echocardiography, the influence of subvalvar pathology on the early hemodynamic result of closed mitral commissurotomy in 132 patients with severe rheumatic mitral stenosis (56 males, 76 females, mean age 25.2 yr, range 10-55) in our tertiary care hospital in North India from July 89 to December 91. The mitral subdistance ratio was calculated by dividing the distance between the papillary muscle tip and mitral valve in systole (apical 4-chamber view) by left ventricular diastolic length (apical long axis view). Nineteen patients with mild subvalvar pathology (mitral subdistance ratio > 0.18) and 71 patients with moderate, achieved a larger valve area (2.26 cm2 SD 0.54) than 42 patients with severe subvalvar pathology (mitral subdistance ratio < 0.12, postoperative valve area 2.09 cm2 SD 0.6, p < 0.05). In addition, 9 of these 42 patients (21%) developed significant mitral regurgitation (4 deaths), in contrast to l/19 with mild and 6/71 with moderate subvalvar pathology. We conclude that echocardiography identifies patients with severe subvalvar pathology who fare poorly after closed mitral commissurotomy. However, this procedure would still be practised in developing countries like ours due to financial constraints. Key words: Mitral stenosis; Echocardiography;
Valvotomy
Introduction Rheumatic mitral stenosis continues to be common in India and other developing countries.
Correspondence to: Dr. S. Radhakrishnan, ology, Sanjay Gandhi Postgraduate Institute ences, P.O. Box 375, Lucknow, India.
Dept. of Cardiof Medical Sci-
The disease affects the poor, and open commissurotomy is expensive. Closed mitral commissurotomy is still offered to many of these patients [l-4]. However, little information exists regarding postoperative transvalvar gradient, valve area and valvar regurgitation. We therefore studied echocardiographically the effects of preoperative variables on the postoperative results in patients undergoing closed mitral commissurotomy in our tertiary care hospital.
238
Materials and Methods One hundred and thirty two patients (56 males, 76 females) age lo-55 yr (mean 24.3) with symptomatic severe mitral stenosis who underwent closed mitral commissurotomy at this hospital between July 89 to December 91 formed the basis of this study. Detailed preoperative assessment included history, clinical examination, chest X-ray, electrocardiogram, and cross-sectional echocardiography and color Doppler study. Patients who died in the postoperative period and in whom repeat study was not possible have been excluded from the study. Echocardiography was carried out with Toshiba SSH 65-A or ATL Ultramark- machines both of which were equipped with a color Doppler system and phased array transducers of 2.5 and 3 MHz. The cross-sectional echocardiographic study included assessment of chamber size and function. All the valves were examined for any pathology and the mitral valve for the following features: valve mobility, commissural fusion, subvalvar fusion and calcification. Subvalvar pathology was graded according to the technique used by Akins et al, for angiographic grading of subvalvar pathology [5] and mitral subdistance ratio was calculated as shown in Fig. 1. The apical two- and four-chamber views were used to calculate the mitral subdistance ratio and for grading the severity of subvalvar pathology. The distance was calculated as the ratio of the distance between the papillary muscle tips and the mitral valve in systole to the left ventricular long axis in diastole (apex to aortic valve). We examined the validity of this method of grading in a group of patients (n = 22) who had undergone open mitral commissurotomy and found it to correlate very well with the surgeon’s assessment on the operation table [6] (Table 1). The presence of dense calcification was taken as a contraindication for closed mitral commissurotomy. Calcification, when suspected by echocardiography, was confirmed by fluoroscopy in each case (patients with mild calcification were offered closed commissurotomy if they could not afford an open procedure). The severity of mitral stenosis was assessed by
MSDR=__IN Y -IN
SYSTOLE DIASTOLE
Fig. 1. Calculation of mitral subdistance ratio (MSDR). X = distance between papillary muscle tip to mitral valve in systale; Y = left ventricular diastolic length in long axis view.
Doppler examination. The continuous wave cursor of the 2.5 MHz duplex transducer was aligned parallel to the mitral inflow signal. The mitral valve peak and mean gradients and the mitral valve area by pressure half-time method [7] were calculated from the spectral display. A mean of 3 values in patients with sinus rhythm and 5 values in those with atria1 fibrillation were obtained. Mitral regurgitation was looked for in each case and severity graded according to the method of Nanda et al. [8] with slight modification. Trivial mitral regurgitation was considered as a well-defined jet not extending more than 1 cm distal to TABLE 1 Operative correlation of subvalvar pathology @VP). Echo SVP
Mild Moderate Severe Total
Surgeon’s assessment
Total
Mild
Moderate
Severe
5 5
_ 5 1 6
_ 2 9 11
5 7 10 22
239
the mitral valve and not audible clinically. This modification was considered necessary in view of a large group of patients with such a signal. Patients having trivial to mild mitral regurgitation were considered for closed mitral commissurotomy. Patients with aortic regurgitation and normal left ventricular dimensions were considered for closed commissurotomy. The post operative study was repeated 7-14 days after surgery before discharge. The mitral valve area was again examined for gradients, valve area and the severity of mitral regurgitation. Based on the severity of the subvalvar pathology as judged by mitral subdistance ratio, the patients were divided into 3 groups: Group A: mild subvalvar pathology and mitral subdistance > 0.18; Group B: moderate subvalvar ratio pathology and mitral subdistance ratio 0.12-0.18; and Group C: severe subvalvar pathology and mitral subdistance ratio < 0.12. Statistical methods All values in the text are expressed as mean + standard deviation (SD). The results were analysed using the Student t-test, analysis of variance and multivariate regression analysis both stepwise and full model regression. Age, preoperative valve area and increase in valve area were compared in the 3 groups by the Student r-test and analysis of variance. Postoperative mitral valve area and postoperative mitral regurgitation and the increase in mitral valve area were the endpoints for the regression analysis. Correlation matrix was also calculated for age, subvalvar pathology, preoperative mitral valve area, mitral regurgitation and postoperative mitral valve area and mitral regurgitation, The chi-square test was used to compare the degree of postoperative mitral regurgitation in the 3 groups, individually and collectively. Results Patients In all, 132 patients were studied. There were 56 males (42%) and 76 (58%) females. Ages
TABLE
2
Preoperative characteristics tral commissurotomy. SVP
Mild (n = 19) Moderate (n = 71) Severe (n = 42)
of patients
undergoing
PG CmmHg)
MG
MVA
CmmHg)
(cm21
18.78 SD 5.8 20.93 SD 6.62 20.36 SD 4.8
12.94 SD 4.3 13.83 SD 5.92 13.86 SD 14.26
0.287 SD 0.21 0.795 SD 0.17 0.716 SD 0.20
closed mi-
MR Trivial
Mild
4
2
14
10
11
9
SVP = subvalvar pathology; PG = peak gradient; MG = mean gradient: MVA = mitral valve area; MR = mitral regurgitation.
ranged from lo-55 yr (mean 25.2 yr). Thirty six (27%) patients were in NYHA class I, 74 (56%) in class III, and 22 (17%) in class IV. Forty-eight patients had isolated mitral stenosis. Fifty-three patients had associated aortic regurgitation which was trivial in 20, mild in 23 and of moderate severity in 10. Twelve patients were pregnant and of these, 6 underwent commissurotomy during pregnancy. Mitral valves All patients had severe mitral stenosis. Sixteen patients had mild calcification of the mitral valve. The subvalvar pathology was mild in 19 (14%) patients, moderate in 71 (54%), and severe in 42 (32%) (Table 2). Fifty of the 132 patients (38%) had trivial or mild mitral regurgitation preoperatively. It was slightly more frequent in patients with severe subvalvar pathology (48%) than in those with mild or moderate subvalvar pathology (32% and 34%, respectively). Postoperative status There was a significant increase in valve area and decrease in peak and mean gradients, after surgery in all groups (Table 3). Patients with severe subvalvar pathology, however, achieved lesser valve areas (2.09 cm* SD 0.6) as compared to patients with mild or moderate subvalvar pathology (valve areas 2.27 cm* SD 0.4 and 2.25
240 TABLE 4
TABLE 3 Postoperative characteristics of patients mitral commissurotomy (n = 132). SVP Mild (n = 19) Moderate (?I = 71) Severe fn = 420)
PG
undergoing
MG
Comparison of patients with and without mitral valve calcification.
closed
9.07 SD 3.20
4.34 SD 1.54
2.27 SD 0.40
9.52 SD 3.51
4.50 SD 1.90
2.25 SD 0.58
9.89 SD 2.80
4.80 SD 2.10
2.09 SD 0.67
PG = peak gradient; MG = mean gradient; valve area; SVP = subvalvar pathology.
Mitral valve area (cm*)
Group
MVA
Calcific MS (n = 16) Noncalcific MS (n = 87) *
Preop.
Postop.
0.69 SD 0.23 0.78 SD 0.18
1.60 SD 0.30 2.23 SD 0.54
* Patients with mild and moderate subvalvar pathology only. MS = mitral stenosis.
MVA = mitral
Mitral regurgitation
cm2 SD 0.58 respectively, p < 0.05,Table 3). This difference was even more marked when the 10 patients who developed moderate or severe mitral regurgitation were excluded from the analysis, because abnormal opening of the valve may give falsely high values of valve area. Significant mitral regurgitation occurred mostly in patients with severe subvalvar pathology (see below).
Whenever present preoperatively, regurgitation persisted after operation (Table 5). The increase of trivial/mild regurgitation was 38% preoperatively and 52% post operatively. In addition, 16 (12.1%) patients had moderately severe regurgitation after commisurotomy (Table 5). Significant regurgitation occurred mostly in patients with severe subvalvar pathology. Thus, 9 of 42 patients (21.4%) with severe subvalvar pathology developed moderate or severe regurgitation, and 4 of these 9 died in the postoperative period. Six of 71 patients (8.7%) with moderate subvalvar pathology and 1 of 19 (5%) with mild subvalvar pathology developed moderate regurgitation. Three of 16 patients of calcific mitral stenosis
Calcification Twelve of the patients with mitral calcification had severe and 4 had moderate subvalvar pathology. The postoperative valve areas were less in patients with calcified valves (Table 4). TABLE 5
Effect of closed mitral commissurotomy on the postoperative outcome of mitral regurgitation (MR) in different subvalvar pathology (SVP) groups. Preop. MR
SVP
None
Trivial
Mild
Total
Postoperative MR None
Trivial
Mild
Moderate
Mild Moderate Severe
4 33 11
4
4 14 11
1 _
Mild Moderate Severe
_ _ 1
4 12 10
_ 2 _
2 6
_
Mild Moderate Severe
_ _
_
Mild Moderate Severe
4 33 11
4 1 _
Severe
Total
_
13 47 22
_
4 14 II
_
4 3
6
2 10 9
10 32 21
1 6 3
_ _ 6
19 71 42
241
developed significant regurgitation, and in one it caused death. The cause of mitral regurgitation was avulsion fo the anterior leaflet (3 patients), chordal rupture (2), prolapse of posterior leaflet (2), and tear of posterior leaflet (1 patient). In 8 other patients with significant regurgitation, no damage to the apparatus was detectable by echocardiography, Mitral regurgitation jets were single in 76 patients and multiple in 12. Single jets were most often directed posteriorly (32/76, 42%), though central (20/76) and anterior (22/76) were also common. Of the 12 patients with multiple jets 8 had severe subvalvar pathology and 4 moderate. Using regression analysis both subvalvar pathology grading (p < 0.013) and preoperative mitral valve area (p < 0.0005) were independent predictors for the postoperative mitral valve area achieved. Also, the presence of preoperative mitral regurgitation was an independent predictor of postoperative mitral regurgitation (p < 0.05). Discussion Although cross-sectional Doppler echocardiography has been available for many years, little information on the hemodynamic effects of closed mitral commissurotomy has been published [9111. In addition, present day equipment provides excellent visualization of the subvalvar structures and degree of fibrosis present. We therefore conducted this study to see the hemodynamic effects of closed valvotomy, and the influence of subvalvar pathology on operative results. We conducted the postoperative study 7-14 days after operation, to allow the left anterior thoracotomy site to heal, and also to allow time for postoperative changes in left atria1 compliance, which affect the pressure half time - valve area relationship [121. Our results show that patients with mild or moderate subvalvar pathology achieve excellent improvement in the valve area and transvalvar gradients. Patients with severe subvalvar pathology do less well, with a greater incidence of postoperative mitral regurgitation and smaller increases in valve areas. Although most patients tolerated mitral regurgitation in the early postop-
erative period, 4/14 died. Open valvotomy should therefore be preferred in this subgroup, and closed valvotomy should be offered to the patients only as the last resort. Similarly, the presence of even milk degrees of calcification adversely affects results. Our results are in agreement with those of others [3,4] who found that the presence of subvalvar fusion detected during commissurotomy was an important determinant of the final outcome after closed commissurotomy. In balloon valvotomy, which is similar to closed commissurotomy, the degree of subvalvar pathology also influences the final result [13-151. Our study did not take consecutive patients, as those who were advised to undergo open commissurotomy are not included. We have also not studied the long-term course of these patients, but this is currently being done by us. In conclusion, echocardiographic assessment of the submitral apparatus before operation identifies a group of patients who have severe subvalvar fusion. The group achieves smaller valve areas after closed valvotomy in comparison to patients with mild or moderate subvalvar pathology. These patients also have a three-fold (21%) higher chance of developing significant regurgitation after closed commissurotomy. Open commissurotomy should therefore be preferred in this subgroup. In spite of this, a significant number of patients with severe subvalvar pathology do undergo close commissurotomy at our institute because of financial constraints. References Sujoy R, Gopinath N. Mitral stenosis. Circulation 1988;37-38(suppl V):68-76. Cautam K, Goulshed N, Epstein EJ, Llewellyn MJ. Vargas E, Tallis K. Preoperative clinical predictors of longterm survivors in mitral stenosis - analysis of 200 cases followed up to 27 years after closed mitral valvotomy. Thorax 1986;41:401-406. John S, Bashi W, Jairaj PS et al. Closed mitral valvotomy - early results and long-term follow-up of 3724 consecutive patients. Circulation 1983;68:891-896. Farhat MB, Boussada H, Gandbaskch I et al. Closed versus open mitral commissurotomy in pure non-calcific mitral stenosis - hemodynamic studies before and after operation. J Thorac Cardiovasc Surg 1990,99:639-644.
242 5 Akins CW, Kirklin JW, Block PC et al. Preoperative evaluation fo subvalvar fibrosis in mitral stenosis. Circulation 1979;6O(suppl):171-176. 6 Ravikumar R, Mantri RR, Radhakrishnan S et al. Color Doppler assessment of patients undergoing open mitral commissurotomy (abstract). Indian Heart J 1990;42:221. 7 Hatle L, Angelson BAJ, Tromsdale A. Non-invasive assessment of atrio-ventricular pressure half time by ultrasound. Circulation 1979;60:1096-1104. 8 Nanda NC. In: Atlas of color Doppler echocardiography. Philadelphia: Lea and Febiger, 1989;46-50. 9 Pate1 JJ, Shama D, Mitha ASX et al. Balloon mitral valvuloplasty versus closed mitral commissurotomy - a randomized study (abstract). J Am Coll Cardiol 1990;152:5A. 10 Turi ZG, Reyes VP, Raju BS et al. Percutaneous balloon versus surgical closed commissurotomy for mitral stenosis - A prospective randomized trial. Circulation 1991;83: 1179-1185.
11 Nair M, Arora R, Mohan JC et al. Assessment of mitral subvalvar stenosis by echocardiography - utility of various methods before and after mitral valvotomy. Int J Cardiol 32;3:389-394. 12 Chambers J, Jackson G, Jewitt D. Limitations of Doppler ultrasound in the assessment of function of prosthetic valves. Br Heart J 1990,63:189-194. 13 Inoue K, Owaki T, Nakamura T et al. Clinical applications of transvenous mitral commissurotomy by a new balloon cathether. J Thorac Cardiovasc Surg 1984;87:394-402. 14 Herman HC, Wilkins GT, Abscal VM et al. Percutaneous balloon mitral valvotomy for patients with mitral stenosis - analysis of factors influencing early results. J Thorac Cardiovasc Surg 1988;96:33-38. 15 Wilkins GT, Weyman AE, Abscal VM et al. Percutaneous balloon dilatation of mitral valve - an analysis of echocardiographic variables related to the outcome and mechanism of dilataion. Br Heart J 1988:60:299-308.
