Mitral valve replacement versus reconstruction

Improved mitral valve coaptation and reduced mitral valve annular size after percutaneous mitral valve repair (PMVR) using the MitraClip system

Aims

Improved mitral valve leaflet coaptation with consecutive reduction of mitral regurgitation (MR) is a central goal of percutaneous mitral valve repair (PMVR) with the MitraClip® system. As influences of PMVR on mitral valve geometry have been suggested before, we examined the effect of the procedure on mitral annular size in relation to procedural outcome.

Methods and results

Geometry of the mitral valve annulus was evaluated in 183 patients undergoing PMVR using echocardiography before and after the procedure and at follow-up. Mitral valve annular anterior-posterior (ap) diameter decreased from 34.0 ± 4.3 to 31.3 ± 4.9 mm (P < 0.001), and medio-lateral (ml) diameter from 33.2 ± 4.8 to 32.4 ± 4.9 mm (P < 0.001). Accordingly, we observed an increase in MV leaflet coaptation after PMVR. The reduction of mitral valve ap diameter showed a significant inverse correlation with residual MR. Importantly, the reduction of mitral valve ap diameter persisted at follow-up (31.3 ± 4.9 mm post PMVR, 28.4 ± 5.3 mm at follow-up).

Conclusion

This study demonstrates mechanical approximation of both mitral valve annulus edges with improved mitral valve annular coaptation by PMVR using the MitraClip® system, which correlates with residual MR in patients with MR.

Development of In-Vitro Evaluation System for Annuloplasty Rings

An in-vitro system was devised to study the performance of newly developed annuloplasty rings as well as various conventional rings. The Duran Flexible Annuloplasty Ring was tested to define its characteristics and to validate the system for comparative testing. It was possible to obtain quantitative data using a microscope and a load cell to respectively measure valve orifice area and tensile load on the valve annulus. The results suggest that this apparatus could be employed to characterize the features and functional performance of other types of annuloplasty ring.

Multiple purpose simulator using a natural porcine mitral valve

An in vitro pulsatile simulator with a porcine mitral valve was developed in order to simulate physiologic and diseased mitral valve conditions. Evaluation of these conditions was conducted from a hydrodynamic and annulus behavior point of view. We found it possible to simulate mild "mitral valve prolapse" and to obtain quantitative data related to the condition. The diseased condition produced a 40% greater regurgitant volume than that observed under the normal condition (p < 0.0001). Regarding the leakage volume, the diseased condition exhibited about 2.6 times more leakage than the normal condition. The mitral valve simulator proposed in this study is considered fairly stable with respect to both hemodynamics and the behavior of the annulus, and it is an adequate simulator for modeling various types of normal and diseased mitral valve conditions.

Valve repair in mitral regurgitation complicated by severe annulus calcification

BACKGROUND

Valvuloplasty has significant advantages over valve replacement for mitral regurgitation, but the presence of severe calcification of the mitral valve apparatus has been thought to preclude successful valve reconstruction in general. The purpose of this report is to assess the results of valvuloplasty in patients with severe mitral regurgitation having extensive calcification extending from the mitral annulus to underlying myocardium and parts of the papillary muscles.

METHODS

Thirty-seven adult patients with severe mitral regurgitation and calcification were operated on between April 1990 and January 1998. Twenty-six patients had degenerative disease, 4 had acute bacterial endocarditis, 6 had postrheumatic fever, and 1 patient had Marfan's disease. The valve repair comprised of en bloc decalcification with extensive leaflet debridement and reconstruction of the annulus. Autologous pericardium was used in patch-extended endocardial annuloplasty or leaflet repair. Valve competence was retained after correction of regurgitation by sliding atrioplasty, rotation paracommissural sliding plasty, cusp remodeling, or chordal repair. All patients required a prosthetic annuloplasty.

RESULTS

Follow-up echocardiography at 47 months (range, 3 to 92 months) showed no or only trivial mitral regurgitation in 33 patients; 3 had grade I-II mitral regurgitation and 1 required valve replacement after 3 months. Freedom of reoperation at 1 and 5 years was 94.6%. At last examination, 33 patients were in New York Heart Association functional class I and 3 in class I-II; there has been no mortality and no thromboembolic events.

CONCLUSIONS

Valvuloplasty can be safely and successfully carried out in patients suffering from regurgitation associated with severe calcification of the mitral apparatus. With encouraging beneficial midterm results, we suggest patients with calcified valves should not be excluded from mitral repair.

Chordal transposition for anterior mitral prolapse: early and long-term results

OBJECTIVE

Chordal transposition was advocated for correction of anterior mitral prolapse. We have evaluated the early and late results of this technique in different anatomical presentations.

METHODS

From 1986 to 1995, 185 mitral valve repairs were carried out for pure mitral regurgitation due to a degenerative disease. Eighty-nine patients had either an anterior prolapse (39) or prolapse of both leaflets (50) at initial presentation and underwent chordal transposition from the mural leaflet to the anterior leaflet. The corrective procedure was completed by polytetrafluoroethylene or pericardial posterior annuloplasty. Twenty patients presented a complex pathology and 26 had chordal elongation of mural leaflet. Annular calcifications were found in 9 patients. Seven patients required shortening of transposed chordae and two patients the additional shortening of an anterior chorda.

RESULTS

Operative mortality was 3.3% and follow-up was 95% complete (average 41 months). There were five postreconstruction valve replacements (two earlier and three later) for a probability of freedom from late reoperation or 3+ mitral regurgitation of 88.6 +/- 4.8% at 5 years. Of the patients 79% presented no or trivial residual MR, 17% moderate MR and 4% severe MR. The presence of a complex pathology or posterior chordal elongation did not influence the entity of postoperative residual regurgitation. On the contrary, the patients with annular calcifications had a residual regurgitation/left atrium area ratio greater than patients without annular calcification (15.8 +/- 11.5% vs. 6.1 + 9.9%; P = 0.009).

CONCLUSIONS

Chordal transposition is an effective and easily carried out technique for the correction of anterior mitral prolapse. The presence of a complex pathology or posterior chordal elongation do not rule out the procedure. The absence of annular calcification is important in order to obtain a satisfactory correction.

Echocardiographic predictors of survival after surgery for mitral regurgitation in the age of valve repair

The objective of this study was to identify echocardiographic and clinical predictors of survival after mitral valve surgery when mitral repair is an option. In 132 patients undergoing mitral valve repair or replacement for the diagnosis of mitral regurgitation, preoperative echocardiograms were analyzed quantitatively and reviewed by two independent observers for structural abnormalities of the mitral valve. In Cox regression analysis, clinical factors such as age (mortality rate ratio [MRR] 1.7/decade, 95% confidence intervals [CI] 1.1, 2.4), and New York Heart Association class IV (MRR 3.1, 95% CI 1.4, 6.7) and echocardiographic factors including morphologic evidence of endocarditis or myxomatous disease (MRR 0.3, 95% CI 0.1, 0.7) were significant predictors of overall survival, although valve repair itself was not. End-systolic dimensions and volumes were not, likely related to the small number of patients with markedly increased end-systolic dimensions or volumes (5 patients [4%] with end-systolic dimension > 5.5 cm, 12 patients [9%] with end-systolic volume index > 60 ml/m2). New York Heart Association class IV (MRR 2.9, 95% CI 1.3, 6.4), age (MRR 1.7/decade, 95% CI 1.2, 2.6), and the presence of calcification (MRR 4.6, 95% CI 1.3, 16.2) were independent predictors of survival in multivariate analysis. In this contemporary cohort of patients undergoing repair or replacement for mitral regurgitation, factors such as echocardiographically determined cause of disease and presence of calcification predicted survival; traditional measurements such as end-systolic dimensions and volumes were less predictive, most likely because patients underwent surgery before their ventricles became markedly enlarged. Clinical factors such as age and functional status remained the most potent predictors of survival after surgery for mitral regurgitation.

Severe calcification does not affect long-term outcome of mitral valve repair

Some surgeons have suggested that the presence of severe calcification in the mitral valve annulus or leaflets precludes successful repair. Our institution has attempted to repair these calcified valves when good annular and leaflet mobility could be achieved by annular debridement and leaflet resection. From June 1979 through June 1993 558 mitral valve repairs were performed using Carpentier's techniques. When calcified valves were encountered, these techniques were modified to include annular debridement and mechanical leaflet decalcification. Calcification was identified preoperatively in 49 patients (8.8%) by either left ventricular fluoroscopy or echocardiography and was debrided in 64 patients (11.5%). This included 24 annular debridements, 28 leaflet debridements, and 12 annular and leaflet debridements. Patient ages ranged from 13 to 83 years (mean age, 62.3 years), and 25 patients (39.1%, 25/64) had concomitant cardiac procedures. Operative mortality was 6.2% (4/64) overall and 2.6% (1/39) for isolated mitral valve repairs. Calcium debridement was performed in 19.3% (23/119) of patients with a rheumatic cause compared with 9.3% (41/439) of the nonrheumatic patients (p < 0.01). Long-term follow-up revealed the necessity for reoperation in 7.8% (5/64) in patients with calcium debridement as compared with 7.7% (38/494) with no debridement (p = not significant). Cumulative freedom from reoperation at 10 years was 83.3% for all patients, 88.1% for debrided patients, and 82.6% for nondebrided patients (p = not significant). Cox proportional hazards analysis revealed that the presence of rheumatic disease significantly increased the risk of reoperation (odds ratio = 3.28; p < 0.001), whereas calcium debridement had no significant effect. These results demonstrate that when good annulus and leaflet motion can be achieved in calcified mitral valves, calcium debridement allows durable repairs.

Repair of the anterior mitral leaflet

BACKGROUND

Repair rather than replacement of the diseased mitral valve has been the goal of the cardiac surgeon. Although well accepted for posterior leaflet pathology, a diseased anterior leaflet was believed by some to be irreparable.

AIMS

To assess the result of reconstructive mitral valve surgery involving the anterior mitral leaflet in a selected group of patients.

METHODS

Twenty consecutive patients with degenerative (19), ischaemic (one) and congenital/calcific mitral regurgitation were evaluated. There were five females and 15 males with a mean age of 62 +/- 12 years (41-75 years). The technique used to repair these valves included chordal transposition, leaflet plication commissuroplasty and a new technique we call leaflet repositioning.

RESULT

There were no deaths, follow-up is complete with mean follow-up of 31 +/- five months (two-102) months. All patients have had 2DE and 13 TOE as well. There have been no reoperations due to failure of the repair, 95% of patients are in NYHA Class I-II post operative, while 15% have significant residual regurgitation.

The changing unnatural history of valvular regurgitation

In the past 15 years three major advancements have improved the lot of our patients with left-sided valvular regurgitation. First, the concept that mitral and aortic regurgitation were similar volume overloading lesions has changed. Mitral regurgitation constitutes a nearly pure volume overload wherein the excess volume is ejected against relatively low pressure into the left atrium. On the other hand, aortic regurgitation represents a combined pressure and volume overload in which the excess volume being pumped is ejected against the relatively high pressure of the aorta. These differences in loading between mitral and aortic regurgitation produce a different response to operation. Afterload reduction after correction of aortic regurgitation increases ejection performance if it was decreased preoperatively. Conversely, afterload increases after mitral valve replacement, decreasing ejection performance. These differences make the left ventricle in mitral regurgitation less tolerant of preoperative dysfunction than the left ventricle in aortic regurgitation. Second, with respect to aortic regurgitation, reproducible indexes have been developed that identify when left ventricular dysfunction is present, leading to earlier operation in an attempt to avoid permanent ventricular dysfunction. In turn, earlier operation has led to a fall in operative mortality rate and an almost universal increase in left ventricular function if it was depressed preoperatively. Third, with regard to mitral regurgitation, recognition of the importance of the mitral valve apparatus in maintaining left ventricular function has led to an increased emphasis on chordal preservation during mitral valve operations.(ABSTRACT TRUNCATED AT 250 WORDS)

Mitral valve repair in the extensively calcified mitral valve annulus

Mitral valve replacement in patients with an extensively calcified mitral annulus is associated with an increased risk of ventricular rupture. Until now techniques of mitral valve repair have not been applied to patients with a heavily calcified mitral valve annulus. We present 12 patients who underwent extensive decalcification of the annulus with subsequent mitral valve repair between 1987 and 1990. Ages ranged from 11 to 78 years; 6 patients were in New York Heart Association functional class II, 4 were in class III, and 2 were in class IV. All patients had varying degrees of mitral insufficiency. There were no deaths, reoperations, or thromboembolic events. Postoperative echocardiography revealed minimal residual mitral insufficiency in only 2 of 12 patients. All patients are currently in New York Heart Association class I or II. We believe mitral valve repair can be done safely on patients with an extensively calcified mitral annulus, thus avoiding the risks of left ventricular rupture, thromboembolic events, and hemorrhagic complications associated with mitral valve replacement.

Doppler echocardiographic comparison of the Carpentier and Duran anuloplasty rings versus no ring after mitral valve repair for mitral regurgitation

To compare the hemodynamic results of different anuloplasty techniques of primary valve repair for mitral regurgitation, 122 patients were prospectively studied with Doppler echocardiograms 5 to 10 days after operation. Seventy-seven patients had mitral valve prolapse, 27 had coronary artery disease, 13 patients had rheumatic mitral valve lesions and 5 patients had infective endocarditis. Forty-eight patients received the flexible Duran ring, 46 received the more rigid Carpentier ring and 28 patients received no ring. Doppler echocardiography demonstrated a significant decrease in mitral valve area estimated by the pressure half-time method in patients who received either a Carpentier (2.6 +/- 0.8 cm2) or Duran ring (2.8 +/- 0.8 cm2) when compared with patients who received no ring (3.2 +/- 0.7 cm2) (p = 0.01). No significant differences were observed for peak transmitral diastolic velocity, peak transmitral diastolic gradient, or the grade of mitral regurgitation by color flow Doppler mapping between patients with and without rings. The etiology of mitral disease and concomitant surgical procedures accompanying mitral valve repair did not significantly influence mitral valve area, peak velocity or peak gradient. These data suggest that Carpentier and Duran rings decrease the hemodynamic mitral valve area; however, the decrease in valve area is small and not associated with a clinically important increase in transvalvular gradient.

Intraoperative echocardiography in mitral and tricuspid valve repair

Echocardiography with Doppler color flow mapping is a very useful intraoperative technique in patients undergoing mitral or tricuspid valve repair. In the patient who is a repair candidate, this technique can be used intraoperatively to answer important clinical questions: the severity of the regurgitation; the morphological basis of the regurgitant lesion; and the feasibility of repair. Other important issues such as the impact of physiological interventions on regurgitation severity, the presence of associated lesions, and the state of ventricular function can also be addressed. In the patient who has undergone a valve repair, this technique can be used intraoperatively prior to chest closure to assess the adequacy of the repair procedure and to detect associated complications such as outflow tract obstruction.

A quantitative comparison of transesophageal and epicardial color Doppler echocardiography in the intraoperative assessment of mitral regurgitation

Epicardial and transesophageal color Doppler echocardiography are both widely used for the intraoperative assessment of mitral regurgitation (MR); however, it has not been established whether grading of regurgitation is comparable when evaluated by these 2 techniques. MR jet size was quantitatively compared in 29 hemodynamically and temporally matched open-chest epicardial and transesophageal color Doppler echocardiography studies from 22 patients (18 with native and 4 with porcine mitral valves) scheduled to undergo mitral valve repair or replacement. Jet area, jet length and left atrial area were analyzed. Comparison of jet area measurements as assessed by epicardial and transesophageal color flow mapping revealed an excellent correlation between the techniques (r = 0.95, p less than 0.001). Epicardial and transesophageal jet length measurements were also similar (r = 0.77, p less than 0.001). Left atrial area could not be measured in 18 transesophageal studies (62%) due to foreshortening, and in 5 epicardial studies (17%) due to poor image resolution. Acoustic interference with left atrial and color flow mapping signals was noted in all patients with mitral valve prostheses when imaged by epicardial echocardiography, but this did not occur with transesophageal imaging. Thus, in patients undergoing valve repair or replacement, transesophageal and epicardial color flow mapping provide similar quantitative assessment of MR jet size. Jet area to left atrial area ratios have limited applicability in transesophageal color flow mapping, due to foreshortening of the left atrial borders in transesophageal views. Transesophageal color flow mapping may be especially useful in assessing dysfunctional mitral prostheses due to the lack of left atrial acoustic interference.

Mitral valve reconstruction in the elderly population

The technique, efficacy, and long-term results of mitral valve reconstruction have been well demonstrated and reported by Carpentier and other investigators. However, most of the results reported have been in patients aged less than 65 years. Between April 1985 and September 1988, we performed mitral valve reconstruction in 176 patients using Carpentier's classification and technique for repair. Ages ranged from 15 to 86 years (mean age, 63 years). Of the repairs, 96/176 (55%) had concomitant cardiac procedures. Patients aged 65 years or more accounted for 52% (92/176) of the population and 35% (65/176) were more than 70 years old. Hospital mortality (30 day) was 4% (4/84) in the group aged less than 65 years. Hospital mortality for the group aged more than 65 years was 12% (11/92), compared with an overall 8.5% mortality. These results suggest an increased morbidity with mitral valve repair in the patients aged more than 65 years, but this group represents an even higher risk group with mitral valve replacement.

Applicability of mitral valvuloplasty techniques in a North American population

Records of 520 patients who underwent mitral valve operations were reviewed to determine the pathophysiology, etiology, anatomy of the valve lesion and use of valvuloplasty techniques. Pure mitral regurgitation, present in 269 patients (52%), was the most common lesion while rheumatic valvulitis, seen in 286 patients (55%), was the most common etiology. Degenerative lesions were found in 168 patients, 33% of the total and 63% of the pure mitral regurgitation group. Two-hundred seventy patients (52%) were treated with valvuloplasty techniques. The incidence of reconstructive procedures was determined for each of the various patient subsets. Overall hospital mortality was 5.6% in the series: 8.4% for mitral replacement compared with 3% for mitral valvuloplasty (p = 0.007). Among patients undergoing primary isolated mitral procedures, hospital mortality for replacement was 7.5% compared with 1.4% for valvuloplasty (p = 0.018). Mitral valvuloplasty seems to provide a therapeutic alternative applicable to the spectrum of mitral valve pathology seen in a North American population.

A cost-effectiveness comparison of surgical treatments for mitral valve disease

This study compares the cost-effectiveness of mitral valve reconstruction and replacement. Published clinical data were used to determine the effectiveness of each procedure. Both direct and indirect costs were calculated. The findings indicate that reconstruction has lower costs per year of life extended than replacement due to better outcomes. Changing outcome probabilities and discount rates did not alter these results. Cost savings in excess of 40% may be achieved by early reconstruction for suitable patients. These results suggest that the prevailing practice of delaying surgery until replacement is needed should be reconsidered, especially for patients who could benefit from reconstruction.

The Puig-Massana-Shiley annuloplasty ring for mitral valve repair: experience in 126 patients

Between October, 1982, and December, 1984, 126 patients at the Texas Heart Institute underwent mitral valve repair for mitral insufficiency utilizing the Puig-Massana-Shiley annuloplasty ring. Resection of a triangular-shaped wedge of the mural leaflet and direct suture repair was done in 42 patients, and anterior leaflet repair was used in 2 patients. There were 79 male (63%) and 47 female (37%) patients with a mean age of 58 years. Preoperatively, 95% were in New York Heart Association (NYHA) Functional Class III or IV. Concomitant cardiac operations were performed in 82 patients and included coronary artery bypass grafting (49%), aortic valve replacement (16%), repair of ventricular septal defect (2%), resection of left ventricular aneurysm (2%), and repair of atrial septal defect (1%). There were 8 early deaths (6.3%) and 11 late deaths (8.7%). In 44 patients undergoing mitral valve repair as an isolated primary procedure, operative mortality was 2.3%. Murmurs of mitral insufficiency were present in 5 patients postoperatively, but only 1 required early reoperation for mitral valve replacement. Follow-up data have been obtained on 80% of the patients. Postoperative Functional Class was obtained for 63 of the 82 surviving patients and showed 92% of these patients to be in NYHA Functional Class I or II. Mitral valve repair incorporating the Puig-Massana-Shiley annuloplasty ring and valve leaflet revision is a reliable technique that is not technically demanding. We believe these methods should be attempted for correction of pure mitral insufficiency, particularly in circumstances where other cardiac repairs are required.

The evolution of reparative techniques for the mitral valve

Forty-eight adult patients underwent mitral valve repair for nonischemic valvular incompetence between 1963 and 1981. Early in our experience, 21 individuals received wedge leaflet resection or leaflet plication with posteromedial commissural annuloplasty. More recently, midleaflet annuloplasty has been employed in 13 patients and is now our preferred technique. Operative mortality was 6.3%, and all deaths occurred prior to 1973. Eventually valve replacement was necessary in 10 patients; all replacements were done prior to 1977. Technical errors and progression of rheumatic disease each accounted for half of these replacements. Five-year survival by the life table method was 74 +/- 9% for the entire group. Survival at 5 years for patients with prolapsing leaflets was significantly better (87 +/- 7%) than for those with normal leaflet motion (46 +/- 14%). A residual postoperative murmur of mitral insufficiency correlated with the likelihood of subsequent valve replacement. Important technical aspects of valve repair are described, and criteria for optimal patient selection are discussed. The evolution of reparative methods has led to a better understanding and broader application of mitral valve reconstruction.

Mitral annuloplasty in endomyocardial fibrosis: an alternative to valve replacement

The case of a patient with left ventricular endomyocardial fibrosis (EMF) causing severe mitral regurgitation is presented. Excision of the fibrotic tissue through the left atrium and mitral annuloplasty resulted in symptomatic relief and uncomplicated pregnancy. An X-linked congenital dermatological condition, Bloch-Sulzberger syndrome (incontinentia pigmenti), associated with chronic eosinophilia, was also present. This occurrence with EMF has not previously been reported. Atrioventricular valve reconstruction is a feasible alternative to valve replacement in EMF.

Two-dimensional echocardiographic evaluation of mitral valve calcification. Sensitivity and specificity

The effectiveness of two-dimensional echocardiography in assessing mitral valve calcification was compared to radiography of the surgically excised valves in 43 patients affected by rheumatic disease of the mitral valve. Mitral valve calcification was graded as absent or present if single thin or multiple dense conglomerate echoes defined the valvular orifice in short axis view, provided the sensitivity of the instrumentation was adequately optimized. The radiograph of the excised valve was similarly graded. The interobserver reproducibility for both two-dimensional echocardiography and radiography was 100 percent. There were 14 true positives, 19 true negatives, 10 false positives and no false negatives, thus giving, for two-dimensional echocardiography, a sensitivity of 100 percent and a specificity of 65 per cent. It is concluded that two-dimensional echocardiography is an extremely sensitive method for assessing mitral valve calcification, and is prospectively useful also in planning reconstruction versus replacement in mitral valve surgery. Nevertheless, the consistent number of false positives affecting two-dimensional echocardiography represents a definite limit to the specificity of the technique.

Morphometric investigations in mitral stenosis using two dimensional echocardiography

A method is proposed for comparing the orifice size and the morphology of stenotic mitral valves, removed intact at the time of replacement, with the preoperative two dimensional echocardiographic cross-sections. The excised mitral valve apparatus is suspended on a specially constructed mounting. To avoid shrinkage the orifice is stabilised with an airfilled balloon. A radiography is taken directing the x-ray beam perpendicular to the valve orifice. In 40 of 51 patients this method provided the means of relating the echocardiographic cross-sections to the morphology of the valve. Planimetry of the valve area compared favourably with the postoperatively determined orifice size. Agreement was found in 34 of 40 patients in orifice shape between preoperative echocardiograms and x-rays of th excised valve. The relation between intraoperative estimation of size of the valve, using dilators with known diameters, and the postoperative results was less favourable. Areas of calcification were identified on echocardiography as dense conglomerate echoes. In 30 patients (75%) the localisation of calcium deposits and in 67% the degree of calcification was in agreement with the x-rays of the valve taken after operation. In addition to determination of the area, two dimensional echocardiography allows detailed studies of the stenotic valves, and is of particular importance for planning operative treatment.

A new valve retractor for mitral valve procedures

Optimal exposure greatly facilitates reconstructive mitral valve procedures. We describe an effective method for exposing this valve using a specially designed mitral valve retractor. This technique proved useful in 321 patients who underwent operation on the mitral valve.

Echocardiographic evaluation of mitral stenosis in predicting mitral valve replacement vs commissurotomy. Relation to hemodynamic measurements

Fifty-one patients with mitral stenosis were studied by M-mode echocardiograms to verify the possibility of predicting if they will require mitral valve replacement or commissurotomy. Fifteen of 18 patients with heavy calcification and restricted or poor valvular mobility underwent mitral valve replacement. Twelve of 14 patients with normal valve amplitude underwent mitral commissurotomy regardless of the presence of valvular calcification. A newly derived measurement, the MT/ST, which is the ratio between the maximal thickness of the widest echo from the mitral valve and the maximal thickness of the left ventricular margin of the interventricular septum, was used to assess valvular calcification. Values above 1.7 were present only in valves with restricted or poor mobility and indicated mitral valve replacement in 14 of 15 cases. All of the patients undergoing mitral valve replacement who had MT/ST ratios between 1.5 and 1.7 had restricted or poor valvular mobility. Of the patients with MT/ST ratios less than 1.5, ten of 12 with normal valvular amplitude underwent mitral commissurotomy, and four of five with restricted valvular mobility underwent mitral valve replacement. We conclude that echocardiographic assessment of mitral valvular calcification and amplitude is useful in predicting patients who will require mitral valve replacement vs mitral commissurotomy.

Sensitivity and specificity of echocardiography in the assessment of valve calcification in mitral stenosis

Eighty-seven patients (64 females and 23 males) with mitral stenosis were studied by M-mode echocardiography to assess the sensitivity and the specificity of the echocardiographic technique in the identification of valve calcification. The mitral valves were examined at operation, and the amounts of calcium were graded as heavy, light, or absent. We compared this with the amount of calcification assessed by radiographic, previously accepted echocardiographic, and newly derived echocardiographic criteria. In identifying the presence or absence of valve calcification, radiography was the least sensitive (53.7 per cent), but the most specific (90.9 per cent) technique, and has the highest predictive accuracy (90.6 per cent). Previously accepted echocardiographic criteria had the highest sensitivity (92.6 per cent), but the lowest specificity (12.1 per cent), and the lowest predictive accuracy (63.3 per cent). The newly derived echocardiographic parameter MT/ST (ratio between the maximal thickness of the left ventricular margin of the interventricular septum) was both sensitive (75.9 per cent) and specific (81.8 per cent) and also had a predictive accuracy (87.2 per cent) similar to that of radiographic techniques. The MT/ST ratio is demonstrated to be the most useful non-invasive method for assessing valve calcification in mitral stenosis.

The advantages of open mitral commissurotomy for mitral stenosis

Mitral commissurotomy is the treatment of choice for mitral stenosis. If this is not feasible, replacement of the valve becomes necessary. Open commissurotomy has been performed at Loyola University Medical Center, Maywood, Ill, in 105 patients since 1970. The mean age was 45 years. The indication for surgery was heart failure in 92 of the cases. Sixty of the patients were in class 3 of the New York Heart Association (NYHA) classification. Eighty-five underwent open mitral commissurotomy alone. This was not feasible in 42 patients scheduled for it who required valvular replacement. Twenty-five patients had a left atrial thrombus. Two patients died, one from aortic dissection and the other from acute infarction in the perioperative period. Ninety-eight patients are NYHA class 1 or 2 at present. Two patients required valvular replacement following the commissurotomy. The low mobidity and mortality with excellent long-term results support our contention that open mitral commissurotomy is the treatment of choice for mitral stenosis.

Conservative management of the prolapsed mitral valve

Prolapsed leaflet is the result of ruptured chordae, elongated chordae, or ruptured papillary muscle. Various techniques adapted to each of these lesions were developed, and repair of 213 prolapsed mitral valves was performed between 1969 and 1977. There were 109 patients with ruptured chordae treated by quadrangular resection of the prolapsed leaflet; 103 patients with elongated chordae were treated by either a "sliding plasty" of the papillary muscle or a "shortening plasty" of the chordae; and 1 patient with ruptured papillary muscle was treated by reimplantation. The great majority of patients had an associated annular dilatation or deformation requiring the use of a Carpentier ring to remodel the annulus and reinforce the repair. The operative mortality was 4% and the late mortality, 3%. There were 6 reoperations, 3 of which occurred within 1 year. Thromboembolic complications occurred in only 1 patient (0.5%), even though the majority of patients received no anticoagulation treatment. Actuarial curves demonstrated a 91% survival at 8 years.