Balloon valvotomy for mitral stenosis associated with moderate mitral regurgitation

Balloon

Valvotomy for Mitral With Moderate Mitral

Stenosis Associated Regurgitation

He Ping Zhang, MD, Habib Gamra, MD, John W. Allen, MD, Francis Y.K. Lau, MD, and Carlos E. Ruiz, MD, PhD

ercutaneous balloon mitral valvotomy is an estabP lished treatment for patients with severe mitral stenosis.1-3Although patients with mild mitral regurgitation (MR) can safely undergo balloon mitral valvotomy, moderate MR is generally considered to be a contraindication to this procedure by most physicians becauseof the possibility of exacerbating the degree of regurgitatibn.“c7 However, the presence of MR before valvotomy has not been specifically identified as a risk factor for further worsening of MR.5,6 The results and safety of this procedure for patients with moderate MR has not been examined either prospectively or retrospectively, probably because such patients usually undergo mitral valve replacement surgery. However, the risk of mitral valve replacement is also high for someof these patients because of their poor clinical status.8 Therefore, balloon mitral valvotomy may be advisable to temporarily relieve symptoms and improve cardiac function. The purpose of this study was to examine and compare the results and risks of mitral valvotomy by using a double-balloon technique in patients who had severe mitral stenosis with and without moderate MR. ... Between February 1986 and February 1994, we performed double-balloon mitral valvotomy in 25 patients with symptomatic rheumatic mitral stenosisand moderate (2+) MR (group 1). We matched 25 patients who had absent (O+, n = 10) or mild (l+, n = 15) MR (group 2) with patients in group 1 on a person-to-personbasis. The rationale for matching groups was to minimize the other factors that may influence the outcome of the procedure. The criteria for matching were: (1) age, 110 years; (2) New York Heart Association functional class, II class; (3) mitral valve echocardiographic score, 54 on a 0 to 16 scale; (4) fluoroscopic calcification, if 0+ exact match, if >O+ then
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sum of the 2 balloon diameters) was chosen according to the size of the mitral annulus measuredby 2-dimensional echocardiography.The average balloon diameter was 11% larger than the annulus diameter for group 1 and 12% larger for group 2. The severity of MR was assessedby left venhiculography and was graded by a 0 to 4+ scale (0+ [absent regurgitation], l+ [mild], 2+ [moderate], 3+ [moderate to severe], and 4+ [severe]) according to the degree of opacification of the left atrium and pulmonary veins.g The degree of valvular calcification assessedby fluoroscopy was graded from 0 (no calcification) to 4+ (heavy calcification). Cardiac output was measuredby thermodilution unless severetricuspid regurgitation was present, in which case the Fick method was used. Mitral valve area was determined by 3 methods: (1) the Gorlin formula; (2) Doppler pressure half-time; and (3) planimetry. Postvalvotomy mittal valve area was measuredby means of the Gorlin formula immediately after valvotomy, and by the Doppler and planimetry methods within 24 hours after valvotomy. Mitral valve echocardiographic score was used to assessvalve morphology.5 The severity of mitral valve thickness, leaflet immobility, valvular calcification, and submitral disease was graded ofi a score of 0 to 4 for each feature. The total echocardiographic score was the sum of the 4 scores. Statistical analyses were performed using SAS software version 6.08 (SAS Institute Incorporated, Gary, North Carolina). Continuous data between the 2 groups TABLE I Baseline Characteristics Moderate

Age(yr) Sex: men/women NYHA II III

functional

(%)

Mild or Absent MR (n = 25)

53 f 14 5 (20)/ 20 (80)

54* 14 5 (20)/ 20 (80)

0.9 1 .o

4 (161 17 (68)

5 14 6 12

(201 (56) (241 (48)

0.7

4 (161

0.5

class (%)

IV Echocardiographic score z-8 (%) Fluoroscopic calcification o+ l+ 2+ 3+ 4+ Atrial fibrillation Bailoon/annulus diameter ratio

4 (16) 1 1 (44)

1, 1995

0.8

(%) 4 3 9 8 1 16 1.11

(16) (12) (36) (321 (41 (64) f 0.16

3 14 4 0 15 1.12

(121 (56) (161 PI (60) * 0.14

MR = mitral regurgitation; NYHA = New York Heart Association

MAY

p Value

0.6 0.7

TABLE II Comparison

1 of Hemodynamic

Variables

and Mitlral Valve

Area*

Before Valvotomy Moderate Mean

left atrial

pressure

(mm Hg) Mean pulmonary artery pressure (mm Hg) Mean mitral valve gradient (mm Hg) CO (L/min) Mitral valve area (cm2) by Gorlin by Doppler by planimetry

MR

Mild

or Absent MR

After Valvotomy Moderate

MR

Mild

or Absent

Absolute MR

Moderate

28 * 8

26 A 6

19 + 6

17~ 6

-10*7

40*

37 i 8

31 * 13

30 * 7

-8*

12

15*7

14 * 5

5*1

5rt2

-lo*

MR

Change Mild

or Absent

-9*9 10

-7 * 8

8

-9 f 5

3.2 i 0.9

3.7 * 1.3

5.2 f 1.5

5.4 f 2.0

2.0 A 1.2

1.7 f 1.5

0.9 * 0.3

0.9 * 0.3 0.9 f 0.3

2.2 e 0.6

2.3 2 0.6 2.0 * 0.4

1.3 * 0.5 0.8 zt 0.5 0.9 zt 0.6

1.4 f 0.6

1 .o f 0.3 1 .o f 0.3

1 .o * 0.3

1.9 i: 0.4 1.9 * 0.3

2.1 f 0.3

MR

-

1.1 i: 0.4 1.1 + 0.5

*Comparison of hemodynomicvalues and mitral valve area before and after valvotomy within each group; all p
-

-

were compared by Student’s paired and El Before q Before unpaired 2-tailed t test, and discrete data n After n After were examined using a &i-square test or Fisher’s exact test whenever it was appropriate. Results are quoted as mean + SD, 1 and the values are consideredto differ sigp=0.0001 nificantly if p CO.05. There were no significant differences between the groups in terms of baseline characteristics(TableI), valve area,and hemodynamic parameters(Table II). Hemodynamic values improved immediately after balloon dilatation in both groups (Table II, Figure 1). When the hemodynamic values and mitral valve area with their absolute changes after valvotomy were compared between the groups, no significant differences were found (Table II). An increase in mitral valve areas by 250% to a final area>1.5 cm2 after valvoModerate Mild or Moderate Mild or tomy was achieved in 23 patients (92%) MR Absent MR MR Absent MW in both groups. . Although the increase in MR after FIGURE1. Improvements in hemoctynamic values after vahrotomy in patients with valvotomy was similar for both groups moderak mitral regu itation (MR) and in patients with mild or absent MR before (Figure 2), 5 patients in group 1 devel- valvotomy. Lefi, meanYeI9 atr’al pressure; tight, mean mitral valve gradient. oped 3+ MR after balloon dilatation from preexisting moderate (2+) MR. No emerMild or Absent MR Moderate M R gent surgery was required in either group. POST PRE POST An atria1septal defect with a shunt >1.5:1 !vlvl PRE was detected by oximetry in 2 patients from each group. There were no other complications during the procedure. In group 1,16 patients (64%) were followed for a meanperiod of 38 + 25 months (range 1 to 78); in group 2, 15 patients (60%) were followed for a mean period of 32 + 24 months (range 4 to 77). Of those, 63% of patients in group 1 and 80% in group 2 were symptom-free (p = 0.4). One patient had a stroke at 62 months and 1 patient died 9 months after the procedure in group 1. Two patients had mitral valve replacementsin both groups. Table III showshemodynamic data, mitral valve FIGURE2. Angiographic mitral regurgitation (MR) before and after balloon area determined by planimetry, and late mitral valvotomy. BRIEF REPORTS

061

follow-up results in 5 patients who developed 3+ MR immediately after valvotomy and in 4 patients who required mitral valve replacementsat follow-up. ... This report is the Erst study, to our knowledge, to compare the results of balloon mitral valvotomy in 2 comparable groups-one with moderate (2+) MR and a second with absent or mild MR before the procedure. Despite increases in technical experience, the increase in MR after balloon mitral valvotomy is unpredictable., Therefore, the safety of ,balloon mitral valvotomy in patients with MR has been a concern. In fact, balloon mitral valvotomy has generally been considered a contraindication for patients with moderate or more severe (22+) MR. Our Endings suggestthat moderate MR (2+) may not be an absolutecontraindication to balloon mitral valvotomy. A mild increase in MR is often found after balloon valvotomy. This increase appearsto be caused by the same mechanism responsible for the increase in mitral valve areaafter balloon dilatation, which splits the tissue along the natural planes of one or both commissures.4,“10JThis has been previously demonstratedby color Doppler flow in which a localized regurgitant jet originated at the site of successfully separatedcommissures. Such regurgitation had no clinical consequence,4 and may decreasewith time.12 We found no worsening of MR after valvotomy in 40% of the patients, and an actual reduction in MR in another 40% of the patients with preexisting moderate (2+) MR. One possible reasonfor a decreasein the severity of MR after balloon dilatation may be related to commissural splitting. Before balloon dilatation, the papillary muscles and tendons are fused into a solid Ebrous mass,shortened,and densely adherentto the valve; thus, the valve leaflets cannot open adequately in diastole or rise properly to close in systole. After successfulballoon dilatation, one or both fused commissuresare separated, and the mitral valve may becomerelatively more mobile, permitting better closure during systole. In contrast, a severe increase in MR after balloon mitral valvotomy appearsto be related to rupture of the anterior or posterior mitral valve leafletsrather than commissural splitting. In patients who developed severeMR during balloon dilatation, surgical findings have conEm-redthat the leaflets were torn and detachedor the subvalvular apparatusdamaged,or a combination of these.4J0 This damageis similar to that associatedwith significant MR created during open or closed mitral surgical commissurotomy in which MR may be produced by tearing of or incision in the anterior or posterior leaflet, or by rupturing the chordae tendineae.r3 In previous studies, the rate of increase in MR after balloon mitral valvotomy ranged from 19% to 67%.3-7 Although in our study the rate of increase in MR was similar to other studies, mild (l+) increase led to moderate to severe(3+) MR in 20% of the patients with preexisting moderate (2+) MR. The prognosis in patients who develop moderate to severeMR after either surgical commissurotomy14or balloon mitral valvotomy7 is poor and mitral valve replacement is usually required. Furthermore, Alfonso et all5 showed that patients with preexisting.mild ( 1+) MR who underwent balloon mitral

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valvotomy were seldom event-free at follow-up. In our study, we did not find a higher risk of cardiac events at follow-up in patients with preexisting moderate (2+) MR, and 4 of 5 patients who developed 3+ MR immediately after valvotomy had few mild symptoms and did not require mitral valve replacement.However, our sample size was too small and only 64% of them were included in the subsequentfollow-up. Thus, we cannot exclude the possibility of a surgical procedure in patients lost to follow-up. A larger number of patients with longer folXlow-up is neededto determine the long-term efficacy of the procedure. However, most patients in our study had hemodynamic and clinical improvement after successful balloon mitral valvotomy, and the need for mitral valve replacement was postponed. In summary, the possibility of developing moderate to severe (3+) MR after balloon dilatation was greater in patients with preexisting moderate MR. Nevertheless, improvements in hemodynamics and increases in mitral valve area can be equally achieved using balloon mitral valvotomy for treatment of mitral stenosis in patients with or without moderate MR. Acknowledgment: We wish to thank Peter Whittaker, PhD, for review of the manuscript. 1. Cohen DJ, Kuntz RE, Gordon SPF, Piana RN, Safian RD, McKay RG. Bairn DS, Grossman W, Diver DJ. Predictors of long-term outcome after percutaneous balloon mitral valvuloplasty. New Engl J Med 1992;327:1329-1335. 2. Arora R. Kalra GS, Murty GSR, Trehan V, Jolly N, Mohan JC, Sethi KK, Nigam

M. Khalilullah M. Percutaneous transatrial mitral commissurotomy: immediate and intermediate results. JAm Coil Cardiol 1994,23:1327-1332. 3. Ruiz CE, Allen JW, Lau FYK. Percutaneous double balloon valvotomy for severe rheumatic mitral stenosis. Am J Cardiol 1990;65:473477. 4. Essop MR, Wisenbaugh T, Skoularigis J, Middlemost S, Sareli P. Mitral regurgitation following mitral balloon valvotomy. Differing mechanisms for severe versus mild-to-moderate lesions. Circularion 1991;84: 1669-1679. 5. Abascal VM, Wilkins GT, Choong CY, Block PC, Palacios IF, Weyman AE. Mitral regurgitation after percutaneous balloon mitral valvuloplasty in adults: evaluation by pulsed Doppler echocardiography. JAm Coil Cardiol 1988;11:257-263. 6. Sancho M, Medina A, de Lezo JS, Hemandez E, Pan M, Coello I, Romero M, Melian F, Segura J, Jimenez F, Vivancos R, Laraudogoitia E, Valles F. Factors influencing progression of mitral regurgitation after transarterial balloon valvuloplasty for mitral stenosis. Am J Cardiol 1990;66:737-740. 7. Herrmann HC, Lima JC. Feldman T, Chisholm R, Isner J, O’Neill W, Ramaswamy K. Mechanism and outcome of severe mitral regurgitation after Inoue balloon valvuloplasty. JAm Coil Cardiol 1993;22:783-789. 8. Scott WC, Miller DC, Haverich A, Mitchell RS, Oyer PE, Stinson EB, Jamieson SW, Baldwin JC, Shumway NE. Operative risk of mitral valve replacement: discriminant analysis of 1329 procedures. Circulafion 1985;72(suppl II):&108-H- 119. 9. Sellers RD, Levy MJ, Amplatz K. Lillehei CW. Left retrograde cardioangio~graphy in acquired cardiac disease. Technique, indications and interpretation in 700 cases. Am .I Cardiol 1964:14:437-447. 10. Reid CL, McKay CR, Chandmratna PAN, Kawanishi DT, Rahimtoola SH. Mechanisms of increase in mitral valve area and influence of anatomic features in double-balloon, catheter balloon valvuloplasty in adults with rheumatic mitral stenosis: a Doppler and two dimensional echocardiographic study. Circulation 1987;76: 628636. 11. Ribeiro PA, Zaibag MA, Rajendran V, Ashmeg A, Kasab SA, Famidi YA, Halim M, Idris M, Fagih MR. Mechanism of mitral valve area increase by in vitro single and double balloon mitral valvotomy. Am J Cardiol 1988;62:264-269. 12. Ruiz CE, Zhang HP, Game H, Allen JW, Lau FYK. Late clinical and echocardiographic follow-up after percutaneous balloon dilatation of the mitral valve. Br Heart J 1994;71:4%&4.58. 13. Brock RC. The surgical and pathological anatomy of the mitral valve. Br hrearr J 1952;14:489-513. 14. Dalby AJ, Firth BG, Forman R. Preoperative factors affecting the outcome of isolated mitral valve replacement: a 10 year review.Am J Cardioll981;47:826-834. 15. Alfonso F, Macaya C, Hernandez R, Banuelos C, Goicolea J, Iniguez A, Fernandez-Ortiz A, Zarco P. Early and late results of percutaneous mitral valvuloplasty for mitral stenosis associated with mild mitral regurgitation. Am J Cardiol 1993;71:1304-1310.

Comparison of the Bruce and Ramp Protocols in the Assessment of Left Ventricdar Performance During Exercise in Healthy Women Kashmira Bhadha, MD, James D. Walter, PhD, Diana DiMarzio, David Cassel, BS, Jaekyeong Heo, MD, and Abdulmassih uring dynamic exercisein healthy subjects,both the D Frank-Starling mechanism and increased contractility are important compensatorymechanismsto augment cardiac output.1-18It has been suggestedthat women are more likely to utilize the Frank-Starling mechanism while men utilize increased contractility. Also, exercise protocols that result in large and unequal work increments, such as the Bruce protocol, may yield a nonlinear relation between oxygen consumption and work rate. The ramp protocol, on the other hand, uses a constant and continuous increase in workload.19 The present study comparesthe Bruce and ramp protocols in healthy women by measuring oxygen conFrom the Philadelphia Heart Institute, Presbyterian Medical Center, Philadelphia, Pennsylvania. Dr. Iskandrian’s address is: 51 North 39th Street, Philadelphia, Pennsylvania 19104. Manuscript received October 20, 1994; revised manuscript received January 30, 1995, and accepted February 1, 1995.

RN, Virginia Cave, RN, S. Iskandrian, MD

sumption and assessing left ventricular (LV) performance with use of the ambulatory nuclear detector. ... The healthy women were employees or spousesof employeesat the Philadelphia Heart Institute. They were free of coronary risk factors, had normal cardiac examinations and resting electrocardiograms, and none had angina or ST-segment depression during exercise. All but 2 exercisedregularly and 5 were athletes.They signed a consent form approved by the institutional review board. Subjects were randomized as to which of the 2 protocols (Bruce or ramp) was performed lirst. The 2 exercise studies were separatedby 230 minutes. All tests were continued to volitional fatigue or dyspnea.The ramp protocol was customizedto each subjectto yield an evercise time of approximately 10minutes by steadyincreases in speedand inclination of the treadmill. Respiratory gas exchange was measured continuously throughout exercise by the 2001 System(Medical Graphics CorpoBRIEF REPORTS

963