ORIGINAL
PAPER
Clinical Outcomes After Tricuspid Valve Annuloplasty in Addition to Mitral Valve Surgery Gille Koppers, MS;1,2 David Verhaert, MD;1 Frederik H. Verbrugge, MD;1,2 Rozette Reyskens, RN;1 Herbert Gutermann, MD;3 Chris Van Kerrebroeck, MD, PhD;3 Pieter Vandervoort, MD;1,2 W. H. Wilson Tang, MD;4 Robert Dion, MD, PhD;2,3 Wilfried Mullens, MD, PhD1,2 From the Department of Cardiology, Ziekenhuis Oost-Limburg, Genk, Belgium;1 the Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium;2 the Department of Cardiovascular Surgery, Ziekenhuis Oost-Limburg, Genk, Belgium;3 and the Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH4
Current guidelines recommend tricuspid valve annuloplasty (TVP) together with mitral valve surgery in cases of tricuspid annulus dilation (40 mm) or functional tricuspid valve regurgitation >2 ⁄ 4. Baseline clinical and echocardiographic data of patients undergoing mitral valve surgery in a single tertiary care hospital between 2007 and 2010 were analyzed. Mortality and heart failure hospitalization data were collected and groups with or without TVP were compared. Patients with TVP (n=89) had similar baseline characteristics compared with patients without (n=86), except for lower right ventricular fractional area change and more concomitant aortic valve surgery. Mortality was higher in the TVP group at 30 days (14% vs 5%; P=.04), but the
difference was no longer significant at the end of followup. More patients were hospitalized for heart failure in the TVP group (31% vs 17%; hazard ratio, 2.1; 95% confidence interval, 1.1–4.0; P=.05). Right ventricular sphericity index was the only preoperative parameter predicting death or heart failure hospitalizations. In conclusion, patients undergoing TVP in addition to mitral valve surgery are at high risk for early death or subsequent heart failure hospitalizations, which might be partly explained by more complex heart disease. The extent of preoperative right ventricular remodeling may be predictive of adverse outcomes. 2012 Wiley Periodicals, inc.
Functional tricuspid valve regurgitation (TR), defined as tricuspid valve incompetence in the absence of structural leaflet disease, is the most common type of tricuspid valve pathology, particularly in the setting of left-sided heart disease.1–3 When left untreated after left-sided valvular surgery, functional TR does not spontaneously regress and can worsen over time.4,5 Therefore, concomitant tricuspid valve annuloplasty (TVP) is generally recommended during left-sided valvular surgery when a significant degree of TR (>2 ⁄ 4) is present.6,7 Recently, it has also been advocated to perform TVP in the presence of tricuspid annulus dilation without significant TR, since dilation is an ongoing disease process that often deteriorates to severe functional TR over the long-term.8,9 However, this recommendation has been derived from studies evaluating the effects of TVP in a very select population undergoing solitary mitral valve repair. Whether results can be extrapolated to patients scheduled for mitral valve annuloplasty (MVP) or replacement (MVR) in addition to other cardiac surgery is unknown. Moreover, neither of the widely adopted surgical risk models (ie, European System for Cardiac Operative Risk Evaluation [Euro-
SCORE; Cambridge, United Kingdom] and Society of Thoracic Surgeons [STS]) score take TVP into account. Therefore, mortality cannot be accurately predicted in patients undergoing TVP. Data on subsequent heart failure (HF) admissions are also lacking in this group and preoperative predictors for adverse events are currently not known. The objective of this study is to compare clinical outcomes of patients undergoing MVP ⁄ MVR during left-sided heart surgery either with (in case of tricuspid annulus dilation or functional TR) or without TVP. In addition, we evaluated the prognostic value of preoperative echocardiographic parameters in this particular population.
Address for correspondence: Wilfried Mullens, MD, PhD, Department of Cardiology, Ziekenhuis Oost-Limburg, Schiepse Bos 6, 3600 Genk, Belgium, Europe E-mail:
[email protected] Manuscript received: March 28, 2012; revised: July 27, 2012; accepted: August 13, 2012 DOI: 10.1111/chf.12004
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METHODS Study Population Consecutive patients (n=175) who underwent MVP ⁄ MVR with or without coronary artery bypass grafting (CABG) and ⁄ or aortic valve surgery between 2007 and 2010 in a single tertiary care hospital (Ziekenhuis Oost-Limburg) and with subsequent clinical follow-up in the same center were studied. In our local clinical practice, mitral surgery was always performed in case of a severe (3 ⁄ 4) organic regurgitation. In patients with moderate mitral valve regurgitation (2 ⁄ 4) from an organic cause, surgery was performed only in case of symptoms, left ventricular dysfunction, atrial fibrillation, or pulmonary hypertension. Patients with functional mitral valve regurgitation were operated only if they had persistent mitral valve regurgitation Congest Heart Fail. 2013;19:70–76
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(2) and symptoms despite optimal medical treatment or if concomitant CABG or aortic valve surgery was indicated. All patients included had mitral valve regurgitation 2 ⁄ 4. Mitral valve repair was always favored above replacement if technically feasible. Additional TVP was performed in all patients with a dilated tricuspid annulus 40 mm or TR >2 ⁄ 4. The study complied with the Declaration of Helsinki, the locally appointed ethics committee approved the research protocol, and informed consent for prospective followup was obtained from all study participants. Surgical Procedure All surgical procedures were performed through midline sternotomy under normothermic cardiopulmonary bypass with intermittent antegrade warm-blood cardioplegia. Patients with an indication for revascularization underwent CABG first. The mitral valve was exposed through a vertical transseptal approach along the right border of the foramen ovale, leaving the left atrial roof untouched. MVP was performed after thorough intraoperative visual and echocardiographic valve analysis. Ring size (Carpentier-Edwards Physioring, Edwards Lifesciences, Irvine, CA) was determined after careful measurement of the height of the anterior leaflet. In cases of functional mitral valve regurgitation, downsizing by two sizes (ie, size 26 when measuring 30) was applied to ensure a valve leaflet coaptation length of at least 8 mm. Rings were inserted using 12 to 14 deep U-shaped simple horizontal sutures using Ethibond 2-0 (Ethicon, Inc, Somerville, NJ). If indicated, additional aortic prosthetic valve replacement or aortic valve repair was performed. TVP was performed using a CarpentierEdwards MC3 ring. The ring size was visually matched to the area of the anterior leaflet. Restored leaflet coaptation (8 mm for the mitral valve) was confirmed during surgery by filling the ventricles with saline through a bulb syringe and visually inspecting the leaflets. Peroperative transesophageal echocardiography was used to assess the left ventricular and valve function after weaning from cardiopulmonary bypass. If the result of the mitral valve repair was not satisfactory, further downsizing was performed. Baseline Transthoracic Echocardiographic Measurements Comprehensive 2-dimensional echocardiographic examinations were performed with a commercially available system (Philips Medical Systems, iE33, Amsterdam, The Netherlands) by experienced diagnostic cardiac sonographers. Images were acquired in the left lateral decubitus position and standard 2dimensional and Doppler data, triggered to QRS complex, were digitally stored in cine loops in DICOM format. Analysis of the images was performed offline by two independent investigators experienced with
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echocardiographic measurements blinded to surgical and clinical data at the time of analysis. All reported echocardiographic measurements were averaged from 3 consecutive cycles and assessed as recommended by the American Society of Echocardiography.10 Left ventricular diameters were measured from the parasternal long-axis view. The left ventricular ejection fraction (LVEF) was obtained by using Simpson’s method from the apical 4- and 2-chamber views.10 Right ventricular (RV) end-systolic and end-diastolic areas were measured by planimetry. RV fractional area change (RVFAC) was used to determine RV systolic function and was calculated with the following formula: RVFAC=[(diastolic area – systolic area) ⁄ diastolic area] 100%.11 RV long-axis length and shortaxis width were measured at the mid-ventricular level and used to calculate RV sphericity index (RVSI) at the end of systole.12 Tricuspid valve annulus diameter was measured at the end of systole and diastole as the distance between the midpoints of reflection of the septal and mural endocardium on the anterior and septal tricuspid leaflets, respectively.13 Mitral valve regurgitation and TR severity were assessed by color Doppler flow mapping.14 Study End Points Patients were followed from the day of surgery and all-cause 30-day mortality was analyzed using data documented in the electronic health record of the hospital. The observed mortality rate was then compared with the predicted mortality by calculation of the EuroSCORE. Patients were further followed until the occurrence of a first subsequent hospitalization for HF, death, or censoring at May 1, 2011. Time to death or first HF hospitalization was a secondary end point, with an HF hospitalization defined as an admission of more than 12 hours for worsening HF symptoms that required parenteral therapy. Statistical Analysis Continuous variables were expressed as meanstandard deviation and categorical variables as percentages. Data from the TVP) and TVP+ group were compared using the independent Student t test and chi-square test, respectively. Statistical significance was set at a 2-tailed probability level, with a=0.05. Kaplan-Meier survival curves were calculated for all patients stratified in 2 groups. The Cox proportional hazards regression model was used to determine the prognostic value of both clinical and echocardiographic parameters. Variable selection in multivariate analysis was based on the clinical and statistical significance of the univariate analysis. The authors had full access to the data and take responsibility for its integrity. All statistical analyses were performed using SPSS for Windows, release 17.0 (SPSS Inc, Chicago, IL). All authors have read and agreed to the manuscript as written.
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RESULTS
TABLE II. Baseline Medical Therapy
Baseline Clinical and Echocardiographic Characteristics of the Study Population A total of 198 patients undergoing MVP ⁄ MVR was screened for eligibility in this study. Seven were excluded because of suboptimal baseline echocardiographic image quality and 16 because of missing follow-up data. The final study population therefore comprised 175 patients (88 men and 87 women; 15% MVR and 85% MVP). Eighty-nine patients had an indication for TVP (TVP+ group), while the remaining (TVP) group) consisted out of 86 patients. Baseline demographics and echocardiographic data of both groups are presented in Table I. The TVP+ group less frequently had ischemic etiology of mitral valve regurgitation and RVFAC was lower compared with the TVP) group. Baseline medical therapy is presented in Table II. Procedural Characteristics All patients underwent successful MVP ⁄ MVR and TVP, defined as no residual mitral ⁄ tricuspid valve regurgitation and a coaptation length of the mitral valve leaflets of 8 mm in the immediate postoperative phase. The mean mitral ring size used was 314 mm and the mean tricuspid ring size used was 312 mm. Patients in the TVP) group had more concomitant CABG performed, but less aortic valve sur-
TABLE I. Baseline Characteristics TVP )
TVP +
Patients, No.
86
89
Age, y Female sex, %
6811 47
6912 53
.60 .40
Diabetes, % Arterial hypertension, %
18 43
16 58
.73 .08
P Value
Hypercholesterolemia, % Creatinine
42 1.21.7
41 1.10.3
.90 .13
LVEF, % MR grade
5814 2.70.9
5416 31.0
.07 .12
TR grade TA diameter, cm
0.60.6 3.00.5
1.81.0 3.70.6
