The Additional Prognostic Value of Left Atrial Volume on the Outcome of Patients After Surgical Ventricular Reconstruction

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1 The Additional Prognostic Value of Left Atrial Volume on the Outcome of Patients After Surgical Ventricular Reconstruction Serenella Castelvecchio, MD, Marco Ranucci, MD, Francesco Bandera, MD, Ekaterina Baryshnikova, PhD, Francesca Giacomazzi, MD, and Lorenzo Menicanti, MD, for the Surgical and Clinical Outcome Research (Score) Group Departments of Cardiac Surgery and Cardiothoracic and Vascular Anesthesia and Intensive Care Unit, IRCCS Policlinico San Donato, Milan, Italy Background. Left atrial volume (LAV) is a powerful predictor of outcome in patients with chronic heart failure (HF). It is unknown whether LAV provides additional prognostic information in patients undergoing surgical ventricular reconstruction (SVR). Our objective was to assess the prognostic power of LAV on survival in patients with HF after undergoing SVR. Methods. One hundred twenty-eight patients (109 men aged 64 9 years) referred to our center for surgical ventricular reconstruction had an echocardiographic assessment of LAV at admission. Results. Overall, 18 patients experienced operative mortality. The median follow-up time for the 110 survivors was 32 months. At Cox regression analysis, left atrial volume index (LAVI) (LAV/body surface area ml/m 2 ) was inversely associated with survival rate (hazard ratio [HR], for every 1 ml/m 2 of LAVI; 95% confidence interval [CI], ; p 0.001). The predictive value of LAVI was independent of age and the more powerful preoperative diastolic restrictive pattern (RP) (HR, 1.56; 95% CI, ; p for LAVI quartile; HR, 1.09; 95% CI, ; p for age; and HR, 7.31; 95% CI, ; p for diastolic RP). A receiver operating characteristic (ROC) curve analysis for separate models was applied to determine the discriminatory power of each determinant of survival. The best accuracy was achieved by including the LAVI quartile, which increased the accuracy of survival prediction up to 0.87 (95% CI, ). Conclusions. Preoperative LAV is a powerful indicator of poor outcome after SVR and improves the accuracy of survival prediction when added to other independent determinants. (Ann Thorac Surg 2013;95:141 7) 2013 by The Society of Thoracic Surgeons The relationship between left atrial (LA) enlargement and cardiovascular outcome has been well established in different clinical settings [1]. LA volume (LAV), as determined by echocardiography, provides a sensitive morphologic index directly related to the severity of left ventricular (LV) dysfunction and the prognosis of patients with chronic heart failure (HF) [2 5]. Additionally, LAV is closely associated with LV diastolic function, reflecting elevation of ventricular filling pressures [6, 7]. Surgical ventricular reconstruction (SVR) has been widely adopted to reverse LV remodeling in patients with ischemic HF [8]. The aim of SVR is to exclude scar tissue from the LV wall, thereby restoring the physiologic volume and shape and improving LV systolic function and clinical status. Studies have shown that SVR is effective and relatively safe, with a favorable 5-year outcome [8 11], although the additional benefit of SVR to coronary artery bypass grafting remains debated [12]. Accepted for publication August 10, Address correspondence to Dr Castelvecchio, Department of Cardiac Surgery, IRCCS Policlinico San Donato, Via Morandi 30, 20097, San Donato Milanese, Milan, Italy; castelvecchio.serenella@gmail.com. One of the concerns is the potential detrimental impact of LV surgical reduction on diastolic function [12]. Our group demonstrated that severe diastolic dysfunction, when associated with mitral regurgitation (MR) and higher New York Heart Association (NYHA) functional class, is a risk factor for in-hospital mortality after SVR [10]. Furthermore, we have shown that severe degrees of diastolic dysfunction and expression of elevated filling pressures occur in the majority of patients affected by ischemic HF who undergo SVR [13]. Indeed, additional postsurgical worsening of diastolic function occurs in a minority of patients, ranging from 18% at discharge up to 21.7% at midterm follow-up [13, 14]. Moreover, regardless of whether the diastolic function worsens, and to what extent, the clinical effects on the long-term outcome of patients undergoing SVR have not been investigated yet. LAV was previously suggested to be an index of diastolic dysfunction severity and duration, as glycosylated hemoglobin is for diabetic patients. Unlike either multiple load-dependent measurements (derived from Doppler and tissue Doppler ultrasonography) or the more complex pressure-volume loops, which reflect instantaneous hemodynamic status, LAV is the expression 2013 by The Society of Thoracic Surgeons /$36.00 Published by Elsevier Inc

2 142 CASTELVECCHIO ET AL Ann Thorac Surg LEFT ATRIAL VOLUME AND SURGICAL CARDIAC OUTCOME 2013;95:141 7 Abbreviations and Acronyms BSA body surface area EDVI end-diastolic volume index EF ejection fraction ESVI end-systolic volume index HF heart failure LA left atrium LAV left atrial volume LAVI left atrial volume index LV left ventricular MR mitral regurgitation NYHA New York Heart Association RP restrictive pattern SVR surgical ventricular reconstruction of long-term exposure of the left atrium to abnormal LV diastolic function and filling pressures, providing more powerful prognostic information in ischemic patients with HF. The aim of the present study was to assess the prognostic power of LAV on the long-term outcome (defined as survival free from all causes of death) of patients with ischemic HF undergoing SVR. wave deceleration time [DTE]). All measurements were obtained from the mean of 3 beats for patients with sinus rhythm and 5 beats for those with atrial fibrillation. Restrictive pattern (RP) was defined as E/A 2orE/A between 1 and 2 but with DTE 140 ms or DTE 140 ms in cases of atrial fibrillation [2]. MR was assessed using a 4-degree scale, based on color and continuous wave Doppler examination, independently by 2 different cardiologists. Follow-Up Survival was assessed on the basis of the occurrence of death from any cause during the follow-up period. Follow-up was conducted either at the hospital during routine clinical evaluation or by telephone contact with the patients, their relatives, or family doctors and was 100% complete. If the patient was not seen in the hospital or telephone interview was not possible, we contacted the National Registry of Death. Surgical Technique Details of the surgical technique have been previously reported [8]. Briefly, the procedure was performed on the arrested heart with antegrade cold blood cardioplegia. Material and Methods Study Design This was a retrospective study based on the database of the IRCCS Policlinico San Donato for patients undergoing SVR. The study design was submitted to the local ethics committee, which waived the need for approval in consideration of the retrospective nature of the study. All the patients admitted to the study gave informed consent for the scientific analysis of their clinical data in an anonymous form. Patient Selection One hundred twenty-eight patients (109 men 64 9 years) with previous anterior myocardial infarction and LV remodeling referred to our center for SVR underwent complete transthoracic echocardiography with assessment of LAV at admission. All patients underwent SVR; coronary artery bypass grafting was performed in 121 patients (95%) and mitral valve repair in 39 patients (30%). Indications for operation were HF or angina, or a combination of the 2 conditions. Echocardiography LAV was measured at the end of LV systole from the apical 4-chamber view (monoplane evaluation using area-length method) and normalized for body surface area (BSA) (LAVI LAV/BSA, ml/m 2 ). End-diastolic volume (EDV) and end-systolic volume (ESV) were calculated from the apical 4-chamber view using the Simpson method, indexed to BSA (EDVI and ESVI, ml/m 2 ). Ejection fraction was calculated as EDV ESV/EDV 100 (%). Diastolic function was assessed measuring transmitral flow (E and A wave peak velocities, E/A ratio, and E Table 1. Demographics, Clinical Profile, and Echocardiographic Data of the Patient Population (N 128) Variable Number (%) or mean (SD) Male sex 109 (85) Age (y) 64.4 (10.2) BSA (m 2 ) 1.83 (0.15) Family history of cardiovascular disease 51 (40) Hypertension 76 (59) Dyslipidemia 75 (58) Diabetes on medication 30 (23) Smoking history 78 (61) Previous cerebrovascular accident 10 (7.8) Atrial fibrillation 17 (13) Ventricular arrhythmias 19 (15) QRS length (ms) 117 (26) NYHA class 2.6 (0.6) NYHA class 2 75 (59) Hemoglobin value (mg/dl) 13.2 (1.8) Serum creatinine value (mg/dl) 1.3 (0.6) EDVI (ml/m 2 ) 112 (34) ESVI (ml/m 2 ) 80 (32) EF (%) 30 (8.3) Left ventricular mass (g/m 2 ) 178 (46) LAVI (ml/m 2 ) 52.3 (16.8) Diastolic RP 44 (34) TAPSE (mm) 19.7 (4.1) Moderate or severe MR (3 or 4 /4 ) 41 (32) BSA body surface area; EDVI end-diastolic volume index; EF ejection fraction; ESVI end-systolic volume index; LAVI left atrial volume index; MR mitral regurgitation; NYHA New York Heart Association; RP restrictive pattern; SD standard deviation; TAPSE tricuspid annular plane systolic excursion.

3 Ann Thorac Surg CASTELVECCHIO ET AL 2013;95:141 7 LEFT ATRIAL VOLUME AND SURGICAL CARDIAC OUTCOME Complete coronary revascularization was performed first. After completion of coronary grafting, the left ventricle was opened with an incision parallel to the left anterior descending artery, starting at the middle scarred region and ending at the apex. Surgical ventricular reconstruction was performed using a mannequin (TRISVR, Chase Medical, Richardson, TX,) filled at 50 to 60 ml/m 2 to optimize the size and shape of the new ventricle. The mannequin shape helped in orienting the plane of the endoventricular circular suture at the transitional zone obliquely toward the aortic flow tract and, mainly, in rebuilding the new apex. When necessary, the mitral valve was repaired through the ventricular opening with a posterior annuloplasty. Statistical Analysis Data are presented as mean with a standard deviation of the mean for continuous variables, and as number and percentage for categorical variables. The long-term survival rate was explored with Kaplan-Meier curves. The potential effects of the LAVI and other preoperative variables on long-term follow-up were preliminary explored with a Cox regression analysis, producing HRs and 95% CIs. The patients were divided into quartiles according to the LAVI value, and differences in survival rate between the quartiles were explored with a log-rank test. All the factors associated with survival rate at a p value less than 0.1 were entered into a multivariable stepwise forward Cox regression analysis, again producing HRs and 95% CIs. Only the factors significantly (p 0.05) associated with the long-term survival rate in the multivariable model were defined as independent predictors of long-term outcome. To address the accuracy of prediction of the identified independent variables and to take into account the problem of multicollinearity, different predictive models were structured, with an estimate of their accuracy based on receiver operating characteristic (ROC) curves analysis and area under the curve (AUC) evaluation. As an additional analysis, the LAVI value and LAVI distribution quartile were investigated for association with the operative mortality (defined as mortality within 30 days after operation) using a logistic regression analysis. Statistical calculations were performed using a computerized statistical program (SPSS, version 13.0; SPSS, Inc, Chicago, IL). Results 143 The demographics, clinical profile, and preoperative echocardiographic data of the patient population are shown in Table 1. Overall, 18 patients (14%) experienced operative mortality. One patient died of stroke. Among patients who died perioperatively, 10 had undergone concomitant mitral valve repair. The mortality rate at follow-up was 11.7% (15 patients), for a total mortality rate of 25.8% (33 patients). The median follow-up time for the survivors (110 patients) was 32 months (range months). The overall survival rate, inclusive of operative mortality, is shown in Fig 1. LA dimensions were tested for association with survival at follow-up with a Cox regression analysis. LAVI was inversely associated with survival rate (HR, for every 1 ml/m 2 of LAVI; 95% CI, ; p 0.001). According to LAVI, the patient population was divided into quartile-based groups. The quartile-based group data are shown in Table 2. Survival rate according to the quartile distribution of LAVI is shown in Fig 2. Differences among quartiles were assessed using a log-rank test. Patients in the first quartile of distribution had a significantly better survival rate when compared with patients in the third (p 0.008) and Fig 1. Kaplan Meier survival curve for the overall population. All-cause mortality is reported; 30-day in-hospital mortality is included.

4 144 CASTELVECCHIO ET AL Ann Thorac Surg LEFT ATRIAL VOLUME AND SURGICAL CARDIAC OUTCOME 2013;95:141 7 Table 2. Quartiles of Distribution According to the LAVI Quartile Number LAVI (ml/m 2 ) Mean (SD) Median Range First (0.99) Second (0.35) Third (0.78) Fourth (1.96) LAVI left atrial volume index; SD standard deviation. Table 3. Univariate and Multivariate Cox Regression Analysis for Survival at Follow-Up Factor Hazard Ratio 95% Confidence Interval p Value Univariate analysis Age (y) QRS length ( m) Preoperative atrial fibrillation Hemoglobin (mg/dl) ESVI (ml/m 2 ) LAVI (quartile) Diastolic RP TAPSE (mm) Moderate to severe MR NYHA class Multivariate analysis Age (y) LAVI (quartile) Diastolic RP ESVI end-systolic volume index; LAVI left atrial volume index; MR mitral regurgitation; NYHA New York Heart Association; RP restrictive pattern; TAPSE tricuspid annular plane systolic excursion. fourth (p 0.002) quartiles, whereas the difference between the first and second quartiles was not significant (p 0.121). Because of the presence of confounding factors strongly related to LAVI, other possible determinants of survival at follow-up were investigated using univariate and multivariable Cox regression models (Table 3). Univariate factors associated with the survival rate were age, QRS length, preoperative atrial fibrillation, preoperative hemoglobin value, ESVI, diastolic RP, tricuspid annular plane systolic excursion, moderate or severe MR, and New York Heart Association (NYHA) functional class. These variables were included in a multivariable stepwise forward Cox regression model together with the quartile of distribution of LAVI. In this model, the independent predictors of survival at follow-up remained the LAVI quartile, age, and the presence of a preoperative diastolic RP. The LAVI quartile was not significantly associated with age (p 0.518); conversely, there was a significant (p 0.001) association between the LAVI quartile and the presence of a diastolic RP (first quartile, 4 cases [12.5%]; second quartile, 11 cases [34.3%]; third quartile, 12 cases [37.5%]; fourth quartile, 17 cases [53%]). To assess the additional predictive value of the LAVI and its interaction with the other determinants of survival at multivariate analysis (age and RP), a diagnostic statistical analysis was performed using a ROC curve analysis for separate models. Using the regression coefficients derived from the Cox regression analysis, 3 predictive models were built: model 1 was based on age alone; model 2 was based on age plus the presence of a diastolic RP; and model 3 was based on age, diastolic RP, and LAVI quartile (Fig 3). Model 1 had a modest level of accuracy (AUC, 0.70; 95% CI, ); model 2 had a considerably increased level of accuracy of the prediction (AUC, 0.85; 95% CI, ). The best accuracy was reached with the inclu- Fig 2. Survival rate according to the quartile distribution of LAVI. (LAVI left atrial volume index.)

5 Ann Thorac Surg CASTELVECCHIO ET AL 2013;95:141 7 LEFT ATRIAL VOLUME AND SURGICAL CARDIAC OUTCOME Fig 3. The receiver operator characteristic curves for separate models. (LAVI left atrial volume index; RP restrictive pattern.) sion of the LAV quartile (model 3), which increased the accuracy of survival prediction at follow-up to an AUC of 0.87 (95% CI, ). Given the additional value of the LAVI, possible cutoff values were investigated by testing the LAVI (continuous variable) as a predictor of mortality at follow-up (regardless of the duration of follow-up). The best cutoff value for LAVI was 50 ml/m 2, which predicted mortality at follow-up with 73% sensitivity and 65% specificity. To address the potential role of LAVI as a determinant of operative mortality, adequate logistic regression models having LAVI and LAVI quartiles as independent variables were explored. Both LA-derived factors were not significantly associated with operative mortality. Comment The major findings of this study include the following: (1) LAVI is almost invariably increased in patients with ischemic HF who are referred for SVR, (2) preoperative LAVI is a powerful indicator of poor outcome after SVR, and (3) LAVI improves the accuracy of survival prediction when added to the other independent determinants of survival at follow-up. 145 Relationship Between LV Remodeling, Systolic HF, and LA Size Myocardial infarction results in a complex of structural changes involving both the infarcted and noninfarcted zones, leading to LV remodeling [15]. Initially, LV volumes increase, a response that is sometimes considered adaptive, in association with stroke volume augmentation in an effort to maintain a normal cardiac output as the ejection fraction declines [16]. However, beyond this early stage, the remodeling process is driven predominantly by eccentric hypertrophy of the noninfarcted remote regions, resulting in increased wall mass, chamber enlargement, and geometric distortion. These changes, along with a decline in performance of hypertrophied myocytes, increased neurohormonal activation, collagen synthesis, fibrosis, and remodeling of the extracellular matrix within the noninfarcted zone, result in a progressive decline in ventricular performance together with changes in diastolic properties of the left ventricle [15]. Scar formation increases chamber stiffness, whereas the compensatory hypertrophy of the remote zone is responsible for delayed relaxation [17]. The resulting increase of filling pressure within the ventricle might be responsible in turn for further LV dilatation. Simultaneously, with increased stiffness or reduced compliance of the left ventricle, LA pressure increases to preserve LV filling. As a result, the Frank-Starling mechanism begins to operate in the left atrium, leading to chamber dilatation and increasing contractility [18]. Our results, in agreement with previous works [2], showed large degrees of atrial enlargement in a population of patients with severe HF who underwent SVR. This finding mainly reflects the severity of LV systolic dysfunction and the long-standing remodeling. A certain degree of MR was frequent, but moderate or severe regurgitation was found in only 32% of the baseline population. This percentage is lower if we consider only the patients included in the follow-up (10 patients who had undergone mitral valve repair experienced operative mortality), making the mitral valve dysfunction less of a determinant in the genesis of LA enlargement. This finding is sustained by the multivariate analysis, which excluded MR from the factors associated with clinical outcome. LAV and Prediction of Outcome The strongest result of our study is the predictive value of LAV in a cohort of patients undergoing SVR. Previous studies that aimed to identify the pathophysiologic determinants of LAV showed that LAV is was determined by the degree of LV dilatation, diastolic dysfunction, and the extent of MR in a large group of patients with systolic HF, LAV being the most powerful prognostic marker of survival independent of any of its determinants [2]. Other studies that included LA size in the survival analysis reported that the diastolic RP had a higher predictive power than did atrial size [19, 20]. Different explanations might account for different results, eg, the patient cohorts are always different from 1 study to another (different prevalence of diastolic RP), or the definition of RP is not the same between different authors (ie, DTE 140 ms or 125 ms or 115 ms, respectively in the previously mentioned studies). We adopted the definition used by Rossi and coworkers [2] and found a higher rate of severe diastolic dysfunction (34% versus 22%, respectively). This observation could explain the stronger association to the outcome of the preoperative diastolic RP in respect to the LAV, although the multivariate analysis showed a predictive significance of both LA enlargement and diastolic RP.

6 146 CASTELVECCHIO ET AL Ann Thorac Surg LEFT ATRIAL VOLUME AND SURGICAL CARDIAC OUTCOME 2013;95:141 7 Of the 3 variables identified by multivariate analysis, age was not related to LAV, excluding any age-related enlargement from the causes of atrial remodeling. Moreover LAV was statistically associated with RP, confirming the role of diastolic dysfunction in determining LA enlargement. The adjunctive prognostic value of LA enlargement was clearly demonstrated by ROC curves applied to different models built with the results of multivariate analysis. Although there was a minor impact with respect to diastolic RP, LAVI conferred an adjunctive prognostic value, reflecting the known pathophysiologic implications. From a clinical point of view, the identification of 50 ml/m 2 as a cutoff able to predict mortality with 73% sensitivity and 65% specificity can improve the selection of patients in whom the greatest survival benefit after SVR can be expected. Additionally, we could not identify LAVI as a predictor of operative mortality. Risk factors for operative mortality were already addressed in a previous study [10], in which LAVI was not considered in the potential factors. The present study suggests that LA dimensions are more reliable as predictors of late rather than early mortality. Diastolic Dysfunction, LAV, and Survival After SVR In fact, the additional benefit of SVR to cardiopulmonary bypass grafting remains debated after the results of the STICH (Surgical Treatment for Ischemic Heart Failure) trial [12]. No difference was reported in the occurrence of the primary outcome between the group undergoing coronary artery bypass grafting and the combined procedure group. As a possible explanation for the lack of benefit expected with SVR, it has been hypothesized that benefits anticipated from surgical LV volume reduction (producing reduced wall stress and improvement in systolic function) are counterbalanced by a reduction in diastolic compliance, leading in turn to a worsening in diastolic function. This hypothesis implies a preserved diastolic function or a diastolic function not severely impaired before SVR, but no prospective data have been published to support such a hypothesis. Data from previous observational studies showed conflicting results, which are difficult to compare because of the well-known limitations (including different populations or different methods to assess diastolic function) and therefore are not yet conclusive [21]. Our group has already shown that diastolic dysfunction occurs in the majority of patients who are suitable for SVR, remaining stable or worsening infrequently after operation, and therefore contrasting with the proposed hypothesis [13]. In our previous studies, we assessed diastolic function only by Doppler measurements, which are load dependent and do not give information about longterm dysfunction [13, 14]. In the present study, we specifically analyzed the LAV as an index of the severity of the underlying chronic disease. Our data outline the strict relationship between diastolic function and atrial enlargement but do not support the role of SVR in precipitating diastolic dysfunction. The evidence of such severe degrees of LA enlargement, and particularly the strong association between the LAVI quartile and the presence of a diastolic RP, is the expression of a clear long-standing presurgical diastolic dysfunction. Furthermore, the additional prognostic value of LAVI provides, for the first time, an important link to long-term prognosis, giving the opportunity to improve the outcome of patients undergoing SVR. Strengths and Weaknesses of the Study This was a retrospective study subject to the biases inherent in this type of study design. Furthermore, LAV measurements after SVR were not reported in the present study. However, the aim of this study was to assess the baseline prognostic value of LAV on the long-term outcome in association with other confounding factors. The strength of the present study is, first, to provide evidence, for the first time, that LAV is a powerful predictor of poor outcome after SVR. Second, we remarked on the relevance of incorporating the LAVI assessment in the evaluation of diastolic dysfunction, which remains a complex matter of difficult assessment. In this regard, old or new techniques, less or more invasive, applied at different time points, suffer from shortcomings when used as an estimate of LV filling pressure bring up the issue of whether such measurements reflect impaired diastolic function or are merely abnormal measurements. Conclusions In patients with chronic HF who are suitable for SVR the evaluation of LAVI may improve the selection of patients in whom the greatest survival benefit after SVR can be expected and thereby optimize the outcome. Future studies are warranted to further understand the postsurgical course of LA remodeling, the extent of reversibility of LA enlargement, if any, and the impact of such changes on the outcome. References 1. Abhayaratna WP, Seward JB, Appleton CP, et al. Left atrial size: physiologic determinants and clinical applications. J Am Coll Cardiol 2006;47: Rossi A, Cicoira M, Zanolla L, et al. Determinants and prognostic value of left atrial volume in patients with dilated cardiomyopathy. J Am Coll Cardiol 2002;40: Dini FL, Cortigiani L, Baldini U, et al. Prognostic value of left atrial enlargement in patients with idiopathic dilated cardiomyopathy and ischemic cardiomyopathy. Am J Cardiol 2002; 89: Moller JE, Hillis GS, Oh JK, et al. Left atrial volume: a powerful predictor of survival after acute myocardial infarction. Circulation 2003;107: Rossi A, Cicoira M, Bonapace S, et al. Left atrial volume provides independent and incremental information compared with exercise tolerance parameters in patients with heart failure and left ventricular systolic dysfunction. Heart 2007;93: Tsang TS, Barnes ME, Gersh BJ, Bailey KR, Seward JB. Left atrial volume as a morphophysiologic expression of left ventricular diastolic dysfunction and relation to cardiovascular risk burden. Am J Cardiol 2002;90: Pritchett AM, Mahoney DW, Jacobsen SJ, et al. Diastolic dysfunction and left atrial volume: a population-based study. J Am Coll Cardiol 2005;45:87 92.

7 Ann Thorac Surg CASTELVECCHIO ET AL 2013;95:141 7 LEFT ATRIAL VOLUME AND SURGICAL CARDIAC OUTCOME 8. Menicanti L, Castelvecchio S. Left ventricular reconstruction concomitant to coronary artery bypass surgery: when and how? Curr Opin Cardiol 2011;26: Athanasuleas CL, Buckberg GD, Stanley AW, et al; RESTORE group. Surgical ventricular restoration in the treatment of congestive heart failure due to post-infarction ventricular dilation. J Am Coll Cardiol 2004;44: Menicanti L, Castelvecchio S, Ranucci M, et al. Surgical therapy for ischemic heart failure: single-center experience with surgical anterior ventricular restoration. J Thorac Cardiovasc Surg 2007;134: Witkowski TG, ten Brinke EA, Delgado V, et al. Surgical ventricular restoration for patients with ischemic heart failure: determinants of two-year survival. Ann Thorac Surg 2011;91: Jones RH, Velazquez EJ, Michler RE, et al; STICH Hypothesis 2 Investigators. Coronary bypass surgery with or without surgical ventricular reconstruction. N Engl J Med 2009; 360: Castelvecchio S, Menicanti L, Ranucci M, Di Donato M. Impact of surgical ventricular restoration on diastolic function: implications of shape and residual ventricular size. Ann Thorac Surg 2008;86: Di Donato M, Menicanti L, Ranucci M, et al. Effects of surgical ventricular reconstruction on diastolic function at midterm follow-up. J Thorac Cardiovasc Surg 2010;140: Konstam MA, Kramer DG, Patel AR, Maron MS, Udelson JE. Left ventricular remodeling in heart failure: current concepts 147 in clinical significance and assessment. JACC Cardiovasc Imaging 2011;4: Cohen MV, Yang XM, Neumann T, Heusch G, Downey JM. Favorable remodelling enhances recovery of regional myocardial function in the weeks after infarction in ischemically preconditioned hearts. Circulation 2000;102: Raya T, Gay R, Lancaster L, Aguirre M, Moffett C, Goldman S. Serial changes in left ventricular relaxation and chamber stiffness after large myocardial infarction in rats. Circulation 1988;77: Braunwald E, Brockenbrough EC, Frahm CJ, Ross J, Jr.Left atrial and left ventricular pressures in subjects without cardiovascular disease: observations in eighteen patients studied by transseptal left heart catheterization. Circulation 1961;24: Giannuzzi P, Temporelli PL, Bosimini E, et al. Independent and incremental prognostic value of Doppler-derived mitral deceleration time of early filling in both symptomatic and asymptomatic patients with left ventricular dysfunction. J Am Coll Cardiol 1996;28: Pinamonti B, Di Lenarda A, Sinagra G, Camerini F. Restrictive left ventricular filling pattern in dilated cardiomyopathy assessed by Doppler echocardiography: clinical, echocardiographic and hemodynamic correlations and prognostic implications. Heart Muscle Disease Study Group. J Am Coll Cardiol 1993;22: Castelvecchio S, Menicanti L, Di Donato M. Surgical ventricular restoration to reverse left ventricular remodeling. Curr Cardiol Rev 2010;6: The Society of Thoracic Surgeons: Forty-Ninth Annual Meeting Mark your calendars for the Forty-Ninth Annual Meeting of The Society of Thoracic Surgeons (STS) to be held at the Los Angeles Convention Center, Los Angeles, California, from January 26 30, Visit Los Angeles to learn from the experts, network with colleagues from around the world, and prepare for whatever your future may hold. This preeminent educational event in cardiothoracic surgery is open to all physicians, residents, fellows, engineers, perfusionists, physician assistants, nurses, or other interested individuals who work with cardiothoracic surgeons. Meeting attendees will be provided with the latest scientific information for practicing cardiothoracic surgeons. Attendees will benefit from traditional Abstract Presentations and Invited Lectures, as well as Surgical Forums, Early Morning Sessions, Surgical Motion Pictures, and Procedural Hands-On Courses. Parallel sessions on Monday and Tuesday will focus on specific subspecialty interests. An advance program with a registration form, hotel reservation information, and details regarding spouse/ guest activities was mailed to STS members this Fall. Nonmembers may contact the Society s Secretary, David A. Fullerton, MD, to receive a copy of the advanced program; however, detailed meeting information will be available on the STS website at David A. Fullerton, MD Secretary The Society of Thoracic Surgeons 633 N Saint Clair St, Ste 2320 Chicago, IL Telephone: (312) Fax: (312) sts@sts.org website: by The Society of Thoracic Surgeons Ann Thorac Surg 2013;95: /$36.00 Published by Elsevier Inc