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Ann Thorac Surg 2007;83:1651-1657
© 2007 The Society of Thoracic Surgeons
Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine and Barnes-Jewish Hospital, St. Louis, Missouri
Accepted for publication September 19, 2006.
* Address correspondence to Dr Damiano, Suite 3108 Queeny Tower, 1 Barnes-Jewish Hospital Plaza, St. Louis, MO 63110 (Email: damianor{at}wustl.edu).
Presented at the Fifty-third Annual Meeting of the Southern Thoracic Surgical Association, Tucson, AZ, Nov 8–11, 2006.
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Abstract |
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Methods: A retrospective review was performed of 245 patients (129 women) with a mean age of 83.6 ± 2.9 years who had AVR with (n = 140) or without CABG (n = 105) at a single institution from 1993 to 2005. Data were analyzed with a multivariate logistic regression for predictors of operative mortality, Kaplan-Meier estimates of survival, and a Cox multivariate proportional analysis of factors influencing long-term survival.
Results: Mean preoperative New York Heart Association (NYHA) classification was 3.1 ± 0.9, and 78% (192/245) of patients were classified as NYHA class III or IV. Operative (30-day) mortality was 9% (22/245). Independent risk factors for operative mortality included postoperative renal failure (odds ratio [OR], 20.9; 95% confidence interval [CI], 6.5 to 67.6; p < 0.001), postoperative permanent stroke (OR, 11.3; 95% CI, 1.7 to 75.1; p = 0.019), or intraoperative/postoperative intraaortic balloon pump (IABP) placement (OR, 14.9; 95% CI 2.9 to 75.8; p = 0.002). Survival after surgery was 82% (n = 183) at 1 year and 56% (n = 88) at 5 years. Prognostic factors for decreased long-term survival were regurgitant valve pathology (hazard ratio [HR], 6.0; 95% CI, 2.5 to 14.2; p = 0.002), intraoperative/postoperative IABP (HR, 2.9; 95% CI, 1.4 to 6.0; p = 0.010), postoperative renal failure (HR, 3.5, 95% CI, 2.2 to 5.7; p < 0.001), and postoperative stroke (HR, 7.0, 95% CI, 3.2 to 15.9; p < 0.001). Performing concomitant CABG was protective in terms of operative mortality (OR, 0.3; 95% CI, 0.09 to 0.83; p = 0.017) and improved long-term survival (HR, 0.7, 95% CI, 0.47 to 0.96; p = 0.020). Preoperative NYHA classification did not affect operative or long-term survival.
Conclusions: Patients aged 80 years and older who undergo AVR have acceptable short-term and long-term survival regardless of NYHA status. Concomitant CABG improved operative and long-term survival in this population. Despite their increased age, aggressive surgical treatment is warranted for most patients.
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Introduction |
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TopAbstractIntroductionMaterial and MethodsResultsCommentDiscussionAcknowledgmentsReferences |
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The decision between continued medical management and surgical intervention for aortic valve disease in elderly patients is becoming increasingly frequent as the population ages. Previous studies have demonstrated increased risk of mortality with the addition of coronary artery bypass grafting (CABG) to the procedure [6, 8]. With these issues in mind, this study examined results of aortic valve replacement with or without CABG in patients aged 80 years and older to determine the risk factors for early and late mortality.
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Material and Methods |
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Members of the Division of Cardiothoracic Surgery, Washington University in St. Louis, performed the surgical procedures at Barnes-Jewish Hospital. Although approaches varied among surgeons, all procedures were done with cardiopulmonary bypass with mild systemic hypothermia (30°C to 34°C). Myocardial protection was achieved with cold blood cardioplegia. The procedures were performed with either a standard or partial median sternotomy. The selection of valve prosthesis type was at the discretion of the operating surgeon. There has been a strong institutional preference for biological valves in this age group regardless of the preoperative presence of atrial fibrillation. CABG was performed for recognized indications.
Statistics
Descriptive statistics were used to describe patient characteristics. Normally distributed continuous data are expressed as mean ± standard deviation throughout. Medians with intraquartile ranges (IQR) are used when continuous data was skewed. Categoric data are expressed as counts and proportions. Unrelated two-group univariate comparisons were performed with paired and independent, two-tailed t tests for means of normally distributed continuous variables and the Wilcoxon rank sum test for skewed data. The 
2 or Fisher exact univariate tests were used to analyze differences in proportions in the categoric data.
The Kaplan-Meier estimate was used to depict survival over time. Survival comparison among groups of patients was completed using the Mantel-Haenszel log-rank test. The 37 potential risk factors for early and late mortality that were examined by univariate testing are detailed in the Appendix.
Factors found to trend towards significance by univariate testing (p 
0.10) were entered into a multivariate analysis. Binary logistic regression analysis of predictor variables for 30-day mortality was performed with estimate odds ratios (ORs) and 95% confidence intervals (CIs) for each of the independent variables in the model displayed. The Cox multivariate proportional hazards regression model was used to identify independent prognostic factors for death in the studied patient population. Hazard ratios (HRs) with 95% CIs were calculated for each of the significant risk factors. All data analysis was performed using SPSS 11.0 (SPSS Inc, Chicago, IL) for Windows (Microsoft Corp, Redmond, WA). All values of p < 0.05 were considered to be statistically significant.
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Results |
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Compared to the population younger than 80 years who underwent AVR or AVR plus CABG at Barnes-Jewish Hospital during the last 10 years, the morbidity rate was significantly higher for renal failure (6%, 27/464, p = 0.008) and atrial fibrillation (32%, 147/464, p < 0.0001), but not for permanent stroke (4%, 20/464, p = 0.55), prolonged ventilation (27%, 124/494, p = 0.72), or reoperation for bleeding (6%, 29/435, p = 0.22).
Operative mortality (death 30 days of surgery) was 12% (11/95), 10% for elective isolated AVR, 6% (7/126) for elective AVR plus CABG, and 16% (4/24) for emergent or urgent AVR with or without concomitant CABG. The 30-day operative mortality was 9% (22/245) for all patients undergoing AVR or AVR with concomitant CABG, in-hospital mortality (death before discharge) was 10% (24/245, Table 4).
Mortality rates were high in some subgroups. Operative mortality for patients younger than 80 years at this institution undergoing AVR or AVR plus CABG during the last 10 years was less than this older population (5%, 23/464, p = 0.051). The mortality rate was 40% (2/5) for immunologically compromised patients, 45% (5/11) for patients who required an intraaortic balloon pump (IABP) intraoperatively or postoperatively, 20% (5/20) for those who had undergone previous cardiac surgery, 41% (12/29) for those who had postoperative renal failure (rise of serum creatinine to 
2.0 g/dL), and 38% (3/8) for those who had a postoperative permanent stroke.
Independent risk factors for 30-day mortality included patients who were in an immunocompromised state (OR, 14.0; 95% CI, 1.7 to 112.3; p = 0.025), had postoperative renal failure (OR, 20.9; 95% CI, 6.5 to 67.6; p < 0.001), postoperative permanent stroke (OR, 11.3; 95% CI, 1.7 to 75.1; p = 0.019), or required an intraoperative/postoperative IABP (OR, 14.9; 95% CI, 2.9 to 75.8; p = 0.002, Table 5). Performing an AVR with concomitant CABG was found to be a protective factor for 30-day mortality (OR, 0.3; 95% CI, 0.08 to .083; p = 0.017) compared with AVR alone. Although patients that underwent urgent or emergent surgery had a higher operative mortality (17%, 4/24) than those undergoing elective procedures (8%, 18/221), the difference did not reach statistical significance (p = 0.13). Operative mortality was not affected by preoperative NYHA status (p = 0.841).
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Comment |
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TopAbstractIntroductionMaterial and MethodsResultsCommentDiscussionAcknowledgmentsReferences |
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Such results can be accomplished at an acceptable operative risk even among patients with advanced symptoms of heart failure. Despite the advanced age and NYHA heart failure status of these patients, mortality rates in the modern era at Barnes-Jewish Hospital were less than 10%. There were slightly higher rates of renal failure and postoperative atrial fibrillation compared with younger patients undergoing the same surgery, but rates of stroke, prolonged ventilation, and reoperation for bleeding were similar.
Some attention has been paid to the prediction of outcome in elderly patients undergoing AVR based on preoperative risk factors. In 1999, Bouma and colleagues [12] analyzed the records of 205 consecutive patients aged 70 years or older with critical aortic stenoses who were treated either medically or surgically. AVR was performed in 94 patients, with a 30-day operative mortality of 2.2%. In these surgically treated patients, a previous CABG moderately impaired renal function (creatinine, 110 to 250 µmol/L), and age 80 years or older, and a history of myocardial infarction were associated with an increased risk of death. The 3-year survival was 80% in the surgical group and 49% in the medical group. These results demonstrated that good operative outcomes can be achieved in the elderly with critical aortic stenosis and confirmed the clear survival advantage of surgical intervention versus medical management alone in this elderly population. This report, however, described a younger group than that reported in our series.
Logeais and colleagues [13] found age 75 years or older, left ventricular failure, lack of sinus rhythm, and emergent status to be presurgical independent predictive factors of mortality, but they failed to determine a specific high-risk group for which aortic valve surgery should be contraindicated. In an analysis of 1400 patients who underwent AVR or AVR and CABG between 1996 and 2001 at the Heart Institute Lahr at Baden/Lahr, Germany [14], age 80 years or older was found to be an independent predictor of operative mortality.
Elderly patients may have an increased mortality strictly attributable to their advanced age; however, the results of this study argue that the increased risk is not prohibitive. The present study did indicate a few high-risk groups in this elderly population with prohibitive operative mortality rates. These included immunocompromised patients and patients with pure regurgitant valve disease. Likewise, long-term results for patients with pure regurgitant valve disease were poor. Although numbers were small in these groups, caution should be exercised before recommending surgery in these patients.
Florath and colleagues [14] reported that NYHA classification was not an independent risk factor for operative mortality for patients aged 80 years and older. This current study also showed no difference in operative or long-term mortality for patients according to preoperative NYHA functional class. Previous studies suggested early intervention may be warranted in this patient population because of this probable increase in risk [15, 16]. The results of the present study, however, demonstrated that patients with advanced heart failure have acceptable 5-year survivals and should be considered for operative intervention.
Postoperative risk factors for poor survival included renal failure and permanent stroke. Both of these complications significantly decreased long-term survival. Although this is not surprising, when these problems occur, their presence can be used to help predict prognosis.
One of the surprising findings in this study was that patients who underwent concomitant CABG fared better both in the perioperative period and in long-term survival. Previous analyses have found that CABG increased mortality in elderly patients who were also undergoing AVR [6, 8]. This contradiction could be explained by the improvement in both surgical and perioperative care that these elderly patients receive since these former studies were conducted. As experience increases in operating on octogenarians, development of improvements in hospital mortality is to be expected. Although the additional procedure adds time to the surgery, the improved short-term and long-term outcome argues that revascularization should be aggressive whenever indicated in this population.
Retrospective studies have inherent limitations. Selection bias in favor of healthier patients by cardiologists and their subsequent referral to surgery could have skewed results toward better outcomes. Controlling for this bias would be difficult, because a large number of surgeons and cardiologists were involved in the care of these patients, and no database exists of those patients who were not offered a surgical intervention or who refused the procedure. Nevertheless, most of these patients were of advanced NYHA functional class and many required CABG or other concomitant procedures, suggesting that this subgroup was not highly selected. Several surgeons were involved during this 12-year period, and this could increase the variability in the data. The large number of surgeons would, however, limit the effect that surgeon-dependant factors might have had on outcomes.
Patients older than 80 years have acceptable early and late outcomes after AVR with and without concomitant CABG. Morbidity was acceptable in this group, and 5-year survival was 56%. Risk factors for early death included immunocompromised state, postoperative renal failure, or stroke, and perioperative need of intraaortic balloon pump. Long-term survival was detrimentally influenced by aortic valve regurgitation, postoperative renal failure and stroke, use of IABP, and was improved by addition of coronary artery revascularization to the procedure.
Patients 80 years and older who undergo AVR had acceptable short-term and long-term survival regardless of NYHA status. Moreover, contrary to previous studies, concomitant CABG improved operative and long-term survival in this patient population. Aggressive surgical treatment of both aortic valve disease and concomitant coronary artery disease is warranted for most patients, despite their increased age.
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Appendix |
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Gender, age, race, previous cardiac surgery, history of tobacco use, coronary artery disease, diabetes, dialysis, hypertension, pulmonary hypertension, cerebrovascular accident, history of transient ischemic attack, history of chronic obstructive pulmonary disease, history of peripheral vascular disease, history of cerebral vascular disease, history of myocardial ischemia, unstable angina, cardiogenic shock, required preoperative resuscitation, arrhythmia, New York Heart Association classification, ejection fraction, aortic valve (AV) peak gradient, AV valve area, aortic value replacement (AVR) size, AVR type, operative priority of either emergent versus elective, chronic renal insufficiency, immunocompromised state, AV pathology, operative category of either lone AVR or AVR with coronary artery bypass grafting, aortic cross-clamp time, cardiopulmonary bypass time, intraoperative/postoperative intra-aortic balloon pump placement, postoperative renal failure, and postoperative permanent cerebrovascular accident.
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Discussion |
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TopAbstractIntroductionMaterial and MethodsResultsCommentDiscussionAcknowledgmentsReferences |
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So this generated three questions. First is your finding that outcomes in the group that got both an aortic valve and a CABG were better than the group that just got an aortic valve alone. As you pointed out, that is somewhat contrary to what one typically finds in the literature, and I was wondering if you might have any insight into why that might be the case?
DR MELBY: Thank you for your kind comments. That is indeed a question that we asked: why would these elderly patients do better with CABG? The obvious answer may be that they are now protected from myocardial ischemia, and that may play a role. Furthermore, over the last decade there has been improvement in surgical technique and in perioperative care and this may have contributed as well to their better outcomes.
DR FULLERTON: The second question relates to attempting to guide clinical practice. Your study nicely points out that if a couple of things happen intraoperatively or postoperatively, they are associated with bad outcomes. Specifically, if somebody requires a balloon pump or if they have a stroke or if they go into renal failure, their outcomes are worse. The only two factors I gleaned from your data that were preoperative indicators that might help stratify the decision-making process were whether or not somebody had isolated aortic regurgitation, which of course was only six patients out of your 190, and the other small number of patients that were immunocompromised preoperatively for one reason or another. I realize that may not be the focus of your manuscript, but do you have any insight as to what you do in the office when you are trying to counsel some 83-year-old person about what the likelihood that they are going to see 90 is before the operation?
DR MELBY: That is a great point. It can be difficult in these patients to preoperatively assess their postoperative outcome. The fact that overall 56% of the patients were alive at five years I think is encouraging. Trying to tease out some of preoperative factors that might indicate prognosis was difficult. We did the analysis on 30 preoperative variables. We were surprised that so few came out in our analysis to have a bad prognosis. So unfortunately we do not have any further factors that can help to predict who will do poorly. Those small groups that did poorly, though, had very high mortalities: the immunocompromised, as you pointed out, and those with pure regurgitant pathology. Also, patients who suffered postoperative stroke or renal failure did poorly.
DR FULLERTON: Finally, our group is interested in the senescent myocardium and some of the factors that change as a function of age. One of the things that caught my eye about your data was that 9% of your patients were characterized as having a low cardiac output state postoperatively and 5% required a balloon pump. That is a little bit unusual for a series of aortic valve replacements, particularly when the vast majority were for aortic stenosis, because typically such people do fairly well from a cardiac function standpoint. Do your results provide any insight into some of the changes in the biology of the elderly myocardium?
DR MELBY: That is a great question. First of all, anyone that required a pre- or intra-operative intra-aortic balloon pump was included in our analysis. It may have seemed that 9% was a large group, but the number is not quite as large as it first appears, as some of those patients came to surgery with an intra-aortic balloon pump. Trying to tease out why some patients required cardiac support postoperatively is intriguing. Unfortunately, in this study we don’t have any data that could help in the understanding of the biology and molecular mechanisms that could explain the myocardial stunning or injury seen in a small number of these patients.
DR FULLERTON: Well, thanks very much. I enjoyed your manuscript.
DR MELBY: Thank you.
DR HORMOZ AZAR (Norfolk, VA): A very nice study, congratulations. I just have one question. Would you please elaborate on your myocardial protection, the details of myocardial protection that you used in this group of patients, and also the core temperature during perfusion? Thank you.
DR MELBY: On some of the technical details of the surgery, maybe it would be better to let our moderator Dr Moon articulate on some of those, as he had experience with some of these patients.
DR MARC MOON (St. Louis, MO): We have had a lot of turnaround at Washington University over the last decade, so there is a lot of different surgeons doing a lot of different things. So I think we can’t really speculate a proper answer to that question. That may take a little more time and a little more consistent approach.
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Acknowledgments |
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TopAbstractIntroductionMaterial and MethodsResultsCommentDiscussionAcknowledgmentsReferences |
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80 years: results from the National Cardiovascular Network J Am Coll Cardiol 2000;35:731.This article has been cited by other articles:
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|
|
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|
|
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|
|
|
|
|
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|
|
|
|
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|
|
|
|
|
|
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|
|
|
|
 |
|
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|
|
|
|
|
|
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|
|
 |
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