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Ann Thorac Surg 2005;80:112-117
© 2005 The Society of Thoracic Surgeons

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Original article: Cardiovascular

Impact of Complete Revascularization on Long-Term Survival After Coronary Artery Bypass Grafting in Octogenarians

Division of Cardiothoracic Surgery, Washington University School of Medicine, St. Louis, Missouri

Accepted for publication February 3, 2005.

^_* Address reprint requests to Dr Moon, Division of Cardiothoracic Surgery, Washington University School of Medicine, 3108 Queeny Tower, 1 Barnes-Jewish Plaza, St. Louis, MO 63110-1013 (Email: moonm{at}msnotes.wustl.edu).

Presented at the Fifty-first Annual Meeting of the Southern Thoracic Surgical Association, Cancun, Mexico, Nov 2–4, 2004.

	Abstract

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BACKGROUND: Complete revascularization is important in young patients undergoing coronary artery bypass grafting, but this principle remains less absolute in elderly patients. The purpose of this study was to determine how complete revascularization influenced long-term survival after coronary artery bypass grafting in octogenarians.

METHODS: From 1986 to 2003, 500 consecutive patients 80 to 94 years of age underwent coronary artery bypass grafting. Complete revascularization was defined as placement of at least one graft to each of the three major vascular regions that included a 50% diameter lesion. Revascularization was complete in 400 (80%) patients and incomplete in 100 (20%) patients. Mean (± standard deviation) follow-up was 51 ± 41 months and was 99% complete (2,102 total patient-years).

RESULTS: Operative mortality was 8% ± 2% (±95% confidence interval) and was statistically lower with complete (7% ± 3%) versus incomplete (13% ± 7%) revascularization (p < 0.05). Of 459 operative survivors, there were 261 late deaths. Multivariate regression analysis identified six independent predictors of late death: earlier operative year, male sex, peripheral or cerebrovascular disease, congestive heart failure, and incomplete revascularization (p < 0.03 for all). Excluding operative deaths, mean survival (Kaplan-Meier) was 82 months with complete revascularization compared with 65 months with incomplete revascularization (p < 0.008). Survival was 62% ± 3% with complete versus 45% ± 6% with incomplete revascularization at 5 years and 39% ± 3% with complete versus 25% ± 6% with incomplete revascularization at 8 years (p < 0.008).

CONCLUSIONS: In octogenarians undergoing coronary artery bypass grafting, complete revascularization correlated with improved long-term survival, increasing mean survival by almost 25% compared with incomplete revascularization.

	Introduction

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Coronary artery disease is a leading cause of morbidity and mortality in the elderly. Almost 30% of octogenarians have symptomatic coronary artery disease, and these patients are increasingly referred for coronary artery bypass grafting (CABG) [1, 2]. Recent reports suggest that older patients with ischemic heart disease are best served by aggressive revascularization to relieve symptoms and improve quality of life [3, 4]. Unfortunately, the majority of outcome studies on elderly patients undergoing CABG report more adverse outcomes and less successful revascularization compared with younger patients [5, 6].

Complete revascularization is an important goal of CABG. The natural history of coronary artery disease suggests that once a stenosis exists, progression of the disease is likely. Importantly, complete revascularization has been shown to improve long-term survival and function after CABG in young patients [7–9]. However, the majority of studies excluded older patients because they are at higher risk during CABG and may be less likely to obtain this benefit owing to their advanced age. Thus, the principle of complete revascularization remains less absolute in elderly patients, specifically in octogenarians, in whom limited life expectancy may minimize the potential benefits of this well-accepted but more aggressive operative strategy. In a previous report from our unit, 358 octogenarians were reviewed after CABG with a mean follow-up of 55 ± 38 months [10]. In that study, although use of the internal mammary artery (IMA) was associated with improved midterm survival, up to 6 years after CABG, complete revascularization did not have a significant impact on midterm survival in these elderly patients. It was speculated that limited follow-up in the elderly population may have minimized the potential benefits of complete revascularization previously demonstrated in younger subsets of patients. Therefore, the purpose of the current investigation was to evaluate the impact of complete versus incomplete revascularization on long-term survival after CABG in octogenarians.

	Material and Methods

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From January 1986 to May 2003, 500 consecutive patients 80 years of age or older underwent isolated, first-time CABG procedures at Washington University Medical Center (Barnes-Jewish Hospital) by 18 different surgeons. There were 260 (52%) men and 240 (48%) women, with a mean age (± one standard deviation) of 83 ± 3 years (range, 80 to 94 years). Twenty-two (4%) patients had one-vessel disease, 124 (29%) patients had two-vessel disease, and 354 (71%) patients had three-vessel disease. As previously defined, complete revascularization was accomplished when at least one graft was placed to each of the three major vascular regions distal to a 50% diameter narrowing, if one existed [7–10]. It was not considered necessary to bypass all obstructed marginal branches of the circumflex coronary artery or diagonal branches of the left anterior descending coronary artery for revascularization to be considered complete. Revascularization was complete in 400 (80%) patients and incomplete in 100 (20%) patients. Revascularization was incomplete in 19% of patients with two-vessel disease and 22% of patients with three-vessel disease. Operative year did not influence completeness of revascularization (p = 0.11). Selected preoperative and intraoperative clinical patient characteristics are listed in Table 1. The number of vessels bypassed (p < 0.001), cross-clamp time (p < 0.02), and cardiopulmonary bypass time (p < 0.005) were all lower with incomplete revascularization, and there was a tendency for an increased incidence of diabetes mellitus (p = 0.08), peripheral vascular disease (p = 0.09), and 3 or 4+ mitral regurgitation (p = 0.07). Off-pump CABG was performed in 37 patients.

For survival comparisons, the complete revascularization group was further separated into total and subtotal revascularization. Total revascularization was defined as grafting to all diseased diagonal and obtuse marginal branches as well as both the posterior descending and posterolateral branches of the right coronary artery when multiple lesions were present. Subtotal revascularization was defined as complete but not total revascularization. Revascularization was total in 244 (49%) patients, subtotal in 156 (31%), and incomplete in 100 (20%) patients.

Patients were contacted for follow-up by mail or telephone during a 3-month closing interval ending September 2003. Cumulative long-term follow-up totaled 2,102 patient-years and was 99% complete (7 patients were lost to follow-up). Mean follow-up was 51 ± 41 months. Follow-up data included present functional status, general health perception, and current symptoms.

Operative mortality included any death that occurred during the initial hospitalization or within 30 days of operation for discharged patients. Long-term survival data included death from all causes. Continuous data are reported as mean ± one standard deviation and were compared between groups using Student’s t test or analysis of variance as appropriate. Clinically important ratios are reported with 95% confidence limits. Actuarial survival estimates were calculated using the Kaplan-Meier method and were compared using the log-rank test. Variability of the actuarial estimates is expressed as ± one standard error of the mean. Univariate analysis (² test) and multivariate stepwise regression analysis were used to determine the preoperative and intraoperative risk factors that were significant, independent predictors of operative mortality and late death (SigmaStat 2.03, SPSS Inc, Chicago, IL). Odds ratios (OR) are reported with 95% confidence intervals (CI). Twenty-three variables were analyzed: age, year of operation, sex, hypertension, diabetes, pulmonary disease, cerebrovascular disease, peripheral vascular disease, chronic renal insufficiency, recent myocardial infarction ([MI] less than 2 weeks), remote MI (more than 2 weeks), angina (absent, stable, unstable), congestive heart failure, ejection fraction, status (urgent, elective), left main disease (greater than 50% stenosis), mitral regurgitation (3 to 4+), use of the IMA, total vessels bypassed, on-pump versus off-pump, preoperative intraaortic balloon pump, extent of disease (single-vessel, double-vessel, triple-vessel), and incomplete versus complete revascularization.

	Results

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Operative mortality rate was 8% ± 2% overall (41 of 500 patients): 5% ± 2% (16 of 348 patients) for elective CABG and 16% ± 6% (25 of 152 patients) for urgent or emergent CABG (p < 0.001). The causes of operative death were cardiac (n = 27), pulmonary (n = 11), and stroke (n = 3). Multivariate regression analysis identified two factors to be independent predictors of operative mortality: (1) urgent or emergency operation (p < 0.001; OR = 4.1 [95% CI, 2.1 to 7.9]) and (2) increased age (p = 0.03). Operative mortality tended to be higher with incomplete (13% ± 7%) versus complete (7% ± 3%) revascularization, but the difference did not reach statistical significance (p = 0.08). There were no differences in the incidence of postoperative complications in the complete and incomplete revascularization groups (Table 2).

View larger version (15K): [in this window] [in a new window]   Fig 1. Long-term survival estimates for octogenarians after isolated, first-time coronary artery bypass grafting for all patients (including operative deaths) and for operative survivors. The numbers of patients at risk at 1, 5, 8, and 10 years are indicated.

View larger version (16K): [in this window] [in a new window]   Fig 2. Long-term survival estimates for octogenarians undergoing coronary artery bypass grafting with complete versus incomplete revascularization (excluding operative deaths). The numbers of patients at risk at 1, 5, and 8 years are indicated.

View larger version (15K): [in this window] [in a new window]   Fig 3. Long-term survival estimates for octogenarians undergoing coronary artery bypass grafting with complete versus incomplete revascularization, excluding patients who did not have at least 12 months follow-up. The numbers of patients at risk at 5 and 8 years are indicated.

View larger version (16K): [in this window] [in a new window]   Fig 4. Long-term survival estimates for octogenarians undergoing coronary artery bypass grafting with total, subtotal, and incomplete revascularization (excluding operative deaths). The numbers of patients at risk at 5 and 8 years are indicated for total (top), subtotal (middle), and incomplete (bottom) revascularization.

	Comment

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In the present study, complete revascularization improved long-term survival after CABG in octogenarians. Survival 8 years after CABG was 39% ± 3% with complete revascularization compared with 25% ± 6% with incomplete revascularization (p = 0.008; Fig 2). This important finding contradicts the theory that elderly patients will not live long enough to benefit from complete revascularization. Unfortunately, this retrospective review does not identify why incomplete revascularization impacts survival. It is possible that incomplete revascularization may be a marker of more severe coronary artery disease that is not amenable to grafting owing to diffusely diseased small vessels, calcification, and infracted myocardium distal to the vessel. These three causes account for 84% of the incomplete revascularization group in this series. However, the significant improvement in survival and the excellent quality of life of octogenarians after complete revascularization strongly suggest that every reasonable effort should be made to place at least one graft into any of the three major vascular regions with a significant stenosis.

The current study was subject to all the limitations inherent to a nonrandomized, nonblinded study, including potential selection bias as to which patients underwent complete versus incomplete revascularization. Multivariate analysis was used in an attempt to account for selection bias, but such biases are impossible to eliminate when patient analysis is retrospective. Furthermore, survival analysis comparisons between complete and incomplete revascularization were performed comparing only patients who survived greater than 1 year in an attempt to exclude most of the patients who underwent a "lesser procedure" because they were deemed high risk.

In a previous report from our unit, use of the IMA during CABG in octogenarians was associated with diminished operative mortality and improved late survival [10]. In that report, the IMA was used in only 65% of patients (231 of 358 patients). Since that time, IMA use has been substantially more liberal. During the last 4 years, the IMA was used in 87% of patients (124 of 142 patients), including 97% of elective and 78% of urgent or emergent cases. Thus, selection bias toward using veins only in sicker patients may have contributed to the findings of improved survival with IMA use in that previous report. However, Ferguson and colleagues [14] demonstrated similar results with almost 100,000 patients, aged 75 years or older, from The Society of Thoracic Surgeons National Cardiac Database. In that study, 77% of elderly patients received an IMA graft and it reduced operative mortality from 6% to 4% (p < 0.0001).

In summary, the current report demonstrated that octogenarians undergoing complete revascularization had better long-term survival than those undergoing incomplete revascularization. Mean survival with complete revascularization was nearly 25% higher than with incomplete revascularization. Therefore, elderly patients can expect a significant survival advantage with complete revascularization without increased morbidity and should not be left with ischemic regions after CABG.

	Discussion

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DR JOSEPH CRAVER (Atlanta, GA): I enjoyed it very much. It is a nicely presented article. I would ask the author to help define complete revascularization, because I see this as "regionally complete" as opposed to "complete." How do you differentiate the two? I would wonder if you had three groups here, would the complete patient cohort have the same result as a "regionally" complete cohort?

DR MOON: In retrospect it is very difficult to determine the difference between regional and a total complete revascularization. We defined complete revascularization as most previous studies have done, looking at the three major vascular regions. Whether or not all the diseased branches were bypassed, including all diagonals and obtuse marginals, was not considered in determining complete revascularization. Certainly that could be evaluated, but again, there is debate whether total revascularization is necessary for long-term survival, even in young patients, although it may be more beneficial for elimination of angina.

DR CRAVER: I think you are differentiating yourself from the traditional idea of what complete revascularization means, and as many of us know, in older patients frequently you will have six or so that are big: three big marginals, a big diagonal left anterior descending coronary artery, and a right. So you have to decide in teaching your residents where you start and where you stop. That was one thought. Your title is a bit misleading with regard to that, and I think "regionally complete" would be a good idea for the title.

Secondly, in discussing the longevity rates, perhaps looking at it like the cancer boys do, at 3-year intervals rather than 5-year intervals, would be helpful in this population over 80, because they just don’t live that long. I noted that you did that as you moved toward the tenth year, but not in the first 5 years when the dropout was statistically significant. My thought is that the regionally complete and the actually complete would probably overlap, and then there would be some differentiation if regions were left ungrafted.

Last question. Of the ones that were incomplete, were they incomplete because there was no graftable vessel in that region or because you elected to cut the operation short?

DR MOON: Thank you, Doctor Craver, for your comments. We did the survival analysis year by year. Looking at the first 2 years, there was no difference in survival between complete and incomplete revascularization, and that is consistent with what the studies from Emory and the Cleveland Clinic showed in younger patients, that the survival curves did not start to diverge until the sixth to eighth year.

As far as the last question, it is difficult, in retrospect, to look at the reasons for incomplete revascularization based on the operative reports alone. In many cases, it is difficult to know whether the surgeons were performing a "get in, and get out" type of procedure or whether the vessels were no good. The fact that the incomplete revascularization group had a higher incidence of diabetes mellitus and peripheral vascular disease probably suggests that there was some dependence on vessel quality.

DR ROBERT POSTON (Baltimore, MD): Mark, I congratulate you for persistence in sticking with this topic of incomplete revascularization over the years. It obviously has great impact on how we manage elderly patients, particularly when we start thinking about the appropriate application of minimally invasive or off-pump surgery to these patients.

My main concern with your data is about selection bias: patients with incomplete revascularization were likely sicker to begin with, which may be the most important reason they had a worse outcome. This could be in part rebutted by your data if you were able to demonstrate a "dose-response effect" of revascularization, or, in other words, show that anatomically complete revascularization led to better outcome than regionally complete revascularization.

A second point of concern is that vein graft attrition after coronary artery bypass grafting has never been shown to correlate with patient survival. It would be interesting to see if your subjects diagnosed with graft failure, particularly those with low ejection fraction or diabetes, showed a difference in survival. Along with a dose-response effect, demonstrating the influence of "withdrawal of therapy" would provide convincing evidence that there is something other than just a selection effect in your data.

DR MOON: It is obviously impossible, as you know, to perform a prospective study looking at completeness of revascularization unless we decide ahead of time that in some patients we are not going to bypass the region, which would not be ethically sound. In retrospect, when we looked at our series a few years back with 358 patients, we could not identify a significant difference in survival with complete revascularization, but now at 500 patients with a little bit longer follow-up, we did statistically find a difference in the complete revascularization group. Teasing out diabetes mellitus and peripheral vascular disease will probably take a few more years of data collection and analysis.

DR VINOD H. THOURANI (Atlanta, GA): I have two quick questions and comments for you. Number one, I think a propensity analysis may be able to delineate some of these selection biases that the last two speakers have discussed and I would like to know if you are planning on doing that?

And number two is, off-pump may be of particular importance in the elderly population. From your database, were you able to tease out the results in this patient subgroup with regards to on-pump versus off-pump? If so, can you give us an idea in these elderly patients whether off-pump would be more beneficial?

That was an excellent presentation. Thank you very much.

DR MOON: As far as on-pump versus off-pump goes, very few of these patients (n = 37) had off-pump surgery, so we could not really analyze that group statistically. I think it will take a number of more years to be able to tease out all the various factors that may play a role in determining survival, and obviously selection bias will always play a role. That is why we tried to eliminate the patients who we thought could be predicted to be sicker by repeating the analysis for the subgroup of patients who survived greater than 12 months postoperatively. Otherwise, a propensity analysis could be done, although we did not perform one for this study.

DR DANIEL L. MILLER (Atlanta, GA): What percentage of those patients was greater than 90 years old, and then, how old is too old for Barnes? I know your oldest was 94.

DR MOON: I operated on an 98-year-old lady a couple of months ago for aortic stenosis, a disease process for which there is probably no age limit, as you can make those patients instantly better if things go well. On the other hand, although we can decrease symptoms and improve longevity with coronary artery bypass grafting, there are other, less-invasive options, stenting and whatnot for patients with limited life expectancy. If we could do a stent to a left anterior descending coronary artery and leave the other vessels alone in a frail, elderly patient and prolong their life by 6 months or a year, maybe that is the way to go, but I think it depends on the eyeball test. When you walk into the room and see the patient, your assessment oftentimes is better than any functional study that we can do. As to how many were older than 90, approximately 2%; not very many.

	Acknowledgments

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The authors gratefully acknowledge the clinical contributions of Charles B. Huddleston, MD, William A. Gay, Jr, MD, James L. Cox, MD, Thomas B. Ferguson, Sr, MD, Thoralf M. Sundt III, MD, Michael Rosenbloom, MD, Thomas L. Spray, MD, T. Bruce Ferguson, Jr, MD, R. Morton Bolman, MD, Scott H. Johnson, MD, Eric N. Mendeloff, MD, and Clarence S. Weldon, MD.

	References

Top Abstract Introduction Material and Methods Results Comment Discussion Acknowledgments References

 

1. Lucas JW, Schiller JS, Benson V. Summary health statistics for U.S. adultsNational Health Interview Survey, 2001. Vital Health Stat 10 2004;218:1-134.[Medline]
2. Peterson ED, Jollis JG, Bebchuk JD, et al. Changing mortality following myocardial revascularization in the elderlythe National Medicare Experience. Ann Intern Med 1994;121:919-927.[Abstract/Free Full Text]
3. Graham MM, Ghali WA, Faris PD, et al. Survival after coronary revascularization in the elderly Circulation 2002;105:2378-2384.[Abstract/Free Full Text]
4. TIME Investigators Trial of invasive versus medical therapy in elderly patients with chronic symptomatic coronary artery disease (TIME)a randomized trial. Lancet 2001;358:951-957.[Medline]
5. Weintraub WS, Craver JM, Cohen CL, et al. Influence of age on results of coronary artery surgery Circulation 1991;84(Suppl 3):226-235.
6. Mohan R, Amsel BJ, Walter PJ. Coronary artery bypass grafting in the elderlya review of studies on patients older than 64, 69 or 74 years. Cardiology 1992;80:215-225.[Medline]
7. Bell MR, Gersh BJ, Schaff HV, et al. Effect of completeness of revascularization on long-term outcome of patients with three-vessel disease undergoing coronary artery bypass surgery. A report from the Coronary Artery Surgery Study (CASS) registry Circulation 1992;86:446-457.[Abstract/Free Full Text]
8. Jones EL, Weintraub WS. The importance of completeness of revascularization during long-term follow-up after coronary artery operations J Thorac Cardiovasc Surg 1996;112:227-237.[Abstract/Free Full Text]
9. Scott R, Blackstone EH, McCarthy PM, et al. Isolated bypass grafting of the left internal thoracic artery to the left anterior descending coronary artery. Late consequences of incomplete revascularization J Thorac Cardiovasc Surg 2000;120:173-184.[Abstract/Free Full Text]
10. Moon MR, Sundt TM, Pasque MK, et al. Influence of internal mammary artery bypass grafting and completeness of revascularization on long-term outcome in octogenarians Ann Thorac Surg 2001;72:2003-2007.[Abstract/Free Full Text]
11. Alexander KP, Anstrom KJ, Muhlbaier LH, et al. Outcomes of cardiac surgery in patients age 80 yearsresults the National Cardiovascular Network. J Am Coll Cardiol 2000;35:731-738.[Abstract/Free Full Text]
12. Data analyses of the STS National Cardiac Surgery Database (the eighth year, January 1999). The Society of Thoracic Surgeons. Available at: http://www.sts.org..
13. Osswald BR, Blackstone EH, Tochtermann U, et al. Does the completeness of revascularization affect early survival after coronary artery bypass grafting in elderly patients? Eur J Cardiothorac Surg 2001;20:120-126.[Abstract/Free Full Text]
14. Ferguson TB, Coombs LP, Peterson ED. Internal thoracic artery grafting in the elderly patient undergoing coronary artery bypass graftingroom for process improvement?. J Thorac Cardiovasc Surg 2002;123:869-880.[Abstract/Free Full Text]

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This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Benjamin D. Kozower Marc R. Moon Hendrick B. Barner Nader Moazami Jennifer S. Lawton Michael K. Pasque Ralph J. Damiano, Jr Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kozower, B. D. Articles by Damiano, R. J. Search for Related Content PubMed PubMed Citation Articles by Kozower, B. D. Articles by Damiano, R. J., Jr Related Collections Coronary disease