| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
J Thorac Cardiovasc Surg 2004;127:179-184
© 2004 The American Association for Thoracic Surgery
Surgery for acquired cardiovascular disease |
a Division of Cardiac Surgery, University of Brescia Medical School, Brescia, Italy
b Division of Cardiology, University of Brescia Medical School, Brescia, Italy
c Division of Cardiothoracic Surgery, Columbia University, Presbyterian Medical Center, New York, NY, USA
Read at the Eighty-third Annual Meeting of The American Association for Thoracic Surgery, Boston, Mass, May 4-7, 2003.
Received for publication May 2, 2003; revisions received August 6, 2003; accepted for publication August 11, 2003.
* Address for reprints: Claudio Muneretto, MD, UDA Cardiochirurgia-Spedali Civili, P.le Spedali Civili, 1, 25123 Brescia, Italy
munerett{at}master.cci.unibs.it
 |
Abstract |
|---|
 Top Abstract MethodsDiscussionConclusionReferences |
|---|
METHODS: We prospectively enrolled 160 patients aged more than 70 years scheduled to undergo isolated myocardial revascularization. Patients were assigned at random to group 1, 80 patients undergoing total arterial revascularization (left internal thoracic artery on left anterior descending coronary artery plus radial artery), or group 2, 80 patients undergoing standard coronary artery bypass graft surgery (left internal thoracic artery on left anterior descending coronary artery plus saphenous veins). The radial artery was used in all cases as a composite Y-graft.
RESULTS: Preoperative characteristics and risk factors (EuroSCORE: group 1 = 7.9 vs group 2 = 8.1), number of grafted coronary vessels (group 1 = 2.4 vs group 2 = 2.5), aortic crossclamping time (group 1 = 37 ± 7 minutes vs group 2 = 38 ± 7 minutes), ventilation time (group 1 = 22 ± 12 hours vs group 2 = 23 ± 11 hours), intensive care unit stay (group 1 = 39 ± 10 hours vs group 2 = 40 ± 9 hours), and hospital mortality (group 1 = 3.8% vs group 2 = 5%) were comparable between the groups. Comparison between the 2 groups in terms of early postoperative complications showed a higher incidence of cerebrovascular accidents in group 2 (group 1 = 0 patients vs group 2 = 4 patients, 5%). At a mean follow-up of 16 ± 3 months, patients in group 1 showed superior clinical results with a lower incidence of graft occlusion (group 1 = 2 vs group 2 = 11; P = .06) and angina recurrence (group 1 = 2 patients vs group 2 = 12 patients; P = .03). Multivariate analysis identified saphenous vein grafts as independent predictors for graft occlusion and angina recurrence.
CONCLUSIONS: Left internal thoracic artery-radial artery composite grafts proved to be a safe procedure in elderly patients. It improved the clinical outcome, providing a significantly higher graft patency rate and a lower incidence of late cardiac events.
The use of the radial artery (RA) is progressively gaining popularity after its revival by Acar and colleagues and the favorable reports of several centers7-9 describing its use as a composite Y/T-graft with the left internal thoracic artery (LITA). We therefore prospectively evaluated the clinical outcome of elderly patients undergoing total arterial revascularization with composite LITA-RA grafts compared with conventional CABG surgery.
|
Methods |
|---|
|
TopAbstractMethodsDiscussionConclusionReferences |
|---|
Exclusion criteria for enrollment included age less than 70 years of age, single-vessel disease, emergency operations, concomitant procedures other than coronary surgery, LV ejection fraction less than 20%, Euroscore greater than 10, and the presence of a positive Allen's test. The institutional review board approved the study protocol.
Patients undergoing RA harvesting were assessed with respect to their nondominant hand circulation by means of the Allen's test and oximetric plethysmography.
Surgical strategy
Radial artery Y/T end-to-side anastomosis was performed on the fascial side of the LITA with an 8-0 polypropylene running suture before cardiopulmonary bypass institution. We previously described our technique for the arrangement of composite arterial grafts according to target stenosis and coronary vessels anatomy.10 In particular, in this subset of patients, we used only configuration types 2 and 3. In configuration type 2, the RA was anastomosed end-to-side to the in situ LITA in a Y/T-graft fashion, whereas in configuration type 3, the RA was first divided into 2 segments and then anastomosed end-to-side on the LITA in a double Y-graft fashion. The RA and the SVGs were routinely used to bypass native coronary vessels with a target stenosis of at least 70%, whereas a coronary artery stenosis of 60% was considered to be the threshold value when using the LITA.
Two surgeons performed all of the operations in the present study and were equally represented in both the SVG and LITA-RA groups.
Postoperative medications
In patients scheduled to receive the RA grafts, oral diltiazem was given the day before operation at a dose of 60 mg every 8 hours. Intravenous diltiazem infusion (mean dose: 0.5-1.5 µg · kg · min) was administered throughout the operation and during the first 48 hours after surgery. Thereafter, diltiazem oral therapy (
120 mg/day) was continued for at least 6 months.
Follow-up
Follow-up visits were performed at 1, 6, and 12 months. Additional clinical data were collected from patients' cardiologists and home physicians. We evaluated the outcome of the patients enrolled in the present study with respect to early postoperative complications (short-term), hospital mortality, and occurrence of late cardiac-related events (recurrence of angina/myocardial infarction, graft occlusion, need of percutaneous transluminal coronary angioplasty [PTCA] reintervention, and death). At angiography, graft patency was defined according to Fitzgibbon classification, that is, grade A (unimpaired graft run-off), grade B (reduced graft caliber <50% of the grafted coronary artery), and grade C (occluded graft).
Statistical analysis
The 
2 test was used to analyze preoperative and postoperative discrete variables, and the unpaired t test or the Mann-Whitney test was used for continuous variables (expressed as mean ± SD). Multivariate analysis was performed using the Cox regression model for angina recurrence (time-dependent variable), and multivariate stepwise logistic regression was used for graft occlusion (time-independent variable). Survival curves were calculated with the Kaplan-Meier method. SPSS software was used for statistical analysis (SPSS 11.5, SPSS Inc, Chicago, Ill).
Preoperative and perioperative data
There were no significant differences between the groups in the preoperative variables, such as age (group 1: 77.3 ± 3 years vs group 2: 76.8 ± 2 years, P = .217), female gender (group 1: 43.7% vs group 2: 46.2%, P = .874), and preoperative risk factors (EuroSCORE: group 1 = 7.9 ± 2.1 vs group 2: 8.1 ± 2.5, P = .585); in particular, the prevalence of diabetes was 48.7% and 45% in groups 1 and 2, respectively. Five patients initially randomized in group 1 were excluded from the study because of a positive Allen test (3 patients) and significant atherosclerotic lesions of the RA (2 patients). However, a minimal atherosclerotic wall involvement of the RA did not jeopardize its use.
Double-vessel disease was observed in 36 patients (45%) in group 1 and in 38 patients (47.5%) in group 2 (P = .87), and triple-vessel disease was found in 39 patients (48.7%) in group 1 and in 37 patients (46.2%) in group 2 (P = .87). Moreover, 5 patients (6.2%) in groups 1 and 2 had left main stem stenosis (P = .74). Patients in both groups demonstrated a similar distribution of target coronary vessels (group 1: LITA-LAD = 80, RA-diagonal = 12, RA-circumflex = 57, RA-right coronary artery = 43 vs group 2: LITA-LAD = 80, SVG-diagonal = 14, SVG-circumflex = 62, SVG-right coronary artery = 44) and received a similar number of graft anastomoses (mean number of anastomoses in group 1: 2.4 ± 0.5 vs group 2: 2.5 ± 0.2, P = .408). The LITAs and the SVGs were used as single grafts in the majority of cases (LITA: 80/80 anastomoses, 100%; SVG: 196/200 anastomoses, 98%), whereas the RA was more extensively used for sequential anastomoses (32/192 anastomoses, 16.6%). Table 1 illustrates additional intraoperative and perioperative data.
|
Hospital mortality was similar in the 2 groups (Table 1). A total of 3 patients in each group died of sepsis and multiorgan failure, and 1 patient in group 2 died of intractable arrhythmia.
Follow-up
We evaluated 76 patients (98%) in group 1 and 76 patients (100%) in group 2 by means of clinical visits and cycloergometric tests.
Recurrence of angina (defined as chest pain of Canadian Cardiovascular Society class II or higher) was detected in 2 patients in group 1 and 10 patients in group 2 (P = .03), new onset of myocardial infarction (defined as an abnormal increase in cardiac-specific enzyme values, eg, CK-MB and troponin I) occurred in 1 patient in group 1 and 7 patients in group 2 (P = .06), need of PTCA reintervention was observed only in patients receiving SVGs (group 1: 0 patients vs group 2: 8 patients, P = .01), and late mortality was similar between the 2 groups (group 1 = 2 patients vs group 2 = 3 patients; P = .98).
Angiographic evaluation was performed in 89.6% and 88.1% of hospital survivors in groups 1 and 2, respectively, after a mean period of 16 ± 3 months. Table 2 provides a detailed outline of target coronary artery vessels, depicting a similar distribution between the groups. Angiography demonstrated a graft patency rate of 100% and 98.5% for the LITA in groups 1 and 2 (Fitzgibbon grade A), respectively. RA grade A patency rates (98.6%) were significantly higher (P = .033) when compared with SVG grade A patency rates (88.5%). Therefore, 1 RA and 11 SVGs were classified as Fitzgibbon grade C.
|
|
|
Discussion |
|---|
|
TopAbstractMethodsDiscussionConclusionReferences |
|---|
However, despite recent studies demonstrating the beneficial effects of total arterial grafting in the younger population,10,11 most surgeons still consider SVGs as the conduits of choice for myocardial revascularization in elderly patients. This is because of the belief that arterial grafting in elderly patients may be associated with a higher perioperative morbidity and mortality when compared with younger patients.4
Because both advanced age and the presence of several comorbidities12 may significantly affect the quality of the saphenous vein conduit and the degree of native coronary vessel disease, we evaluated in a prospective and randomized study the impact of total arterial revascularization with composite LITA-RA grafts in elderly patients. As outlined in the Methods section, we adopted only a few exclusion criteria to minimize the disproportionate distribution of high-risk patients into 1 particular group, the impact of selection bias and the effect of randomization.
In our study, patients receiving total arterial revascularization LITA-RA composite grafts did not show any increase in terms of perioperative morbidity and mortality when compared with the conventional group, demonstrating that total arterial grafting can be safely performed in elderly patients; conversely, the postoperative incidence of leg wound infections (because of an impaired healing process in this subset of patients) and cerebrovascular accidents was considerably higher in patients receiving SVGs. These results highlight the importance of reducing the degree of ascending aortic manipulation in this high-risk group of patients. Even if the differences did not reach a significant value, it should be noted that all the cerebrovascular accidents occurred in group 2. We therefore foresee that this difference would become significant in a larger cohort of patients.
Moreover, the major advantages of total arterial revascularization were particularly evident at mid-term: Sixteen months postoperatively, patients with LITA-RA composite grafts showed a significantly better clinical outcome with a lower incidence of angina and myocardial infarction recurrence (angina: group 1 = 2 patients vs group 2 = 10 patients, P = .03; myocardial infarction: group 1 = 1 patient vs group 2 = 7 patients, P = .06). In addition, no patient in group 1 needed coronary reintervention, whereas 8 patients in group 2 underwent PTCA (P = .01).
Angiographic evaluation confirmed the clinical results, demonstrating significantly higher graft patency rates of the RA when compared with saphenous veins, regardless of the target coronary arteries.
Multivariate analysis identified SVGs, diabetes, and hyperlipidemia as independent predictors for angina recurrence and graft occlusion. In the Cox regression model, patients receiving SVGs demonstrated a higher risk of developing angina recurrence (hazard ratio of 2.3). As a consequence, the actuarial event-free survival was significantly better in patients receiving LITA-RA composite grafts (Figure 2).
|
|
Conclusion |
|---|
|
TopAbstractMethodsDiscussionConclusionReferences |
|---|
Discussion
Dr Brian F. Buxton (Heidelberg, Australia). Dr Muneretto, thank you for your excellent presentation this morning. I congratulate you and your colleagues on undertaking this prospective randomized trial in such an elderly group of patients.
There are a few exclusions in your entry criteria; therefore, the results are widely applicable and of interest to most adult cardiac surgeons. It should be emphasized, however, that the follow-up, defined as mid-term, is only 16 months. The surgical mortality and morbidity are low in both groups, indicating a very high quality of surgery.
A major strength of this article is the very high proportion of angiograms performed in both groups. If we focus on the secondary graft patency (non-LITA), there were 1 of 75 radial failures compared with 11 of 100 SVG failures. This is a very large difference, as you indicated, in your study. It raises, in my mind, 2 questions.
I noted in your article that the preparation of the RA grafts was performed very carefully using calcium channel blockers, and that this was continued into the postoperative period. I am wondering whether the SVGs were afforded the same level of protection as the RA grafts because this may be a factor?
Second, were the trial surgeons equally distributed between the 2 types of surgical groups? For instance, did the senior surgeons or the more experienced surgeons perform the operations in the RA composite graft group and the less-trained surgeons perform the operations in the opposite group? The reason for raising these issues is that our own RA patency and clinical outcomes study, which we presented here last year, showed that there was little difference between saphenous vein and RA graft patency at 5 years.
A weakness in your study is the inclusion of angina in the composite end point of event-free survival. Events that you included were death, reintervention, myocardial infarction, and angina. Death and reintervention are very robust end points; however, angina is a very weak end point and when included in a composite end point carries the same weight as death during the analysis. Therefore, the conclusion should receive some skepticism. The last question I ask is if angina was removed as an end point, would the difference in outcome between the composite arterial and conventional groups be significant?
In summary, Mr Chairman, I believe this is a very important article. I think Dr Muneretto and colleagues' preliminary data are very impressive. I believe a longer follow-up will be necessary to provide convincing evidence of the benefits of these grafts compared with conventional grafting, to justify the title that this is "the treatment of choice," and to convince surgeons to alter their practice. Thank you very much, and I thank the association and the 2 chairmen, Dr Crawford and Dr David, for the invitation.
Dr Muneretto. Thank you very much, Dr Buxton, for your kind remarks.
Concerning your first question on whether the SVGs were treated with the same level of protection as the RA grafts, both SVGs and RA grafts were harvested by resident surgeons; however, staff surgeons always evaluated the quality of the grafts before their use.
SVGs were routinely stored in heparinized saline solution, whereas, to avoid any damage derived from storage, the RA (after intraluminal dilatation with papaverine solution) was maintained in situ until the composite graft anastomosis was performed.
We did not use any calcium channel blocker in patients receiving SVGs because there is no evidence of beneficial effects of those drugs on saphenous grafts.
The quality of SVGs obviously affected the patency of those conduits, but my feeling is that with the increasing age of the patient population, the quality of SVGs is progressively worsening, and that this process became particularly evident in the last few years.
As far as the surgical skill is concerned, there were only 2 surgeons performing operations in this study, and they were equally active in the arterial conduit and SVG groups. Therefore, I can exclude that differences in surgeons' experience and technical skill could negatively affect results in the SVG group.
Your last question concerning the inclusion of angina in the composite end point of event-free survival is very interesting. I have to agree with you that angina may be a weak end point, but its weakness depends on the definition criteria used.
In our study, very strict criteria were applied, and postoperative angina was recorded only when patients had postoperative angina of class II or more (Canadian class) with a concomitant demonstration of ischemia at myocardial scintigraphy.
Actually, a new onset of myocardial infarction may be considered a weak point because the definition of myocardial infarction may be weak too.
However, in our study, a new onset of myocardial infarction was recorded only in case of significant release of specific cardiac enzymes, thus reducing the risk of statistical survey errors.
In addition, the reason why we decided to include angina as the primary end point of the study, even with some concern about its weakness, is the fact that angina is the most important symptom affecting the quality of life of patients who undergo coronary surgery. In addition, especially in elderly patients, relief of angina is the primary goal of coronary surgery; therefore, we believe that angina should always be considered in the composite end point of myocardial revascularization.
Finally, to answer your last question, if angina is removed from the composite end point of event-free survival, the differences in patients' outcomes between the composite arterial and the conventional groups still remain significant.
Dr John W. Hammon Jr (Winston-Salem, NC). I also congratulate the authors for this very nice study and particularly the zeal required to do a randomized prospective study. We also share your feelings about all arterial grafting techniques and that they provide superior patency rates and neurologic outcomes.
I have 2 questions. To achieve your low pump times and ischemia times, did you suture the radial grafts to the side of the internal thoracic artery before instituting bypass? Do you believe that this technique could lend itself to an off-pump–type regimen?
Dr Muneretto. Thank you Dr Hammon for your questions.
Actually, we performed the anastomosis of the composite graft before the institution of cardiopulmonary bypass to reduce pump time. When we have a composite graft with more than 1 side branch, the RA is sutured first to avoid any storage. Then, all the side branches (after intraluminal injection of papaverine) are distally occluded, and the proximal clamp is removed. Then, the RA and venous cannulation sites are prepared, and cardiopulmonary bypass is instituted.
Your second question deals with a relevant aspect of arterial revascularization with composite graft. We definitely believe that the composite graft technique allows surgeons to easily perform off-pump full arterial revascularization. Composite graft technique, enhancing the length of the grafts, allows an extensive mobilization of the heart, reduces the risk of technical pitfalls and, most important, avoids the need of any aortic manipulation.
Therefore, in our opinion, the composite graft technique makes off-pump surgery easy and safe when compared with the standard technique.
Dr Alain F. Carpentier (Paris, France). I rise to congratulate the authors and to answer the question raised by the discussant regarding the long-term result of the use of the RA. I introduced the use of the RA before this association in the early 1970s, and 3 years later I advised abandoning this technique because of the high incidence of spasm and occluded artery. However, 8 years later, I saw a patient who was supposed to have an occluded artery postoperatively, but the artery was fully patent. This is why we revived the use of the RA. This has been reported by my pupil Dr Acar.
Now, the reason I remind you of this story is because spasm is an important component of the operation. We know that the RA is very different than the anterior descending. So you did not answer the important question raised by the first discussant with regard to the use of a calcium antagonism that we advised in the second part of our experience. Did you use a calcium antagonist? If so, how long did you use it to explain your good results?
Dr Muneretto. It is a pleasure to discuss this aspect with you because you pioneered the use of the RA in cardiac surgery. When we started the extensive use of the RA in our department, we considered the calcium antagonist treatment as one of the key issues to achieve good clinical results.
Our protocol for prevention of RA spasm includes preoperative treatment 1 week before the operation (diltiazem 120 mL/day orally). At the time of the operation and postoperatively during the first 48 hours, diltiazem is administered by intravenous infusion (0.5-2 
· kg · min). Then, diltiazem is switched to oral administration, and therapy is continued for at least 6 months.
|
References |
|---|
|
TopAbstractMethodsDiscussionConclusionReferences |
|---|
This article has been cited by other articles:
|
|
 |
|
  H. Nakajima, J. Kobayashi, K. Toda, T. Fujita, Y. Shimahara, Y. Kasahara, and S. Kitamura Angiographic evaluation of flow distribution in sequential and composite arterial grafts for three vessel disease Eur J Cardiothorac Surg, December 21, 2011; (2011) ezr057v1. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Sugimura, M. Toyama, M. Katoh, M. Kotani, Y. Kato, and K. Hisamoto Outcome of composite arterial Y-grafts in off-pump coronary artery bypass Asian Cardiovasc Thorac Ann, April 1, 2011; 19(2): 119 - 122. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Nasso, R. Coppola, R. Bonifazi, F. Piancone, G. Bozzetti, and G. Speziale Arterial revascularization in primary coronary artery bypass grafting: Direct comparison of 4 strategies--results of the Stand-in-Y Mammary Study. J. Thorac. Cardiovasc. Surg., May 1, 2009; 137(5): 1093 - 1100. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Damgaard, J. Wetterslev, J. T. Lund, N. B. Lilleor, M. J. Perko, H. Kelbaek, J. K. Madsen, and D. A. Steinbruchel One-year results of total arterial revascularization vs. conventional coronary surgery: CARRPO trial Eur. Heart J., April 2, 2009; 30(8): 1005 - 1011. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. F. Buxton, P. A. R. Hayward, A. E. Newcomb, S. Moten, S. Seevanayagam, and I. Gordon Choice of conduits for coronary artery bypass grafting: craft or science? Eur J Cardiothorac Surg, April 1, 2009; 35(4): 658 - 670. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Zacharias, T. A. Schwann, C. J. Riordan, S. J. Durham, A. S. Shah, and R. H. Habib Late Results of Conventional Versus All-Arterial Revascularization Based on Internal Thoracic and Radial Artery Grafting Ann. Thorac. Surg., January 1, 2009; 87(1): 19 - 26. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Gongora and T. M. Sundt III Myocardial Revascularization with Cardiopulmonary Bypass Card. Surg. Adult, January 1, 2008; 3(2008): 599 - 632. [Full Text]
|
|
|
|
|
|
S. M. Wildhirt, B. Voss, F. von Canal, M. Benz, J. B. Grammer, R. Bauernschmitt, P. Tassani, and R. Lange Graft function, histopathology and morphometry of radial arteries used as conduits for myocardial revascularization in patients beyond age 70 Eur J Cardiothorac Surg, August 1, 2006; 30(2): 333 - 340. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. J. F. Baskett, F. H. Cafferty, S. J. Powell, R. Kinsman, B. E. Keogh, and S. A. M. Nashef Total Arterial Revascularization is Safe: Multicenter Ten-Year Analysis of 71,470 Coronary Procedures Ann. Thorac. Surg., April 1, 2006; 81(4): 1243 - 1248. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Nakajima, J. Kobayashi, O. Tagusari, K. Bando, K. Niwaya, and S. Kitamura Functional Angiographic Evaluation of Individual, Sequential, and Composite Arterial Grafts Ann. Thorac. Surg., March 1, 2006; 81(3): 807 - 814. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Parvaiz, J. T. Lund, and H. Kelbaek The Arterial Sling Operation: One-Year Follow-Up Ann. Thorac. Surg., October 1, 2005; 80(4): 1375 - 1380. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Matsuura, J. Kobayashi, O. Tagusari, K. Bando, K. Niwaya, H. Nakajima, T. Yagihara, and S. Kitamura Off-Pump Coronary Artery Bypass Grafting Using Only Arterial Grafts in Elderly Patients Ann. Thorac. Surg., July 1, 2005; 80(1): 144 - 148. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Gatti, C. Bentini, G. Maffei, F. Ferrari, M. Dondi, P. Pacilli, and P. Pugliese Noninvasive Dynamic Assessment With Transthoracic Echocardiography of a Composite Arterial Y-Graft Achieving Complete Myocardial Revascularization Ann. Thorac. Surg., April 1, 2005; 79(4): 1217 - 1224. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. M. Wildhirt INVITED COMMENTARY Ann. Thorac. Surg., November 1, 2004; 78(5): 1621 - 1622. [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
