ATS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Ann Thorac Surg 2010;90:1501-1506. doi:10.1016/j.athoracsur.2010.06.023
© 2010 The Society of Thoracic Surgeons
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Personal Folders
Right arrow Download to citation manager
Right arrow Author home page(s):
Tohru Asai
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Suzuki, T.
Right arrow Articles by Nishimura, O.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Suzuki, T.
Right arrow Articles by Nishimura, O.
Related Collections
Right arrow Coronary disease
Right arrowRelated Article

Original Articles: Adult Cardiac

Left Main Coronary Artery Disease Does Not Affect the Outcome of Off-Pump Coronary Artery Bypass Grafting

Tomoaki Suzuki, MD, PhD*, Tohru Asai, MD, PhD, Keiji Matsubayashi, MD, PhD, Atsushi Kambara, MD, Norihiko Hiramatsu, MD, Takeshi Kinoshita, MD, Osamu Nishimura, MD

Department of Cardiovascular Surgery, Shiga University of Medical Science, Otsu City, Shiga, Japan

Accepted for publication June 7, 2010.

Abbreviations and Acronyms BITA = bilateral internal thoracic arteries; CABG = coronary artery bypass grafting; CHF = congestive heart failure; COPD = chronic obstructive pulmonary disease; Cre = serum creatinine; CRF = chronic renal failure; GEA = gastroepiploic artery; IABP = intraaortic balloon pump; ICU = intensive care unit; LMCA = left main coronary artery; LVEF = left ventricular ejection fraction; NYHA = New York Heart Association; OPCAB = off-pump coronary artery bypass grafting; PCI = percutaneous coronary intervention; SD = standard deviation

* Address correspondence to Dr Suzuki, Department of Cardiovascular Surgery, Shiga University of Medical Science, Otsu City, Shiga, Japan (Email: suzukit{at}belle.shiga-med.ac.jp).


   Abstract
Top
 Abstract
Introduction
 Patients and Methods
 Results
 Comment
 References
 
Background: Left main coronary artery (LMCA) stenosis (≥50%) has historically been recognized as a risk factor among patients undergoing coronary artery bypass grafting.

Methods: From January 2002 to December 2008, a total of 665 patients, 268 of whom had significant LMCA disease, underwent isolated off-pump coronary artery bypass surgery at Shiga Medical University Hospital. We compared the clinical results in the 237 patients with LMCA stenosis (LMCA group) with those in the propensity score-matched 237 patients without LMCA stenosis (non-LMCA group). We performed off-pump surgery in all coronary artery bypass grafting cases with no exclusion criteria.

Results: All procedures were performed by off-pump technique without conversion to on-pump. Two patients in the LMCA group (2 of 237; 0.8%) and four in the non-LMCA group (4 of 237; 1.7%) died within 30 days after surgery. Follow-up was completed in 96.2% of the patients. The rates of six-year freedom from all cause death were 87.3% and 60.7% in the LMCA group and non-LMCA group, respectively (p = 0.17), and the corresponding rates for the combined endpoint of cardiac death, myocardial infarction, angina pectoris, repeat coronary intervention, and heart failure were 80.4% and 70.4% (p = 0.98). Multivariate Cox regression analysis revealed chronic renal failure as a statistically significant predictor for late cardiac event.

Conclusions: Off-pump coronary artery bypass grafting is feasible and safe in patients with critical LMCA stenosis and LMCA disease is not recognized as a risk factor after off-pump coronary artery bypass grafting in either the short or the long term.


   Introduction
Top
 Abstract
 Introduction
Patients and Methods
 Results
 Comment
 References
 
Left main coronary artery (LMCA) disease represents a significant independent predictor of mortality in patients with ischemic heart disease. Patients identified with LMCA stenosis are acknowledged to be at increased risk when receiving medical therapy alone as compared with surgical revascularization [1–3]. The standard therapy for patients with LMCA disease is coronary artery bypass grafting (CABG). Off-pump coronary artery bypass grafting (OPCAB) has recently become widespread internationally, and has produced good clinical outcomes. However, because of concern about the ability to tolerate beating-heart surgery, patients with LMCA stenosis have been excluded from off-pump revascularization [4].

Left main coronary artery stenosis has historically been recognized as a risk factor for early death among patients undergoing CABG [5, 6]. A number of recent reports, however, have indicated the safety and efficacy of OPCAB in patients with LMCA disease [7–10]. There are, moreover, reports [11, 12] of similar long-term survival after CABG regardless of LMCA disease status.

We became skeptical as to whether LMCA stenosis was still a significant risk factor after CABG. The purpose of the present study was to compare short-term and long-term clinical outcome after OPCAB surgery between propensity-matched groups with and without LMCA disease.


   Patients and Methods
Top
 Abstract
 Introduction
 Patients and Methods
Results
 Comment
 References
 
All patients had previously granted permission for use of their medical records for research purposes. The Institutional Review Board approved this study.

From January 2002 to December 2008, a total of 665 patients, 268 of whom had significant LMCA disease, underwent isolated OPCAB surgery under a single surgeon (T.A.) at Shiga Medical University Hospital. We have calculated a propensity score for LMCA disease to get one-to-one match pairs with similar clinical characteristics. Logistic regression with backward selection was performed to calculate the propensity score. By matching propensity score, 237 pairs were successfully matched in a one-to-one manner. We compared the clinical results between these propensity-matched groups. We performed OPCAB in all CABG cases with no exclusion criteria. Patients with acute myocardial infarction were included, but patients who had undergone a salvage procedure were excluded from the study. Postoperative renal failure was defined as the requirement for hemodialysis. Postoperative stroke was defined as a new neurologic event persisting for more than 24 hours after onset and was confirmed by computed tomography. Follow-up was achieved by direct communication with the patient, the patient's family, or the attending physician. Significant LMCA disease was defined as LMCA with stenosis greater than 50%, assessed visually by the physician performing the coronary angiography.

Anesthetic and Surgical Techniques
A standard anesthetic technique was used for all patients. The induction of anesthesia was achieved with fentanyl citrate (5 to 10 µg/kg), thiopental (3 to 5 mg/kg), or propofol infusion (3 to 4 mg/kg/hour), and vecuronium bromide (0.1 mg/kg). Anesthesia was maintained with fentanyl, propofol (2 to 3 mg/kg), and low concentrations of sevoflurane as necessary. Anticoagulation was achieved with heparin (1 mg/kg) after the conduits were harvested. The activated clotting time was maintained at 250 seconds or greater. Heparin was reversed with protamine after completion of the anastomosis. Standard intraoperative monitoring techniques were used. Pulmonary artery flotation catheters were used routinely and provided continuous evaluation of cardiac output. Transesophageal echocardiography was used routinely.

All procedures were performed through a median sternotomy. The conduits (one or both internal thoracic arteries, the right gastroepiploic artery, and saphenous vein) were harvested and skeletonized. We used bilateral internal thoracic arteries routinely for two-vessel or three-vessel disease patients who required grafting to the left anterior descending artery and circumflex artery. A common combination for internal thoracic artery graft placement was in situ grafting of the left internal thoracic artery to the circumflex area and the right internal thoracic artery to the left anterior descending area. We also aggressively used the skeletonized right gastroepiploic artery to reconstruct the distal right coronary artery as an in situ graft. We used a suction-type mechanical stabilizer (Octopus 4.3; Medtronic, Minneapolis, MN) to immobilize the target coronary artery, but did not use heart positioning. An intracoronary shunt tube and carbon dioxide blower were used routinely. The distal anastomosis was constructed with 7-0 polypropylene using a standard technique. A red blood cell saving device was used in all cases.

Statistical Analysis
Data are presented as the mean ± standard deviation. Categoric variables were analyzed using the {chi}2 or Fisher's exact test. Continuous variables were examined using the t test or the Mann-Whitney U test.

We have calculated a propensity score for LMCA disease to get one-to-one match pairs with similar clinical characteristics. Logistic regression with backward selection was performed to calculate the propensity score. The C statistic was calculated to assess the discriminatory ability of the model. Each patient with LMCA disease was then matched to one patient without LMCA disease using propensity scores identical to within 3%.

Univariate and multivariate Cox proportional hazard regression analyses were performed for the analysis of late mortality and cardiac event. The multivariate analyses were performed with a stepwise forward regression model in which each variable with a probability value of less than 0.20 in the univariate analysis was entered in the model. Actuarial survival and event-free survival curves were estimated using the Kaplan-Meier method comparing differences between groups with the log-rank test. Calculated p values of less than 0.05 were considered significant. Data were analyzed using SPSS 11.5.1 (SPSS Inc, Chicago, IL) for Windows (Microsoft Corp, Redmond, WA).


   Results
Top
 Abstract
 Introduction
 Patients and Methods
 Results
Comment
 References
 
The preoperative characteristics of the patients are summarized in Table 1. Preoperative patient comorbidities and cardiac characteristics were equally distributed in the two matched groups. The discriminatory ability of the logistic model as measured by C statistic was 0.63 (p < 0.001) and the Hosmer-Lemeshow goodness-of-fit test was not statistically significant (p = 0.83), indicating good discriminative power and acceptable calibration of the model, respectively.


View this table:
[in this window]
[in a new window]

  		Table 1 Preoperative Patient Characteristics in Propensity-Matched Groups
 
Short-Term Results
Outcome after surgery is shown in Table 2. There were no significant differences in the number of grafts per patient (3.34 ± 1.0 vs 3.41 ± 1.2; p = 0.22) or the rate of achievement of complete revascularization (97% vs 98%; p = 0.10). Bilateral internal thoracic artery use was higher in the LMCA group (69% vs 56%; p < 0.01). The rates of all arterial revascularization (60% vs 59%) and gastroepiploic artery use (39% vs 45%; p = 0.19) were equally distributed in the two groups. There was no significant difference in other morbidities: perioperative myocardial infarction (0.4% vs 0.8%), bleeding reoperation (2% vs 2%), cerebrovascular accident (0.4% vs 0.4%), acute renal failure (3% vs 2%), prolonged ventilator support for respiratory insufficiency (>24 hours) (3% vs 3%), and deep sternal infection (1.2% vs 0.4%). Two patients in the LMCA group (2 of 237; 0.8%) died: one of low output syndrome and one of multisystem organ failure. Four patients in the non-LMCA group (4 of 237; 1.7%) died: two of ruptures of abdominal aortic aneurysms, one of rupture of a descending thoracic aortic aneurysm, and one of superior mesenteric artery thrombus.


View this table:
[in this window]
[in a new window]

  		Table 2 Operative and Postoperative Data
 
Long-Term Results
Follow-up was completed in 96.2% (456 of 474) of the patients. The mean follow-up duration was 3.9 ± 1.4 years. Six-year freedom from death from all causes was 87.3% in the LMCA group and 60.7% in the non-LMCA group (p = 0.17); the rates of freedom from the combined endpoint of cardiac death, myocardial infarction, angina pectoris, repeat coronary intervention, and heart failure requiring treatment were 80.4% in the LMCA group and 70.4% in the non-LMCA group (p = 0.98) (Figs 1; 2). Go Multivariate Cox proportional hazards regression analysis showed independent predictor of long-term cardiac events (cardiac death, myocardial infarction, angina pectoris, repeat coronary intervention, and heart failure) was chronic renal failure (hazard ratio = 0.3, 95% confidence interval = 0.2 to 0.6, p < 0.001) (Table 3).


Figure 1
View larger version (15K):
[in this window]
[in a new window]

  		Fig 1. Six-year actuarial freedom from death of any cause after off-pump coronary surgery according to LMCA (black line) or non-LMCA (grey line). (LMCA = left main coronary artery.)

 

Figure 2
View larger version (15K):
[in this window]
[in a new window]

  		Fig 2. Six-year actuarial freedom from any cardiac event (cardiac death, myocardial infarction, angina pectoris, coronary reintervention, and heart failure) according to LMCA (black line) or non-LMCA (grey line). (LMCA = left main coronary artery.)

 

View this table:
[in this window]
[in a new window]

  		Table 3 Univariate and Multivariate Cox Proportional Hazard Regression Analyses of Late Cardiac Events (Cardiac Death, Myocardial Infarction, Angina Pectoris, Repeat Coronary Intervention, and Heart Failure)
 

   Comment
Top
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
References
 
Past studies comparing medical therapy alone with surgical revascularization document a significant survival benefit for patients with critical left main coronary artery disease who undergo surgery [1–3, 13, 14]. Even now, CABG is recommended for patients with critical LMCA stenosis [15, 16]. However, significant LMCA stenosis has been regarded as a risk factor for patients undergoing CABG [5, 6]. Although these patients are high risk, the long-term prognosis is improved by CABG compared with medical therapy alone.

Following the development of technology, pioneering cardiologists have recently performed percutaneous coronary intervention in patients with LMCA disease and reported good results compared with CABG [17–21]. However, the use of percutaneous coronary intervention for these patients is still controversial and requires additional supporting evidence.

Numerous studies [5, 6] have identified the presence of LMCA disease as an independent predictor of postoperative morbidity and mortality in patients undergoing CABG. Such reports were based upon data presented in the 1970s to 1990s, when the techniques of surgery, anesthesia, and medical management were less advanced than now. During the last two decades, there have been major improvements in almost all fields relating to the perioperative management of patients undergoing CABG. Coronary artery bypass grafting has also progressed thanks to better management, with options including more frequent use of arterial graft, more use of internal thoracic arteries, and improved techniques in off-pump surgery.

There have been many recent reports of complete revascularization achieved safely through OPCAB with excellent early-stage clinical outcomes, superior or equal to those of conventional CABG with cardiopulmonary bypass. However, there are still some patients who cannot be treated with OPCAB, such as those with a severe risk factor. While OPCAB for patients with LMCA stenosis remains challenging [4], a number of recent reports have indicated the safety and efficacy of the technique in LMCA stenosis patients [7–10]. Yeatman and colleagues [9] reported the safety and efficacy of OPCAB for critical LMCA disease in a comparison of 75 OPCAB cases and 312 conventional CABG procedures. Lu and colleagues [10] also evaluated OPCAB surgery in a comparison of on-pump surgery using a risk-adjusted model. In our OPCAB series, the number of distal anastomoses per patient was 3.34 in the LMCA group and 3.41 in the non-LMCA group, with complete revascularization achieved in 96.6% and 98.3%, respectively. There were thus no significant differences between the two groups. No patient in either group was converted from off-pump to on-pump. Operative mortality was 0.8% in the LMCA group and 1.7% in the non-LMCA group and postoperative morbidity was equally frequent in the two groups with no significant differences. These early-stage results of the study also indicated the feasibility and effectiveness of the OPCAB approach for patients with significant LMCA disease.

In contrast to previous studies, Cosgrove and colleagues [11] report that LMCA disease is not an independent risk factor for operative mortality after CABG. Since their report, several studies [11, 12, 22] have recorded equal early-stage survival in patients with LMCA stenosis compared with other patients and similar long-term survival after CABG. Jönsson and colleagues [22] demonstrated an improvement in surgical results over three decades (1970s to 1990) and the neutralization of LMCA stenosis as a risk factor for both early and late death during the 1990s. Indeed, there was a pronounced decrease over time in the risk of both early and late death in patients with LMCA undergoing CABG. Contributory to this improvement were technical advances in surgery, anesthesia, and intensive care management. Improvement in medical management, including the use of statins, an effective antithrombotic drug, and β-blocker, was also a factor.

Patients with LMCA stenosis have been recognized as having a poorer prognosis after CABG than those without. The present study showed a 6-year survival rate for all causes of death: 87.3% in the LMCA group and 60.7% in the non-LMCA group with no significant difference. Freedom from any cardiac event (cardiac death, myocardial infarction, angina pectoris, percutaneous coronary intervention, cardiac failure) was 80.4% in the LMCA group and 70.4% in the non-LMCA group. We found no significant difference in long-term clinical outcome between the two groups. In the present study, LMCA stenosis was thus not recognized as a risk factor after CABG in either short-term or long-term outcomes.

A limitation of the present study is that it is non-randomized and is a retrospective study comparing outcome in patients with and without LMCA disease undergoing OPCAB. Our study population was small, resulting in insufficient statistical power. However, all of the procedures were consecutive and conducted within a single institute by a single surgeon. Additionally, comparison of preoperative demographic and risk factors demonstrated that the two cohorts were well-matched. We concluded that OPCAB is feasible and safe in patients with critical LMCA stenosis and that LMCA disease is not a risk factor after OPCAB surgery in either the short- or long-term.


   References
Top
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 References
 

  1. Campeau L, Corbara F, Crochet D, Petitclerc R. Left main coronary artery stenosis: the influence of aortocoronary bypass surgery on survival Circulation 1978;57:1111-1115.[Abstract/Free Full Text]
  2. Taylor HA, Deumite NJ, Chaitman BR, Davis KB, Killip T, Rogers WJ. Asymptomatic left main coronary artery disease in the Coronary Artery Surgery Study (CASS) registry Circulation 1989;79:1171-1179.[Abstract/Free Full Text]
  3. Eagle KA, Guyton RA, Davidoff R, et al. ACC/AHA 2004 guideline update for coronary artery bypass graft surgery: summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1999 Guidelines for Coronary Artery Bypass Graft Surgery) Circulation 2004;110:1168-1176.[Free Full Text]
  4. Emmert MY, Salzberg SP, Seifert B, et al. Routine off-pump coronary artery bypass grafting is safe and feasible in high-risk with left main disease Ann Thorac Surg 2010;89:1125-1130.[Abstract/Free Full Text]
  5. Eagle KA, Guyton RA, Davidoff R, et al. ACC/AHA guidelines for coronary artery bypass graft surgery: executive summary and recommendations: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to revise the 1991 guidelines for coronary artery bypass graft surgery) Circulation 1999;100:1464-1480.[Free Full Text]
  6. Davierwala PM, Maganti M, Yasu TM. Decreasing significamce of left ventricular dysfunction and reoperative surgery in predicting coronary artery bypass grafting-associated mortality: a twelve-year study J Thorac Cardiovasc Surg 2003;126:1335-1344.[Abstract/Free Full Text]
  7. Dewey TM, Magee MJ, Edgerton JR, Mathison M, Tennison RN, Mack MJ. Off-pump bypass grafting is safe in patients with left main coronary disease Ann Thorac Surg 2001;72:788-792.[Abstract/Free Full Text]
  8. Beauford RB, Saunders CR, Lunceford TA, et al. Multivessel off-pump revascularization in patients with significant left main coronary artery stenosis: early and midterm outcome analysis J Card Surg 2005;20:112-118.[Medline]
  9. Yeatman M, Caputo M, Ascione R, Ciulli F, Angelini GD. Off-pump coronary artery bypass surgery for critical left main stem disease: safety, efficacy and outcome Eur J Cardiothorac Surg 2001;19:239-244.[Abstract/Free Full Text]
  10. Lu JCY, Grayson AD, Pullan DM. On-pump versus off-pump surgical revascularization for left main stem stenosis: risk adjusted outcomes Ann Thorac Surg 2005;80:136-143.[Abstract/Free Full Text]
  11. Cosgrove DM, Loop FD, Lytle BW, et al. Primary myocardial revascularization. Trends in surgical mortality. J Thorac Cardiovasc Surg 1984;88(5 pt 1):673-684.[Abstract]
  12. d'Allonnes FR, Corbineau H, Le Breton H, Leclercq C, Leguerrier A, Daubert C. Isolated left main coronary artery stenosis: long term follow up in 106 patients after sugery Heart 2002;87:544-548.[Abstract/Free Full Text]
  13. Yusuf S, Zucker D, Peduzzi P, et al. Effect of coronary artery bypass graft surgery on survival: overview of 10-year results from randomized trials by the Coronary Artery Bypass Graft Surgery Trialists Collaboration Lancet 1994;344:563-570.[Medline]
  14. Caracciolo EA, Davis KB, Sopko G, et al. Comparison of surgical and medical group survival in patients with left main coronary artery disease. Long-term CASS experience. Circulation 1995;91:2325-2334.[Abstract/Free Full Text]
  15. Taggart DP, Thomas B. Ferguson Lecture. Coronary artery bypass grafting is still the best treatment for multivessel and left main disease, but patients need to know. Ann Thorac Surg 2006;82:1966-1975.[Free Full Text]
  16. Shemin RJ. Coronary artery bypass grafting versus stenting for unprotected left main coronary artery disease: where lies the body of proof? Circulation 2008;118:2326-2329.[Free Full Text]
  17. Seung KB, Park DW, Kim YH, et al. Stent versus coronary-artery bypass grafting for left main coronary artery disease N Engl J Med 2008;358:1781-1792.[Medline]
  18. Takagi H, Kawai N, Umemoto T. Stenting versus coronary artery bypass grafting for unprotected left main coronary artery disease: a meta-analysis of comparative studies J Thorac Cardiovasc Surg 2009;137:e54-e57.[Free Full Text]
  19. Chieffo A, Morici N, Maisano F, et al. Percutaneous treatment with drug-eluting stent implantation versus bypass surgery for unprotected left main stenosis: a single-center experience Circulation 2006;113:2542-2547.[Abstract/Free Full Text]
  20. Chieffo A, Stankovic G, Bonizzoni E, et al. Early and mid-term results of drug eluting stent implantation in unprotected left main Circulation 2005;111:791-795.[Abstract/Free Full Text]
  21. Takagi T, Stankovic G, Finci L, et al. Results and long-term predictors of adverse clinical events after elective percutaneous interventions on unprotected left main coronary artery Circulation 2002;106:698-702.[Abstract/Free Full Text]
  22. Jönsson A, Hammar N, Nordquist T, Ivert T. Left main coronary artery stenosis no longer a risk factor for early and late death after coronary artery bypass surgery- an experience covering three decades Eur J Cardiothorac Surg 2006;30:311-317.[Abstract/Free Full Text]

Related Article

Invited Commentary
Ki-Bong Kim
Ann. Thorac. Surg. 2010 90: 1506. [Extract] [Full Text] [PDF]



This article has been cited by other articles:


Home page
 Ann. Thorac. Surg.Home page
A. K. Sharma
OPCAB Technique for High-Risk Patients
Ann. Thorac. Surg., September 1, 2012; 94(3): 1036 - 1036.
[Full Text] [PDF]

Home page
 J. Thorac. Cardiovasc. Surg.Home page
H.-L. Gan, J.-Q. Zhang, W. Xiao, S. Zhao, F.-j. Huang, C.-x. Gu, C.-s. Lu, and P.-S. Wang
Ostial left main coronary artery stenosis as an additional risk factor in off-pump coronary artery bypass grafting
J. Thorac. Cardiovasc. Surg., January 1, 2012; 143(1): 103 - 110.
[Abstract] [Full Text] [PDF]

Home page
 Ann. Thorac. Surg.Home page
K.-B. Kim
Invited Commentary
Ann. Thorac. Surg., November 1, 2010; 90(5): 1506 - 1506.
[Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Personal Folders
Right arrow Download to citation manager
Right arrow Author home page(s):
Tohru Asai
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Suzuki, T.
Right arrow Articles by Nishimura, O.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Suzuki, T.
Right arrow Articles by Nishimura, O.
Related Collections
Right arrow Coronary disease
Right arrowRelated Article

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