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


     

Ann Thorac Surg 2010;89:414-420. doi:10.1016/j.athoracsur.2009.11.036
© 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):
Cristina Firanescu
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 van Straten, A. H.M.
Right arrow Articles by van Zundert, A. A.J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by van Straten, A. H.M.
Right arrow Articles by van Zundert, A. A.J.
Related Collections
Right arrow Coronary disease

Original Articles: Adult Cardiac

Peripheral Vascular Disease as a Predictor of Survival After Coronary Artery Bypass Grafting: Comparison With a Matched General Population

Albert H.M. van Straten, MDa, Cristina Firanescu, MDa, Mohamed A. Soliman Hamad, MDa,*, M. Erwin S.H. Tan, MD, PhDa, Joost F.J. ter Woorst, MDa, Elisabeth J. Martens, PhDb,c,d, André A.J. van Zundert, MD, PhDe,f

a Department of Cardiothoracic Surgery, Catharina Hospital, Eindhoven, The Netherlands
b Department of Education and Research, Catharina Hospital, Eindhoven, The Netherlands
c Department of Anesthesiology, Catharina Hospital, Eindhoven, The Netherlands
d Department of Medical Psychology, Centre of Research on Psychology in Somatic Diseases, Tilburg University, Tilburg, The Netherlands
e Brabant Medical School, Eindhoven, The Netherlands
f University Hospital Ghent, Ghent, Belgium

Accepted for publication November 12, 2009.

* Address correspondence to Dr Soliman Hamad, Department of Cardiothoracic Surgery, Catharina Hospital, Michelangelolaan 2, Postbus 1350, 5602 ZA Eindhoven, The Netherlands (Email: aasmsn{at}cze.nl).


   Abstract
Top
 Abstract
Introduction
 Material and Methods
 Results
 Comment
 References
 
Background: The European system for cardiac operative risk evaluation, the most popular European scoring system in cardiac surgery, uses the extracardiac arteriopathy as a risk factor for early mortality. We studied the effect of peripheral vascular disease (PVD) on early and late mortality in a large group of patients undergoing isolated coronary artery bypass surgery (CABG) surgery.

Methods: During a ten-year period (January 1998 through December 2007) 10,626 patients underwent isolated CABG in our hospital. The primary endpoints of this study were early and late all-cause mortality. For each year of the study period, general population cohorts were matched with the patient groups for age and gender (expected survival).

Results: Out of 10,504 patients included in the analysis, 1,222 (11.63%) patients had PVD. The PVD was identified as an independent risk factor for late mortality (death at any time after hospital discharge) (hazard ratio of 1.67 [1.43 to 1.95], p < 0.0001), but not for early mortality (death within 30 days or before discharge) (hazard ratio of 1.06 [0.70 to 1.60], p = 0.776). Patients without PVD had a better survival than patients with PVD (log-rank p < 0.0001) and even a better survival compared to the normal Dutch population survival (p value < 0.002). The PVD patients had a worse than expected survival (log-rank p < 0.0001).

Conclusions: Peripheral vascular disease is an independent risk factor only for late mortality but not for early mortality. Compared with age-matched and sex-matched cohorts from the general Dutch population, the ten-year survival of patients with peripheral vascular disease was worse; whereas the survival of patients with no peripheral vascular disease was better.


   Introduction
Top
 Abstract
 Introduction
Material and Methods
 Results
 Comment
 References
 
Patients with peripheral vascular disease (PVD) are known to have a high prevalence of coronary artery disease and they often undergo coronary artery bypass grafting (CABG) [1]. The prevalence of PVD in patients with coronary artery disease varied in several studies between 26% and 71% [2–5]. Peripheral vascular disease was found to increase twofold to threefold the risk of cardiovascular mortality [6]. In patients with coronary artery disease (CAD), lower extremity PVD was independently associated with poorer outcomes [7]. The operative mortality with CABG is estimated to be 1.6-fold to 2.9-fold higher in patients with PVD [8, 9].

In 1999 the European system for cardiac operative risk evaluation (EuroSCORE) was introduced in Europe [10] and had become widely used as a scoring system to predict early mortality in cardiac surgical patients. The standard EuroSCORE underestimated the risk in certain very high-risk patients, and therefore in 2003 a more precise logistic regression model was introduced [11]. In both calculating methods, the extracardiac arteriopathy (limb arteries or carotid pathology) is identified as a risk factor for early mortality in cardiac surgical patients.

The value of PVD as an independent predictor for early mortality after CABG, demonstrated in a noncontemporaneous series [2], can be debated considering the results of more recent cohorts [12]. These results still sustain the fact that PVD is an important predictor for increased late mortality.

To our knowledge, there are no large recent studies assessing the impact of PVD on early and late survival after CABG. Therefore, we analyzed PVD as a risk factor for early and late mortality in a large group of patients with isolated CABG operated in the Department of Cardiothoracic Surgery, Catharina Hospital, Eindhoven, The Netherlands, between 1998 and 2008.


   Material and Methods
Top
 Abstract
 Introduction
 Material and Methods
Results
 Comment
 References
 
Patients
Data of all patients undergoing isolated CABG at a single center (Catharina Hospital, Eindhoven, The Netherlands) between January 1998 and December 2007 were analyzed. Starting in January 1998, clinical data, including demographic data, risk factors, and complications, were prospectively collected in our database. The Institutional Research Review Board approved this study and waived the need for patient consent.

Definition
The presence of PVD was prospectively registered. We defined PVD as disease of the leg arteries below the aortic bifurcation, one of the common carotid arteries, the abdominal aorta, or disease of the arm arteries starting with the subclavian arteries. The presence of peripheral vascular disease was confirmed by any of the following findings: (1) Presentation of the patient (eg, intermittent claudications); (2) angiographic or echocardiographic evidence of stenosis in one or more of the above mentioned vessels; (3) history of a revascularization procedure of one of the above mentioned vessels (eg, femopopliteal bypass, carotid stenting).

Study Endpoints
The primary endpoints of this study were early and late all-cause mortality. We calculated the independent predictive value of PVD for early and late mortality, corrected for confounders. The analyzed confounders were preoperative, intraoperative, and postoperative characteristics.

Survival of Age-matched and Gender-matched Cohorts From the General Population
For calculating survival of general population cohorts, data from the database of the Dutch Central Bureau for Statistics (CBS), which can be downloaded online (www.cbs.nl), were used. For each year of the study period, general population cohorts were matched with the patient groups for age and gender. The year of operation of the patients group is the starting point for the general population cohorts.

Operative Techniques
All patients received short-acting anesthetic drugs to facilitate early extubation. Extracorporeal circulation (ECC) was performed using normothermic nonpulsatile flow. Cold crystalloid cardioplegia ("St Thomas" solution) or warm blood cardioplegia was used to induce and maintain cardioplegic arrest, according to the surgeon's preference. All patients undergoing CABG with the use of ECC received (according to the standard hospital protocol) a low dose of aprotinin (2 million KIU kallikrein inactivation units) administered in the prime solution of the ECC.

Follow-Up
Follow-up data concerning mortality were gathered using databases from health insurance companies. The data of 9% of the patients in the total patient group could initially not be retrieved from these databases. We therefore contacted the general practitioners by telephone to obtain information about the mortality data of those patients. For the remaining patients, we contacted the city authorities where the patients lived at the time of the operation. The closing interval was October to December 2007. However, 122 patients (1.1%) were lost to follow-up. Early mortality was defined as death within 30 days postoperatively or death at anytime if the patient did not leave the hospital or a transfer tertiary hospital alive. Late mortality was defined as any-cause mortality that occurred at any time after hospital discharge.

Statistical Analyses
Discrete variables were compared with the {chi}2 test and are presented as numbers and percentages. Continuous variables were compared with a t test and the analysis of variance and are presented as means ± standard deviations. Univariate and multivariate logistic regression analyses were performed to investigate the effect of biomedical variables on early mortality. Multivariate analyses were used to test for the potentially confounding effect of biomedical and demographic factors on outcomes. Cox proportional hazard regression analyses were performed for the same analyses of late mortality. Values for p less than 0.05 were considered statistically significant. If significant at p less than 0.05, confounders were included into the multivariable logistic and Cox regression analyses. Long-term survival was described using the Kaplan-Meier method. Comparisons of long-term survival were done using log-rank statistics. The zero time point indicates the time of CABG. Hazard ratios (HR) with 95% confidence intervals are reported. All statistical analyses were performed using SPSS software (Statistical Product and Services Solutions, version 15.0; SPSS Inc, Chicago, IL).


   Results
Top
 Abstract
 Introduction
 Material and Methods
 Results
Comment
 References
 
During a ten-year period (January 1998 to December 2007) 10,626 patients underwent isolated CABG in our hospital; 122 patients (1.1%) were lost to follow-up. The minimum follow-up for surviving patients was two months. Mean follow-up was 4.45 ± 2.9 years (range, 0 to 10.16 years) (0 years for intraoperative deaths). In 9,282 patients, no preoperative PVD was diagnosed while 1,222 (11.63%) patients did have preoperative PVD.

Baseline characteristics stratified by PVD are shown in Table 1. Using normal (Gaussian) distribution curves, all the continuous variables were normally distributed. Patients with PVD were older, had a worse creatinine clearance, and showed, more often, hypertension, diabetes, and a lower preoperative hemoglobin level. Duration of ECC was longer in PVD patients and the number of grafts and transfused red blood cells (RBC) units was higher. Perioperative myocardial infarction occurred more often in PVD patients.


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

  		Table 1 Baseline Characteristics Stratified by Peripheral Vascular Disease
 
Table 2 shows the incidences of early and late mortality stratified by the presence of preoperative PVD. Early as well as late mortality occurred more frequently in PVD patients. During the study period, the overall early mortality rate in our department decreased from 2.9% in 1998 to 1% in 2007.


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

  		Table 2 Early and Late Mortality Stratified by the Presence of Peripheral Vascular Disease (PVD)
 
Risk factors for early mortality identified by univariate and multivariable logistic regression analyses are shown in Table 3. Univariate logistic regression analysis revealed PVD as a risk factor for early mortality. All risk factors that were identified with the univariate logistic regression analyses were entered into the multivariable logistic regression model. The presence of PVD was not an independent risk factor for early mortality. Even when only preoperative risk factors were entered into the multivariable analysis PVD was not revealed as an independent risk factor (HR 1.29 [0.88 to 1.89]) with a p value of 0.179.


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

  		Table 3 Predictors of Early Mortality; Univariate and Multivariable Logistic Regression Analyses
 
Results of Cox regression analyses for risk factors of late mortality are shown in Table 4. Univariate analyses revealed PVD as a risk factor for late mortality. All risk factors identified with univariate analyses were entered into the multivariate Cox regression model. In this case, PVD was identified as an independent risk factor for late mortality. When only the preoperative risk factors were entered into the multivariate analysis PVD was still an independent risk factor with a hazard ratio of 1.70 (1.46 to 1.98) and a p value of less than 0.0001.


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

  		Table 4 Predictors of Late Mortality; Univariate and Multivariate Cox Regression Analyses
 
Figure 1 shows the long-term survival rates stratified by PVD and the corresponding normal Dutch survival (expected survival). The non-PVD patients had a better survival than PVD patients after CABG (log-rank p value < 0.0001). The non-PVD patients had a better survival after CABG when compared with the normal Dutch survival (p value < 0.002). However, PVD patients had a worse than expected survival (log-rank p value < 0.0001). One, five, and nine year survival rates are shown in Table 5. There was no difference between survival of non-PVD patients and expected survival (p value = 0.656, 0.422, and 0.456, respectively). For PVD patients, the actual survival was worse than the expected survival (p value = 0.02, 0.01, and < 0.0001, respectively).


Figure 1
View larger version (19K):
[in this window]
[in a new window]

  		Fig 1. Kaplan-Meier survival curves of patients with and without peripheral vascular disease (PVD) and the survival of the normal Dutch population (matched for age and sex with the PVD groups).

 

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

  		Table 5 Survival at One, Five, and Nine a Years Stratified by PVD Groups
 

   Comment
Top
 Abstract
 Introduction
 Material and Methods
 Results
 Comment
References
 
This retrospective study of a large number of patients undergoing isolated CABG confirms that the presence of PVD is an independent predictor of poorer long-term survival after isolated CABG. On the other hand, PVD was not found to significantly affect early mortality in this study.

In our studied group, 11.6% of the patients undergoing CABG had the preoperative diagnosis of PVD. The presence of PVD was associated with a poorer patient condition due to older age and higher incidence of comorbidities such as hypertension, diabetes, lower preoperative hemoglobin level, and renal dysfunction. These patients' characteristics have probably influenced the intraoperative parameters as well. Patients with PVD needed a longer ECC time, more grafts, and more RBC transfusions. Perioperative myocardial infarction occurred more often in PVD patients. However, even after adjusting for these confounding factors, the presence of PVD was found to be an independent predictor of poorer long-term survival after CABG.

It is not clear why patients with PVD needed more grafts than the other patients. It is possible that patients with PVD have more extensive CAD involving more vessels. The need for more grafts might explain the longer ECC time needed in these patients. The finding that patients with PVD need more RBC transfusion must be cautiously interpreted because the preoperative hemoglobin level was lower in these patients than in patients without PVD.

Early Mortality
In our study early mortality was 2.3% for non-PVD patients and 3.6% for the patients with PVD (p = 0.006). The multivariate logistic regression analysis did not find PVD as an independent risk factor for early mortality with a low hazard ratio of 1.06(0.70 to 1.60), p = 0.776. The same result was described by Chu and colleagues [12]. On the other hand Birkmeyer and colleagues [2] showed different results, with an in-hospital mortality rate of 2.4-fold higher in patients with PVD (7.7%) than in patients without evidence of PVD (3.2%). In their study PVD was an independent predictor for early mortality, but these findings represent the results of a noncontemporaneous sample [2].

The EuroSCORE risk assessment [10] found extracardiac arteriopathy as an important determinant of the early mortality with an additive weight of 2 points and a β coefficient of 0.655. The incidence of PVD in their database was similar to ours (5.8% with intermittent claudication, 4.4% carotid disease, and 1.3% abdominal aortic disease in the EuroSCORE database versus a total PVD prevalence of 11.6% in the present study). Gummert and colleagues [13] found, in a large cohort of patients with isolated CABG, a discrepancy between the hospital overall mortality and the predicted mortality (2.6% vs 5.2%), suggesting an overestimation of the operative risk. Our results are contesting the predictive value of PVD for early mortality, raising the question if the extracardiac arteriopathy should be used as one of the predictive risk elements in the EuroSCORE risk stratification model.

Late Mortality
In the current study, PVD was identified as an independent risk factor for late mortality with a hazard ratio of 1.67 (1.43 to 1.95). Other studies have also shown poorer prognosis for CABG in patients with PVD [14–16]. Chu and colleagues [12] found a nine-year survival rate of 82.8% ± 2.4% for patients without PVD and 72.9% ± 4.1% for patients with PVD in a smaller group of patients (n = 1,164). Gersh and colleagues [14] found a 10% to 20% decrease in survival after CABG in patients with PVD. The effect of PVD on long-term survival after CABG may have several explanations. For example, PVD may be a marker of more severe associated coronary atherosclerotic disease. It is also possible that patients with PVD have more diffuse coronary disease than those without PVD, leading to poorer survival after CABG. Another possibility is that decreased long-term survival among PVD patients after CABG is due to noncardiac mortality even if revascularization was successful. One of the limitations of our study is that the cause of late death was unknown. Knowing the cause of death would have highlighted the causal relationship between PVD and decreased long-term survival after CABG.

Comparison With the General Population
Obviously, advanced age is associated with a poorer late survival rate. The non-PVD patients, as shown in this study, are often younger. Although proper statistical testing can be used to distinguish between effects caused by age and gender, interpretation of survival curves remains difficult. Also, variation in life expectancy over the years has been well documented in The Netherlands by the Dutch Central Bureau for Statistics. This organization keeps track of mortality rates of the overall Dutch population. We used the Central Bureau for Statistics database (www.CBS.nl) to calculate the survival of age-matched and sex-matched general population groups. Because the mortality rates of the Dutch general population varied during the study period, we performed the matching of the cohorts for each year of the study period. We consider this the normal Dutch survival or the expected survival of patients groups. We compared the late survival of the patient groups with this expected survival. However, caution in interpreting these results is needed because the Central Bureau for Statistics database contains data of the total Dutch population, including patients described in this study as well as patients who were treated in other Dutch cardiac surgery centers. However, the number of patients in The Netherlands who undergo a CABG is relatively small compared with the total number of persons in the general population.

We found that the survival rate after CABG in non-PVD patients was not only better than in PVD patients, but also better than the survival rates of the general Dutch population. An explanation for this might be that a certain percentage of the general population has PVD and coronary disease. The treatment with aspirin, anticholesterolemic drugs, and beta-blockers, as well as the protection obtained by the revascularization, may contribute to the improved survival and explain why non-PVD patients have a better survival rate than the matched general Dutch population. Furthermore, before undergoing CABG patients are screened for severe underlying disease. If a severe underlying disease is present an alternative treatment to a CABG must be considered, thus biasing the CABG group.

When accepting a patient for surgery, a careful assessment of the risk should take place using a risk stratification model that fits with the current population. This decision-making tool should include the factors that identify patients at risk. That is why we consider our results as being valuable when informing the patients about their prognosis after CABG. Instead of informing them whether they will do better or worse than other patients with or without PVD who undergo CABG, we can inform them how their survival will be compared with the normal survival of people of the same age and sex. For non-PVD patients, it might be reassuring to know that after their CABG operation (at least for the next ten years) their survival will be no worse or even better than the normal Dutch survival, unless they have other risk factors for late mortality.

Limitations
This is a retrospective observational study. Therefore, we must be cautious in interpreting our results. As mentioned above, the study endpoint is any-cause mortality. We were not able to report causes of death or other morbidities that might be equally interesting.

Conclusions
Peripheral vascular disease (PVD) is not an independent risk factor for early mortality after CABG. The inclusion of PVD as a risk factor for increased early mortality in the risk stratification models should be reevaluated considering these recent results. The presence of PVD is identified as an independent risk factor for late mortality. The non-PVD patients had a better long-term survival than PVD patients and even a better survival when compared with the normal Dutch survival rates. Patients with PVD had a worse than expected survival with an increased risk for late mortality after CABG when compared with non-PVD patients.


   References
Top
 Abstract
 Introduction
 Material and Methods
 Results
 Comment
 References
 

  1. Hertzer NR, Beven EG, Young JR, et al. Coronary artery disease in peripheral vascular patients. A classification of 1000 coronary angiograms and results of surgical management. Ann Surg 1984;199:223-233.[Medline]
  2. Birkmeyer JD, O'Connor GT, Quinton HB, et al. The effect of peripheral vascular disease on in-hospital mortality rates with coronary artery bypass surgery. Northern New England Cardiovascular Disease Study Group. J Vasc Surg 1995;21:445-452.[Medline]
  3. Sukhija R, Aronow WS, Yalamanchili K, Sinha N, Babu S. Prevalence of coronary artery disease, lower extremity peripheral arterial disease, and cerebrovascular disease in 110 men with an abdominal aortic aneurysm Am J Cardiol 2004;94:1358-1359.[Medline]
  4. Dieter RS, Tomasson J, Gudjonsson T, et al. Lower extremity peripheral arterial disease in hospitalized patients with coronary artery disease Vasc Med 2003;8:233-236.[Abstract/Free Full Text]
  5. Poredos P, Jug B. The prevalence of peripheral arterial disease in high risk subjects and coronary or cerebrovascular patients Angiology 2007;58:309-315.[Medline]
  6. McDermott MM. The magnitude of the problem of peripheral arterial disease: epidemiology and clinical significance Cleve Clin J Med 2006;73(suppl 4):S2-S7.[Abstract/Free Full Text]
  7. Makowsky MJ, McAlister FA, Galbraith PD, et al. Alberta Provincial Program for Outcome Assessment in Coronary Heart Disease (APPROACH) Investigators Lower extremity peripheral arterial disease in individuals with coronary artery disease: prognostic importance, care gaps, and impact of therapy Am Heart J 2008 Feb;155:348-355.[Medline]
  8. Higgins TL, Estafanous FG, Loop FD, Beck GJ, Blum JM, Paranandi L. Stratification of morbidity and mortality outcome by preoperative risk factors in coronary artery bypass patients. A clinical severity score. JAMA 1992;267:2344-2348.[Abstract/Free Full Text]
  9. O'Connor GT, Plume SK, Olmstead EM, et al. Multivariate prediction of in-hospital mortality associated with coronary artery bypass graft surgery. Northern New England Cardiovascular Disease Study Group. Circulation 1992;85:2110-2118.[Abstract/Free Full Text]
  10. Nashef SA, Roques F, Michel P, Gauducheau E, Lemeshow S, Salamon R. European system for cardiac operative risk evaluation (EuroSCORE) Eur J Cardiothorac Surg 1999;16:9-13.[Abstract/Free Full Text]
  11. Michel P, Roques F, Nashef SA, EuroSCORE Project Group Logistic or additive EuroSCORE for high-risk patients? Eur J Cardiothorac Surg 2003;23:684-687.[Abstract/Free Full Text]
  12. Chu D, Bakaeen FG, Wang XL, Dao TK, LeMaire SA, Coselli JS, Huh J. The impact of peripheral vascular disease on long-term survival after coronary artery bypass graft surgery Ann Thorac Surg 2008;86:1175-1180.[Abstract/Free Full Text]
  13. Gummert JF, Funkat A, Osswald B, et al. EuroSCORE overestimates the risk of cardiac surgery: results from the national registry of the German Society of Thoracic and Cardiovascular Surgery Clin Res Cardiol 2009;98:363-369.[Medline]
  14. Gersh BJ, Califf RM, Loop FD, Akins CW, Pryor DB, Takaro TC. Coronary bypass surgery in chronic stable angina Circulation 1989;79(6 pt 2):I46-I59.[Medline]
  15. Magovern JA, Sakert T, Magovern GJ, et al. A model that predicts morbidity and mortality after coronary artery bypass graft surgery J Am Coll Cardiol 1996;28:1147-1153.[Abstract]
  16. Rosenthal GE, Vaughan Sarrazin M, Hannan EL. In-hospital mortality following coronary artery bypass graft surgery in Veterans Health Administration and private sector hospitals Med Care 2003;41:522-535.[Medline]



This article has been cited by other articles:


Home page
 Ann. Thorac. Surg.Home page
O. Ozeke, M. Gungor, and C. Ozer
Is Remote Ischemic Preconditioning Triggered by Intermittent Claudication Secondary to Peripheral Arterial Disease Responsible for Preventing Early Mortality After Coronary Artery Bypass Surgery?
Ann. Thorac. Surg., January 1, 2011; 91(1): 333 - 334.
[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):
Cristina Firanescu
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 van Straten, A. H.M.
Right arrow Articles by van Zundert, A. A.J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by van Straten, A. H.M.
Right arrow Articles by van Zundert, A. A.J.
Related Collections
Right arrow Coronary disease

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