© Borgis - New Medicine 3/2003, s. 34-36
Radoslaw Zwolinski, Janusz Zaslonka, Ryszard Jaszewski, Witold Pawlowski, Bogdan Jegier, Andrzej Walczak, Leszek Markuszewski, Alicja Iwaszkiewicz, Stanislaw Ostrowski
Coronary bypass surgery in a group of operated patients over 75 years of age – 15 year study
Department of Cardiac Surgery, Institute of Cardiology, Medical University of Lodz, Poland
Head: prof. Janusz Zaslonka, MD, PhD
Summary
The benefits of coronary revascularisation for ischaemic heart disease (IHD) are well-documented for patients with coronary artery disease (CAD) in general. In the last two decades concomitant improvements in medical treatment and interventional cardiology for CAD have changed referral patterns for CABG, and have increased the number of older and high-risk patients proceeding to surgery. This study was undertaken to analyze the trends and results of surgical treatment during the last 15 years.
Purpose: The study was undertaken to outline changes in an elderly (> 75) population of patients referred for CABG during the last 15 years.
Material: From 1988 to 2002, 5320 patients underwent the CABG procedure. This study included all operated patients over 75 years of age.
Methods: The 15 years were subdivided into five time periods of 3 years. Group 1 was 1988-1990, group 2 1991-1993, group 3 1994-1996, group 4 1997-1999, and group 5 between 2000 and 2002.
Results: There is a significant increase in operated patients over 75 years of age, and this population is getting older. On the basis of EuroSCORE our findings show an increase in elderly patients who were referring to CABG facing a medium or high risk from surgery. Despite the increase in high-risk patients, the risk of hospital mortality has not significantly changed but there is an increased number of perioperative morbidities. We therefore believe that earlier indication for CABG, especially in an elderly population of patients, should be revised, and expanded criteria for CABG should be considered.
Introduction
The benefits of coronary revascularisation for ischaemic heart disease (IHD) are well-documented for patients with coronary artery disease (CAD) in general. Because of improvements in surgical and anesthesiological techniques and myocardial protection, the outcome has improved over the last two decades, with significant decreasing hospital mortality in the total population. In last twenty years concomitant improvements in medical treatment and interventional cardiology for CAD have changed referral patterns for CABG, and have increased the number of older and high-risk patients proceeding to surgery (1). The demographics of patients undergoing coronary artery bypass grafting (CABG) have changed over time and may contribute to the differing operative mortality. During the last few years, cardiac surgeons and cardiologists have noted a trend towards surgical treatment of older and sicker patients. Cardiac surgery in the elderly is a high-risk procedure because many of these patients have concomitant systemic disease and other disabilities (2, 3, 4). This study was undertaken to analyze the trends and results of surgical treatment during the last 15 years. Most previous publications have focused on the risk factors and results of treatment in all groups of patients. In our study we have tried to describe the trends and results of surgery in a population of operated patients over 75 years of age. This study was designed to answer the question: is the population of patients referred to surgery, older and sicker, or sicker and concomitantly older?
Material
From 1988 to 2002, 5320 patients underwent a CABG procedure. This study included 183 operated patients over 75 years of age (Fig. 1).
Fig. 1 Distribution of coronary artery bypass grafting during the study including patients> 75 years of age.
Methods
The 15 years were subdivided into five time periods of 3 years each. Group 1 was operated patients between 1988-1990, group 2 between 1991-1993, group 3 between 1994-1996, group 4 between 1997-1999, and group 5 between 2000 and 2002.
Surgical Technique
The operative technique included a standard median sternotomy, and routine aortic and right atrial canulation. All procedures were performed on a cardiopulmonary bypass with hypothermia at 33-35°C. Myocardial protection was performed with an infusion of cold (4°C) crystaloid St. Thomas´ Hospital cardioplegia. Revascularisation was performed during a single aortic cross-clamping. The left internal mammary artery (LIMA) was used to bypass the left anterior descending artery or its diagonal branches as a sequential graft.
Results
There is a significant increase of operated patients over 75 years of age, and this population is getting older. The percentage of men and women referred to CABG is at the same level approximately 60/40%.
In this population the number of patients undergoing CABG with neurological, uro-nephrological problems and with a history of myocardial infarction increased during the study. In this population the number of patients referred to surgery with left main stenosis and with poor LVEF also increased. A significant decline in emergency operations was noticed.
Table 1 presents the clinical characteristics of patients from groups 3, 4 and 5.
Table 1. Baseline characteristics and clinical history prior to surgery.
| | Group 3 | Group 4 | Group 5 |
| men | 6 (60%) | 26 (62%) | 84 (65%) |
| women | 4 (40%) | 16 (38%) | 46 (35%) |
| diabetes mellitus | 3 (30%) | 9 (21%) | 29 (22,3%) |
| hypertension | 6 (60%) | 26 (61.9%) | 88 (68%) |
| hyperlipidemia | 7 (70%) | 31 (73.8%) | 99 (76%) |
| peripheral vascular atherosclerosis | 1 (10%) | 9 (21%) | 30 (23%) |
| neurological pathology | 0 | 2 (4.7%) | 9 (6.9%) |
| uro-nephrological pathology | 0 | 2 (4.7%) | 9 (7%) |
| left main stenosis | 1 (10%) | 5 (11.9%) | 19 (14.6%) |
| preoperative myocardial infarction | 4(40%) | 27 (64%) | 90 (69%) |
| poor LVEF (50-30%) | 1 (10%) | 7 (14.3%) | 26 (20%) |
| Euro-SCORE | 5,8 | 6.1 | 6.2 |
| urgent operation | 1 (10%) | 4 (9.5%) | 7 (5.4%) |
| mortality | 1 (10%) | 6 (14.2%) | 16 (12.3%) |
The clinical condition of patients indicated for CABG has been confirmed by the EuroScore test (5). Our findings showed an increase in elderly patients referred for CABG with a medium or high risk in surgery.
Discussion
The study revealed that surgical practice is constantly changing. In the last two decades a concomitant improvement in medical treatment and interventional cardiology for CAD have changed referral patterns for CABG, and have increased the number of older and higher-risk patients referred for surgery (1, 6, 7).
Mortality in operated patients over 75 years of age is relatively high, but comparable with that found by other authors considering large groups of patients (8, 9). This higher mortality rate and the increasing number of patients referred for CABG> 75 could suggest that stronger selection criteria for CABG in an older population of patients can limit the number of patients referred for surgery. For older patients, with a limited long-term survival, it will be important to study, not only survival, but also the quality of life, to justify the benefits from CABG. In a recent meta-analysis by Duits (10), in which seventeen prospective quality of life studies were reviewed in patients after CABG, only one study looked at patients older than 70 years. In that study (11) it was found that an age above 70 years was associated with a reduced improvement of quality of life. These differences were presented in the energy, sleep, and social isolation sections from the Nottingham Health Profile Questionnaire used for the study.
Our findings confirmed a time-related increase in the preoperative risk profile of patients. Advances in technology and anaesthesia, a new approach to intensive care after surgery, improvement in medical management as well as methods of myocardial protection, and use of internal mammary artery grafts may have all contributed to a reduced mortality rate in the last decade (12).
On a EuroSCORE basis, our findings demonstrated an increase in elderly patients who were referred for CABG with medium and high risk of surgery.
Despite the increase in high-risk patients the risk of hospital mortality has not significantly changed. The significant decline in emergency operations can be explained by the improvement of invasive and non-invasive cardiological treatments provided to stabilize patients before referring for CABG.
Conclusion
We believe that an earlier indication for CABG, especially in the elderly, should be revised, and expanded criteria for CABG should be individually considered. On the basis of our study we conclude that in the last 15 years surgery sicker and concomitantly older patients were reffered for surgery.
Piśmiennictwo
1. Abramov D. et al.: Trends in coronary artery bypass surgery results: a recent 9-year study. Ann. Thorac. Surg. 2000; 70:84-90. 2. Jones E.S. et al.: Coronary bypass surgery: is the operation different today? J. Thorac. Surg. 1991; 101:108-115. 3. Magovern J.A. et al.: A model that predicts morbidity and mortality after coronary artery bypass graft surgery. J. Am. Coll. Cardiol. 1996; 28:1147-53. 4. Katz N.M., Chase G.A.: Risk of cardiac operations for elderly patients: reduction of age factors. Ann. Thorac. Surg. 1997; 63:1309-14. 5. Nashef S.A.M. et al.: European system for cardiac operative risk evaluation (EuroSCORE). Eur. J. Cardio-thorac Surg. 1999; 16:9-13. 6. Herlitz J. et al.: Mortality, risk indicators for death, and mode of death in young and elderly patients during five years after coronary artery bypass graft. Clin. Cardiol. 2000; 23: 421-426. 7. Noyez L. et al.: Coronary bypass surgery: what is changing? Analysis of 3834 patients undergoing primary isolated myocardial revascularisation. Eur. J. Cardio-thorac Surg. 1998; 13:365-369. 8. He G.W. et al.: Determinations of operative mortality in elderly patients undergoing coronary artery bypass grafting. Emphasis on the influence of internal mammary artery grafting on mortality and morbidity. J. Thorac. Cardiovasc Surg. 1994; 108:73-81. 9. Khan S.S. et al.: Interaction of age and preoperaive risk factors in predicting operative mortality for coronary bypass surgery. Circulation 1992; 86:186-190. 10. Duits A.A. et al.: Prediction of quality of life after coronary artery bypass graft surgery: a review and evaluation of multiple recent studies. Psychosom Med. 1997; 59: 257-268. 11. Chocron S. et al.: Prospective study of quality of life before and after open heart operations. Ann. Thorac. Surg. 1996; 61:153-157. 12. Tu J.V., Wu K.: The improving outcomes of coronary artery bypass graft surgery in Ontario, 1981 to 1995. Can. Med. Assoc. J. 1998; 159: 221-7.
