- Email: [email protected]
Coronary Artery Bypass Graft Should Be Considered in Octogenarians With Multivessel Coronary Disease
Canadian Journal of Cardiology
-
(2016) 1e3
Editorial
Coronary Artery Bypass Graft Should Be Considered in Octogenarians With Multivessel Coronary Disease Bobby Yanagawa, MD, PhD,a John D. Puskas, MD,b Subodh Verma, MD PhD,a and Jan O. Friedrich, MD, MSc, D Philc a
Division of Cardiac Surgery, Li Ka Shing Knowledge Institute of St Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada b
c
Department of Cardiothoracic Surgery, Mount Sinai Beth Israel, New York, New York, USA
Departments of Critical Care and Medicine, Li Ka Shing Knowledge Institute of St Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada
See article by Zhang et al., pages xxx-xxx of this issue. Octogenarians represent a growing subpopulation for interventionalists and surgeons who perform coronary revascularization. Care of elderly patients requires careful consideration of coronary artery disease in the context of multiple accumulating chronic medical conditions, frailty, cognitive and functional impairment, quality of life, and goals of care. From a cardiac perspective, advanced age is associated with heart failure, valvulopathy, atrial fibrillation, and conduction defects in addition to coronary disease. The coronary anatomy of elderly patients is frequently more diffusely calcified and often challenging for the interventionalist and surgeon. Furthermore, age alone is a powerful predictor of adverse procedural events with greater risk of mortality, stroke, extended intensive care unit and hospital stays, and protracted time to full recovery. However, there is no doubt that octogenarians can benefit from coronary intervention.1 In this issue of the Canadian Journal of Cardiology, Zhang et al. present a meta-analysis of retrospective studies of coronary artery bypass graft (CABG) vs percutaneous coronary intervention (PCI) in octogenarians.2 This study offers some important insights. The authors found acceptable procedural and long-term mortality with PCI and CABG. The primary findings are lower in-hospital mortality in patients who underwent PCI and greater overall survival for patients who underwent CABG. Considering these findings, they conclude that the decision for either revascularization approach should be on the basis of a determination of the patient and their expected life expectancy or ‘future health outlook.’ A few methodological points deserve mention. First, the included studies were identified from an initial search strategy Received for publication January 26, 2016. Accepted January 28, 2016. Corresponding author: Dr Bobby Yanagawa, Division of Cardiac Surgery, St Michael’s Hospital, University of Toronto, Room 008D, 8th Floor Bond Wing, 30 Bond St, Toronto, Ontario M5B 1W8, Canada. Tel.: þ1-416-8645706; fax: þ1-416-864-5031. E-mail: [email protected] See page 3 for disclosure information.
that included only 117 articles, a relatively small number, suggesting either that some articles might have been missed or that the comparative effectiveness of CABG vs PCI has been rarely studied in octogenarians. Second, the quality of the included retrospective studies was deemed to be ‘outstanding’ but the authors do not provide enough details to explain how they arrived at these high quality ratings using their quality assessment tool. Regardless, retrospective studies are subject to more bias than randomized controlled trials (RCTs) or even prospective observational studies. Indeed, there appear to be some systemic differences between the CABG and PCI groups in the included retrospective studies (eg, average patient age in the CABG group is never older and the proportions of patients with hypertension and diabetes were typically slightly greater in the CABG groups compared with the PCI groups). Unfortunately, the authors were not able to identify CABG vs PCI RCTs that enrolled exclusively elderly patients, or reports of subgroups of elderly patients in CABG vs PCI RCTs as has been done for other subpopulations such as those with diabetes.3 Third, and perhaps most importantly, the authors do not provide the mean duration of follow-up or the time interval at which “overall survival” was assessed. This is particularly relevant in 80-year-old patients in whom “long-term” survival might only be a few years (eg, 6-month survival has different implications than 5-year survival). In the included studies follow-up ranged between 1 and 7.7 years with an average of 3 years. There was some variability in how the given procedures were performed in both arms of the included studies. As the authors state, PCI was performed with oldergeneration and bare-metal stents in some studies. Similarly, there was limited description of whether CABG was performed on-pump (ONCAB) or off-pump (OPCAB), the potential importance of which is described later. Finally, for short-term mortality I2 ¼ 47% (which one can consider moderate heterogeneity); because this did not meet the authors’ predefined heterogeneity threshold of I2 > 50%, they conducted a fixed effects analysis, which ignored this heterogeneity and yielded a statistically-significant result (P ¼ 0.03).
http://dx.doi.org/10.1016/j.cjca.2016.01.033 0828-282X/Ó 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
2
Random effects analysis, which adjusts for this heterogeneity, would have been the more conservative approach and would not have produced a statistically significant result (P ¼ 0.26). The take-home message is that octogenarians might have a survival benefit with CABG beyond approximately 3 years. We have previously reported progressively lower rates for overall mortality in patients older than 75 years who undergo CABG, which declined significantly from 6.0% in the earliest era (19901996) to 1.9% in the most recent era (2003-2010), despite the overall increase in comorbidities in our elderly patients.4 Importantly, age older than 80 years did not predict mortality in this series. However, before considering revascularization in elderly patients, several important points deserve attention. One cannot begin to discuss long-term benefit without operative survival. To determine the risk of operative mortality, one must include an assessment of frailty, which affects approximately half of all elderly patients with coronary disease or heart failure.5 Frailty is a representation of physiologic reserve that encompasses weakness, sarcopenia, weight loss, physical inactivity, and slowness.6 It affects operative morbidity and mortality and functional recovery from the insult of cardiac surgery.7,8 However, frailty is not adequately captured by the EuroSCORE and Society of Thoracic Surgeons (STS) mortality risk scores. It has traditionally been assessed using the surgeons’ ‘eyeball’ test. One wonders whether this was done implicitly by the clinicians in the included retrospective studies because the overall PCI population appeared slightly older and higher-risk, meaning that clinicians might have thought they would not tolerate CABG. There are now more than 19 different validated frailty assessment tools, many of which have been linked to cardiac interventional and surgical outcomes.9 Use of risk prediction models for frailty will be important to complement existing surgical risk models to more accurately determine a patients’ overall risk of mortality. This preoperative assessment of surgical risk should be carefully balanced by the need for repeat revascularization in the PCI group in increasingly older and frailer patients. When considering outcomes for the elderly, it is also important to stress that survival alone is not enough. Frail patients suffer a rapid loss of function after even short hospital stays and the recovery from sternotomy can take more than 6 months, with the possible need for intensive rehabilitation. Thus, one needs to determine not just the number of years but the quality of the years of added life that we can offer elderly patients. These complex decisions, more than ever, warrant a heart team approach, which might include input from the cardiologist, cardiac surgeon, geriatrician or geriatric cardiologist, physiotherapist, family or other caregivers, and of course, the patient. Finally, stroke is a complication that many consider worse than death. It is surprising to find that stroke rates in patients who underwent CABG and PCI were not different. Puskas et al.10 reviewed stroke events in 10,860 patients who underwent CABG and showed that age according to decade (odds ratio, 1.9; 95% confidence interval [CI], 1.7-2.1, P ¼ 0.00001) was an independent risk factor for stroke as well as previous transient ischemic attack and presence of carotid bruit. The results from this meta-analysis were also inconsistent with those of a previous meta-analysis that showed a lower rate of stroke with PCI (odds ratio, 0.14; 95% CI, 0.02-0.76) in patients older than 70 years
Canadian Journal of Cardiology Volume - 2016
with left main coronary disease compared with CABG.11 To mitigate this devastating complication, surgical revascularization should include more aggressive neuroprotective strategies for vulnerable patients: (1) preoperative workup should include routine use of carotid duplex studies and any suggestion of ascending aortic calcification on preoperative imaging should prompt a noncontrast computed tomography imaging of the chest. Intraoperative epiaortic ultrasound should be used to assess the calcific burden of the ascending aorta; (2) ONCAB should be performed with slightly higher perfusion pressures, particularly in patients with severe peripheral vascular disease and carotid stenosis to avoid watershed injury; (3) OPCAB with minimal or no-touch aortic procedure should be considered to reduce surgical morbidity in the elderly patient, in particular to decrease the risk of stroke. A meta-analysis of 100 studies and > 19,000 patients reported a significant linear relationship between risk profile and benefits of OPCAB for all-cause mortality, myocardial infarction, and stroke.12 A meta-analysis of 16 retrospective studies and > 18,000 patients reported lower incidence of stroke in the OPCAB vs ONCAB cohorts (relative risk, 0.65; 95% CI, 0.49- 0.87; P < 0.01).13 Similarly, a reduction of stroke from 3% to 1% was found in patients older than 70 years of age with OPCAB.14 A systematic review of RCTs that compared OPCAB and ONCAB concluded that it is reasonable to perform OPCAB to reduce risks of stroke (class IIa, level of evidence, A].15 Notably, stroke reduction with OPCAB was not shown in the German Off-Pump CABG in Elderly Patients (GOPCABE) trial of OPCAB vs ONCAB in patients older than 75 years of age.16 Furthermore, in the Coronary Artery Bypass Grafting Surgery Off- or On-pump Revascularisation Study (CORONARY), there was no difference in stroke with OPCAB and ONCAB overall but a trend toward improved composite primary outcomes with OPCAB in the subpopulations with higher EuroSCORE and age older than 70 years.17 This inconsistency in prospective trials could be because elderly patients recruited to RCTs are typically less sick, with fewer comorbidities and lower predicted risk of stroke, than the nonrandomized elderly population referred for CABG and would thus be less likely to benefit from OPCAB with respect to stroke reduction. Whether CABG is performed in octogenarians with cardiopulmonary bypass or with OPCAB, minimizing aortic manipulation should be a high strategic priority. The importance of the care of elderly cardiac patients is reflected in the burgeoning field of geriatric cardiology. The outcomes of surgical and interventional revascularization in elderly patients are generally more uncertain, with higher periprocedural risks, protracted recovery, and the need to assess the competing risks of noncardiac mortality. This makes the decision-making more individualized and nuanced. Overall, this report suggests that octogenarians with multivessel coronary artery disease, reasonable operative risk, and anticipated survival > 3 years should be considered for surgical revascularization. Otherwise, PCI should be the modality of choice. Surgically, the use of OPCAB with minimal aortic manipulation might further improve the procedural risks and for PCI, the choice of newer generation drug-eluting stents should further decrease the risk of in-stent restenosis, a major limitation of coronary stenting, and a major cause of death, myocardial infarction, and reintervention. Finally, the lack of prospective data should signal a call for more high-quality data
Yanagawa et al. Underutilization of CABG in the Elderly
to determine the optimal revascularization strategy with a focus on elderly patients in the primary analysis. Disclosures The authors have no conflicts of interest to disclose. References 1. Graham MM, Ghali WA, Faris PD, et al. Survival after coronary revascularization in the elderly. Circulation 2002;105:2378-84.
3
9. de Vries NM, Staal JB, van Ravensberg CD, et al. Outcome instruments to measure frailty: a systematic review. Ageing Res Rev 2011;10:104-14. 10. Puskas JD, Winston AD, Wright CE, et al. Stroke after coronary artery operation: incidence, correlates, outcome, and cost. Ann Thorac Surg 2000;69:1053-6. 11. Alam M, Virani SS, Shahzad SA, et al. Comparison by meta-analysis of percutaneous coronary intervention versus coronary artery bypass grafting in patients with a mean age of 70 years. Am J Cardiol 2013;112: 615-22.
2. Zhang Q, Zhao X, Gu H, et al. Clinical outcomes of coronary artery bypass grafting versus percutaneous coronary intervention in octogenarians with coronary artery disease. Can J Cardiol 2016. XX:xx-xx.
12. Kowalewski M, Pawliszak W, Malvindi PG, et al. Off-pump coronary artery bypass grafting improves short-term outcomes in high-risk patients compared with on-pump coronary artery bypass grafting: meta-analysis. J Thorac Cardiovasc Surg 2016;151:60-77.e58.
3. Verma S, Farkouh ME, Yanagawa B, et al. Comparison of coronary artery bypass surgery and percutaneous coronary intervention in patients with diabetes: a meta-analysis of randomised controlled trials. Lancet Diabetes Endocrinol 2013;1:317-28.
13. Altarabsheh SE, Deo SV, Rababa’h AM, et al. Off-pump coronary artery bypass reduces early stroke in octogenarians: a meta-analysis of 18,000 patients. Ann Thorac Surg 2015;99:1568-75.
4. Yanagawa B, Algarni KD, Yau TM, et al. Improving results for coronary artery bypass graft surgery in the elderly. Eur J Cardiothorac Surg 2012;42:507-12. 5. Afilalo J, Alexander KP, Mack MJ, et al. Frailty assessment in the cardiovascular care of older adults. J Am Coll Cardiol 2014;63:747-62. 6. Afilalo J, Karunananthan S, Eisenberg MJ, et al. Role of frailty in patients with cardiovascular disease. Am J Cardiol 2009;103:1616-21. 7. Sündermann S, Dademasch A, Praetorius J, et al. Comprehensive assessment of frailty for elderly high-risk patients undergoing cardiac surgery. Eur J Cardiothorac Surg 2011;39:33-7. 8. Makary MA, Segev DL, Pronovost PJ, et al. Frailty as a predictor of surgical outcomes in older patients. J Am Coll Surg 2010;210:901-8.
14. Athanasiou T, Al-Ruzzeh S, Kumar P, et al. Off-pump myocardial revascularization is associated with less incidence of stroke in elderly patients. Ann Thorac Surg 2004;77:745-53. 15. Puskas JD, Martin J, Cheng DC, et al. ISMICS Consensus Conference and statements of randomized controlled trials of off-pump versus conventional coronary artery bypass surgery. Innovations (Phila) 2015;10: 219-29. 16. Diegeler A, Börgermann J, Kappert U, et al. Off-pump versus on-pump coronary-artery bypass grafting in elderly patients. N Engl J Med 2013;368:1189-98. 17. Lamy A, Devereaux PJ, Prabhakaran D, et al. Off-pump or on-pump coronary-artery bypass grafting at 30 days. N Engl J Med 2012;366: 1489-97.
-
(2016) 1e3
Editorial
Coronary Artery Bypass Graft Should Be Considered in Octogenarians With Multivessel Coronary Disease Bobby Yanagawa, MD, PhD,a John D. Puskas, MD,b Subodh Verma, MD PhD,a and Jan O. Friedrich, MD, MSc, D Philc a
Division of Cardiac Surgery, Li Ka Shing Knowledge Institute of St Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada b
c
Department of Cardiothoracic Surgery, Mount Sinai Beth Israel, New York, New York, USA
Departments of Critical Care and Medicine, Li Ka Shing Knowledge Institute of St Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada
See article by Zhang et al., pages xxx-xxx of this issue. Octogenarians represent a growing subpopulation for interventionalists and surgeons who perform coronary revascularization. Care of elderly patients requires careful consideration of coronary artery disease in the context of multiple accumulating chronic medical conditions, frailty, cognitive and functional impairment, quality of life, and goals of care. From a cardiac perspective, advanced age is associated with heart failure, valvulopathy, atrial fibrillation, and conduction defects in addition to coronary disease. The coronary anatomy of elderly patients is frequently more diffusely calcified and often challenging for the interventionalist and surgeon. Furthermore, age alone is a powerful predictor of adverse procedural events with greater risk of mortality, stroke, extended intensive care unit and hospital stays, and protracted time to full recovery. However, there is no doubt that octogenarians can benefit from coronary intervention.1 In this issue of the Canadian Journal of Cardiology, Zhang et al. present a meta-analysis of retrospective studies of coronary artery bypass graft (CABG) vs percutaneous coronary intervention (PCI) in octogenarians.2 This study offers some important insights. The authors found acceptable procedural and long-term mortality with PCI and CABG. The primary findings are lower in-hospital mortality in patients who underwent PCI and greater overall survival for patients who underwent CABG. Considering these findings, they conclude that the decision for either revascularization approach should be on the basis of a determination of the patient and their expected life expectancy or ‘future health outlook.’ A few methodological points deserve mention. First, the included studies were identified from an initial search strategy Received for publication January 26, 2016. Accepted January 28, 2016. Corresponding author: Dr Bobby Yanagawa, Division of Cardiac Surgery, St Michael’s Hospital, University of Toronto, Room 008D, 8th Floor Bond Wing, 30 Bond St, Toronto, Ontario M5B 1W8, Canada. Tel.: þ1-416-8645706; fax: þ1-416-864-5031. E-mail: [email protected] See page 3 for disclosure information.
that included only 117 articles, a relatively small number, suggesting either that some articles might have been missed or that the comparative effectiveness of CABG vs PCI has been rarely studied in octogenarians. Second, the quality of the included retrospective studies was deemed to be ‘outstanding’ but the authors do not provide enough details to explain how they arrived at these high quality ratings using their quality assessment tool. Regardless, retrospective studies are subject to more bias than randomized controlled trials (RCTs) or even prospective observational studies. Indeed, there appear to be some systemic differences between the CABG and PCI groups in the included retrospective studies (eg, average patient age in the CABG group is never older and the proportions of patients with hypertension and diabetes were typically slightly greater in the CABG groups compared with the PCI groups). Unfortunately, the authors were not able to identify CABG vs PCI RCTs that enrolled exclusively elderly patients, or reports of subgroups of elderly patients in CABG vs PCI RCTs as has been done for other subpopulations such as those with diabetes.3 Third, and perhaps most importantly, the authors do not provide the mean duration of follow-up or the time interval at which “overall survival” was assessed. This is particularly relevant in 80-year-old patients in whom “long-term” survival might only be a few years (eg, 6-month survival has different implications than 5-year survival). In the included studies follow-up ranged between 1 and 7.7 years with an average of 3 years. There was some variability in how the given procedures were performed in both arms of the included studies. As the authors state, PCI was performed with oldergeneration and bare-metal stents in some studies. Similarly, there was limited description of whether CABG was performed on-pump (ONCAB) or off-pump (OPCAB), the potential importance of which is described later. Finally, for short-term mortality I2 ¼ 47% (which one can consider moderate heterogeneity); because this did not meet the authors’ predefined heterogeneity threshold of I2 > 50%, they conducted a fixed effects analysis, which ignored this heterogeneity and yielded a statistically-significant result (P ¼ 0.03).
http://dx.doi.org/10.1016/j.cjca.2016.01.033 0828-282X/Ó 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
2
Random effects analysis, which adjusts for this heterogeneity, would have been the more conservative approach and would not have produced a statistically significant result (P ¼ 0.26). The take-home message is that octogenarians might have a survival benefit with CABG beyond approximately 3 years. We have previously reported progressively lower rates for overall mortality in patients older than 75 years who undergo CABG, which declined significantly from 6.0% in the earliest era (19901996) to 1.9% in the most recent era (2003-2010), despite the overall increase in comorbidities in our elderly patients.4 Importantly, age older than 80 years did not predict mortality in this series. However, before considering revascularization in elderly patients, several important points deserve attention. One cannot begin to discuss long-term benefit without operative survival. To determine the risk of operative mortality, one must include an assessment of frailty, which affects approximately half of all elderly patients with coronary disease or heart failure.5 Frailty is a representation of physiologic reserve that encompasses weakness, sarcopenia, weight loss, physical inactivity, and slowness.6 It affects operative morbidity and mortality and functional recovery from the insult of cardiac surgery.7,8 However, frailty is not adequately captured by the EuroSCORE and Society of Thoracic Surgeons (STS) mortality risk scores. It has traditionally been assessed using the surgeons’ ‘eyeball’ test. One wonders whether this was done implicitly by the clinicians in the included retrospective studies because the overall PCI population appeared slightly older and higher-risk, meaning that clinicians might have thought they would not tolerate CABG. There are now more than 19 different validated frailty assessment tools, many of which have been linked to cardiac interventional and surgical outcomes.9 Use of risk prediction models for frailty will be important to complement existing surgical risk models to more accurately determine a patients’ overall risk of mortality. This preoperative assessment of surgical risk should be carefully balanced by the need for repeat revascularization in the PCI group in increasingly older and frailer patients. When considering outcomes for the elderly, it is also important to stress that survival alone is not enough. Frail patients suffer a rapid loss of function after even short hospital stays and the recovery from sternotomy can take more than 6 months, with the possible need for intensive rehabilitation. Thus, one needs to determine not just the number of years but the quality of the years of added life that we can offer elderly patients. These complex decisions, more than ever, warrant a heart team approach, which might include input from the cardiologist, cardiac surgeon, geriatrician or geriatric cardiologist, physiotherapist, family or other caregivers, and of course, the patient. Finally, stroke is a complication that many consider worse than death. It is surprising to find that stroke rates in patients who underwent CABG and PCI were not different. Puskas et al.10 reviewed stroke events in 10,860 patients who underwent CABG and showed that age according to decade (odds ratio, 1.9; 95% confidence interval [CI], 1.7-2.1, P ¼ 0.00001) was an independent risk factor for stroke as well as previous transient ischemic attack and presence of carotid bruit. The results from this meta-analysis were also inconsistent with those of a previous meta-analysis that showed a lower rate of stroke with PCI (odds ratio, 0.14; 95% CI, 0.02-0.76) in patients older than 70 years
Canadian Journal of Cardiology Volume - 2016
with left main coronary disease compared with CABG.11 To mitigate this devastating complication, surgical revascularization should include more aggressive neuroprotective strategies for vulnerable patients: (1) preoperative workup should include routine use of carotid duplex studies and any suggestion of ascending aortic calcification on preoperative imaging should prompt a noncontrast computed tomography imaging of the chest. Intraoperative epiaortic ultrasound should be used to assess the calcific burden of the ascending aorta; (2) ONCAB should be performed with slightly higher perfusion pressures, particularly in patients with severe peripheral vascular disease and carotid stenosis to avoid watershed injury; (3) OPCAB with minimal or no-touch aortic procedure should be considered to reduce surgical morbidity in the elderly patient, in particular to decrease the risk of stroke. A meta-analysis of 100 studies and > 19,000 patients reported a significant linear relationship between risk profile and benefits of OPCAB for all-cause mortality, myocardial infarction, and stroke.12 A meta-analysis of 16 retrospective studies and > 18,000 patients reported lower incidence of stroke in the OPCAB vs ONCAB cohorts (relative risk, 0.65; 95% CI, 0.49- 0.87; P < 0.01).13 Similarly, a reduction of stroke from 3% to 1% was found in patients older than 70 years of age with OPCAB.14 A systematic review of RCTs that compared OPCAB and ONCAB concluded that it is reasonable to perform OPCAB to reduce risks of stroke (class IIa, level of evidence, A].15 Notably, stroke reduction with OPCAB was not shown in the German Off-Pump CABG in Elderly Patients (GOPCABE) trial of OPCAB vs ONCAB in patients older than 75 years of age.16 Furthermore, in the Coronary Artery Bypass Grafting Surgery Off- or On-pump Revascularisation Study (CORONARY), there was no difference in stroke with OPCAB and ONCAB overall but a trend toward improved composite primary outcomes with OPCAB in the subpopulations with higher EuroSCORE and age older than 70 years.17 This inconsistency in prospective trials could be because elderly patients recruited to RCTs are typically less sick, with fewer comorbidities and lower predicted risk of stroke, than the nonrandomized elderly population referred for CABG and would thus be less likely to benefit from OPCAB with respect to stroke reduction. Whether CABG is performed in octogenarians with cardiopulmonary bypass or with OPCAB, minimizing aortic manipulation should be a high strategic priority. The importance of the care of elderly cardiac patients is reflected in the burgeoning field of geriatric cardiology. The outcomes of surgical and interventional revascularization in elderly patients are generally more uncertain, with higher periprocedural risks, protracted recovery, and the need to assess the competing risks of noncardiac mortality. This makes the decision-making more individualized and nuanced. Overall, this report suggests that octogenarians with multivessel coronary artery disease, reasonable operative risk, and anticipated survival > 3 years should be considered for surgical revascularization. Otherwise, PCI should be the modality of choice. Surgically, the use of OPCAB with minimal aortic manipulation might further improve the procedural risks and for PCI, the choice of newer generation drug-eluting stents should further decrease the risk of in-stent restenosis, a major limitation of coronary stenting, and a major cause of death, myocardial infarction, and reintervention. Finally, the lack of prospective data should signal a call for more high-quality data
Yanagawa et al. Underutilization of CABG in the Elderly
to determine the optimal revascularization strategy with a focus on elderly patients in the primary analysis. Disclosures The authors have no conflicts of interest to disclose. References 1. Graham MM, Ghali WA, Faris PD, et al. Survival after coronary revascularization in the elderly. Circulation 2002;105:2378-84.
3
9. de Vries NM, Staal JB, van Ravensberg CD, et al. Outcome instruments to measure frailty: a systematic review. Ageing Res Rev 2011;10:104-14. 10. Puskas JD, Winston AD, Wright CE, et al. Stroke after coronary artery operation: incidence, correlates, outcome, and cost. Ann Thorac Surg 2000;69:1053-6. 11. Alam M, Virani SS, Shahzad SA, et al. Comparison by meta-analysis of percutaneous coronary intervention versus coronary artery bypass grafting in patients with a mean age of 70 years. Am J Cardiol 2013;112: 615-22.
2. Zhang Q, Zhao X, Gu H, et al. Clinical outcomes of coronary artery bypass grafting versus percutaneous coronary intervention in octogenarians with coronary artery disease. Can J Cardiol 2016. XX:xx-xx.
12. Kowalewski M, Pawliszak W, Malvindi PG, et al. Off-pump coronary artery bypass grafting improves short-term outcomes in high-risk patients compared with on-pump coronary artery bypass grafting: meta-analysis. J Thorac Cardiovasc Surg 2016;151:60-77.e58.
3. Verma S, Farkouh ME, Yanagawa B, et al. Comparison of coronary artery bypass surgery and percutaneous coronary intervention in patients with diabetes: a meta-analysis of randomised controlled trials. Lancet Diabetes Endocrinol 2013;1:317-28.
13. Altarabsheh SE, Deo SV, Rababa’h AM, et al. Off-pump coronary artery bypass reduces early stroke in octogenarians: a meta-analysis of 18,000 patients. Ann Thorac Surg 2015;99:1568-75.
4. Yanagawa B, Algarni KD, Yau TM, et al. Improving results for coronary artery bypass graft surgery in the elderly. Eur J Cardiothorac Surg 2012;42:507-12. 5. Afilalo J, Alexander KP, Mack MJ, et al. Frailty assessment in the cardiovascular care of older adults. J Am Coll Cardiol 2014;63:747-62. 6. Afilalo J, Karunananthan S, Eisenberg MJ, et al. Role of frailty in patients with cardiovascular disease. Am J Cardiol 2009;103:1616-21. 7. Sündermann S, Dademasch A, Praetorius J, et al. Comprehensive assessment of frailty for elderly high-risk patients undergoing cardiac surgery. Eur J Cardiothorac Surg 2011;39:33-7. 8. Makary MA, Segev DL, Pronovost PJ, et al. Frailty as a predictor of surgical outcomes in older patients. J Am Coll Surg 2010;210:901-8.
14. Athanasiou T, Al-Ruzzeh S, Kumar P, et al. Off-pump myocardial revascularization is associated with less incidence of stroke in elderly patients. Ann Thorac Surg 2004;77:745-53. 15. Puskas JD, Martin J, Cheng DC, et al. ISMICS Consensus Conference and statements of randomized controlled trials of off-pump versus conventional coronary artery bypass surgery. Innovations (Phila) 2015;10: 219-29. 16. Diegeler A, Börgermann J, Kappert U, et al. Off-pump versus on-pump coronary-artery bypass grafting in elderly patients. N Engl J Med 2013;368:1189-98. 17. Lamy A, Devereaux PJ, Prabhakaran D, et al. Off-pump or on-pump coronary-artery bypass grafting at 30 days. N Engl J Med 2012;366: 1489-97.