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The predicament of offering elective percutaneous coronary intervention at sites without on-site cardiac surgery
Editorial
The predicament of offering elective percutaneous coronary intervention at sites without on-site cardiac surgery Mandeep Singh, MD Rochester, MN
Many technological and pharmacologic advances in percutaneous coronary intervention (PCI) have been made over the past 25 years. Steerable guidewires, coronary artery stents, and new antiplatelet therapies have improved the success rate of PCI procedures. In addition, high-risk patients who, in the past, would have undergone surgical revascularization are now undergoing PCI. Despite performance of high-risk PCI procedures, the need for emergency coronary artery bypass surgery (CABG) has been steadily decreasing. Currently, the need for emergent CABG as a consequence of failure of PCI is reported to be b0.5%.1 This study by Melberg et al2 add to the growing literature on the safety of percutaneous coronary interventions (PCI) in a community hospital setting without on-site cardiac surgical facilities. The study is unique with its prospective, randomized design. The authors elaborated on logistics of patients inclusion and procedural safety measures, including expeditious transport program. Of 1064 appropriate patients, 609 met authors’ predefined angiographic criteria for low risk. Patients were excluded if they had unprotected left main stenosis, proximal left anterior descending stenosis, left anterior descending luminal diameter b2.5 mm, ejection fraction b35%, or dominant contralateral artery to previous infarction. Also excluded were patients with shock, acute myocardial infarction, and significant valvular disease. The authors did not report any deaths, emergent CABG, or stroke over the course of the study. One dissection was successfully managed with stents. There are several problems with generalizability of the results of this study. The study was underpowered to answer the primary hypothesis, bWhether patients could be selected angiographically to safely undergo PCI at a community hospital without on-site surgical backup.Q Secondly, the patient selection criteria and risk categorization was solely based on angiographic variables. It is
From the Mayo Clinic, Cardiac Catheterization Lab, Rochester, MN. Submitted July 18, 2005; accepted August 12, 2005. E-mail: [email protected] Am Heart J 2006;152:810-1 0002-8703/$ - see front matter n 2006, Published by Mosby, Inc. doi:10.1016/j.ahj.2005.08.024
now documented, by various risk models for prediction of inhospital complications after PCI, that acuity of presentation, left ventricular function, and comorbid illnesses such as renal failure or peripheral vascular disease are paramount in risk determination.3 - 6 The performance of PCI for acute myocardial infarction in a catheterization-capable, community hospital without on-site surgical suites initially met with similar resistance. More recently, many observational studies and 1 randomized trial favored such an approach.7 - 9 The lack of similar support for elective PCI in hospitals without on-site surgery may stem from several key issues. Firstly, time to treatment is not crucial as in patients treated for acute myocardial infarction. The procedure can be tailored to suit patients comfort and needs. He or she can choose the center and/or the physician performing the coronary interventions. Secondly, although the incidence of emergent CABG after unsuccessful PCI with the current armamentarium in a stable low-risk patient will be even b1 in 200, the problems still exist with accurately predicting this complication. Therefore, it is still not clear which patients can or cannot be safely performed at centers without cardiac surgery. In a recent study, female sex and the American College of Cardiology/American Heart Association type C lesions were found to be the predictors of emergent CABG.1 The current risk models either do not address prediction of emergent CABG after PCI or include this complication under composite events. Moreover, none of the current models are derived from stable low-risk population, as included in the current study. The lack of any validated models makes it difficult for the interventional consultants to choose patients suitable for PCI at these sites or predict which patients are more likely to have complications. Thirdly, in the rare setting when the patient needs emergent CABG, the associated morbidity and mortality is significant. Additional time delays in lieu of transport to a center with surgical facilities may be detrimental.10 This fear may sway the patients away from the centers not equipped with cardiac surgery. Fourthly, the volume-outcome relationships favor performance of PCI at centers with on-site surgery, which traditionally have higher angioplasty volumes as compared with community hospitals.11 The current American College of
American Heart Journal Volume 152, Number 5
Cardiology and American Heart Association guidelines do not, therefore, support performance of such elective procedures at hospitals without on-site surgical programs.12 On the contrary, the advantages of performance of PCI at community hospitals cannot be ignored. The geographic or socioeconomic factors limit access to such high-volume centers, such that alternative health care delivery mechanisms, including performance of such procedures, need to be developed and adopted. So far, the available studies in this field are limited to singlecenter, observational studies. At Mayo Health System sites without on-site cardiac surgery, we have performed PCI in stable patients and also primary PCI for acute myocardial infarction with excellent results.7,13 For these centers to perform PCI without surgical backup, rigorous quality assurance measures need to be in place. The mechanisms of patient safety are paramount if efforts are to be made in sustaining such programs. The standard of care and outcomes must measure up to a tertiary care hospital. Most of the guidelines outlined for performance of primary PCI should also be extended to elective PCI. It is important to underscore the importance of patient selection at these centers. There are several excellent models that can accurately predict not only inhospital mortality but also other major adverse cardiovascular outcomes, including the need for emergent CABG. The use of only angiographic variables in risk assessment may ignore important patient-centered and presentation variables that are paramount in outcome of these procedures. This Norwegian study is an important step that will help expand the conduct of elective PCI at centers without surgical backup. More studies with larger numbers and broader indications using the validated models for risk prediction are needed for us to determine the safety of these procedures at facilities without surgical backup. The successful performance of PCI at hospitals without on-site surgery requires an integrated approach involving physicians, allied health staff, and the logistic constraints of the institution. In hospitals without the on-site surgical facility, development of systems for effective and prompt transfer to a hospital with such facility is important. Another requirement for the performance of PCI without on-site cardiac surgery should be continuous analysis of all aspects of such a program, including clinical and procedural outcomes. However, to what extent this will be a practical and effective approach for most of community hospitals in the United States and abroad is predicated on adhering to rigorous quality standards by
Singh 811
these institutions and acceptance by the cardiovascular community of its safety and efficacy.
References 1. Seshadri N, Whitlow PL, Acharya N, et al. Emergency coronary artery bypass surgery in the contemporary percutaneous coronary intervention era. Circulation 2002;106:2346 - 50. 2. Melberg T, Nilsen DWT, Larsen AI, et al. Non-emergent coronary angioplasty without on-site surgical back-up: a randomized study evaluating outcomes in low-risk patients. Am Heart J 2006;152:888 - 95. 3. Singh M, Lennon RJ, Holmes DR Jr, et al. Correlates of procedural complications and a simple integer risk score for percutaneous coronary intervention. J Am Coll Cardiol 2002;40:387 - 93. 4. Moscucci M, Kline-Rogers E, Share D, et al. Simple bedside additive tool for prediction of in-hospital mortality after percutaneous coronary interventions. Circulation 2001;104:263 - 8. 5. Shaw RE, Anderson HV, Brindis RG, et al. Development of a risk adjustment mortality model using the American College of Cardiology–National Cardiovascular Data Registry (ACC-NCDR) experience: 1998-2000. J Am Coll Cardiol 2002;39:1104 - 12. 6. Resnic FS, Ohno-Machado L, Selwyn A, et al. Simplified risk score models accurately predict the risk of major in-hospital complications following percutaneous coronary intervention. Am J Cardiol 2001; 88:5 - 9. 7. Singh M, Ting HH, Gersh BJ, et al. Percutaneous coronary intervention for ST-segment and non–ST-segment elevation myocardial infarction at hospitals with and without on-site cardiac surgical capability. Mayo Clin Proc 2004;79:738 - 44. 8. Wharton TP Jr, Grines LL, Turco MA, et al. Primary angioplasty in acute myocardial infarction at hospitals with no surgery on-site (the PAMI–No SOS study) versus transfer to surgical centers for primary angioplasty. J Am Coll Cardiol 2004;43:1943 - 50. 9. Aversano T, Aversano LT, Passamani E, et al. Thrombolytic therapy vs primary percutaneous coronary intervention for myocardial infarction in patients presenting to hospitals without on-site cardiac surgery: a randomized controlled trial. Jama 2002;287:1943 - 51. 10. Lotfi M, Mackie K, Dzavik V, et al. Impact of delays to cardiac surgery after failed angioplasty and stenting. J Am Coll Cardiol 2004;43:337 - 42. 11. Wennberg DE, Lucas FL, Siewers AE, et al. Outcomes of percutaneous coronary interventions performed at centers without and with onsite coronary artery bypass graft surgery. JAMA 2004;292:1961 - 8. 12. Smith SC Jr, Dove JT, Jacobs AK, et al. ACC/AHA guidelines of percutaneous coronary interventions (revision of the 1993 PTCA guidelines) — executive summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (committee to revise the 1993 guidelines for percutaneous transluminal coronary angioplasty). J Am Coll Cardiol 2001; 37:2215 - 39. 13. Ting HH, Garratt KN, Singh M, et al. Low-risk percutaneous coronary interventions without on-site cardiac surgery: two years’ observational experience and follow-up. Am Heart J 2003;145: 278 - 84.
The predicament of offering elective percutaneous coronary intervention at sites without on-site cardiac surgery Mandeep Singh, MD Rochester, MN
Many technological and pharmacologic advances in percutaneous coronary intervention (PCI) have been made over the past 25 years. Steerable guidewires, coronary artery stents, and new antiplatelet therapies have improved the success rate of PCI procedures. In addition, high-risk patients who, in the past, would have undergone surgical revascularization are now undergoing PCI. Despite performance of high-risk PCI procedures, the need for emergency coronary artery bypass surgery (CABG) has been steadily decreasing. Currently, the need for emergent CABG as a consequence of failure of PCI is reported to be b0.5%.1 This study by Melberg et al2 add to the growing literature on the safety of percutaneous coronary interventions (PCI) in a community hospital setting without on-site cardiac surgical facilities. The study is unique with its prospective, randomized design. The authors elaborated on logistics of patients inclusion and procedural safety measures, including expeditious transport program. Of 1064 appropriate patients, 609 met authors’ predefined angiographic criteria for low risk. Patients were excluded if they had unprotected left main stenosis, proximal left anterior descending stenosis, left anterior descending luminal diameter b2.5 mm, ejection fraction b35%, or dominant contralateral artery to previous infarction. Also excluded were patients with shock, acute myocardial infarction, and significant valvular disease. The authors did not report any deaths, emergent CABG, or stroke over the course of the study. One dissection was successfully managed with stents. There are several problems with generalizability of the results of this study. The study was underpowered to answer the primary hypothesis, bWhether patients could be selected angiographically to safely undergo PCI at a community hospital without on-site surgical backup.Q Secondly, the patient selection criteria and risk categorization was solely based on angiographic variables. It is
From the Mayo Clinic, Cardiac Catheterization Lab, Rochester, MN. Submitted July 18, 2005; accepted August 12, 2005. E-mail: [email protected] Am Heart J 2006;152:810-1 0002-8703/$ - see front matter n 2006, Published by Mosby, Inc. doi:10.1016/j.ahj.2005.08.024
now documented, by various risk models for prediction of inhospital complications after PCI, that acuity of presentation, left ventricular function, and comorbid illnesses such as renal failure or peripheral vascular disease are paramount in risk determination.3 - 6 The performance of PCI for acute myocardial infarction in a catheterization-capable, community hospital without on-site surgical suites initially met with similar resistance. More recently, many observational studies and 1 randomized trial favored such an approach.7 - 9 The lack of similar support for elective PCI in hospitals without on-site surgery may stem from several key issues. Firstly, time to treatment is not crucial as in patients treated for acute myocardial infarction. The procedure can be tailored to suit patients comfort and needs. He or she can choose the center and/or the physician performing the coronary interventions. Secondly, although the incidence of emergent CABG after unsuccessful PCI with the current armamentarium in a stable low-risk patient will be even b1 in 200, the problems still exist with accurately predicting this complication. Therefore, it is still not clear which patients can or cannot be safely performed at centers without cardiac surgery. In a recent study, female sex and the American College of Cardiology/American Heart Association type C lesions were found to be the predictors of emergent CABG.1 The current risk models either do not address prediction of emergent CABG after PCI or include this complication under composite events. Moreover, none of the current models are derived from stable low-risk population, as included in the current study. The lack of any validated models makes it difficult for the interventional consultants to choose patients suitable for PCI at these sites or predict which patients are more likely to have complications. Thirdly, in the rare setting when the patient needs emergent CABG, the associated morbidity and mortality is significant. Additional time delays in lieu of transport to a center with surgical facilities may be detrimental.10 This fear may sway the patients away from the centers not equipped with cardiac surgery. Fourthly, the volume-outcome relationships favor performance of PCI at centers with on-site surgery, which traditionally have higher angioplasty volumes as compared with community hospitals.11 The current American College of
American Heart Journal Volume 152, Number 5
Cardiology and American Heart Association guidelines do not, therefore, support performance of such elective procedures at hospitals without on-site surgical programs.12 On the contrary, the advantages of performance of PCI at community hospitals cannot be ignored. The geographic or socioeconomic factors limit access to such high-volume centers, such that alternative health care delivery mechanisms, including performance of such procedures, need to be developed and adopted. So far, the available studies in this field are limited to singlecenter, observational studies. At Mayo Health System sites without on-site cardiac surgery, we have performed PCI in stable patients and also primary PCI for acute myocardial infarction with excellent results.7,13 For these centers to perform PCI without surgical backup, rigorous quality assurance measures need to be in place. The mechanisms of patient safety are paramount if efforts are to be made in sustaining such programs. The standard of care and outcomes must measure up to a tertiary care hospital. Most of the guidelines outlined for performance of primary PCI should also be extended to elective PCI. It is important to underscore the importance of patient selection at these centers. There are several excellent models that can accurately predict not only inhospital mortality but also other major adverse cardiovascular outcomes, including the need for emergent CABG. The use of only angiographic variables in risk assessment may ignore important patient-centered and presentation variables that are paramount in outcome of these procedures. This Norwegian study is an important step that will help expand the conduct of elective PCI at centers without surgical backup. More studies with larger numbers and broader indications using the validated models for risk prediction are needed for us to determine the safety of these procedures at facilities without surgical backup. The successful performance of PCI at hospitals without on-site surgery requires an integrated approach involving physicians, allied health staff, and the logistic constraints of the institution. In hospitals without the on-site surgical facility, development of systems for effective and prompt transfer to a hospital with such facility is important. Another requirement for the performance of PCI without on-site cardiac surgery should be continuous analysis of all aspects of such a program, including clinical and procedural outcomes. However, to what extent this will be a practical and effective approach for most of community hospitals in the United States and abroad is predicated on adhering to rigorous quality standards by
Singh 811
these institutions and acceptance by the cardiovascular community of its safety and efficacy.
References 1. Seshadri N, Whitlow PL, Acharya N, et al. Emergency coronary artery bypass surgery in the contemporary percutaneous coronary intervention era. Circulation 2002;106:2346 - 50. 2. Melberg T, Nilsen DWT, Larsen AI, et al. Non-emergent coronary angioplasty without on-site surgical back-up: a randomized study evaluating outcomes in low-risk patients. Am Heart J 2006;152:888 - 95. 3. Singh M, Lennon RJ, Holmes DR Jr, et al. Correlates of procedural complications and a simple integer risk score for percutaneous coronary intervention. J Am Coll Cardiol 2002;40:387 - 93. 4. Moscucci M, Kline-Rogers E, Share D, et al. Simple bedside additive tool for prediction of in-hospital mortality after percutaneous coronary interventions. Circulation 2001;104:263 - 8. 5. Shaw RE, Anderson HV, Brindis RG, et al. Development of a risk adjustment mortality model using the American College of Cardiology–National Cardiovascular Data Registry (ACC-NCDR) experience: 1998-2000. J Am Coll Cardiol 2002;39:1104 - 12. 6. Resnic FS, Ohno-Machado L, Selwyn A, et al. Simplified risk score models accurately predict the risk of major in-hospital complications following percutaneous coronary intervention. Am J Cardiol 2001; 88:5 - 9. 7. Singh M, Ting HH, Gersh BJ, et al. Percutaneous coronary intervention for ST-segment and non–ST-segment elevation myocardial infarction at hospitals with and without on-site cardiac surgical capability. Mayo Clin Proc 2004;79:738 - 44. 8. Wharton TP Jr, Grines LL, Turco MA, et al. Primary angioplasty in acute myocardial infarction at hospitals with no surgery on-site (the PAMI–No SOS study) versus transfer to surgical centers for primary angioplasty. J Am Coll Cardiol 2004;43:1943 - 50. 9. Aversano T, Aversano LT, Passamani E, et al. Thrombolytic therapy vs primary percutaneous coronary intervention for myocardial infarction in patients presenting to hospitals without on-site cardiac surgery: a randomized controlled trial. Jama 2002;287:1943 - 51. 10. Lotfi M, Mackie K, Dzavik V, et al. Impact of delays to cardiac surgery after failed angioplasty and stenting. J Am Coll Cardiol 2004;43:337 - 42. 11. Wennberg DE, Lucas FL, Siewers AE, et al. Outcomes of percutaneous coronary interventions performed at centers without and with onsite coronary artery bypass graft surgery. JAMA 2004;292:1961 - 8. 12. Smith SC Jr, Dove JT, Jacobs AK, et al. ACC/AHA guidelines of percutaneous coronary interventions (revision of the 1993 PTCA guidelines) — executive summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (committee to revise the 1993 guidelines for percutaneous transluminal coronary angioplasty). J Am Coll Cardiol 2001; 37:2215 - 39. 13. Ting HH, Garratt KN, Singh M, et al. Low-risk percutaneous coronary interventions without on-site cardiac surgery: two years’ observational experience and follow-up. Am Heart J 2003;145: 278 - 84.