Catheterizatlon and Cardiovascu\ar Diagnosis 27:14 (1992)
Editorial The Hot and Cold Issues of Laser Angioplasty Thomas J. Linnemeier, MD, FACC By 1990, a clinical trial found the thermal laser system to have a high complication rate, to be ineffective in A monumental advance in the treatment of coronary treating chronic total occlusions, and to have no lower disease occurred the day Andreas Gruentzig translumirestenosis rate than conventional balloon angioplasty nally dilated a coronary artery [ 1,2]. From the moment [ 121. This technique quickly took a backseat to the rapof that first coronary angioplasty, cardiologists were no idly expanding field of excimer laser angioplasty . longer solely diagnosticians and masters of medical management, they became “interventionalists. ” Despite the Excimer Laser Angioplasty explosive worldwide growth of coronary angioplasty in In the mid-1980s an exciting new laser source, the the early 1980s, it became clear that the technique was excimer or “cool-tip” laser, was tested in vitro [13,14]. not a panacea. The need for emergency surgical standby Incredibly precise cuts could be made through cadaveric was an undisputed dogma. The term “restenosis” becalcified atherosclerotic tissue. Though this technology came part of our vocabulary. The ability to treat chronic was considerably more expensive, its precision could not total occlusions remained elusive, demanding further inbe ignored; thus development proceeded at a rapid pace. vestigation. By 1989, the excimer laser proved successful in a multicenter coronary clinical trial with few complications Early Laser Investigation [15]. Chronic total occlusions were, by protocol, not In the early 1980s, physicians, politicians, and the attempted unless first crossed by a guidewire. Technical public were excited by the mystical and potentially pow- improvements continued and soon excimer laser angioerful “laser,” a legacy of Einstein’s genius [3]. In 1982, plasty was performed without subsequent balloon angioa laser was first used to relieve obstructions in cadaveric plasty [ 161. Despite early reports of high restenosis rates coronary arteries [4]. Could a laser open a chronic total [ 171 enthusiasm persisted among many cardiologists. occlusion, “seal” a dissection, and affect restenosis? In While many radiologists and vascular surgeons abanan effort to answer these questions, the newly created doned the technique of laser angioplasty, cardiologists field of “laser angioplasty” rapidly expanded, with continued to experiment and gather data [ 18,191. more attention given to laser sources and laser catheters Avoiding the issues of chronic total occlusion and rethan to vascular biology. Investigators, fearful of a po- stenosis, laser investigators focused on angiographic letentially catastrophic coronary perforation, used the pe- sion morphology. Cook et al. [20] suggested excimer ripheral vasculature as a “testing ground” for lasers. laser angioplasty was safe and effective therapy for leIn 1984, a laser was used to open occlusions in the sions not ideal for conventional balloon angioplasty , peripheral vasculature in vivo [5]. The problem of per- based on the A-B-C lesion morphology criteria estabforation was partially solved in 1986 when a heated lished by others [21,22]. Other potentially less expensive metal cap was added to the tip of the laser fiber [6]. ‘‘cool-tip” laser sources were developed to compete Within one month this “hot-tip’’ technology was used in with the excimer, such as the holmium system. the coronary artery in conjunction with conventional balOn January 3 1, 1992, the Food and Drug Administraloon angioplasty [7]. Scores of physicians, whether radiologists, cardiologists, or vascular surgeons, academicians or private practitioners, famous or infamous, were From the Cardiac Catheterization Laboratories, St. Vincent Hospital quite interested if not anxious to have this technology at and Health Care Center, Indiana Heart Institute, Indianapolis, Inditheir fingertips. Limited trials continued [8-101 and in ana. 1989 coronary laser thermal angioplasty was performed successfully without the need for subsequent balloon an- Received March 21, 1992; revision accepted March 25, 1992. gioplasty [ 111. Major manufacturers of coronary balloon Address reprint requests to Thomas J . Linnemeier, M.D., F.A.C.C., equipment began investing significant amounts of re- Northside Cardiology, P.C., 8402 Harcourt Road #300, Indianapolis, IN 46260. search and development funds into laser technology. HISTORICAL PERSPECTIVES
0 1992 Wiley-Liss, Inc.
2
Linnemeier
radio [36]. Obviously this woman, and the editors who elected to print her letter, did not look kindly upon the laser as a marketing tool. These and other issues were nationally televised on ABC’s “20/20” and viewed by millions on February 7, 1992. Dr. Timothy Johnson clearly expressed his concerns to the public, [37]: “So, PHYSICIAN CONCERNS along comes the excimer laser, an expensive but potenInitial disagreement over the training of cardiologists, tially exciting new technology. The company. . . . starts radiologists, and vascular surgeons portended a menac- selling it to hospitals and doctors start evaluating it on ing rift and subsequent battle over “turf” among the patients and investors see the potential for profit. All of subspecialties, especially in the United States. Some in- this just at the time that the cost of health care in this vestigators studied the thermal laser system [23] while country is becoming a crisis. But, should we introduce others favored the excimer laser [24]. Radiologists [25] this kind of new technology widely before we know exwere skeptical that thermal angioplasty helped lower the actly how important it is and how much it is going to restenosis rate in the peripheral vasculature as suggested cost? Should it be hyped in the media and advertised to in studies primarily authored by cardiologists [26]. the public? Who should pay for its evaluation and should While some radiologists were snickering [27] over the the researchers who are doing the evaluating own stock cardiologists’ definition of “laser success” [28], others in the company that makes the product? The story of the were expressing reservations over equipment costs, en- excimer laser illustrates just how troubling these questrepreneurial physicians, muddled data and terminology, tions can be.” The concerns Dr. Timothy Johnson expressed to the and the total lack of randomized trials. In addition, radiologists made public their concerns that the peripheral lay public are similar to those critical of laser angioplasty vasculature was being used by cardiologists, not as a in the interventional medical community. testing ground for laser investigation, but as a ploy to begin performing conventional peripheral interventions FUTURE DIRECTION ~91. Some vascular surgeons and radiologists were critical For a physician to derive financial benefit from a techof “institutes” and “centers” that advertised unproven nique or device invented by him is nothing new. The laser technology as a means to attract patients [30,31]. earliest pioneers of peripheral and coronary angioplasty , One vascular surgeon [32] was critical of peripheral laser however, were rarely disputed as being unbiased investrials published by radiologists [33] and even suggested tigators. The explosion of new devices for treating corthat those radiologists lacked the skills necessary to comonary disease that have not been adequately compared to petently perform the technique. conventional treatment, however, has created a credibilOne study [19] suggested that excimer laser angioity problem for the profession. This problem has the plasty performed without subsequent balloon angioplasty attention of American medicine and the public. Given had a lower restenosis rate than laser followed by balloon this controversy the following guidelines need to be reangioplasty , while another study suggested just the opviewed and given consideration. posite [34]. Some likened laser coronary angioplasty to the experience of Sisyphus, the legendary king of Corinth condemned for eternity to roll a heavy rock up a Conflict of Interest Guidelines that define potential conflict of interest hill in Hades only to have it roll down again as it neared have been established by the cardiology community the top [35]. As a result of discord within and between specialties, [38,39] remain valid today and should be adhered to. a plethora of entrepreneurial techniques, the high equip- Furthermore, when multicenter trials are in progress, ment costs, and the virtual lack of randomized trials, the nonstockholding investigators deserve to know which ininterventional community is left in a state of turmoil vestigators hold stock in that company, and stockholding regarding laser angioplasty. Of utmost concern is that investigators have the duty to share that information. Nonstockholding investigators should not find out on nathis turmoil has spread to the lay community. tional television that after years of collaborative research many of their coinvestigators are stockholders. AttendPUBLIC CONCERNS ees and participants of educational courses and national In a Letter to The Editor of the N e w England Journal programs, such as the American College of Cardiology of Medicine, a woman wrote of her annoyance with Scientific Sessions, the American Heart Association Sci‘‘miracle peddlers” advertising laser angioplasty on the entific Sessions, the Radiological Society of North
tion granted approval for the first of what will certainly be many excimer lasers (Advanced Interventional Systems, Inc., Irvine, CA) for the treatment of coronary disease.
Laser Angioplasty
America, and the Society for Cardiac Angiography and Interventions, also deserve that information. “Miracle Peddling” The practice of ‘‘miracle peddling” or advertising lasers to the lay public should be curbed. At least a portion of the public and medical community is offended by it. To market investigational laser devices as potential miracle cures that have not received approval by the Food and Drug Administration is premature and unethical. Comparison of New Devices to Balloon Angioplasty Based on Lesion Morphology The A-B-C lesion morphology system established by Ryan et al. [21] (1988 AHNACC guidelines) and refined by Ellis et al. [22] was designed to help predict success and complications of coronary angioplasty . This system has served the interventional cardiology community well. The evaluation of progressive new technologies, however, cannot and should not be compared to old standards [40,41]. Some have suggested that a niche for laser angioplasty has been established [42]. A niche for coronary laser angioplasty has been established only if the 1988 AHA/ ACC guidelines are meaningful predictors of angioplasty outcome in 1992. At the Indiana Heart Institute (St. Vincent Hospital, Indianapolis), during the calendar year of 1991, 2,617 percutaneous cardiac interventional procedures were performed. At least 50% of these patients had either multivessel disease or Type B or C lesion morphology [43]. Only 1% (26 patients) required emergency coronary artery bypass surgery and only 0.03% (1 patient) died. Therefore, in experienced hands and with improved balloon technology, the lesion morphology system is probably not an adequate predictor of success or complication today. Though safer angioplasty should always be a goal, treating chronic total occlusions and reducing restenosis are even greater challenges and cannot be forgotten. Randomized Trials To date, not one controlled multicenter randomized trial comparing conventional balloon angioplasty to excimer laser angioplasty in either the peripheral or coronary vasculature has been published. Such a trial needs to be done not only for scientific reasons but also to rest the concerns of critics. The excimer laser has reached a state of technical refinement that such a comparison is now fair. The primary investigator in the coronary arterial tree should be a cardiologist and in the peripheral vasculature a radiologist or vascular surgeon. The primary investigators should not hold a financial interest in the laser being investigated. These trials should be funded at least in part by the laser industry which has the
3
potential for tremendous gain if proven effective. Only a head-to-head randomized trial of balloon angioplasty versus laser angioplasty will prove or disprove the value of the laser, mend wounds among the subspecialties, silence critics, and advance the percutaneous treatment of cardiovascular disease.
REFERENCES 1. Gruentzig A: Transluminal dilatation of coronary artery stenosis
(letter). Lancet 1:263-266, 1978. 2. Gruentzig AR, Myler RK, Stertzer SH, et al: Coronary percutaneous transluminal angioplasty: Preliminary results (abstract). Circulation 58(Suppl 1I):II-56, 1978. 3. Einstein A: Zur quanteentheoris der Strahlung. Physiol Z 18: 121-128, 1917. 4. Choy DSJ, Stertzer SH, Rotterdam HZ, et al.: Laser coronary angioplasty; Experience with 9 cadaver hearts. Am J Cardiol50: 1209, 1982. 5 . Geschwind H, Boussignaac G, Teissiere B, et al: Percutaneous transluminal laser angioplasty in man (letter). Lancet 1:844, 1984. 6. Cumberland DC,Taylor DI, Welsh CL, et al: Percutaneous laser thermal angioplasty: Initial clinical results with a laser probe in total peripheral artery occlusions. Lancet 1457-1459, 1986. 7. Cumberland DC,Oakley GDG, Smith GH, et al: Percutaneous laser-assisted coronary angioplasty (letter). Lancet 2:214, 1986. 8. Sanborn TA, Bonan R, Cumberland DC,et al: Percutaneous laser-assisted balloon angioplasty with flexible central lumen laser probe catheters (abstract). Circulation 78(Suppl II):295, 1988. 9. Linnemeier TJ, Bonan R, Cumberland DC, et al: Human percutaneous laser-assisted coronary angioplasty of saphenous vein gypass grafts: Early multicenter experience (abstract). Circulation 78(Suppl II):295, 1988. 10. Linnemeier TJ, Cumberland DC, Rothbaum DA, et al: Human percutaneous laser-assisted coronary angioplasty: Efforts to reduce spasm and thrombosis (abstract). J Am Coll Cardiol 13:61A, 1989. 11. Linnemeier TI, Cumberland DC: Percutaneous laser coronary angioplasty without balloon angioplasty (letter) Lancet 154-155, 1989. 12. Linnemeier TJ, Rothbaum DA, Cumberland DC, et al: Percutaneous laser-assisted thermal coronary angioplasty in native coronary arteries and saphenous vein grafts: Initial results and angiographic follow-up. J Inv Cardiol 2:133-138, 1990. 13. Grundfest WS, Litvack F, Forrester JS, et al: Laser ablation of atherosclerotic plaque without adjacent tissue injury. J Am Coll Cardiol 5929-933, 1985. 14. Isner JM, Donaldson RF, Deckelbaum LI, et al: The excimer laser: Gross, light microscopic and ultrastructural analysis of potential advantages for use in laser therapy of cardiovascular disease. J Am Coll Cardiol 6:1102-1109, 1985. 15. Margolis JR, Litvack F, Grundfest W, Eigler N, Goldenberg T, Laudenslager J, Tsoi D, Wong S, Segalowitz, J, Hestrin L, Rothbaum D, Linnemeier T, Helfant R, Forrester J: Excimer laser coronary angioplasty: Results of a multicenter study (abstract). Circulation 8O(Suppl 1I):II-477, 1989. 16. Rothbaum DA, Litvack F, Margolis J, Eigler N, Linnemeier T, King S, Douglas J, Tsoi D, Cook S, Hestrin L, Goldenberg T, Segalowitz J, Grundfest W, Forrester J: Stand-alone percutaneous excimer laser coronary angioplasty (abstract). J Am Coll Cardiol 15:26A, 1990.
4
Linnemeier
17. Rothbaum D, Linnemeier T, Landin R, Ball M, Hodes Z, Riddell
and patency in laser angioplasty (letter and response). Radiology
R, Morgan S: Excimer laser coronary angioplasty: Angiographic restenosis rate at six month follow-up (abstract). J Am Coll Cardiol 17:205A, 1991. 18. Litvack F, Eigler NL, Margolis JR, Grundfest WS, Rothbaum D, Linnemeier T, Hestrin LB, Tsoi D, Cook SL, Krauthamer D, Goldenberg T, Laudenslager JR, Segalowitz J, Forrester JS: Percutaneous excimer laser coronary angioplasty. Am J Cardiol 66:
170:576-578, 1989. 29. Ring El: New interventional devices and the need for restraint. Radiology 170:945-946, 1989. 30. Strandness E, Barnes RW, Katzen B, et at: Indiscriminate use of laser angioplasty. Radiology 172:945-946, 1989. 31. Strandness DE, Barnes RW, Katzen BT, et al. Indiscriminate use of laser-assisted angioplasty (letter). N Engl J Med 321:1417, 1989. 32. Diethrich EB. Value of laser-assisted angioplasty in the community hospital (letter). Radiology 170:877, 1989. 33. Levy JM, Hessel SJ, Horsley WW, et al. Value of laser-assisted angioplasty in the community hospital. Radiology 170: 10171018, 1989. 34. Kent KM, Satler LF, Kehoe MK, et al. Stand alone excimer laser angioplasty (abstract). Circulation 84(Suppl 1I):II-363, 1991. 35. Isner JM, Rosenfield KR, Losordo DW. Excimer laser atherectomy. The greening of Sisyphus. Circulation 81:2018-2021, 1990. 36. Fischl, Irene. The Miracle Peddlers (letter). N Engl J Med 321: 1417, 1989. 37. Johnson T.“20/20”. American Broadcasting System, Inc. Roger Sergel, Producer. Televised February 7, 1992. 38. Frommer PL, Ross J, Benson JA, et al. Task force IV: Scientific
1027-1032, 1990. 19. Karsch KR, Haase KK, Voelker W, et al: Percutaneous coronary
20.
21.
22.
23.
excimer laser angioplasty in patients with stable and unstable angina pectoris. Circulation 81:1849-1859, 1990. Cook SL, Eigler NL, Shefer A, et al: Percutaneous excimer laser coronary angioplasty of lesions not ideal for balloon angioplasty . Circulation 84:632-643, 1991. Ryan TJ, Faxon DP, Gunnar RM, et al: Guidelines for percutaneous transluminal coronary angioplasty. A report of the American College of Cardiology/American Heart Association Task Force on assessment of diagnostic and therapeutic cardiovascular procedures (Subcommittee on percutaneous transluminal coronary angioplasty). Circulation 78:486-502, 1988. Ellis SG, Vandormael MG, Cowley MJ, et al: Coronary morphologic and clinical determinants of procedural outcome with angioplasty for multivessel coronary disease: Implications for patient selection. Circulation 82:1193-1202, 1990. Sanborn TA: Laser angioplasty. What has been learned from experimental studies and clinical trials? Circulation 78:769-774,
1988. 24. Forrester IS: Laser angioplasty. Now and in the future. Circulation 78:777-779, 1988. 25. McLean GK, Burke DR, Marinelli DL: Comment on the clinical appropriateness of an emerging technology. Radiology 172:941942, 1989. 26. Sanborn TA, Cumberland DC, Greenfield AJ, et al: Percutaneous
laser thermal angioplasty: Initial results and I-year follow-up in 129 femoropopliteal lesions. Radiology 168:121-125, 1988. 27. Jeans WD: Technical success, clinical success, and patency in laser angioplasty (letter). Radiology 173572, 1989. 28. Sanborn TA, Nordstrom LA: Technical success, clinical success,
responsibility and integrity in medical research. J Am Coll Cardiol 16:24-29, 1990. 39. Conti CR, Williams JF, Anderson JL, et al. Task force V: The relation of cardiovascular specialists to industry, institutions and organizations. J Am Coll Cardiol 16:30-33, 1990. 40. Holmes D, Kent K, Myler R, et al. The NHLBI PTCA registry as a standard for comparison of new devices: When should we use it and what should we compare? Circulation 84: 1828-1830, 1991. 41. Faxon DP, Holmes DP, Hartzler G, et al. ABC’s of coronary angioplasty: Have we simplified it to much? Cathet Cardiovasc Diagn 25: 1-3, 1992. 42. Diethrich EB. Has excimer coronary laser angioplasty finally found a niche? Circulation 84:939-9414, 1991. 43. Linnemeier TJ. Director statistics, St. Vincent Hospital cardiac catheterization laboratories, Indiana Heart Institute, 1991.
Editorial The Hot and Cold Issues of Laser Angioplasty Thomas J. Linnemeier, MD, FACC By 1990, a clinical trial found the thermal laser system to have a high complication rate, to be ineffective in A monumental advance in the treatment of coronary treating chronic total occlusions, and to have no lower disease occurred the day Andreas Gruentzig translumirestenosis rate than conventional balloon angioplasty nally dilated a coronary artery [ 1,2]. From the moment [ 121. This technique quickly took a backseat to the rapof that first coronary angioplasty, cardiologists were no idly expanding field of excimer laser angioplasty . longer solely diagnosticians and masters of medical management, they became “interventionalists. ” Despite the Excimer Laser Angioplasty explosive worldwide growth of coronary angioplasty in In the mid-1980s an exciting new laser source, the the early 1980s, it became clear that the technique was excimer or “cool-tip” laser, was tested in vitro [13,14]. not a panacea. The need for emergency surgical standby Incredibly precise cuts could be made through cadaveric was an undisputed dogma. The term “restenosis” becalcified atherosclerotic tissue. Though this technology came part of our vocabulary. The ability to treat chronic was considerably more expensive, its precision could not total occlusions remained elusive, demanding further inbe ignored; thus development proceeded at a rapid pace. vestigation. By 1989, the excimer laser proved successful in a multicenter coronary clinical trial with few complications Early Laser Investigation [15]. Chronic total occlusions were, by protocol, not In the early 1980s, physicians, politicians, and the attempted unless first crossed by a guidewire. Technical public were excited by the mystical and potentially pow- improvements continued and soon excimer laser angioerful “laser,” a legacy of Einstein’s genius [3]. In 1982, plasty was performed without subsequent balloon angioa laser was first used to relieve obstructions in cadaveric plasty [ 161. Despite early reports of high restenosis rates coronary arteries [4]. Could a laser open a chronic total [ 171 enthusiasm persisted among many cardiologists. occlusion, “seal” a dissection, and affect restenosis? In While many radiologists and vascular surgeons abanan effort to answer these questions, the newly created doned the technique of laser angioplasty, cardiologists field of “laser angioplasty” rapidly expanded, with continued to experiment and gather data [ 18,191. more attention given to laser sources and laser catheters Avoiding the issues of chronic total occlusion and rethan to vascular biology. Investigators, fearful of a po- stenosis, laser investigators focused on angiographic letentially catastrophic coronary perforation, used the pe- sion morphology. Cook et al. [20] suggested excimer ripheral vasculature as a “testing ground” for lasers. laser angioplasty was safe and effective therapy for leIn 1984, a laser was used to open occlusions in the sions not ideal for conventional balloon angioplasty , peripheral vasculature in vivo [5]. The problem of per- based on the A-B-C lesion morphology criteria estabforation was partially solved in 1986 when a heated lished by others [21,22]. Other potentially less expensive metal cap was added to the tip of the laser fiber [6]. ‘‘cool-tip” laser sources were developed to compete Within one month this “hot-tip’’ technology was used in with the excimer, such as the holmium system. the coronary artery in conjunction with conventional balOn January 3 1, 1992, the Food and Drug Administraloon angioplasty [7]. Scores of physicians, whether radiologists, cardiologists, or vascular surgeons, academicians or private practitioners, famous or infamous, were From the Cardiac Catheterization Laboratories, St. Vincent Hospital quite interested if not anxious to have this technology at and Health Care Center, Indiana Heart Institute, Indianapolis, Inditheir fingertips. Limited trials continued [8-101 and in ana. 1989 coronary laser thermal angioplasty was performed successfully without the need for subsequent balloon an- Received March 21, 1992; revision accepted March 25, 1992. gioplasty [ 111. Major manufacturers of coronary balloon Address reprint requests to Thomas J . Linnemeier, M.D., F.A.C.C., equipment began investing significant amounts of re- Northside Cardiology, P.C., 8402 Harcourt Road #300, Indianapolis, IN 46260. search and development funds into laser technology. HISTORICAL PERSPECTIVES
0 1992 Wiley-Liss, Inc.
2
Linnemeier
radio [36]. Obviously this woman, and the editors who elected to print her letter, did not look kindly upon the laser as a marketing tool. These and other issues were nationally televised on ABC’s “20/20” and viewed by millions on February 7, 1992. Dr. Timothy Johnson clearly expressed his concerns to the public, [37]: “So, PHYSICIAN CONCERNS along comes the excimer laser, an expensive but potenInitial disagreement over the training of cardiologists, tially exciting new technology. The company. . . . starts radiologists, and vascular surgeons portended a menac- selling it to hospitals and doctors start evaluating it on ing rift and subsequent battle over “turf” among the patients and investors see the potential for profit. All of subspecialties, especially in the United States. Some in- this just at the time that the cost of health care in this vestigators studied the thermal laser system [23] while country is becoming a crisis. But, should we introduce others favored the excimer laser [24]. Radiologists [25] this kind of new technology widely before we know exwere skeptical that thermal angioplasty helped lower the actly how important it is and how much it is going to restenosis rate in the peripheral vasculature as suggested cost? Should it be hyped in the media and advertised to in studies primarily authored by cardiologists [26]. the public? Who should pay for its evaluation and should While some radiologists were snickering [27] over the the researchers who are doing the evaluating own stock cardiologists’ definition of “laser success” [28], others in the company that makes the product? The story of the were expressing reservations over equipment costs, en- excimer laser illustrates just how troubling these questrepreneurial physicians, muddled data and terminology, tions can be.” The concerns Dr. Timothy Johnson expressed to the and the total lack of randomized trials. In addition, radiologists made public their concerns that the peripheral lay public are similar to those critical of laser angioplasty vasculature was being used by cardiologists, not as a in the interventional medical community. testing ground for laser investigation, but as a ploy to begin performing conventional peripheral interventions FUTURE DIRECTION ~91. Some vascular surgeons and radiologists were critical For a physician to derive financial benefit from a techof “institutes” and “centers” that advertised unproven nique or device invented by him is nothing new. The laser technology as a means to attract patients [30,31]. earliest pioneers of peripheral and coronary angioplasty , One vascular surgeon [32] was critical of peripheral laser however, were rarely disputed as being unbiased investrials published by radiologists [33] and even suggested tigators. The explosion of new devices for treating corthat those radiologists lacked the skills necessary to comonary disease that have not been adequately compared to petently perform the technique. conventional treatment, however, has created a credibilOne study [19] suggested that excimer laser angioity problem for the profession. This problem has the plasty performed without subsequent balloon angioplasty attention of American medicine and the public. Given had a lower restenosis rate than laser followed by balloon this controversy the following guidelines need to be reangioplasty , while another study suggested just the opviewed and given consideration. posite [34]. Some likened laser coronary angioplasty to the experience of Sisyphus, the legendary king of Corinth condemned for eternity to roll a heavy rock up a Conflict of Interest Guidelines that define potential conflict of interest hill in Hades only to have it roll down again as it neared have been established by the cardiology community the top [35]. As a result of discord within and between specialties, [38,39] remain valid today and should be adhered to. a plethora of entrepreneurial techniques, the high equip- Furthermore, when multicenter trials are in progress, ment costs, and the virtual lack of randomized trials, the nonstockholding investigators deserve to know which ininterventional community is left in a state of turmoil vestigators hold stock in that company, and stockholding regarding laser angioplasty. Of utmost concern is that investigators have the duty to share that information. Nonstockholding investigators should not find out on nathis turmoil has spread to the lay community. tional television that after years of collaborative research many of their coinvestigators are stockholders. AttendPUBLIC CONCERNS ees and participants of educational courses and national In a Letter to The Editor of the N e w England Journal programs, such as the American College of Cardiology of Medicine, a woman wrote of her annoyance with Scientific Sessions, the American Heart Association Sci‘‘miracle peddlers” advertising laser angioplasty on the entific Sessions, the Radiological Society of North
tion granted approval for the first of what will certainly be many excimer lasers (Advanced Interventional Systems, Inc., Irvine, CA) for the treatment of coronary disease.
Laser Angioplasty
America, and the Society for Cardiac Angiography and Interventions, also deserve that information. “Miracle Peddling” The practice of ‘‘miracle peddling” or advertising lasers to the lay public should be curbed. At least a portion of the public and medical community is offended by it. To market investigational laser devices as potential miracle cures that have not received approval by the Food and Drug Administration is premature and unethical. Comparison of New Devices to Balloon Angioplasty Based on Lesion Morphology The A-B-C lesion morphology system established by Ryan et al. [21] (1988 AHNACC guidelines) and refined by Ellis et al. [22] was designed to help predict success and complications of coronary angioplasty . This system has served the interventional cardiology community well. The evaluation of progressive new technologies, however, cannot and should not be compared to old standards [40,41]. Some have suggested that a niche for laser angioplasty has been established [42]. A niche for coronary laser angioplasty has been established only if the 1988 AHA/ ACC guidelines are meaningful predictors of angioplasty outcome in 1992. At the Indiana Heart Institute (St. Vincent Hospital, Indianapolis), during the calendar year of 1991, 2,617 percutaneous cardiac interventional procedures were performed. At least 50% of these patients had either multivessel disease or Type B or C lesion morphology [43]. Only 1% (26 patients) required emergency coronary artery bypass surgery and only 0.03% (1 patient) died. Therefore, in experienced hands and with improved balloon technology, the lesion morphology system is probably not an adequate predictor of success or complication today. Though safer angioplasty should always be a goal, treating chronic total occlusions and reducing restenosis are even greater challenges and cannot be forgotten. Randomized Trials To date, not one controlled multicenter randomized trial comparing conventional balloon angioplasty to excimer laser angioplasty in either the peripheral or coronary vasculature has been published. Such a trial needs to be done not only for scientific reasons but also to rest the concerns of critics. The excimer laser has reached a state of technical refinement that such a comparison is now fair. The primary investigator in the coronary arterial tree should be a cardiologist and in the peripheral vasculature a radiologist or vascular surgeon. The primary investigators should not hold a financial interest in the laser being investigated. These trials should be funded at least in part by the laser industry which has the
3
potential for tremendous gain if proven effective. Only a head-to-head randomized trial of balloon angioplasty versus laser angioplasty will prove or disprove the value of the laser, mend wounds among the subspecialties, silence critics, and advance the percutaneous treatment of cardiovascular disease.
REFERENCES 1. Gruentzig A: Transluminal dilatation of coronary artery stenosis
(letter). Lancet 1:263-266, 1978. 2. Gruentzig AR, Myler RK, Stertzer SH, et al: Coronary percutaneous transluminal angioplasty: Preliminary results (abstract). Circulation 58(Suppl 1I):II-56, 1978. 3. Einstein A: Zur quanteentheoris der Strahlung. Physiol Z 18: 121-128, 1917. 4. Choy DSJ, Stertzer SH, Rotterdam HZ, et al.: Laser coronary angioplasty; Experience with 9 cadaver hearts. Am J Cardiol50: 1209, 1982. 5 . Geschwind H, Boussignaac G, Teissiere B, et al: Percutaneous transluminal laser angioplasty in man (letter). Lancet 1:844, 1984. 6. Cumberland DC,Taylor DI, Welsh CL, et al: Percutaneous laser thermal angioplasty: Initial clinical results with a laser probe in total peripheral artery occlusions. Lancet 1457-1459, 1986. 7. Cumberland DC,Oakley GDG, Smith GH, et al: Percutaneous laser-assisted coronary angioplasty (letter). Lancet 2:214, 1986. 8. Sanborn TA, Bonan R, Cumberland DC,et al: Percutaneous laser-assisted balloon angioplasty with flexible central lumen laser probe catheters (abstract). Circulation 78(Suppl II):295, 1988. 9. Linnemeier TJ, Bonan R, Cumberland DC, et al: Human percutaneous laser-assisted coronary angioplasty of saphenous vein gypass grafts: Early multicenter experience (abstract). Circulation 78(Suppl II):295, 1988. 10. Linnemeier TJ, Cumberland DC, Rothbaum DA, et al: Human percutaneous laser-assisted coronary angioplasty: Efforts to reduce spasm and thrombosis (abstract). J Am Coll Cardiol 13:61A, 1989. 11. Linnemeier TI, Cumberland DC: Percutaneous laser coronary angioplasty without balloon angioplasty (letter) Lancet 154-155, 1989. 12. Linnemeier TJ, Rothbaum DA, Cumberland DC, et al: Percutaneous laser-assisted thermal coronary angioplasty in native coronary arteries and saphenous vein grafts: Initial results and angiographic follow-up. J Inv Cardiol 2:133-138, 1990. 13. Grundfest WS, Litvack F, Forrester JS, et al: Laser ablation of atherosclerotic plaque without adjacent tissue injury. J Am Coll Cardiol 5929-933, 1985. 14. Isner JM, Donaldson RF, Deckelbaum LI, et al: The excimer laser: Gross, light microscopic and ultrastructural analysis of potential advantages for use in laser therapy of cardiovascular disease. J Am Coll Cardiol 6:1102-1109, 1985. 15. Margolis JR, Litvack F, Grundfest W, Eigler N, Goldenberg T, Laudenslager J, Tsoi D, Wong S, Segalowitz, J, Hestrin L, Rothbaum D, Linnemeier T, Helfant R, Forrester J: Excimer laser coronary angioplasty: Results of a multicenter study (abstract). Circulation 8O(Suppl 1I):II-477, 1989. 16. Rothbaum DA, Litvack F, Margolis J, Eigler N, Linnemeier T, King S, Douglas J, Tsoi D, Cook S, Hestrin L, Goldenberg T, Segalowitz J, Grundfest W, Forrester J: Stand-alone percutaneous excimer laser coronary angioplasty (abstract). J Am Coll Cardiol 15:26A, 1990.
4
Linnemeier
17. Rothbaum D, Linnemeier T, Landin R, Ball M, Hodes Z, Riddell
and patency in laser angioplasty (letter and response). Radiology
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