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Is the leaking balloon angioplasty catheter a better catheter?
1051
JACC Vol. 14. No. 4 October
1989:1051-2
Editorial Comment
Is the Leaking Balloon Angioplasty Catheter a Better Catheter?* MARTIAL Montreal,
G. BOURASSA,
MD, FACC
Quebec,, Canada
Because of the presence of multiple proximal and distal sideholes, the autoperfusion balloon angioplasty catheter allows passive perfusion of blood through its central lumen while the balloon is inflated. This unique property can serve two major purposes. First, the catheter allows longer balloon inflation periods with less severe myocardial ischemia during routine coronary angioplasty. In animal and human studies (I ,2), the autoperfusion catheter led to significant amelioration of ischemia during balloon inflations of at least 2 to 3 min. Second, the catheter prevents myocardial necrosis during much longer periods of coronary occlusion that occur when coronary angioplasty is complicated by acute coronary thrombosis or severe coronary dissection. In this issue of the Journal. Campbell et al. (3) have shown that the autoperfusion balloon angioplasty catheter is effective in maintaining coronary flow and coronary hemodynamics and in preventing the development of substantial necrosis during 90 min of circumflex coronary artery occlusion in dogs. Myocardial ischemia and injury during coronary angioplasty. Profound myocardial dysfunction regularly accom-
panies balloon inflation during coronary angioplasty (4,5). Several hemodynamic and mechanical variables are transiently, but markedly, disturbed during dilation. Within 20 s of the onset of balloon inflation, there is evidence of ischemit regional left ventricular dysfunction, and frank akinesia and dyskinesia are present at 60 s after balloon inflation. With balloon deflation and consequent reperfusion, there is prompt recovery of regional function with restoration to preinfarction levels by 60 s. Thus, short periods of occlusion of a coronary artery during angioplasty in humans are well tolerated, and repeated short occlusions do not have a cumulative ischemic effect. In the experimental animal, reversibility of ischemic
changes is dependent on the duration of coronary occlusion. Following periods of occlusion of <2 min, myocardial function recovers promptly and completely after reperfusion. With occlusions of r5 min, the myocardium is stunned and regional myocardial function may not return to preischemic levels until 6 h after reperfusion. Repeated 5-min episodes of ischemia may have a cumulative effect and result in areas of myocardial necrosis (6). Permanent coronary occlusions follow a highly predictable pattern in dogs (7). However, after acute coronary thrombosis in humans, the time course and severity of ischemia vary among individuals because of much greater variation in preexisting collateral vessels. area of myocardium at risk and cardiac metabolic demands. Autoperfusion during routine coronary angioplasty. In his early animal experiments, Andreas R. Gruentzig used distal coronary perfusion with arterial blood through the dilation catheter during coronary angioplasty. However, he later abandoned this approach and did not use it or recommend its use in humans, thereby shedding some doubts on the value of this procedure during routine coronary angioplasty. Since its onset, the procedure of coronary angioplasty has been performed to achieve the best possible cosmetic result. The balloon is sized to the artery, and both undersizing and oversizing are avoided as much as possible because undersizing frequently leads to an inadequate result and oversizing increases the risk of coronary artery dissection. No fixed rules exist concerning the amount of maximal pressure applied or the number and duration of balloon inflations. Inflation pressures vary from 2 to 12 atm, and there may not be any real advantage in increasing pressures beyond those that are necessary to suppress the central notch of the stenosis on the balloon catheter. Duration of inflations varies from 15 to 2120 s. depending on patient tolerance, i.e., severity of angina and electrocardiographic or blood pressure changes. After balloon deflation, the catheter is withdrawn and the guide is left in place. If the result appears inadequate. new balloon inflations are performed at higher pressures or with a larger balloon size. The final cosmetic result is assessed after withdrawal of the dilation system following repeat coronary angiography in the same projections as before angioplasty. The potential
use
qf autoperfksion
balloon
angioplasty
catheters during routine coronury ungioplast_v raises several
Assuming that the autoperfusion catheter increases the patient tolerance to longer periods of balloon inflation. which is likely, there is still no conclusive evidence that longer inflation periods (up to 2 to 3 min) will increase the initial success rate of coronary angioplasty, influence the final cosmetic result or prevent late restenosis. Further studies are required to evaluate these hypotheses. On the
qat~stions. *Editorials published in Joumul I$ the Amrricm College of Curdiolog~ reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology. From the Department of Medicine, Montreal Heart Institute and Lniversity of Montreal Medical School, Montreal, Quebec, Canada. Address for reurints: Martial G. Bourassa. MD, Montreal Heart Institute. 5000 Belanger Street East, Montreal. Quebec HIT IC8. Canada.
01989
by the
Amer~an
College
of Cxdmlogy
073s1097/89/$3.50
1052
BOURASSA EDITORIAL COMMENT
other hand, tolerance to balloon occlusion is highly variable among patients undergoing coronary angioplasty and is probably lowest in patients with severe or unstable angina, multivessel disease with large areas of myocardium at risk, limited collateral circulation and severe left ventricular dysfunction from previous myocardial infarction. In these patients, the autoperfusion catheter might enhance the comfort, ease of performance and overall safety of the procedure. At present, tolerance to myocardial ischemia during coronary angioplasty is enhanced by intravenous or intracoronary administration of nitroglycerin, calcium channel blockers and beta-blocking agents. Additional benefit from the use of the autoperfusion catheter will have to be demonstrated. Alternative methods will have to be evaluated and compared with the efficacy of the autoperfusion catheter, e.g., perfusion of arterial blood, hemoglobin derivatives and fluosol directly into the distal coronary artery or following diastolic retroperfusion in the coronary sinus, and coronary angioplasty using rapid intermittent systolic balloon inflations. Autoperfusion in patients with procedure-related complications. Abrupt coronary closure occurs in 3% to 5% of patients undergoing coronary angioplasty. This lifethreatening complication results from a coronary thrombus, an occlusive coronary dissection, coronary spasm or, more frequently, a combination of these mechanisms. It is more frequent for lesions located in tortuous vessels, at bifurcation points or sharp bends, and for lesions that are long, heavily calcified or have an associated intraluminal thrombus. However, it also occurs in uncomplicated coronary lesions. Administration of antiplatelet agents before and during angioplasty in association with intravenous heparin significantly reduces the risk of abrupt coronary artery closure (8). Once abrupt vessel closure has occurred, prompt restoration of distal coronary blood flow is of the utmost importance, and this often requires emergency coronary bypass surgery. If the autoperfusion balloon angioplasty catheter could serve as a bridge to bypass surgery, it could accomplish two major tasks. First, the necessary measures could be undertaken in an attempt to achieve relief of coronary occlusion in the cardiac catheterization laboratory. Second, the patient could perhaps be better stabilized before coronary bypass surgery. Measures that could be attempted and have at times been effective in reopening the occluded artery include the administration of intravenous or intracoronary nitroglycerin or calcium channel blockers, as well as the administration of heparin or a thrombolytic agent. Repeat coronary angio-
JACC Vol. 14, No. 4 October 1989:1051-2
plasty can successfully reopen the vessel in some cases, particularly when a fresh thrombus is present. Finally, an obstructive coronary dissection can sometimes be tacked up by prolonged low pressure inflation of the balloon catheter. The autoperfusion correct hemodynamic
catheter could relieve angina and instability in patients requiring emer-
gency
coronary bypass surgery. The use of the catheter should not, however, unduly delay emergency bypass surgery. Progression to infarction depends on the duration of ischemia, and mortality and acute myocardial infarction are reduced when the intracorporeal circulation is begun soon after coronary occlusion. In patients undergoing emergency coronary bypass surgery, the incidence of acute myocardial infarction varies from 33% to 49%, postoperative complications are much more frequent than after elective bypass surgery and postoperative mortality varies from 2% to 14% (9). Future studies will be needed to determine whether the autoperfusion catheter can decrease the incidence of emergency coronary bypass surgery and can reduce the risk of complications in patients undergoing emergency bypass surgery after a failed coronary angioplasty.
References I Turi ZG, Campbell CA, Gottimukkala MV, Kloner RA. Preservation of
distal coronary perfusion during prolonged balloon inflation with an autoperfusion angioplasty catheter. Circulation 1987;75:1273-80. 2 Turi ZG, Rezkalla S, Campbell CA, Kloner RA. Amelioration of ischemia during angioplasty of the left anterior descending coronary artery with an autoperfusion catheter. Am J Cardiol 1988;62:513-7. 3 Campbell CA, Rezkalla S, Kloner RA, Turi ZG. The autoperfusion balloon angioplasty catheter limits myocardial ischemia and necrosis during prolonged balloon inflation. J Am Coll Cardiol 1989;14:1046-551. 4 Carlson EB. Hinohara T. Morris KG. Recovery of systolic and diastolic left ventricular function after a 60-second coronary arterial occlusion during percutaneous transluminal coronary angioplasty for angina pectoris. Am J Cardiol 1987:60:460-6. 5. Labovitz AJ, Lewen MK, Kern M, Vandormael M, Deligonal LJ,Kennedy HL. Evaluation of left ventricular systolic and diastolic dysfunction during transient myocardial ischemia produced by angioplasty. J Am Coll Cardiol 1987;10:748-55. 6 Geft I, Fishbein MC, Ninomiya K, et al. Intermittent brief periods of ischemia have a cumulative effect and may cause myocardial necrosis. Circulation 1982;66:1150-3. Reimer KA, Jennings RB. The “wave front phenomenon” of myocardial ischemic cell death. II. Transmural progression of necrosis within the framework of ischemic bed size (myocardium at risk) and collateral flow. Lab Invest 1979;40:633-44. Schwartz L, Bourassa MG. Lesperance J, et al. Aspirin and dipyridamole in the prevention of restenosis after percutaneous transluminal coronary angioplasty. N Engl J Med 1988;318:1714-9. Pelletier LC, Pardini A, Renkin J, David PR, Hebert Y, Bourassa MG. Myocardial revascularization after failure of percutaneous transluminal coronary angioplasty. J Thorac Cardiovasc Surg 1985;90:26S-71.
JACC Vol. 14. No. 4 October
1989:1051-2
Editorial Comment
Is the Leaking Balloon Angioplasty Catheter a Better Catheter?* MARTIAL Montreal,
G. BOURASSA,
MD, FACC
Quebec,, Canada
Because of the presence of multiple proximal and distal sideholes, the autoperfusion balloon angioplasty catheter allows passive perfusion of blood through its central lumen while the balloon is inflated. This unique property can serve two major purposes. First, the catheter allows longer balloon inflation periods with less severe myocardial ischemia during routine coronary angioplasty. In animal and human studies (I ,2), the autoperfusion catheter led to significant amelioration of ischemia during balloon inflations of at least 2 to 3 min. Second, the catheter prevents myocardial necrosis during much longer periods of coronary occlusion that occur when coronary angioplasty is complicated by acute coronary thrombosis or severe coronary dissection. In this issue of the Journal. Campbell et al. (3) have shown that the autoperfusion balloon angioplasty catheter is effective in maintaining coronary flow and coronary hemodynamics and in preventing the development of substantial necrosis during 90 min of circumflex coronary artery occlusion in dogs. Myocardial ischemia and injury during coronary angioplasty. Profound myocardial dysfunction regularly accom-
panies balloon inflation during coronary angioplasty (4,5). Several hemodynamic and mechanical variables are transiently, but markedly, disturbed during dilation. Within 20 s of the onset of balloon inflation, there is evidence of ischemit regional left ventricular dysfunction, and frank akinesia and dyskinesia are present at 60 s after balloon inflation. With balloon deflation and consequent reperfusion, there is prompt recovery of regional function with restoration to preinfarction levels by 60 s. Thus, short periods of occlusion of a coronary artery during angioplasty in humans are well tolerated, and repeated short occlusions do not have a cumulative ischemic effect. In the experimental animal, reversibility of ischemic
changes is dependent on the duration of coronary occlusion. Following periods of occlusion of <2 min, myocardial function recovers promptly and completely after reperfusion. With occlusions of r5 min, the myocardium is stunned and regional myocardial function may not return to preischemic levels until 6 h after reperfusion. Repeated 5-min episodes of ischemia may have a cumulative effect and result in areas of myocardial necrosis (6). Permanent coronary occlusions follow a highly predictable pattern in dogs (7). However, after acute coronary thrombosis in humans, the time course and severity of ischemia vary among individuals because of much greater variation in preexisting collateral vessels. area of myocardium at risk and cardiac metabolic demands. Autoperfusion during routine coronary angioplasty. In his early animal experiments, Andreas R. Gruentzig used distal coronary perfusion with arterial blood through the dilation catheter during coronary angioplasty. However, he later abandoned this approach and did not use it or recommend its use in humans, thereby shedding some doubts on the value of this procedure during routine coronary angioplasty. Since its onset, the procedure of coronary angioplasty has been performed to achieve the best possible cosmetic result. The balloon is sized to the artery, and both undersizing and oversizing are avoided as much as possible because undersizing frequently leads to an inadequate result and oversizing increases the risk of coronary artery dissection. No fixed rules exist concerning the amount of maximal pressure applied or the number and duration of balloon inflations. Inflation pressures vary from 2 to 12 atm, and there may not be any real advantage in increasing pressures beyond those that are necessary to suppress the central notch of the stenosis on the balloon catheter. Duration of inflations varies from 15 to 2120 s. depending on patient tolerance, i.e., severity of angina and electrocardiographic or blood pressure changes. After balloon deflation, the catheter is withdrawn and the guide is left in place. If the result appears inadequate. new balloon inflations are performed at higher pressures or with a larger balloon size. The final cosmetic result is assessed after withdrawal of the dilation system following repeat coronary angiography in the same projections as before angioplasty. The potential
use
qf autoperfksion
balloon
angioplasty
catheters during routine coronury ungioplast_v raises several
Assuming that the autoperfusion catheter increases the patient tolerance to longer periods of balloon inflation. which is likely, there is still no conclusive evidence that longer inflation periods (up to 2 to 3 min) will increase the initial success rate of coronary angioplasty, influence the final cosmetic result or prevent late restenosis. Further studies are required to evaluate these hypotheses. On the
qat~stions. *Editorials published in Joumul I$ the Amrricm College of Curdiolog~ reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology. From the Department of Medicine, Montreal Heart Institute and Lniversity of Montreal Medical School, Montreal, Quebec, Canada. Address for reurints: Martial G. Bourassa. MD, Montreal Heart Institute. 5000 Belanger Street East, Montreal. Quebec HIT IC8. Canada.
01989
by the
Amer~an
College
of Cxdmlogy
073s1097/89/$3.50
1052
BOURASSA EDITORIAL COMMENT
other hand, tolerance to balloon occlusion is highly variable among patients undergoing coronary angioplasty and is probably lowest in patients with severe or unstable angina, multivessel disease with large areas of myocardium at risk, limited collateral circulation and severe left ventricular dysfunction from previous myocardial infarction. In these patients, the autoperfusion catheter might enhance the comfort, ease of performance and overall safety of the procedure. At present, tolerance to myocardial ischemia during coronary angioplasty is enhanced by intravenous or intracoronary administration of nitroglycerin, calcium channel blockers and beta-blocking agents. Additional benefit from the use of the autoperfusion catheter will have to be demonstrated. Alternative methods will have to be evaluated and compared with the efficacy of the autoperfusion catheter, e.g., perfusion of arterial blood, hemoglobin derivatives and fluosol directly into the distal coronary artery or following diastolic retroperfusion in the coronary sinus, and coronary angioplasty using rapid intermittent systolic balloon inflations. Autoperfusion in patients with procedure-related complications. Abrupt coronary closure occurs in 3% to 5% of patients undergoing coronary angioplasty. This lifethreatening complication results from a coronary thrombus, an occlusive coronary dissection, coronary spasm or, more frequently, a combination of these mechanisms. It is more frequent for lesions located in tortuous vessels, at bifurcation points or sharp bends, and for lesions that are long, heavily calcified or have an associated intraluminal thrombus. However, it also occurs in uncomplicated coronary lesions. Administration of antiplatelet agents before and during angioplasty in association with intravenous heparin significantly reduces the risk of abrupt coronary artery closure (8). Once abrupt vessel closure has occurred, prompt restoration of distal coronary blood flow is of the utmost importance, and this often requires emergency coronary bypass surgery. If the autoperfusion balloon angioplasty catheter could serve as a bridge to bypass surgery, it could accomplish two major tasks. First, the necessary measures could be undertaken in an attempt to achieve relief of coronary occlusion in the cardiac catheterization laboratory. Second, the patient could perhaps be better stabilized before coronary bypass surgery. Measures that could be attempted and have at times been effective in reopening the occluded artery include the administration of intravenous or intracoronary nitroglycerin or calcium channel blockers, as well as the administration of heparin or a thrombolytic agent. Repeat coronary angio-
JACC Vol. 14, No. 4 October 1989:1051-2
plasty can successfully reopen the vessel in some cases, particularly when a fresh thrombus is present. Finally, an obstructive coronary dissection can sometimes be tacked up by prolonged low pressure inflation of the balloon catheter. The autoperfusion correct hemodynamic
catheter could relieve angina and instability in patients requiring emer-
gency
coronary bypass surgery. The use of the catheter should not, however, unduly delay emergency bypass surgery. Progression to infarction depends on the duration of ischemia, and mortality and acute myocardial infarction are reduced when the intracorporeal circulation is begun soon after coronary occlusion. In patients undergoing emergency coronary bypass surgery, the incidence of acute myocardial infarction varies from 33% to 49%, postoperative complications are much more frequent than after elective bypass surgery and postoperative mortality varies from 2% to 14% (9). Future studies will be needed to determine whether the autoperfusion catheter can decrease the incidence of emergency coronary bypass surgery and can reduce the risk of complications in patients undergoing emergency bypass surgery after a failed coronary angioplasty.
References I Turi ZG, Campbell CA, Gottimukkala MV, Kloner RA. Preservation of
distal coronary perfusion during prolonged balloon inflation with an autoperfusion angioplasty catheter. Circulation 1987;75:1273-80. 2 Turi ZG, Rezkalla S, Campbell CA, Kloner RA. Amelioration of ischemia during angioplasty of the left anterior descending coronary artery with an autoperfusion catheter. Am J Cardiol 1988;62:513-7. 3 Campbell CA, Rezkalla S, Kloner RA, Turi ZG. The autoperfusion balloon angioplasty catheter limits myocardial ischemia and necrosis during prolonged balloon inflation. J Am Coll Cardiol 1989;14:1046-551. 4 Carlson EB. Hinohara T. Morris KG. Recovery of systolic and diastolic left ventricular function after a 60-second coronary arterial occlusion during percutaneous transluminal coronary angioplasty for angina pectoris. Am J Cardiol 1987:60:460-6. 5. Labovitz AJ, Lewen MK, Kern M, Vandormael M, Deligonal LJ,Kennedy HL. Evaluation of left ventricular systolic and diastolic dysfunction during transient myocardial ischemia produced by angioplasty. J Am Coll Cardiol 1987;10:748-55. 6 Geft I, Fishbein MC, Ninomiya K, et al. Intermittent brief periods of ischemia have a cumulative effect and may cause myocardial necrosis. Circulation 1982;66:1150-3. Reimer KA, Jennings RB. The “wave front phenomenon” of myocardial ischemic cell death. II. Transmural progression of necrosis within the framework of ischemic bed size (myocardium at risk) and collateral flow. Lab Invest 1979;40:633-44. Schwartz L, Bourassa MG. Lesperance J, et al. Aspirin and dipyridamole in the prevention of restenosis after percutaneous transluminal coronary angioplasty. N Engl J Med 1988;318:1714-9. Pelletier LC, Pardini A, Renkin J, David PR, Hebert Y, Bourassa MG. Myocardial revascularization after failure of percutaneous transluminal coronary angioplasty. J Thorac Cardiovasc Surg 1985;90:26S-71.