Virendra S. Mathur, M.D., Ali Massumi, M.D., and Robert J. Hall, M.D.. P ERCUTANEOUS transluminal coro- .... Reul GJ Jr, Cooley DA. Impending myocar-.
Editorial
Percutaneous Transluminal Coronary Angioplasty: How Important Is Stand-by Surgery? Virendra S. Mathur, M.D., Ali Massumi, M.D., and Robert J. Hall, M.D. P ERCUTANEOUS transluminal coronary angioplasty (PTCA) has undergone a major evolution since 1978, when fewer than 100 procedures were performed worldwide. The success rate has steadily improved from around 60% to about 90% currently,' as the experience of the operators has increased along with the availability of better guiding systems, improved balloon catheters, and flexible steerable wires. The applications and indications have also broadened, and the number of patients with multiple lesions and anatomically difficult lesions undergoing balloon angioplasty have also gradually increased. This, of course, is good news for the vast majority of patients concerned. We should not, however, lose sight of the fact that the remaining 10 to 40% of patients - a not insignificant minority - in whom the procedure is not successful still remain in need of definitive treatment. In the early experience at most centers, the reasons for failure included (1) difficulty in positioning the catheter, (2) inability to cross the lesion, (3) inability to dilate the lesion, and (4) acute occlusion of the involved vessel due to dissection, thrombus or spasm. Improved instrumentation has greatly reduced the frequenc%y of the first three, but acute occlusion of the involved vessel remains an important cause of failure. As a rule, patients with acute occlusion of a major vessel experience chest pain and electrocardiographic evidence of ischemia or injury and may develop hemodynamic instability or serious arrhythmias, and in rare instances, cardiac arrest. The final outcome of such a patient, particularly affecting the extent of permanent muscle damage, depends not only upon the severity of the ischemic manifestations, but also upon the speed with which blood supply to the ischemic myocardium can be restored. The impor-
tance of this is highlighted in the article by Kabbani et al2 in this issue of the Journal. The authors report that 16% of patients (97 of 600) had unsuccessful PTCA, and in 45 of these (7.6% of 600 attempts or 46.4% of 97 failures), acute coronary occlusion developed. If immediate revascularization of these patients with acute coronary occlusion cannot be accomplished, the majority will develop classic myocardial infarction with significant myocardial damage and some mortality - clearly an unacceptable option. Myocardial salvage is possible if revascularization can be accomplished with speed, as indicated by data from our institution.3 This is possible even in acute coronary occlusion with ongoing myocardial ischemia. In our institution, emergency surgery was carried out in 61 patients who developed acute coronary occlusion during
attempted PTCA. Significant myocardial infarction with new wall motion abnormality or reduction of ejection fraction developed in only 13% (8 of the 61 patients) of those with acute coronary occlusion (1.5% of 518 patients). Minimal enzyme spill or electrocardiographic change without new wall motion abnormality or drop in ejection fraction developed in another 20% of patients (12 of 61) with acute coronary occlusion (2.3% of 518). More importantly, when myocardial revascularization was completed within 85 minutes, no patient developed significant myocardial infarction. In the absence of facilities for immediate surgical revascularization, PTCA carries great potential for major complications and permanent sequelae in 8 to 12% of patients in these series (up to 20%, according to the National Heart, LunF, and Blood Institute's PTCA Registry). This can be reduced to less than 2% if a skilled team of surgeons, anesthesiologists, and operating room per-
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sonnel are immediately available and if myocardial revascularization can be completed soon after acute coronary occlusion. Surgical standby is required whenever PTCA is attempted. We agree entirely with Kabbani et al2 that standby open-heart services for PTCA are warranted, and that PTCA should be performed only in hospitals with a support staff of skilled cardiovascular surgeons. REFERENCES 1. Hall RJ, Mathur VS, Massumi A, Garcia E, Fighali S. Percutaneous transluminal coronary angioplasty update. Texas Heart Institute Journal 1984; 11(1):10-16. 2. Kabbani SS, Bashour TT, Jones R, Myler RK, Hanna ES, Ellertson DG, Bronstein M, McBride P. Surgical experience following percutaneous transluminal coronary angioplasty. Texas Heart Institute Journal 1984; 1 1(2):112-116.
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3. Angelini P, Fighali S, Coith R, Gonzales F, Leatherman LL, Massumi A, Mathur VS, Reul GJ Jr, Cooley DA. Impending myocardial infarction after attempted coronary angioplasty: Prognostic considerations. Presented at the International Symposium on Interventional Modifications in Coronary Artery Disease, Texas Heart Institute, Houston, Texas, Oct. 13-15, 1983, p 72 (abstract). 4. Dorros G, Cowley MJ, Simpson J, Bentivoglio LG, Block PC. Bourassa M, Detre K, Gosselin AJ, Gruentzig AR, Kelsey SF, Kent KM, Mock MB, Mullin SM, Myler RK, Passamani ER, Stertzer SH, Williams DO. Percutaneous transluminal coronary angioplasty: Report of complications from the National Heart, Lung, and Blood Institute PTCA Registry. Circulation 1983; 67:723.
From the Clayton Foundation for Research Cardiovascular Laboratories and the Texas Heart Institute of St. Luke's Episcopal and Texas Children's Hospitals, Houston, Texas.
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