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Combined intracoronary streptokinase infusion and coronary angioplasty during acute myocardial infarction
Combined lntracoronaryStreptokinase Infusionand Coronary Angioplasty DuringAcute Myocardial Infarction HERMAN K. GOLD, MD, MICHAEL J. COWLEY, MD, IGOR F. PALACIOS, MD, GEORGE W. VETROVEC, MD, CARY W. AKINS, MD, PETER C. BLOCK, MD, and ROBERT C. LEINBACH, MD
PTCA was performed in 28 patients with acute MI immediately after intracoronary streptokinase administration. Indications were failure to obtain reflow in 18 patients and high-grade residual stenosis in 12. PTCA was successful in 11 of 18 cases of streptokinase failure, increasing the overall reflow rate from 88 % to 77 %. PTCA reduced residual coronary stenosis by more than 20 % in 9 of 12 cases in which streptokinase infusion was successful, with 1 acute reocclusion. The frequency of recurrent ischemic
Intracoronary streptokinase administration can restore coronary patency rapidly enough to interrupt MI. However, in most series 20 to 30% of patients have not shown reflow and 5 to 30% of cases have shown reocc1usion.l --*Technical modifications have been introduced to improve on these figures, including subselective catheter positioning, longer streptokinase infusions, guide wire thrombus penetration and uninterrupted heparin anticoagulation. Failure to show reflow and reocclusion remain significant clinical problems. PTCAs can be performed at the time of streptokinase administration without major additional instrumentation. However, the effect of PTCA on coronary patency during acute MI has not been well studied. The incidence of coronary dissection, clot embolization, acute reocclusion and the frequency of recurrent ischemic events during follow-up need further evaluation. We describe the effect of PTCA performed during acute streptokinase administration for MI on the overall patency rate at termination of treatment, percent stenosis acutely, at 10 days and at 5 months, and incidence of ischemic events during hospitalization.
From the Departments of Medicine and Surgery, Massachusetts General Hospital, Boston, Massachusetts, and the Department of Medicine, Medical College of Virginia, Richmond, Virginia. Address for reprints: Herman K. Gold, MD, Cardiac Unit, Massachusetts General Hospital, Boston, Massachusetts 02114.
events in hospital was 78% in patients with a stenosis of 90 % or greater after streptokinase infusion (no PTCA), 14% when residual stenosis was less than 90%, and 8% after successful PTCA. Late restenosis or reocclusion was documented in 5 of 11 PTCA cases (45 % ). Immediate PTCA after streptokinase administration produces increased clinical stability in hospital, but late restenosis is frequent. (Am J Cardiol 1984;53:122C-125C)
Methods We administered intracoronary streptokinase to consenting patients with MI since November 1979. Criteria for thrombolysis include electrocardiographic signs of transmural injury with ST-segment elevation exceeding 0.2 mV in 2 leads, age younger than 75 years, absence of left bundle branch block, no history of transmural MI in the same myocardial zone, no contraindication to streptokinase such as recent streptokinase administration, blood pressure greater than 180/110 mm Hg, history of gastrointestinal bleeding or cerebrovascular accident. PTCA became available for these patients in June 1981. One hundred three patients have been treated with intracoronary streptokinase, with immediate PTCA performed in 28. Streptokinase was given by continuous infusion in a concentration of 1,000 to 2,000 units/ml of saline solution at a rate of 2,000 to 6,000 units/min after a 20,000-unit intracoronary bolus. After the onset of reflow, streptokinase was continued for 30 to 60 minutes longer. Residual percent stenosis in the reflowed coronary artery before PTCA was judged by reviewing developed films in 2 planes and measuring percent diameter stenosis with hand-held calipers. PTCA was performed by the Gruntzig technique, using 3-mm dilating catheters. Only 1 patient was treated with a steerable system. The average number of inflations per lesion was 4.5 for 10 to 30 seconds at 4 to 10 atm. PTCA was defined as successful if it resulted in a 20% or more reduction in percent diameter stenosis. Patients were then returned to the coronary care unit and continued on intravenous heparin by continuous infusion to keep the partial thromboplastin time between 1.5 and 2 times control. Intravenous nitroglycerin was
Jufle 15. 1984
given for 24 to 48 hours, followed by isosorbide dinitrate or low-dose nifedipine unless the systolic pressure fell to less than 100 mm Hg. Anticoagulation was continued in hospital by intravenous heparin for 5 days in 13 cases followed by maintenance with dipyridamole (Persantine) (50 mg 3 times daily) and aspirin (600 mg/day). Continuous heparin therapy was administered in the remainder until discharge angiography, except when it was interrupted by bleeding complications, for CABG or death. Predischarge coronary angiography was performed at 8 to 14 days by the Judkins technique with opacification of the diseased vessel in 2 planes and quantitation of stenosis by the caliper technique. Follow-up angiography was performed at an average of 5.4 months in 11 patients, all of whom had SUCcessful PTCA with coronary patency at discharge.
THE AMERICAN JOURNAL OF CARDIOLOGY
TABLE I
lntracoronary Thrombolysis Anterior
in Table I. There were 51 patients with anterior and 52 with inferior MI. Reflow could not be achieved in the affected artery in 12 patients (24%) with anterior MI and 5 patients (9.6%) with inferior MI. Transient reflow was seen opacifying the distal coronary artery in 9 patients with anterior and 9 patients with inferior MI. Stable reflow was therefore obtained with streptokinase alone in 59% of patients with anterior MI (30 of 51) and 73% of patients with inferior MI (38 of 52). Thirty-five patients had occluded coronary arteries at the termination of the initial streptokinase procedure. The PTCA experience with these 35 cases is shown in Table II. Nine of these patients were seen before June 1981, when PTCA was not performed in this patient category. An additional 10 patients did not undergo PTCA because of coronary tortuosity, diffuse CAD, occlusions at inaccessible sites, or Q-wave development believed to represent completion of MI. Sixteen of the 35 patients without stable reflow after streptokinase administration did undergo PTCA, with 11 successes (69% success rate). Thus, 7 patients with anterior MI and 4 with inferior MI were added to the total number of cases with stable reflow at the end of the initial catheter procedure, yielding a total reflow success rate to 73% and 81%, respectively. The patients who underwent acute PTCA for coronary occlusion can be separated into 2 groups: those who never showed reflow during streptokinase administration (group A) and those who showed transient reflow and reocclusion (group B). Results in group A are listed in Table III. PTCA was successful in 3 of 7 cases, and stenosis did not recur during hospitalization. In 2 cases
Total
52
103
66 17 16
Results of Percutaneous Transluminal Coronary Angioplasty in 35 Patients with No Reflow or Reocclusion at the Termination of the Initial Streptoklnase Procedure Inferior MI 14
21 10
No. of pts PTCA attempts PTCA success Total reflow successes
TABLE Ill
MI
38 E
Anterior MI
: 42152 (81%)
3:/51 (73%)
Acute Percutaneous Transluminal Coronary Angioplasty Afler Failure of Streptokinase Therapy: Percent Coronary Stenoses (Group A)
Involved Artery
Initial Stenosis
SK
STK + PTCA
LAD LAD LAD LAD LAD RCA RCA
100 100 100 100 100 100 100
100 100 100 100 100 100 100
55 55 100’ 100’ 85 :,“;:
10 Days 50 1:: 100 a5 100 100
* Unable to cross lesion. t Reocclosion despite PTCA. LAD = left anterior descending coronary artery; RCA = right coronary artery: SK = stenosis after streptokinase; STK = streptokinase administration.
TABLE IV
Percutaneous Transluminal Coronary Angloplasty for Acute Reocclusion After Transient Reflow: Percent Coronary Stenoses (Group B)
Involved Artery
Initial Stenosis
SK
STK + PTCA
10 Days
LAD LAD LAD LAD LAD RCA RCA RCA RCA
100 100 100 100 100 100 100 100 100
100 100 100 100 100 100 100 100 100
100’ 40
100 40
:8 20 z:
2: loot 100 10 NDNDt
with left anterior descending occlusion, the lesion could not be crossed. In both patients with right coronary
stenosis, PTCA was unsuccessful despite successful crossing of the point of occlusion. In 1 patient, a distal right coronary occlusion was successfully dilated, followed by irreversible occlusion of the proximal right coronary artery secondary to trauma from the guiding catheter. In another patient, the failure of PTCA, also after dilatation of a distal right coronary lesion, was unexplained. Results in group B are shown in Table IV. PTCA was initially successful in establishing reflow in
Inferior
12 9
Results The acute results of intracoronary streptokinase infusion in the total population of 103 patients is shown
MI
z:,
No. of pts Reflow with streptokinase No reflow Transient reflow with acute reocclusion
TABLE II
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Unable to cross lesion. + Cardiac death at 24 hours; reocclusion demonstrated at postmortem examination. $ Noncardiac death. ND = not done: other abbreviations as in Table Ill. l
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STREPTOKINASE
AND PTCA DURING INFARCTION
TABLEV Acute Percutaneous Transluminal Coronary Angioplasty for Residual Coronary Stenosis: Percent Coronary Stenoses (Group C) Involved Artery
Initial Stenosis
LAD LAD LAD RCA RCA RCA RCA RCA RCA LAD RCA RCA
SK
STK + PTCA
10 Days
60
100 100 100 100 100 100 100 100 100 100 99 100
9’8* loo+ 50 20 30 50 3’: 50 40
Unable to cross lesion. + Coronary dissection. t Cardiac death; residual stenosis at postmortem Abbreviations as in Table Ill. l
examination.
8 of 9 patients, but in 1 a residual stenosis of 90% was present and was related to coronary dissection. Follow-up studies were obtained in 7 of 9 patients and showed progression to reocclusion in 2. The patient in whom reocelusion was shown at postmortem examination died with recurrent MI and shock. Reocclusion also developed in the patient with dissection and poor dilatation. PTCA was also performed in 12 patients immediately after completion of intracoronary streptokinase to reduce residual stenosis (group C). In 9 patients, PTCA was performed because residual percent diameter stenosis was 90% or greater. PTCA was used in 3 patients with 60 to 80% residual stenosis when the restored channel was irregular, suggesting retained clot or ulceration. Results in patients undergoing PTCA for residual coronary stenosis are shown in Table V. The average percent stenosis after completion of streptokinase administration was 87%. PTCA produced a greater than 20% reduction in stenosis in 9 patients. One patient showed only a 10% improvement in percent stenosis. In 1 patient the lesion could not be crossed and, in another, coronary dissection was followed by occlusion. Discharge angiography showed progression to occlusion only in the patient in whom the lesion was not crossed. To evaluate the frequency of recurrent ischemic events, we compared patients successfully treated with streptokinase alone to patients with successful PTCA immediately after streptokinase. This analysis excludes patients undergoing early CABG, patients in cardiogenie shock, and patients who died in hospital of nonTABLE VI
In-Hospital lschemia and Reocclusion After Initially Successful Treatment
STK alone stenosis 290 % STK alone stenosis <90% STK + PTCA * Died from ventricular STK = streptokinase.
No. of Pts
MI
Angina
Reocclusion Without Ml
21
3
12
1”
28 18 fibrillation.
1
1
3
0
0
cardiac causes within 10 days. Results are shown in Table VI. Recurrent ischemic events were frequent in patients treated wtih streptokinase alone with a residual coronary stenosis of 90% or greater. Seventy-six percent of these patients had MI or angina or died suddenly during the initial hospitalization. Recurrent MI with greater than 90% stenosis was in the same zone as the initial MI secondary to coronary reocclusion, and occurred after heparin therapy had been discontinued or switched to the combination of Persantine and aspirin. No MIS occurred in-hospital when the coronary stenosis after streptokinase therapy was less than 90% despite cessation of heparin in 54%, but did occur 6 hours after successful PTCA in 1 patient secondary to reocclusion despite full heparinization. Angina after streptokinase therapy was seen predominantly with a residual coronary stenosis of 90% or greater. Five of these 12 patients did not receive a full 10 days of heparin therapy. The source of angina in many of these patients was unclear because most showed significant stenosis of more than 1 major coronary artery. However, a similar percentage of patients with less than 90% stenosis and patients who underwent successful PTCA also showed multivessel CAD, suggesting the causative role of the high-grade residual stenosis in the reperfused vessel. Four patients had reocclusion without MI. Three of these 4 occlusions occurred after heparin therapy was discontinued. Similar to the patients with less than 90% residual stenosis, patients in whom PTCA was successful had few recurrent ischemic events despite cessation of heparin therapy in 44%. By chi-square analysis, the frequency of MI or ischemia after streptokinase is significantly higher in patients with residual coronary stenosis of 90% or greater compared with either of the other groups (p
June 15. 1984
successful left anterior descending PTCA showed plaque embolization into the distal left anterior descending artery at postmortem examination. In this patient the immediate post-PTCA angiogram had shown slow distal left anterior descending flow. Thus, dilatation catheters can be introduced into acutely occluded coronary arteries penetrating the thrombus or plaque and, after visualization of the distal vessel confirming catheter position, can successfully open the occlusion. Failure of PTCA in this series was either related to difficulty reaching and crossing the site of obstruction or to production of acute dissection during the dilating process. All but 1 of these procedures were performed without the use of steerable systems. Introduction of the steerable systems and new guiding catheters will probably improve these results. Recurrent ischemic events in hospital after streptokinase appear to be related to residual high-grade coronary stenosis and are apparently aggravated by interruption of heparin anticoagulation. PTCA produces a more stable hospital course with infrequent early coronary reocclusion. When PTCA was done for residual high-grade coronary stenosis acutely, the risk of acute coronary reocclusion was 8% (1 of 12 patients). After an average of 5.4 months after discharge, 5 of 11patients (45%) in whom PTCA was successful showed coronary restenosis or reocclusion. This occurred despite administration of Persantine and aspirin in 5 and warfarin (Coumadin) in 6. As yet, none of the 3 patients with restenosis have undergone a second PTCA procedure because of mild or absent symptoms. This restenosis rate is higher than several published series of PTCA for stable angina,6,7 but similar to a recent report from Emory University.8 Differences may relate to the more unstable and severe coronary disease during acute MI. PTCA in patients with acute MI immediately after intracoronary streptokinase has been described by Meyer et al? Their success rate was 81%, compared with our 69%. However, none of their patients underwent PTCA for streptokinase failure and none showed a
THE AMERICAN JOURNAL OF CARDIOLOGY
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percent diameter stenosis of 90% or greater before PTCA. There was a suggestion of improved clinical stability after successful PTCA, and the early and late reocclusion rate was 22%. Our results suggest that PTCA can be effective in producing stable coronary reflow despite streptokinase resistance. Sites of coronary obstruction can be passed, allowing visualization of the distal vessel and safe coronary dilatation. The addition of this technique to streptokinase administration increases the rate of stable reflow. When streptokinase infusion is effective, PTCA can be performed with greater success and, in patients with residual stenosis of 90% or more, can result in a lower incidence of recurrent ischemic events in hospital. When residual coronary stenosis is less than 90%, the value of immediate PTCA is uncertain. The late restenosis and reocclusion rate is high, but thus far has not produced unstable or fatal ischemic events. PTCA may increase the ease of clinical management and diminish the need for continuous high-level anticoagulation. References 1. Rentrop P, Blanke H, Karsch KR, Kaiser H, Kostering H, Leltz K. Selective intracoronarythrombolysisin acute myocardial infarction and unstable angina pectoris. Circulation 1981;63:307-317. 2. Ganz W, Buchbinder N, Marcus H, Mondkar A, Yaddahi J, Charurl Y, O’Connor L, Shell W, Fishbein MC, Kass R, Miyamoto A, Swan HJC. Intracoronary thrombolysis in evolving myocardial infarction. Am Heart J 1961;101:4-13. 3. Mathey DG, Kuch KH, Tllsner V, Krebber HJ, Blelfeld W. Nonsurgical coronary artery recanalization in acute transmural myocardial infarction. Circulation 1981;63:489-497. 4. Reduto LA. Smallina RW. Freund GC, Gould KL. lntracoronary infusion of streptokin&e in patsnts with acute myocardial infarction: effects of reperfusion on left ventricular performance. Am J Cardiol 1981;48:403-409. 5. Grrintrig AR, Sennlng A, Siegenthaler WE. Nonoperative dilatation of coronary artery stenosis, percutaneous transluminal coronary angioplasty. N Engl J Med 1979;301:61-68. 6. Holmes DR Jr, Vlietstra R, Smith HZ, Vetrovec GW, Cowley MJ, Kent KM, Detre KM, Myler RK. Restenosis following percutaneous transluminal coronary angioplasty (PTCA): a report from the NHLBI PTCA Registry (abstr). Am j Catdidl 1982;49:905. 7. Griintzig AR, Fischer M, Geebel N, Schlumpf M. Percutaneous transluminal coronary angioplasty. In: Mason DT, Collins JJ. eds. Myocardial Revascularization: Medical and Surgical Advances in Coronary Disease. New York: Ywke Medical Books, 1981:445-451. 6. lschirger T, Gruntzig AR, Hollman J, King S Ill, Douglas J, Meter B, Bradlord J, Tankersley R. Should coronary arteries with less than 60% diameter stenosis be treated by angioplasty? Circulation 1983;68:148-154. 9. Meyer J, Merx W, Schmitz H, Erbel R, Keissllch T, Dorr R, Lambertz H, Bethse C, Krebs W, Bardos P, Minale C, Messmer BJ. Efferf S. Percutaneous transiuminal coronary angioplasty immediately after iniraccwonary streptolysis of transmural myocardial infarction. Circulation 1982;66:905-913.
PTCA was performed in 28 patients with acute MI immediately after intracoronary streptokinase administration. Indications were failure to obtain reflow in 18 patients and high-grade residual stenosis in 12. PTCA was successful in 11 of 18 cases of streptokinase failure, increasing the overall reflow rate from 88 % to 77 %. PTCA reduced residual coronary stenosis by more than 20 % in 9 of 12 cases in which streptokinase infusion was successful, with 1 acute reocclusion. The frequency of recurrent ischemic
Intracoronary streptokinase administration can restore coronary patency rapidly enough to interrupt MI. However, in most series 20 to 30% of patients have not shown reflow and 5 to 30% of cases have shown reocc1usion.l --*Technical modifications have been introduced to improve on these figures, including subselective catheter positioning, longer streptokinase infusions, guide wire thrombus penetration and uninterrupted heparin anticoagulation. Failure to show reflow and reocclusion remain significant clinical problems. PTCAs can be performed at the time of streptokinase administration without major additional instrumentation. However, the effect of PTCA on coronary patency during acute MI has not been well studied. The incidence of coronary dissection, clot embolization, acute reocclusion and the frequency of recurrent ischemic events during follow-up need further evaluation. We describe the effect of PTCA performed during acute streptokinase administration for MI on the overall patency rate at termination of treatment, percent stenosis acutely, at 10 days and at 5 months, and incidence of ischemic events during hospitalization.
From the Departments of Medicine and Surgery, Massachusetts General Hospital, Boston, Massachusetts, and the Department of Medicine, Medical College of Virginia, Richmond, Virginia. Address for reprints: Herman K. Gold, MD, Cardiac Unit, Massachusetts General Hospital, Boston, Massachusetts 02114.
events in hospital was 78% in patients with a stenosis of 90 % or greater after streptokinase infusion (no PTCA), 14% when residual stenosis was less than 90%, and 8% after successful PTCA. Late restenosis or reocclusion was documented in 5 of 11 PTCA cases (45 % ). Immediate PTCA after streptokinase administration produces increased clinical stability in hospital, but late restenosis is frequent. (Am J Cardiol 1984;53:122C-125C)
Methods We administered intracoronary streptokinase to consenting patients with MI since November 1979. Criteria for thrombolysis include electrocardiographic signs of transmural injury with ST-segment elevation exceeding 0.2 mV in 2 leads, age younger than 75 years, absence of left bundle branch block, no history of transmural MI in the same myocardial zone, no contraindication to streptokinase such as recent streptokinase administration, blood pressure greater than 180/110 mm Hg, history of gastrointestinal bleeding or cerebrovascular accident. PTCA became available for these patients in June 1981. One hundred three patients have been treated with intracoronary streptokinase, with immediate PTCA performed in 28. Streptokinase was given by continuous infusion in a concentration of 1,000 to 2,000 units/ml of saline solution at a rate of 2,000 to 6,000 units/min after a 20,000-unit intracoronary bolus. After the onset of reflow, streptokinase was continued for 30 to 60 minutes longer. Residual percent stenosis in the reflowed coronary artery before PTCA was judged by reviewing developed films in 2 planes and measuring percent diameter stenosis with hand-held calipers. PTCA was performed by the Gruntzig technique, using 3-mm dilating catheters. Only 1 patient was treated with a steerable system. The average number of inflations per lesion was 4.5 for 10 to 30 seconds at 4 to 10 atm. PTCA was defined as successful if it resulted in a 20% or more reduction in percent diameter stenosis. Patients were then returned to the coronary care unit and continued on intravenous heparin by continuous infusion to keep the partial thromboplastin time between 1.5 and 2 times control. Intravenous nitroglycerin was
Jufle 15. 1984
given for 24 to 48 hours, followed by isosorbide dinitrate or low-dose nifedipine unless the systolic pressure fell to less than 100 mm Hg. Anticoagulation was continued in hospital by intravenous heparin for 5 days in 13 cases followed by maintenance with dipyridamole (Persantine) (50 mg 3 times daily) and aspirin (600 mg/day). Continuous heparin therapy was administered in the remainder until discharge angiography, except when it was interrupted by bleeding complications, for CABG or death. Predischarge coronary angiography was performed at 8 to 14 days by the Judkins technique with opacification of the diseased vessel in 2 planes and quantitation of stenosis by the caliper technique. Follow-up angiography was performed at an average of 5.4 months in 11 patients, all of whom had SUCcessful PTCA with coronary patency at discharge.
THE AMERICAN JOURNAL OF CARDIOLOGY
TABLE I
lntracoronary Thrombolysis Anterior
in Table I. There were 51 patients with anterior and 52 with inferior MI. Reflow could not be achieved in the affected artery in 12 patients (24%) with anterior MI and 5 patients (9.6%) with inferior MI. Transient reflow was seen opacifying the distal coronary artery in 9 patients with anterior and 9 patients with inferior MI. Stable reflow was therefore obtained with streptokinase alone in 59% of patients with anterior MI (30 of 51) and 73% of patients with inferior MI (38 of 52). Thirty-five patients had occluded coronary arteries at the termination of the initial streptokinase procedure. The PTCA experience with these 35 cases is shown in Table II. Nine of these patients were seen before June 1981, when PTCA was not performed in this patient category. An additional 10 patients did not undergo PTCA because of coronary tortuosity, diffuse CAD, occlusions at inaccessible sites, or Q-wave development believed to represent completion of MI. Sixteen of the 35 patients without stable reflow after streptokinase administration did undergo PTCA, with 11 successes (69% success rate). Thus, 7 patients with anterior MI and 4 with inferior MI were added to the total number of cases with stable reflow at the end of the initial catheter procedure, yielding a total reflow success rate to 73% and 81%, respectively. The patients who underwent acute PTCA for coronary occlusion can be separated into 2 groups: those who never showed reflow during streptokinase administration (group A) and those who showed transient reflow and reocclusion (group B). Results in group A are listed in Table III. PTCA was successful in 3 of 7 cases, and stenosis did not recur during hospitalization. In 2 cases
Total
52
103
66 17 16
Results of Percutaneous Transluminal Coronary Angioplasty in 35 Patients with No Reflow or Reocclusion at the Termination of the Initial Streptoklnase Procedure Inferior MI 14
21 10
No. of pts PTCA attempts PTCA success Total reflow successes
TABLE Ill
MI
38 E
Anterior MI
: 42152 (81%)
3:/51 (73%)
Acute Percutaneous Transluminal Coronary Angioplasty Afler Failure of Streptokinase Therapy: Percent Coronary Stenoses (Group A)
Involved Artery
Initial Stenosis
SK
STK + PTCA
LAD LAD LAD LAD LAD RCA RCA
100 100 100 100 100 100 100
100 100 100 100 100 100 100
55 55 100’ 100’ 85 :,“;:
10 Days 50 1:: 100 a5 100 100
* Unable to cross lesion. t Reocclosion despite PTCA. LAD = left anterior descending coronary artery; RCA = right coronary artery: SK = stenosis after streptokinase; STK = streptokinase administration.
TABLE IV
Percutaneous Transluminal Coronary Angloplasty for Acute Reocclusion After Transient Reflow: Percent Coronary Stenoses (Group B)
Involved Artery
Initial Stenosis
SK
STK + PTCA
10 Days
LAD LAD LAD LAD LAD RCA RCA RCA RCA
100 100 100 100 100 100 100 100 100
100 100 100 100 100 100 100 100 100
100’ 40
100 40
:8 20 z:
2: loot 100 10 NDNDt
with left anterior descending occlusion, the lesion could not be crossed. In both patients with right coronary
stenosis, PTCA was unsuccessful despite successful crossing of the point of occlusion. In 1 patient, a distal right coronary occlusion was successfully dilated, followed by irreversible occlusion of the proximal right coronary artery secondary to trauma from the guiding catheter. In another patient, the failure of PTCA, also after dilatation of a distal right coronary lesion, was unexplained. Results in group B are shown in Table IV. PTCA was initially successful in establishing reflow in
Inferior
12 9
Results The acute results of intracoronary streptokinase infusion in the total population of 103 patients is shown
MI
z:,
No. of pts Reflow with streptokinase No reflow Transient reflow with acute reocclusion
TABLE II
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Unable to cross lesion. + Cardiac death at 24 hours; reocclusion demonstrated at postmortem examination. $ Noncardiac death. ND = not done: other abbreviations as in Table Ill. l
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STREPTOKINASE
AND PTCA DURING INFARCTION
TABLEV Acute Percutaneous Transluminal Coronary Angioplasty for Residual Coronary Stenosis: Percent Coronary Stenoses (Group C) Involved Artery
Initial Stenosis
LAD LAD LAD RCA RCA RCA RCA RCA RCA LAD RCA RCA
SK
STK + PTCA
10 Days
60
100 100 100 100 100 100 100 100 100 100 99 100
9’8* loo+ 50 20 30 50 3’: 50 40
Unable to cross lesion. + Coronary dissection. t Cardiac death; residual stenosis at postmortem Abbreviations as in Table Ill. l
examination.
8 of 9 patients, but in 1 a residual stenosis of 90% was present and was related to coronary dissection. Follow-up studies were obtained in 7 of 9 patients and showed progression to reocclusion in 2. The patient in whom reocelusion was shown at postmortem examination died with recurrent MI and shock. Reocclusion also developed in the patient with dissection and poor dilatation. PTCA was also performed in 12 patients immediately after completion of intracoronary streptokinase to reduce residual stenosis (group C). In 9 patients, PTCA was performed because residual percent diameter stenosis was 90% or greater. PTCA was used in 3 patients with 60 to 80% residual stenosis when the restored channel was irregular, suggesting retained clot or ulceration. Results in patients undergoing PTCA for residual coronary stenosis are shown in Table V. The average percent stenosis after completion of streptokinase administration was 87%. PTCA produced a greater than 20% reduction in stenosis in 9 patients. One patient showed only a 10% improvement in percent stenosis. In 1 patient the lesion could not be crossed and, in another, coronary dissection was followed by occlusion. Discharge angiography showed progression to occlusion only in the patient in whom the lesion was not crossed. To evaluate the frequency of recurrent ischemic events, we compared patients successfully treated with streptokinase alone to patients with successful PTCA immediately after streptokinase. This analysis excludes patients undergoing early CABG, patients in cardiogenie shock, and patients who died in hospital of nonTABLE VI
In-Hospital lschemia and Reocclusion After Initially Successful Treatment
STK alone stenosis 290 % STK alone stenosis <90% STK + PTCA * Died from ventricular STK = streptokinase.
No. of Pts
MI
Angina
Reocclusion Without Ml
21
3
12
1”
28 18 fibrillation.
1
1
3
0
0
cardiac causes within 10 days. Results are shown in Table VI. Recurrent ischemic events were frequent in patients treated wtih streptokinase alone with a residual coronary stenosis of 90% or greater. Seventy-six percent of these patients had MI or angina or died suddenly during the initial hospitalization. Recurrent MI with greater than 90% stenosis was in the same zone as the initial MI secondary to coronary reocclusion, and occurred after heparin therapy had been discontinued or switched to the combination of Persantine and aspirin. No MIS occurred in-hospital when the coronary stenosis after streptokinase therapy was less than 90% despite cessation of heparin in 54%, but did occur 6 hours after successful PTCA in 1 patient secondary to reocclusion despite full heparinization. Angina after streptokinase therapy was seen predominantly with a residual coronary stenosis of 90% or greater. Five of these 12 patients did not receive a full 10 days of heparin therapy. The source of angina in many of these patients was unclear because most showed significant stenosis of more than 1 major coronary artery. However, a similar percentage of patients with less than 90% stenosis and patients who underwent successful PTCA also showed multivessel CAD, suggesting the causative role of the high-grade residual stenosis in the reperfused vessel. Four patients had reocclusion without MI. Three of these 4 occlusions occurred after heparin therapy was discontinued. Similar to the patients with less than 90% residual stenosis, patients in whom PTCA was successful had few recurrent ischemic events despite cessation of heparin therapy in 44%. By chi-square analysis, the frequency of MI or ischemia after streptokinase is significantly higher in patients with residual coronary stenosis of 90% or greater compared with either of the other groups (p
June 15. 1984
successful left anterior descending PTCA showed plaque embolization into the distal left anterior descending artery at postmortem examination. In this patient the immediate post-PTCA angiogram had shown slow distal left anterior descending flow. Thus, dilatation catheters can be introduced into acutely occluded coronary arteries penetrating the thrombus or plaque and, after visualization of the distal vessel confirming catheter position, can successfully open the occlusion. Failure of PTCA in this series was either related to difficulty reaching and crossing the site of obstruction or to production of acute dissection during the dilating process. All but 1 of these procedures were performed without the use of steerable systems. Introduction of the steerable systems and new guiding catheters will probably improve these results. Recurrent ischemic events in hospital after streptokinase appear to be related to residual high-grade coronary stenosis and are apparently aggravated by interruption of heparin anticoagulation. PTCA produces a more stable hospital course with infrequent early coronary reocclusion. When PTCA was done for residual high-grade coronary stenosis acutely, the risk of acute coronary reocclusion was 8% (1 of 12 patients). After an average of 5.4 months after discharge, 5 of 11patients (45%) in whom PTCA was successful showed coronary restenosis or reocclusion. This occurred despite administration of Persantine and aspirin in 5 and warfarin (Coumadin) in 6. As yet, none of the 3 patients with restenosis have undergone a second PTCA procedure because of mild or absent symptoms. This restenosis rate is higher than several published series of PTCA for stable angina,6,7 but similar to a recent report from Emory University.8 Differences may relate to the more unstable and severe coronary disease during acute MI. PTCA in patients with acute MI immediately after intracoronary streptokinase has been described by Meyer et al? Their success rate was 81%, compared with our 69%. However, none of their patients underwent PTCA for streptokinase failure and none showed a
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percent diameter stenosis of 90% or greater before PTCA. There was a suggestion of improved clinical stability after successful PTCA, and the early and late reocclusion rate was 22%. Our results suggest that PTCA can be effective in producing stable coronary reflow despite streptokinase resistance. Sites of coronary obstruction can be passed, allowing visualization of the distal vessel and safe coronary dilatation. The addition of this technique to streptokinase administration increases the rate of stable reflow. When streptokinase infusion is effective, PTCA can be performed with greater success and, in patients with residual stenosis of 90% or more, can result in a lower incidence of recurrent ischemic events in hospital. When residual coronary stenosis is less than 90%, the value of immediate PTCA is uncertain. The late restenosis and reocclusion rate is high, but thus far has not produced unstable or fatal ischemic events. PTCA may increase the ease of clinical management and diminish the need for continuous high-level anticoagulation. References 1. Rentrop P, Blanke H, Karsch KR, Kaiser H, Kostering H, Leltz K. Selective intracoronarythrombolysisin acute myocardial infarction and unstable angina pectoris. Circulation 1981;63:307-317. 2. Ganz W, Buchbinder N, Marcus H, Mondkar A, Yaddahi J, Charurl Y, O’Connor L, Shell W, Fishbein MC, Kass R, Miyamoto A, Swan HJC. Intracoronary thrombolysis in evolving myocardial infarction. Am Heart J 1961;101:4-13. 3. Mathey DG, Kuch KH, Tllsner V, Krebber HJ, Blelfeld W. Nonsurgical coronary artery recanalization in acute transmural myocardial infarction. Circulation 1981;63:489-497. 4. Reduto LA. Smallina RW. Freund GC, Gould KL. lntracoronary infusion of streptokin&e in patsnts with acute myocardial infarction: effects of reperfusion on left ventricular performance. Am J Cardiol 1981;48:403-409. 5. Grrintrig AR, Sennlng A, Siegenthaler WE. Nonoperative dilatation of coronary artery stenosis, percutaneous transluminal coronary angioplasty. N Engl J Med 1979;301:61-68. 6. Holmes DR Jr, Vlietstra R, Smith HZ, Vetrovec GW, Cowley MJ, Kent KM, Detre KM, Myler RK. Restenosis following percutaneous transluminal coronary angioplasty (PTCA): a report from the NHLBI PTCA Registry (abstr). Am j Catdidl 1982;49:905. 7. Griintzig AR, Fischer M, Geebel N, Schlumpf M. Percutaneous transluminal coronary angioplasty. In: Mason DT, Collins JJ. eds. Myocardial Revascularization: Medical and Surgical Advances in Coronary Disease. New York: Ywke Medical Books, 1981:445-451. 6. lschirger T, Gruntzig AR, Hollman J, King S Ill, Douglas J, Meter B, Bradlord J, Tankersley R. Should coronary arteries with less than 60% diameter stenosis be treated by angioplasty? Circulation 1983;68:148-154. 9. Meyer J, Merx W, Schmitz H, Erbel R, Keissllch T, Dorr R, Lambertz H, Bethse C, Krebs W, Bardos P, Minale C, Messmer BJ. Efferf S. Percutaneous transiuminal coronary angioplasty immediately after iniraccwonary streptolysis of transmural myocardial infarction. Circulation 1982;66:905-913.