Effect of Delayed Percutaneous Transluminal Corbnary Angio

Occluded Coronary Arteries A R lasty of er Acute

Myocardlal Infarction J6rome Garot, MD, Marielle Scherrer-Crosbie, MD, Jean-Luc Monin, MD,

Patrick DuPouy, MD, Marie-Laure Bourachot, MD, Emmanuel Teiger, MD, Jean Rosso, MD, Alain Castaigne, MD, Pascal Gueret, MD, and Jean-Luc Dubois-Rand&, MD, PhD

Whether angioplasty of occluded vessels after myocar- dial infarction may have beneficial effects on left ven- tricular function remains unknown. Patients with a first myocardial infarction and thrombolytic therapy who had an occluded infarct-related vessel at delayed coro- nary angiography were referred systematically for an elective coronary angioplasty performed between 3 and 4 weeks after the myocardial infarction. All patients un- derwent stress-redistribution-reiniection thallium-20 1 single-photon emission computed tomography for myo- cardial viability assessment. Prior angioplasty, a quantitative evaluation of global and regional left ven- tricular function, was performed. The study group con- sisted of 38 patients (aged 57 2 10 years); 18 had an- terior wall infarctions and 20 inferior wall infarctions, but before angioplasty 3 had a patent artery and were excluded. Angioplasty was successful in 30 patients. At follow-up 13 patients (43%) had an occluded coronary

artery. In contrast with patients with an occluded coro- nary artery at follow-up, those with a patent coronary artery had no left ventricular enlargement and had an improvement in both left ventricular ejection fraction (from 48 + 9% to 52 ? 9.8%, p = 0.002) and regional wall motion index (A = +0.95 SD, p ~0.01). In patients with a patent vessel at follow-up, there was a positive correlation between the number of myocardial viable segments and improvement of the infarct zone wall mo- tion (r = 0.52; p = 0X135), and the number of necrotic segments at baseline was positively correlated to the 4- month changes in end-diastolic volume indexes (r = 0.6; p = 0.04). Thus, elective revascularization of occluded coronary arteries with viable myocardium after myo- cardial infarction improves left ventricular function and lessens remodeling if the artery remains patent during follow-up.

(Am J Cardiol 1996;77:915-921)

E vidence is accumulating that reestablishing per- fusion of a coronary artery may have prognostic

benefits.“2 However, while most authors agree that attempts to restore vessel patency should be made within 6 hours after the onset of symptoms,3m6 there is controversy about electively restoring coronary patency of occluded coronary arteries when coronary angiography is performed after the acute phase of myocardial infarction.7-9 In addition, it is not yet known whether noninvasive determination of myo- cardial viability after myocardial infarction can pre- dict the long-term results of angioplasty on both the coronary reocclusion rate and left ventricular func- tion. The present prospective study is designed to assess the beneficial effects of coronary angioplasty of occluded vessels when performed within the first weeks after myocardial infarction and to assess the impact of thallium scintigraphy assessment of myo- cardial viability on the long-term results of revas- cularization.

From the Federation de Cardioloaie et lnstitut National de la Santi: et de la Recherche Mkdicale, S&ices de Mitdecine Nuckaire et des Explorations Fonctionnelles, Crkteil, France. Manuscri t received Seotember 29. 1995: revised manuscriot received on 8 accented D&ember 6, i99.5.

Address for reprints: Jean Luc Dubois-Randk, MD, PhD, Fkditration de Cardiologle, Service du Pr A Castoigne, HBpital Henri Mondor, 94010, Crkteil, France.

01996 by Excerpto Medica, Inc All rights reserved.

METHODS Patient selection: Patients with the diagnosis of a

first myocardial infarction and receiving thrombo- lytic therapy who underwent delayed coronary an- giography between December 1993 and March 1995 (n = 135) were prospectively screened. Inclusion criteria for the study were ( 1) diagnosis of a first acute myocardial infarction with characteristic elec- trocardiographic (ECG) ST-segment elevation and confirmation by creatine kinase-MB isoenzyme ele- vation; (2) occlusion of a clearly identified infarct- related coronary artery; (3) left ventricular dysfunc- tion of the infarct area; (4) suitability for coronary angioplasty revascularization; and (5 ) agreement for a control angiogram 4 months after angioplasty. We selected an interval of 3 to 4 weeks after myocardial infarction to analyze left ventricular function and perform coronary angioplasty in order to avoid re- covery of stunned myocardium, which occurs mainly within this period.

Protocol: All patients underwent an initial diag- nostic angiographic study between 6 and 8 days after myocardial infarction. Patients with the inclusion criteria were selected for evaluation of myocardial viability and were referred systematically immedi- ately afterward for an elective coronary angioplasty between 3 and 4 weeks after myocardial infarction. Before angioplasty a quantitative evaluation of global and regional left ventricular function was

0002.9149/96/$15.00 915 PII SOOO2-9 149(96)00028-E

done, and angioplasty was attempted if the infarct- related artery remained occluded after a control cor- onary angiogram and intracoronary injection of 2 mg isosorbide dinitrate. The infarct-related artery was identified by the ECG ST-segment elevation change during the acute stage of infarction, the site of re- gional wall motion abnormalities, and the coronary angiogram. The collateral circulation was graded from 0 to 3 according to the classification of Rentrop et al.”

All patients received aspirin (250 mg/day) and p blockers (atenolol 5 mg/day) if tolerated. Angio- tensin-converting enzyme (ACE) inhibitors were given within the first week of infarction when the first angiographic ejection fraction was <40% (cap- topril 75 to 150 mg/day was given according to the patient’s tolerance [ systolic blood pressure > 80 mm Hg] ) . Medications were not changed after angio- plasty, and the dosage was kept constant until the 4- month control angiogram.

Assessment of myocardial viability: All patients un- derwent stress-redistribution-reinjection thallium- 201 single-photon emission computed tomography (an Elscint large field of view single-head gamma camera [Apex SP6] was used). Beta-blocking agents were stopped 48 hours before the test and reintroduced immediately afterward. Stress was achieved either by bicycle exercise or infusion of dipyridamole (0.56 mg/kg) . Four hours after thal- lium injection 30 40-second redistribution images were acquired using the same rotation protocol ( 180”-clockwise rotation). Thirty-seven MBq ( 1 mCi) thallium-201 was reinjected and 30 30-second reinjection images were acquired 20 minutes after reinjection. The reconstructed tomographic data (64 x 64 cm matrix, Hamming/Harm filter) were dis- played in 3 planes. Sixteen myocardial regions were defined. A 4-point grading system was used as de- scribed by van Eck-Smit et al” (0 = no visible up- take, 1 = severe defect, 2 = moderate defect, 3 = normal uptake). Reversibility was defined as an im- provement of 2 1 grade of initial uptake on the re- distribution or reinjection images. Segments were then classified as normal (poststress thallium-201 uptake = 3)) necrotic (initial uptake = 0 or 1) or viable (moderate irreversible defects or reversible defects [regardless of stress thallium uptake] ) .

Angioplasty procedure: Angioplasty was per- formed according to a standard balloon technique. The procedure was considered successful when the residual luminal narrowing in the dilated segment was <50% and when no major complications oc- curred. Angiography was performed in at least 2 projections after intracoronary injection of 2 mg iso- sorbide dinitrate. Quantitative computer-assisted an- giographic measurements of the dilated lesion were performed. l2

Quantitative evaluation of global and regional left ventricular function: Global left ventricular function was evaluated on 2 orthogonal views (30” right-an- terior oblique and 60” left-anterior oblique posi- tions) . The left ventricular contours were manually

traced by 1 blinded observer and then digitized (computer system by T.S.1, Paris, France). End-di- astolic and end-systolic volume indexes ( ml/m2) and left ventricular ejection fraction were calculated by the area-length method.13 Segmental wall motion was expressed as radial shortening fraction ([end- diastolic radius - end-systolic radius] /end-diastolic radius) of 13 anatomic wall segments by the center gravity method; the right anterior oblique position was used. Segments 1 through 6 were denoted an- terior and 7 to 13 inferior (Figure 1) . The normal range was determined for ejection fraction and each radial segment studied using ventriculograms ob- tained in 40 subjects with atypical chest pain who had no evidence of coronary artery disease or other cardiovascular pathology. To compare values for re- gional anterior or posterior wall motion with normal values and values at follow-up angiography, a stan- dardized motion index expressed in units of standard deviation from the normal mean was calculated ( [ % shortening of a patient’s segment - (mean of the same normal segment] /SD of the normal segment). The wall motion for an individual segment was con- sidered normal if the value lay within 2 SDS of the equivalent mean value in the control population. Re- gional wall function was considered hypokinetic if wall motion of at least 3 segments lay 12 SDS below the normal range. For a given territory (segments 1 through 6 or from 7 through 13)) an average of the 3 most hypokinetic segments was calculated and used for statistical comparisons.

Follow-up: We attempted to obtain a follow-up an- giogram 4 months after successful angioplasty. Res- tenosis was defined by quantitative coronary angio- graphy as the recurrence of ~50% luminal narrowing in a coronary segment that had previously been dilated.

Statistical analysis: Data in the text and tables are presented as mean ? SD. Paired data were com- pared by Student’s t test. Comparisons between groups were made with an unpaired Student’s t test. Differences between proportions were as- sessed by chi-square analysis. Correlations were obtained by the linear regression method. Data in figures are expressed as mean -+ SEM. A p value co.05 was considered to indicate statistical sig- nificance.

RESULTS Baseline characteristics: The study group consisted

of 38 patients (36 men and 2 women) with a mean age of 57 t 10 years (Table I). Eighteen had anterior wall infarction and 20 had inferior wall infarction. The occlusion was located with equal frequency in the left anterior descending coronary artery (47%) and the right coronary artery (47%) and less often in the left circumflex artery (5%). The time between acute myocardial infarction and angioplasty of the infarct-related vessel was 22 -+ 6 days. The mean left ventricular ejection fraction of 45 t 10 % and an- giographically visible collateral vessels were ob- served in 61% of cases. Thirty-five patients under-

916 THE AMERICAN JOURNAL OF CARDIOlOGYa VOL. 77 MAY 1, 1996

FIGURE 1. Regional wall motion definition of he 13 segments analyzed.

went assessment of myocardial viability; the 3 remaining patients had recurrent clinical angina and were directly referred for percutaneous angioplasty. Initial ejection fraction was negatively correlated to the number of necrotic segments (r = 0.7; p = 0.0001).

Immediate outcome: Among the 38 patients re- tained for delayed angioplasty, 3 had a patent cor-

onary artery on the control coronary angiogram before angioplasty and were excluded. Angio- plasty was successful in 30 patients (86%) with a mean luminal diameter after angioplasty of 1.9 ? 0.6 mm (reference diameter 3.02 2 0.7 mm; net gain 1.16 2 0.5 mm) and a residual stenosis of 34% 2 22 %. There were no major in-hospital complications.

TABLE I Baseline Characteristics of the Study Population

Age (~4 Men (%)

Infarct location

Anterior (“A)

Inferior (%)

Thrombolytic agent

Streptokinase (%)

Recombinant tissue plasminogen activator (“A)

Creatine kinase (peak: U/L)

interval between infarction and angioplasty (days)

1 -vessel disease (%)

Multivessel disease (%)

Ejection fraction (“Y)

Enddiastolic volume index, ml/m*

End-systolic volume index, ml/m’

Coronary artery with angioplasty performed

Left anterior descending artery (%)

Right coronary artery (%)

Left circumflex artery (%)

Collateral vessels (grade) (“‘%)

0

1

2

3

Treatment

Aspirin (%)

p blockers (%)

Angiotensinconverting enzyme inhibitors (“A)

Values ore expressed as mean t SD or number @)

572 10

36 (95)

18 (47)

20 (53)

12 (32)

26 (68)

3100 2 1000

22 i 6

24 (63)

1 A (37) 45 k 10

91 f 18

492 18

18 (47)

18 (47)

2 15) 23 (61)

15

3

4

16

38 (100)

32 (84)

21 (55)

Four-month follow-up: Clinical and angiographic follow-up were obtained for all patients. All but 2 patients, who had recurrent angina, were asymptomatic at follow-up; none had recurrent myocardial in- farction. On follow-up angiography 13 patients (43%) had an occluded coronary artery ( 11 with a TIMI grade 0 flow and 2 with a TIM1 1 flow) and 4 had a restenosis HO% but with a TIM1 3 flow.‘”

Changes in left ventricular function: In the group of patients as a whole there was a small but statistically significant increase in ejection frac- tion from 45 +- 10% to 49 2 11 % (p = 0.002). Left ventricular end- diastolic volume index at follow-up increased slightly compared with that recorded before angioplasty (99 -+ 21 versus 91 + 18 ml/m2, respectively, p = 0.04)) whereas no significant change in systolic vol- ume index was observed (52 +- 20 versus 49 -t 18 ml/m’, respectively, NS ) . Wall motion index increased from - (2.6 +- 0.7 to - (2.06 k I U

CORONARY ARTERY DISEASE/ANGIOPlASTY OF OCCLUDED CORONARY ARTERIES 917

FIGURE 2. Effect of a delayed angioplasty strategy of occluded vessels. In the group of patients as a whole there was a small but increase in wall motion index and leti ventricular ejection fraction. The left ventricular end-diastolic volume in-

as compared with the 1 prior angioplasty, whereas no significant change in systolic volume index was observed. When location of the infarction was considered, a significant left ventricular enlargement and a slight increase in left ventricular function were only observed for the anterior infarctions. Results are expressed as mean ? standa J

lobal and regional error of the mean.

l p ~0.05, l *p <O.Ol. BASE = baseline values; F-UP = 4-month follow-up.

standard deviation, p = 0.005. When the location of Figure 3 shows that in patients with an occluded cor- the infarction was considered, significant left ven- onary artery at follow-up, an increase in left ventric- tricular enlargement and a slight increase in global ular volume index was observed; however, this was and regional left ventricular function were observed only significant for end-diastolic volume. No signif- only in anterior infarctions (Figure 2).

Comparison between groups with or without reocclu- icant improvement in either global ejection fraction or regional wall motion was observed. In contrast,

sion: Groups were comparable as shown in Table II. in patients with a patent coronary artery at follow- up, no left ventricular enlargement was observed, whereas improve-

TABLE II Characteristics of the Two Groups of Patients ment in left ventricular ejection

Status of Coronary Artery at fraction (from 48 + 9% to 52 +

Follow-up 9.8%, p = 0.002) and regional wall

Occluded Artery Patent Artery motion was observed (A = +0.95

(n = 13) (n = 17) SD, p <O.Ol ) . Results according to

Age (yd 53 k 11 58 + 9 the infarct location in patients with

Ejection fraction (%) 42% 13 48 t 9 a patent coronary artery at follow-

Wall motion index (units of SD) -2.8 k 0.7 -2.5 2 0.8 up are shown in Figure 4.

Enddiastolic volume index (ml/m2) 93+ 18 892 19 Predictors of reocclusion: Table III End-systolic volume index [ml/m’) 55 k 22 44Ir 14 summarizes the results of the uni- Mean luminol diameter after angioplasty (mm) 1.9 2 0.79 1.94 * 0.6 Stenosis after angioplasty (%) 31 224 36 k 24

variate analysis, including age, in-

Number of viable segments 4.4 t 1.5 5.5 + 2.9 farct location, hemodynamic status

Number of necrotic segments 4.7 + 2.6 3.1 + 2.1 before angioplasty, the immediate Infarct location angiographic result, presence of col-

Anterior (%) 6 I461 9 I531 Inferior (%)

laterals, and the number of necrotic 7 (541 8 (471

Treatment or viable myocardium segments.

fl blockers (%) 10 (81) 14 (85) None of these parameters was a pre- Angiotensinconverting enzyme inhibitors (%) 7 (541 9 (531 dictor of reocclusion at follow-up.

Values are expressed as mean c SD or number (“A), Although patients with reoccluded arteries have more necrotic seg-

918 THE AMERICAN JOURNAL OF CARDIOLOGY@ VOL. 77 MAY 1, 1996

Wall motion index (units of Left ventricular standard deviation) ejection fraction (46)

+l

0 --------

-1

-2

-3

1 --

-4 El Normal range

B F-UP B F-UP

OCCLUDED PATENT AT 4 MONTHS AT 4 MONTHS

End-diastolic

160 1

volume index (mL/mZ)

1 40 B F-UP B F-UP

OCCLUDED PATENT OCCLUDED PATENT AT 4 MONTHS AT 4 MONTHS AT 4 MONTHS AT 4 MONTHS

20

I

/ /

10 '

B F-UP

OCCLUDED AT 4 MONTHS

B F-UP

PATENT AT 4 MONTHS

End-systolic volume index (mUmE)

2oJ B F-UP B F-UP

FIGURE 3. Effect of delayed ongioplosty according to the final status of the artery at follow-up. In patients with on occluded coronary artery at follow-up there was an increase in left ventricular volume. No significant improvement in either global ejection fraction or regional wall motion was observed. In patients with a patent coronary artery at fallow-up there was no left ventricular enlargement of the left ventricle, whereas an improvement in left ventricular ejection fraction and regional wall motion was observed. Results are expressed OS mean + standard error of the mean. l p <0.05, l *p <O.Ol. B = baseline values; F-UP = 4-month follow-up.

CORONARY ARTERY DISEASE/ANGIOPlASTY OF OCCLUDED CORONARY ARTERIES 919

%

60 - * l

50

40 1 TT

I 1

FIGURE 4. Resulk according to the infarct location in patients with a patent coronary artery at follow-up. Results are expressed in percentage from baseline: mean ~fr standard error of the mean. *p <0.05. EF = left ventricular ejection fraction; EDVI = leh ventricular end-diastolic volume index; ESVI = left ventricular end-systolic volume index.

ments (4.7 + 2.6 versus 3.1 + 2.1) and fewer viable segments (4.4 ? 1.5 versus 5.5 5 2.9) than patients without reoccluded arteries, no significant difference was observed.

Thallium imaging and left ventricular function at fol- low-up: In patients with a patent coronary artery at follow-up, there was no relation between the number of myocardial viable segments and improvement of global ejection fraction. However, in these patients there was a positive correlation between the number of myocardial viable segments and improvement of

the infarct zone wall motion (r = 0.52; p = 0.035). In the group of patients with a patent artery at follow- up there was no significant negative correlation be- tween the number of viable segments and the 4- month variations of both end-diastolic (r = 0.35; p = 0.2) and end-systolic volume indexes (r = 0.44; p = 0.1) . However, the number of necrotic segments at baseline was positively correlated to the 4-month variations in end-diastolic volume index (r = 0.6; p = 0.04), and a trend was observed for end-systolic volume index changes (r = 0.44; p = 0.1).

DISCUSSION Left ventricular function is the most important

predictor of late survival in patients with coronary artery disease.15 However, although there is agree- ment to restore coronary patency at the acute phase of myocardial infarction, there is no consensus for electively restoring patency before discharge in pa- tients with an occluded artery. Indeed, previous stud- ies have suggested that infarct-related lesions have a greater tendency to recur after successful angio- plasty; this may hamper potential beneficial results on left ventricular function and survival.’ In the pres- ent study the overall results of the angioplasty pro- cedure were favorable, with 85% procedural success, data that are comparable to other studies.7”6 When considered as a whole, the strategy of reopening cor- onary arteries before discharge only leads to a mod- est improvement in both global ejection fraction and regional shortening at final follow-up. Indeed, de- spite a slight increase in regional wall motion index, most segments have persistent severe wall motion abnormalities, and enlargement of the left ventricle is observed. Additionally, anterior infarctions seem to benefit more than inferior infarctions. As previ- ously pointed out, the rate of reocclusion is high in our patients and is the limiting factor of the method.7 Indeed, only patients with an open artery at follow- up have an improvement in both ejection fraction

-and regional wall motion, and no significant enlargement of the left ventricle is seen in this population compared with patients with an’ oc- cluded artery. These results agree with those of Miketic et al, I7 who showed that global and regional myocardial dysfunction due to post- infarction ischemia lessen signifi- cantly after successful coronary an- gioplasty of the infarct-related ves- sel with sustained long-term, normal, and complete flow. In the same connection, Linderer et al ” showed that successful angioplasty of a high-grade stenosis in an in- farct-related artery may improve left ventricular ejection fraction and de- crease regional wall abnormalities. However, in the event of arguments to consider that late restoration of complete perfusion is able to pre-

TABLE Ill Univariate Analysis of Potential Predictors of Reocclusion

Reocclusion No reocclusion (n = 13) (n = 17)

Age (~4 53 + 11 58 t9 Thrombolytic agent

Streptokinase (“A) 4 I301 5 (291 Recombinant tissue plasminogen activator (%) 9 (70) 12 (71)

Interval between infarction and angioplasty (days) 22 ? 7 21 +5 Ejection fraction (%) 43% 13 48 2 9 Enddiastolic volume index, ml/m2 93 k 18 892 19 End-systolic volume index, ml/m* 55 2 21 44* 14 Regional wall motion (units of SD) -2.8 t 0.7 -2.5 2 0.8 Infarct location

Anterior (%) 6 I461 9 (53) Inferior (%) 7 (54) 8 (47)

Presence of collaterals (%) 9 (69) 9 (53) Minimal luminal diameter after angioplasty (mm) 1.9 t 0.8 1.94 ? 0.6 Stenosis after angioplasty 0.31 t 0.24 0.36 c 0.24 Number of viable segments 4.4 2 1.5 5.5 2 2.9 Number of necrotic segments 4.7 t 2.6 3.1 k 2.1

Values are expressed CJS mean 2 SD or number (‘%I,

920 THE AMERICAN JOURNAL OF CARDIOLOGY@’ VOL. 77 MAY 1, 1996

serve left ventricular function in patients with a tight stenosis but a still-patent vessel, the present study shows that the beneficial effect of angioplasty when there is sustained long-term patency of the infarct- related vessel extends to patients with a postinfarct occlusion and severe regional abnormalities and con- firms the previous study of Dzavik et a1.19 Despite a slight but significant increase in end-diastolic diam- eter observed for anterior infarctions, this beneficial effect on left ventricular function was observed both for anterior and inferior infarctions.

In the present study we did not find any initial predictors of reocclusion. Neither angiographic vari- ables such as the minimal luminal diameter after an- gioplasty nor the presence of collateral circulation were predictors of reocclusion. However, the popu- lation studied was small and the majority of patients with an occluded coronary artery had visible collat- eral circulation. Consequently, this may explain that no relation was found between collateral circulation and reocclusion rate. The initial result of angioplasty obtained in this study is acceptable and compared favorably with other balloon studies. However, it should also be noted that more recent studies involv- ing stenting report better immediate angiographic re- sults.20 Whether such a method could improve long- term patency of occlusions remains to be determined.

Revascularization is indicated in patients with vi- able myocardium in order to improve left ventricular function and lessen recurrence of cardiac events. In the present study neither the initial status of left ven- tricular function nor the extent of myocardial viabil- ity significantly affected the long-term patency of the infarct-related artery. However, in agreement with previous studies, we found a relation between the number of viable segments and recovery of wall mo- tion contractility.2’ This relation did not exist in pa- tients with a reoccluded coronary artery on follow- up. Additionally, patients with viable myocardium and a patent artery at follow-up tended to have less enlargement of the left ventricle. These results sug- gest that detection of viability by thallium imaging may predict improvement in left ventricular function if the artery remains patent. This also suggests that in a patient who initially had a large extent of viable myocardium, the lack of recovery of wall motion contractility during the follow-up angioplasty of oc- cluded infarct-related vessels means a high proba- bility of reocclusion. Because most reocclusions are clinically silent, this may be an important issue for treatment of these patients.

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2. Van de Werf F. Discrepancies between the effects of coronary rep&u&ion and left ventricular function. Lancer 1989; I: 1367- 1369. 3. Voght A, van Essen R, Tebbe U, Feuerer W, Appel KF, Neuhaus KL. Impact of early perfusion of the infarct-related artery on short term mortality after thrombolysis for acute myocardial infarction: retrospective analysis of four German multicenter studies. J Am Co// Cardiol 1993; 21:1391-1395. 4. The GUSTO investigators. An international randomized trial comparing four thrombolytic strategies for acute myocardial infarction. N En~l J Mrd 1993;329:673-682. 5. Grines CL, Browne KF, Marco I, Rothbaum D, Stone GW, O’Keefe J, Over- lie P, Donahue B, Chelliah N, Timmis GC, Vliestra RE, Strzeleccki M, Puch- rowltcz-Ochocki S, O’Neil WW, for the Primary Angioplasty in Myocardial Infarction Study Group. A comparison of immediate angioplasty with throm- bolytic therapy for acute myocardial infarction. N Engl J Med 1993:328:673- 679. 6. Abbotsmith CW, Topol EJ, George BS. Stack RS. Kereiakes DJ. Candela RJ, Anderson LC, Harrelson-Woodlief SL, Califf RM. Fate of patlent, with acute myocardial infarction with patency of the infarct-related vessel achieved with successful thrombolysis versus rescue angioplasty. J Am Co// Cardiol 1990;16:770&778. 7. Bauters C. Khanoyan P, MC Fadden EP, Quandalle PH, Lablanche JM, Ber- trand ME. Rertenosis after delayed coronary angioplasty of the culprit vessel in patients with a recent myocardial infarction treated by thrombolysis. Cirru- him 199.5;91:1410-1418. 8. Pitt B. Evaluation of the postinfarct patient. Circulation 1995;91: 1855- 1860. 9. Ellis SG, Mooney MR. Georges BS, Rib&o da Sylva EE, Taley JD. Flanagan WH, Top01 EJ. for the Treatment of Post-Thrombolytic Stenoses (TOPS) Study Group. Randomized trial of late elective angioplasty versus conservative man- agement for patients with residual stenoses after thrombolytic treatment of myo- cardial infarctlon. Circulation 1992;86: l400- 1406. IO. Rentrop KP, Cohen M, Blanke H, Phillips R. Changes in collateral filling immediately followmg controlled coronary occlusion by an angioplasty balloon in man. J Am Co/l Cardiol 1985;.5:587-592. 11. van Eck-Smit BLT, van der Wall EE, Kujiper AFM. Zwinderman AH, Pauwels EKJ. Immediate thallium-201 reinjection followmg stress imaging: a time-saving approach for detection of myocardial viability. J Nucl Med 1993:34:737-743. 12. Geschwind H, Nakamura F, Kvasnicka J, Dubois-Rand6 JL. Excimer and Holmium YAG laser coronary angioplasty. Am Heart J 1993;125:510-522. 13. Sandier H, Dodge HT. The use of single plane angiocardiograms for the calculation of left ventricular volume in man. Am Heart J 1986;80:343m352. 14. The TIMI Study group. The thrombolysis in myocardial infarction (TIMI) trial. Phase I findings. N Eng/ J Mrd 1985;31:932-936. 15. Sheehan FH, Doert R, Schmidt WG. Early recovery of left ventricular func- tion after thrombolytic therapy for acute myocardial infarction: an important determinant of survival. ./Am Co/l Cardiol 1988;12:289-300. 16. Bairn DS, Diver DJ. Feit F, Greenberg MA, Holmes DR, Weiner BH, Wil- liams DO, Schweiger MJ, Brown BG, Frederick MM, Knatterud GL, Braunwald E, for the TIM1 II Investigators. Coronary angioplasty performed withm the Thrombolysis In Myocardial Infarction II study. Circulation 1992;85:93- 105. 17. Miketic S, Carlsson J, Tebbe U. Improvement of global and regional left ventricular function by percutaneous transluminal coronary angioplasty after myocardial infarction. .I Am Co// Curdio/ 1995:25:843%847. 18. Linderer T. Guhl B. Spielberg C, Wunderlich W, Schnitzer L, Schroder R. Effect on global and regional left ventricular functions by percutaneous trans- luminal coronary angioplasty in the chronic rtage after myocardial infarction. Am J Cardiol 1992;69:997- 1002. 19. Dzavik V, Beanlands DS, Davie\ RF, Leddy D, Marquis JF, Tea KK, Ruddy TD, Burton JR, Humen DP. Effects of late percutaneous transluminal coronary angioplasty of an occluded infarct-related coronary artery on left ventricular function in patients with a recent (<6 weeks) Q-wave acute myocardial in- farction (total occlusion post-myocardial infarction intervention study [TO- MISS] -a pdot study). Am J Cardiol 1994;73:856-861. 20. Colombo A, Hall P. Nakamura S, Almagor Y, Maiello L. Martinin G, Gaglione A, Goldberg SL, Tabi? JM. Intracoronary stenting without anticoag- ulation accomplished with intravascular ultrasound guidance. Circuhtion 1995;91:3676-1688. 21. Ragoata M, Belier GA, Watson DD, Paul S. Gimple LW. Quantitative planar rest-redistribution 201.TI imaging in detection of myocardial viability and pre- diction of improvement in left ventricular function after coronary bypass surgery in patients with xverely depressed left ventricular function. Circulution 1993:87:1630-1643.

CORONARY ARTERY DlSEASE/ANGIOPlASTY OF OCCLUDED CORONARY ARTERIES 921