Early Results, Complications and Restenosis Rates After Multilesion and Multivessel Percutaneous

Transluminal Coronary Angioplasty

MARC LAMBERT, MD, RAOUL BONAN, MD, GILLES COT6, MD, JACQUES CREPEAU, MD, PIERRE de GUISE, MD, JACQUES LESPCRANCE, MD,

PAUL ROBERT DAVID, MD, and DAVID D. WATERS, MD

initial results, complications, restenosis rates and clinical outcomes were compared in 78 patients un- dergoing multilesion and 128 patients undergoing multivessel percutaneous transluminal coronary an- gioplasty (PTCA). Multilesion PTCA was defined as a procedure in which a proximal PTCA site had to be crossed to dilate a distal severe narrowing and multivessel PTCA as multiple dilatations without having to cross 1 severe narrowing to dilate anoth- er. The clinical and angiographic features of the 2 groups were similar. More sites per patient were at- tempted among those who underwent multilesion PTCA. Primary success rate per lesion was 88% (236 of 274) among those who underwent mul- tivessel and 73% (155 of 211) among those who underwent multilesion PTCA (p <O.OOl). A success rate of 81% (101 of 124) for proximal lesions among those with multilesion PTCA was not signifi- cantly worse than that for those with multivessel

PTCA; however, lesions distal to proximal sites had a success rate of only 62% (54 of 87), worse than either those with proximal stenoses or multivessel PTCA (p <0.005). Arterial diameter, severity of stenosis or procedural variables did not account for this difference. Complication rates were similar in the 2 groups. Despite a poorer success rate among patients with multilesion PTCA, clinical improvement to functional class 0 or 1 occurred in more than 70% of patients in both groups and was equal in patients with and without successful distal dilata- tions. Restenosis rates per lesion in patients with multivessel (31% ) and multilesion (30 % ) PTCA were similar. Thus, multilesion PTCA has a lower primary success rate than multivessel angioplasty because of the difficulty in dilating lesions distal to other angioplasty sites; however, this is not reflect- ed in differences in clinical outcome.

(Am J Cardiol 1987;60:788-791)

P ercutaneous transluminal coronary angioplasty (PTCA) is the treatment of choice for many patients with coronary artery disease (CAD]. Although origi- nally limited to patients with l-vessel CAD,*r2 it is now administered to selected patients with multivessel CAD with excellent results.3-7 However, multivessel CAD is a heterogeneous disease. PTCA appears to be ideal for some combinations of lesions but relatively contraindicated for others. Further studies are re-

From the Department of Medicine, Montreal Heart Institute, and the University of Montreal Medical School, Montreal, Que- bet, Canada. Manuscript received March 81987; revised man- uscript received and accepted June 151987.

Address for reprints: Raoul Bonan, MD, Montreal Heart Institute, 5000 East, Belanger Street, Montreal, Quebec HlT lC8, Canada.

quired to determine which subgroups of patients with multivessel CAD respond best to this treatment and how outcomes can be improved in other candidates.

We compared the results of “multivessel” and “multilesion” PTCA. We define multivessel PTCA as a procedure in which 2 or more severe narrowings are dilated, but without crossing one to reach the other. The dilated lesions may be in the same arterial system, e.g., the mid-left anterior descending and the first di- agonal branch, or in different arteries entirely. In con- trast, multilesion PTCA was defined as a situation in which a proximal stenosis was crossed to dilate a distal lesion. Both sites may be in the same artery or in a main trunk and a distal branch.

Methods Patients: Between December 1981, when the first

multiple PTCA was performed, and January 1986,

788

October 1, 1987 THE AfvlERiCAN JOURNAL OF CARDIOLOGY Volume SO 76

1,448 patients underwent a first elective PTCA at the Montreal Heart Institute. Using our definitions, 128 patients (8.8%) underwent multivessel PTCA and 78 (5.4%] multilesion PTCA. Patients who underwent multilesion PTCA who also had stenoses dilated in other arteries were still included in the multilesion group. Patients undergoing dilatation for restenosis or during acute myocardial infarction were excluded.

Angioplasty procedure and adjunctive therapy: All dilated segments were studied prospectively by measuring arterial diameter proximal and distal to the stenosis to determine optimal balloon size. The degree of stenosis was measured with a caliper in the view showing the most severe stenosis and was expressed as a percent of luminal narrowing, as compared with the closest normal segment. All measurements were made by an independent experienced cardiovascular radiol- ogist. Data related to the procedure were systematical- ly collected using a standard protocol.

All PTCAs were performed through a percutane- ous femoral approache5 Steerable catheters have been used since April 1982. Since April 1983, based on our experience,*vg we usually use higher inflation pres- sures (8 to 12 atm] and balloons that when inflated are slightly larger in diameter than the adjacent normal coronary segment. The artery judged the most impor- tant with respect to the amount of myocardium at risk was usually dilated first. If this artery was providing collaterals to another vessel, the latter one was dilated first. In the multilesion group the proximal stenosis was sometimes dilated first to allow access to the distal lesion, but the usual procedure was to dilate the distal stenosis first if possible.

Use of antianginal medication was continued up to the time of the procedure. Therapy with aspirin, 650 mg/day, and dipyridamole, 75 mg 3 times daily, was begun 1 day before PTCA and continued for 6 months after if the procedure was successful and the medica- tion was tolerated. Diltiazem, 60 or 90 mg, was admin- istered the evening before and the morning of angio- plasty; in some patients diltiazem use was continued for 6 months.lO

Follow-up: Patients were seen in a regular clinic at 2 and 6 months after angioplasty. Coronary arteriogra- phy was recommended to all patients at 6 months but was performed earlier in those with recurrent angina.

Data analysis: Primary success was defined as a stenosis reduction of more than 2O%, with a residual stenosis diameter of less than 50% in the absence of major complications. Restenosis was considered pres- ent if a 50% or greater diameter narrowing was found at a site that had been successfully dilated. An angio- plasty site in patients undergoing multilesion PTCA was considered distal if another site had to be crossed to reach it; other sites were considered proximal. Thus, distal lesions were not necessarily far from, or proxi- mal sites close to, the coronary orifices.

Values are expressed as mean f standard devi- ation. Univariate analysis was performed using the chi-square test for categorical data and the unpaired t test for continuous variables.

LE I Clinical Characteristics of the Study Patients

Multivessel Multilesion P (n = 128) (n = 78) Va!ue

Age (yr) (mean f SD) 54 i: 9 54 f 9 NS Male 103 (80%) 59 (76%) NS Duration of angina (mo) 18 f 27 22 f 32 NS Previous myocardial infarction 33 (26%) 23 (29%) NS Previous bypass surgery 6 (5%) 5 (6%) NS Systemic hypertension 42 (33%) 28 (36%) NS Diabetes mellitus 16 (13%) 7 (9%) NS Cigarette smoking 92 (72%) 57 (73%) NS LDL cholesterol (mgldl) 171 f 69 159 f 40 NS HDL cholesterol (mgldl) 39f 10 40f 12 NS Triglycerides (mgldl) 228 f 140 184 f 80 <0.05 CCVS functional class

O-1 6 (5%) 3 (4%) 2 50 (39%) 24 (31%) NS 3-4 72 (56%) 51 (65%)

CCVS = Canadian Cardiovascular Society; HDL = high-density lipopro- tein; LDL = low-density lipoprotein; NS = not significant; SD = standard deviation.

Results Clinical and angiographic features: The clinical

characteristics of patients who underwent multivessel and multilesion PTCA are listed in Table I. Triglycer- ide levels were inexplicably higher in patients with multivessel PTCA, but the 2 patient groups were other- wise quite similar. Mean age was 54 years; most pa- tients were men. Fifty-six patients (27%) had a pre- vious myocardial infarction and 123 (60%] were in Canadian Cardiovascular Society functional class 3 or 4.11

The number of arteries with at least a 50% diameter stenoses was 2.19 f 0.5 per patient among patients undergoing multivessel PTCA and 1.84 f 0.7 per pa- tient among those undergoing multilesion PTCA (dif- ference not significant). Angioplasty was attempted at 2 sites in 110 of the patients (86%) undergoing mul- tivessel PTCA and 38 (49%) of those undergoing multi- lesion PTCA (p <O-05). PTCA was attempted on 3 sites in 18 patients undergoing multivessel and 27 undergo- ing multilesion PTCA and on 4 or more sites in the remaining 13 patients undergoing multilesion PTCA.

Results of percutaneous transluminal coronary angioplasty: Primary success per lesion was signifi- cantly more common in those with multivessel PTCA: 236 of 274 stenoses were successfully dilated com- pared with 155 of 211 in multilesion patients (86% vs 73%, p <O.OOl). However, in the multilesion group, the primary success rate for proximal lesions, 101 of 124 [81%), was similar to the multivessel group. In contrast, the primary success rate of 62% (54 of 87) for distal lesions was significantly worse (p X0.005) than for proximal sites in those with multilesion PTCA or for all sites in those with multivessel PTCA. Higher rates for both failure to cross and failure to dilate distal lesions contributed to this difference (Table II).

Procedural variables such as the number of infla- tions per lesion, maximal inflation pressure and bal- loon artery ratio did not differ between the groups. Mean stenosis diameter was reduced from 74 f 14% to

790 MULTILESION VERSUS MULTIVESSEL ANGIOPLASTY

TABLE II Comparison of Multivessel and Multilesion Percutaneous Translumlnal Coronary Angioplasty

Multivessel,

All Sites All Sites

Multilesion

Proximal Sites Distal Sites

No. of pts No. of sites attempted Primary success (% of sites) Failure to cross (% of sites) Failure to dilate (% of sites) Max inflation pressure (atm) Inflations per lesion Balloon artery ratio Arterial diameter (mm) Stenosis diameter (% )

128 274

236 (86 %) 4 (1%)

34 (12%) 8.2 f 2.3 3.2 f 1.7

1.09 f 0.17 2.68 f 0.5

Before PTCA 74 f 14 After PTCA 33 f 20

lntimal dissection (% of sites) 124 (46%)

78 211

155 (73%)’ 10 (5%) 46 (22%) 8.2 f 2.1 3.9 i 2.5

1.05 f 0.20 2.90 f 0.5

75 f 14 33 f 19

92 (44%)

78 124

101 (81%) 2 (2%)

21 (17%) 8.4 f 1.9 4.1 f 2.5

1.04 f 0.16 2.95 A 0.6

77 f 12 30 f 18 55 (44%)

78

54 (ii%)+ 8 (9%)

25 (29%) 7.9 f 2.9 3.3 zk 2.3

1.06 f 0.10 2.88 f 0.5

70 f 13 37f 16

37 (43%)

l p <O.OOl vs multivessel group: Tp <0.005 vs proximal sites and vs multivessel group; all other comparisons statistically not significant.

PTCA = percutaneous transluminal coronary angioplasty.

TABLE Ill Complications of Multivessel and Multilesion Percutaneous Transluminal Coronary Angioplasty

Myocardial infarction Emergency bypass surgery Total

Multivessel (n = 128)

8 (6%) 1 (1%) 9 (7%)

Multilesion (n = 78)

6 (8%) i(l%) 7 (9%)

Total (n = 206)

14 (6.8%) 2 (0.9%)

16 (7.7%)

33 f 20% among those with multivessel PTCA and from 75 f 14% to 33 f 19% in those with multilesion PTCA. Distal stenoses were not more severe than proximal stenoses in those with multilesion PTCA and the adjacent normal vessel diameter was not signifi- cantly narrower.

Eight patients with multivessel and 6 with multile- sion PTCA had myocardial infarction as a complica- tion of coronary angioplasty, and 1 other patient in each group underwent emergency coronary bypass surgery (Table III].

Follow-up: Six months after angioplasty, 81 of the 114 patients (71%] with multivessel PTCA available for follow-up were in Canadian Cardiovascular Soci- ety functional class 0 or 1. Similarly, 56 of 78 patients (72%) with multilesion PTCA were in class 0 or 1. The initial result with respect to the degree of revascular- ization was not predictive of the clinical outcome. All attempted lesions were dilated successfully in 89 of the 128 patients with multivessel PTCA (70%); among 81 of these “successes” available for follow-up, 57 (70%) were in class 0 or 1. However, 24 of the 33 patients (73%) in whom dilatation was incomplete and were available for follow-up were in class 0 or 1. A similar outcome was observed in the patients with multilesion PTCA: 27 of 38 patients (71%] with completely suc- cessful and 28 of 39 (72%) with incompletely success- ful PTCA were in functional class 0 or 1.

Among 65 patients with multilesion PTCA in whom proximal lesions were dilated successfully, 36 had suc-

cessful PTCA of a distal lesion and 29 had an unsuc- cessful result. The outcome with respect to symptoms was identical at 6 months in these subgroups: 23 of 29 (79%] available for follow-up in the distal success group and 19 of 24 (79%) in the distal failure group were in class 0 or 1. From hospital discharge to 6- month follow-up, 1 patient died, 33 required repeat PTCA, 5 underwent bypass surgery and 4 had myocar- dial infarctions (Table IV). The incidence of these events was similar in the multivessel and multilesion groups.

Coronary arteriograms were recorded 5.8 f 3 months after PTCA in 75 patients (59%) with multives- se1 PTCA and in 46 (59%) with multilesion PTCA. Restenosis rates were not significantly different in the 2 groups. In patients with multivessel PTCA, restenosis had occurred at 42 of 135 sites (31%) and in those with multilesion PTCA restenosis had occurred at 32 of 105 sites (30%). At least 1 restenosis was present in 36 of 75 patients (48%) with multivessel PTCA and 21 of 46 (46701 with multilesion PTCA. Restenosis rates among those with multilesion PTCA were 23 of 68 (34%) for proximal sites and 9 of 37 (24%) for distal sites, a differ- ence that was not statistically significant. The correla- tion between symptoms and the degree of restenosis is depicted in Table V.

Discussion This study confirms previous reports3-7 that PTCA

can be performed at multiple sites in selected patients with excellent results. Our patients were classified into 1 of 2 groups: 1 with multivessel PTCA, in which 2 or more dilatations were done without having to cross 1 lesion to reach another, and 1 with multilesion PTCA, in which at least 1 proximal lesion had to be crossed to reach a distal stenosis. Primary success was significantly higher among those with multivessel PTCA, 86% vs 73% (p <O.OOl). This difference was due to a success rate of only 62% for lesions distal to another angioplasty site in those with multilesion

October *, 3387 THE AERiCAN ;OZWX 3F CARDIOLOGY L/o&me $0 79;1

TABLE IV Clinical Outcome of Study Patients at Six-Month Follow-Up

Multivessel Multilesion Total (n = 128) (n = 78) (n = 206)

Clinical follow-up 114 (89%) 78 (100%) 192 (93%) Deaths I (0.9%) 0 1 (0.5%) Repeat PTCA 21 (18%) 12 (15%) 33 (17%) Bypass surgery 2 (1.8%) 3 (3.8%) 5 (2.6%) Myocardial infarction 2 (1.8%) 2 (2.6%) 4 (2.1%)

Difference between groups not statistically significant. PTCA = percutaneous transluminal coronary angioplasty.

PTCA. The success rate for proximal lesions in this group was similar to the rate in those with multivessel PTCA.

Potential explanations: The higher failure rate for lesions distal to another site was not due to more se- vere stenoses (mean 70 f 13% compared with 74 to 77% in the other groups], nor due to smaller arterial diameters (mean 2.88 f 0.5 mm, similar to the other groups]. Both an increase in failure to cross and an increase in failure to dilate contributed to the differ- ence. Procedural variables were similar for proximal and distal sites in multilesion PTCA and for multives- se1 PTCA.

These data suggest that either distal lesions are in- trinsically less amenable to angioplasty or added com- plexity of crossing and dilating serial lesions decreases the primary success rate at the distal site.

Other studies: The overall primary success rate in this study is within the range reported for similar pa- tients undergoing angioplasty during these years.3-6 Other reports have not distinguished between mul- tivessel and multilesion angioplasty as defined in this study. Dorros et aL3 using a reduction in stenosis diam- eter of at least 20% as their criterion, reported an angi- ographic success rate of 155 of 170 (91%) in “tandem” lesions, defined as 2 lesions in series in the same ves- s&l. This rate was similar to success rates for other combinations of multiple PTCA in their study. Multi- ple stenoses in the same artery were dilated in many patients in the study of Vandormael et aL4 but the success rates reported did not subdivide the results in this respect.

Clinical significance: Before angioplasty, 60% of our patients were in functional class 3 or 4; after the procedure, more than 70% were angina-free or in class 1. Although the primary success rate was lower among patients with multilesion PTCA, the clinical outcome was identical to that in patients with mul- tivessel PTCA. Similarly, patients with multilesion PTCA in whom the distal stenosis could not be dilated had a clinical outcome no worse than that in those in whom distal angioplasty was successful. Thus, PTCA of the distal lesion may not be essential in patients with several coronary lesions who undergo angioplasty.

Other studies support this conclusion. Wohlge- lernter et all2 reported that most unstable angina pa- tients with multivessel disease became asymptomatic after angioplasty of the “culprit lesion” and that in

ABLE V Correiation tween Symptoms and atienb with Angisgra

Group Clinical Status Restenosis 2.50% Restenosis 270%

Multivessel Asymptomatic 14/35 (40%) 5135 (14%) (n = 75) Symptomatic 22140 (55 %) 14/40 (35%)

Multilesion Asymptomatic 6/25 (24%) 3/25 (12%) (n = 46) Symptomatic 15/21 (71%) 13121 (62%)

stable angina, dilating only this stenosis produced re- sults equal to complete revascularization.13 In patients with multivessel disease, unstable angina and postin- farction angina, De Feyter et a114-16 usually relieved angina completely by dilating only the “ischemia-re- lated” vessel. In patients with multivessel disease in whom dilatation was successful in the National Heart, Lung, and Blood Institute PTCA registry, relief of angi- na in completely and incompletely revascularized le- sions was similar, with more second angioplasty proce- dures in the former and more bypass surgery in the latter.17

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