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Angiographic restenosis rate in patients with chronic total occlusions and subtotal stenoses after initially successful intracoronary stent placement
Angiographic Restenosis Rate in Patients With Chronic Total Occlusions and Subtotal Stenoses After Initially Successful Intracoronary Stent Placement Kean-Wah Lau,
MBBS,
Zee-Pin Ding, MBBS, MMed, Abdullah Johan, Veronica Kwok, and Yean-Leng Lim
lthough conventional percutaneous transluminal coronary angioplasty (PTCA) has been used for A the treatment of chronic total occlusions for the past 2 decades, it is plagued by 2 major limitations. First, successful recanalization of chronic total occlusions is achieved in only approximately 60% of attempts (range 54% to 72%).1 The main cause of failure is the inability to pass a guidewire and newer devices, including a low-speed rotational angioplasty system2 and laser guidewire,3 through the occluded lesions. Second, after successful recanalization with PTCA, significantly higher rates of restenosis have been observed with these lesions than those associated with previously dilated subtotal stenoses.1,4,5 In contrast to PTCA, stent placement provides a greater immediate luminal gain, which in turn allows for more intimal hyperplasia before the onset of restenosis6 – 8 and counteracts vascular remodeling by providing a rigid endovascular scaffold.8,9 Thus, it is not surprising that, of the 2 techniques, stenting has been shown to yield superior mid-term angiographic and clinical results in the treatment of subtotal stenoses and chronic total occlusions.10 –17 However, what remains unclear is whether stenting of chronic total occlusions can negate the increased proclivity for restenosis compared with stenting of subtotal lesions. Accordingly, the primary purpose of the present study is to compare the restenosis rate of patients with chronic total occlusion and subtotal stenoses matched for certain important variables after initially successful intracoronary stent implantation. •••
From March 1993 to January 1998, 268 patients who did not sustain a myocardial infarction in the previous 2 weeks underwent successful intracoronary stent placement. Follow-up angiographic assessment was obtained in 231 patients (86.2%). Of these patients, 49 (21%) received stents for treatment of nonacute total occlusions, defined as complete interruption of the vessel with the presence of Thrombolysis in Myocardial Infarction trial (TIMI) grade 0 or 1 flow. The remaining 182 patients had stent implantation for treatment of subtotal stenoses. The frequency of restudy was similar in both patient groups. The patients with chronic total occlusion were matched manually on a patient-to-patient basis with those with subtotal stenoses by an investigator who was unaware of the From the National Heart Centre of Singapore, Singapore. Dr. Lau’s address is: Section in Charge, Research and Education, National Heart Centre, 3rd Hospital Avenue, Singapore 0316. Manuscript received August 4, 1998; revised manuscript received and accepted October 26, 1998. ©1999 by Excerpta Medica, Inc. All rights reserved.
RN,
follow-up outcome. The matching process was based on the following criteria: exact stent design used, expanded stent diameter (varies according to maximum inflated balloon size), stent length, and residual percent diameter stenosis after stent placement. The expanded stent diameter was matched to within a range of 60.3 mm, whereas the residual lesion severity was selected to within 15% diameter stenosis. Whenever possible, a match was also made for diabetes. A close match for 6 patients in the chronic total occlusion group could not be found; they were subsequently excluded from the study. The study population thus comprised 43 patients with chronic total occlusion (group 1) (13 with TIMI 0 flow and 30 with TIMI 1 flow) and 43 patients with subtotal stenoses (group 2). Their baseline characteristics (Table I) did not differ significantly; in particular, there was no difference in the proportion of diabetic patients in groups 1 and 2 (35% vs 28%; p 5 0.486). However, patients in group 1 tended to be older (58 vs 56 years), had a higher frequency of past myocardial infarction (63% vs 47%), and were more likely to have impaired left ventricular ejection fraction (35% vs 19%) than patients in group 2. All matched patients underwent single stent placements. Conventional PTCA was performed in other nonstented vessels in 9 patients in group 1 and in 12 patients in group 2. Informed written consent was obtained from all patients before intervention. Angiographic measurements were determined prospectively by calipers using selected cine frames at end-diastole, which showed the worse view without overlap and with the least degree of foreshortening, and by an author who was blinded to the follow-up angiographic result. The centered contrast-filled guide catheter was used as reference. Lesion morphology was classified according to the modified American Heart Association/ American Cardiology College grading system.18 Conventional PTCA and stenting were performed with angiographic guidance only.19,20 The indications for stent placement were classified into 3 categories: (1) bailout stenting for acute or threatened vessel closure (as defined previously19,20), (2) stenting for suboptimal angiographic result, and (3) elective stenting. Suboptimal result was defined as a residual stenosis .25% diameter stenosis after PTCA. After stent deployment, supplementary in-stent dilations were performed using a slightly oversized balloon (10% to 20% larger than the reference vessel size) with or without high-pressure inflations (.12 atm) to ensure uniform circumferential stent expansion and impaction and a residual target lesion ,25% diameter ste0002-9149/99/$–see front matter PII S0002-9149(98)01051-0
963
TABLE I Baseline Variables of Patients With Chronic Total Occlusions and Subtotal Stenoses Treated With Stent Placements
Age (yrs) Coronary risk factor Diabetes mellitus Hypertension Smoking Hyperlipidemia Past myocardial infarction Extent of CAD 1-vessel 2-vessel 3-vessel LVEF ,50%
Chronic Total Occlusions (n 5 43)
Subtotal Stenoses (n 5 43)
p Value
58 6 11
56 6 9
0.181
15 23 7 30 27
(35%) (53%) (16%) (70%) (63%)
12 20 11 28 20
(28%) (47%) (26%) (65%) (47%)
0.485 0.517 0.289 0.645 0.129
25 13 5 15
(58%) (30%) (12%) (35%)
22 10 11 8
(51%) (23%) (26%) (19%)
0.242
0.088
Values are presented as mean 6 SD or number. CAD 5 coronary artery disease; LVEF 5 left ventricular ejection fraction.
nosis. The size of the stents varied according to the diameter of the largest balloon used for the stenting procedure, with the latter parameter denoting the final expanded stent diameter. Patients were reviewed at 1 month and at 5 to 6 months to assess their functional and clinical status (death, myocardial infarction, revascularization, and stroke). To determine the true anatomic in-stent restenosis rate, patients were encouraged to undergo follow-up angiography at .3 months, or earlier if clinically indicated. Restenosis was defined as a stenosis .50% of the luminal diameter at follow-up. Data are expressed as mean 6 SD unless otherwise stated. Comparisons between continuous and categorical variables before and after stenting and between patient groups were made using Student’s t test and chi-square test. A p value ,0.05 was considered statistically significant. As per protocol, there was no observed difference in the stent design, stent length used, final stent size, or residual lesion diameter stenosis immediately after stent implantation in the 2 patient groups (Table II). The reference vessel size (2.9 6 0.3 vs 2.9 6 0.3 mm; p 5 0.718) also was similar. Indications for stenting, segment stented, and lesion morphology were well matched. Patients in group 1, however, were more likely to undergo stenting of the right coronary artery (40% vs 21%); this difference was not significant. Angiographic reassessment was performed at a mean of 4.9 6 1.5 and 5.1 6 2.4 months (p 5 0.668) in groups 1 and 2, respectively. The mean in-stent diameter stenosis was 41 6 33% and 35 6 33%, respectively (p 5 0.453). In-stent restenosis was detected in 14 patients in group 1 (32.5%) and in 12 patients in group 2 (27.9%) (p 5 0.638). There was no difference in the rate of restenosis between those with baseline TIMI 0 and TIMI 1 flow in group 1 (30% vs 38%, respectively; p 5 0.586). An occluded stented segment was found in 2 patients in group 1 (4.6%) and in 3 patients in group 2 (6.9%). Of the patients in group 1 who experienced in-stent restenosis, 11 un964 THE AMERICAN JOURNAL OF CARDIOLOGYT
VOL. 83
TABLE II Angiographic and Procedural Variables of the Two Patient Groups Chronic Total Occlusions (n 5 43) Stenting indication Bailout 9 (21%) Suboptimal 26 (60%) Elective 8 (19%) Vessel treated LAD 21 (49%) LCx 4 (9%) RCA 17 (40%) SVG 1 (2%) Segment treated Proximal 22 (51%) Mid-distal 21 (49%) Lesion morphology* A 0 (0%) B 40 (93%) C 3 (7%) Reference vessel diameter (mm) 2.9 6 0.3 Stent size (mm) 3.1 6 0.3 Stent length (mm) 17.4 6 6.1 Stent type Gianturco-Roubin 2 Palmaz-Schatz 6 Wiktor 3 Cordis 1 NIR 7 Multilink 15 Bestent 9 Lesions diameter stenosis (%) Baseline — Poststent 265 Follow-up 41 6 33 Restenosis rate (%) 14 (32.5%)
Subtotal Stenoses (n 5 43)
p Value
8 (19%) 30 (70%) 5 (12%)
0.577
26 5 9 3
(60%) (12%) (21%) (7%)
0.250
19 (44%) 24 (56%)
0.517
2 (5%) 37 (86%) 4 (9%) 2.9 6 0.3 3.1 6 0.3 16.6 6 5.3
0.323
2 6 3 1 7 15 9
0.718 0.740 0.522 1.00
89 6 8 NA 165 0.829 35 6 33 0.453 12 (27.9%) 0.638
Values are presented as mean 6 SD or number (%). *According to the American Heart Association/American College of Cardiology classification.18 LAD 5 left anterior descending artery; LCx 5 left circumflex artery; NA 5 not applicable; RCA 5 right coronary artery; SVG 5 saphenous vein graft.
derwent successful repeat PTCA, and 1 patient with triple-vessel disease was submitted for bypass surgery. Two remaining patients who had no symptoms and with 50% to 60% recurrent stenoses at the previously stented segments were treated medically. There were no deaths, myocardial infarctions, or strokes during follow-up. •••
Maintained patency of chronic total occlusions after initial successful recanalization is desirable, as it yields improvement in global and regional left ventricular function and avoids adverse left ventricular remodeling in patients with previous myocardial infarctions.15 Unfortunately, observational studies1,4,5 indicated that PTCA of lesions with this feature is associated with a dismal 6-month angiographic restenosis rate of 50% to 70%, which is substantially higher than that associated with PTCA of subtotal stenoses. In contrast, at least 6 recent studies12–17 with a reasonably high 5- to 6-month angiographic restudy rate in a total of 309 chronic total occlusions suggested that intracoronary stenting may significantly enhance the mid-term patency rate compared with MARCH 15, 1999
stand-alone PTCA; the average in-stent restenosis rate in these studies was 29% (range 20% to 40%), with a recurrent occlusion rate of 8%. In the Stenting in Chronic Coronary Occlusion (SICCO) trial14 involving 117 patients randomized to either Palmaz-Schatz stenting or PTCA, this discrepancy was confirmed; the angiographic restenosis rate was 31.6% for the stent group versus 73.7% for the PTCA group (p ,0.001). However, whether stent placement can negate the difference in the risk of restenosis between chronic total occlusions and subtotal stenoses remains unknown. Thus, to examine this aspect and to minimize the confounding factors that may influence the risk of restenosis, we performed manual case matching of several important clinical, angiographic, and stentrelated variables in a prospectively collected series of patients who underwent stent placement for the treatment of chronic total occlusions and subtotal stenoses. Our study indicates that there was no difference in either the 5-month mean in-stent diameter stenosis or the in-stent restenosis rate (32.6% for group 1 vs 27.9% for group 2; p 5 0.638). Furthermore, stent occlusion rate was found to be low in both groups. The present matched comparative study, to the best of our knowledge, is the first of its kind to clearly demonstrate that stent placement in chronic total occlusions is associated with a restenosis rate similar to that of stent placement in subtotal stenoses. Our findings, however, should be considered preliminary and require further verification from large, prospective randomized trials. 1. Meier B. “Occlusion angioplasty.” Light at the end of the tunnel or dead end? (editorial). Circulation 1992;85:1214 –1216. 2. Danchin N, Cassagnes J, Juilliere Y, Machecourt J, Bassand JP, Lablanche JM, Cherrier F. Balloon angioplasty versus rotational angioplasty in chronic coronary occlusions (The BAROCCO Study). Am J Cardiol 1995;75:330 –334. 3. Hamburger JN, Serruys PW, Scabra-Gomes R, Simon R, Kooken JJ, Fleck E, Mathey D, Sievert H, Rutsch W, Buchwald A, et al. Recanalization of total coronary occlusions using a laser guidewire (The European TOTAL Surveillance Study). Am J Cardiol 1997;80:1419 –1423. 4. Puma JA, Sketch MH, Tcheng JE, Harrington RA, Phillips HR, Stack RS,
Califf RM. Percutaneous revascularization of chronic total occlusions: an overview. J Am Coll Cardiol 1995;26:1–11. 5. Violaris AG, Melkert R, Serruys PW. Long-term luminal renarrowing after successful elective coronary angioplasty of total occlusions. A qunatitative angiographic analysis. Circulation 1995;91:2140 –2150. 6. Kuntz RE, Gibson M, Nobuyoshi M, Baim DS. Generalized model of restenosis after conventional balloon angioplasty, stenting and directional atherectomy. J Am Coll Cardiol 1993;21:15–25. 7. Kuntz RE, Safian RD, Levine MJ, Reis GJ, Diver DJ, Baim DS. Novel approach to the analysis of restenosis after the use of 3 new coronary devices. J Am Coll Cardiol 1992;19:1493–1499. 8. Lau KW, Sigwart U: Restenosis—an accelerated arteriopathy: pathophysiology, preventive strategies and research horizons. In: Edelman ER, ed. Molecular Interventions and Local Drug Delivery. London: W.B. Saunders Co. Ltd., 1995: 1–28. 9. Hoffman R, Mintz GS, Dussaillant GR, Popma JJ, Pichard AD, Salter LF, Kent KM, Griffin J, Leon MB. Patterns and mechanisms of instent restenosis: a serial intravascular ultrasound study. Circulation 1996;94:1247–1254. 10. Serruys PW, de Jaegere P, Kiemeneij F, Macaya C, Rutsch W, Heyndrickx G, Emanuelsson H, Marco J, Legrand V, Materne P, et al. A comparison of balloon-expandable-stent implantation with balloon angioplasty in patients with coronary artery disease. N Engl J Med 1994;331:489 – 495. 11. Fischman DL, Leon MB, Baim DS, Schatz RA, Savage MP, Penn I, Detre K, Veltri L, Ricci D, Nobuyoshi M, et al. A randomized comparison of coronarystent placement and balloon angioplasty in the treatment of coronary artery disease. N Engl J Med 1994;331:496 –501. 12. Medina A, Melian F, de Lezo JS, Pan M, Romero M, Hernandez E, Marrero J, Ortega JR, Parlovic D. Effectiveness of coronary stenting for the treatment of chronic total occlusion in angina pectoris. Am J Cardiol 1994;73:1222–1224. 13. Goldberg SL, Colombo A, Maiello L, Barrione M, Finci L, Almagor Y. Intracoronary stent insertion after balloon angioplasty for chronic total occlusions. J Am Coll Cardiol 1995;26:713–719. 14. Sirnes PA, Golf S, Myreng Y, Molstad P, Emanuelsson H, Albertsson P, Brekke M, Mangschau A, Endresen K, Kjekshus J. Stenting in Chronic Coronary Occlusion (SICCO): a randomized, controlled trial of adding stent implantation after successful angioplasty. J Am Coll Cardiol 1996;28:1444 –1451. 15. Belle EV, Blouard P, McFadden EP, Lablanche JM, Bauters C, Bertrand ME. Effects of stenting of recent or chronic coronary occlusions on late vessel patency and left ventricular function. Am J Cardiol 1997;80:1150 –1154. 16. Suttorp MJ, Mast G, Plokker T, Kelder JC, Ernst SMPG, Bal ET. Primary coronary stenting after successful balloon angioplasty of chronic total occlusions: a single-center experience. Am Heart J 1998;135:318 –322. 17. Rau T, Schofer J, Schluter M, Seidensticker A, Berger J, Mathey DG. Stenting of nonacute total coronary occlusions: predictors of late angiographic outcome. J Am Coll Cardiol 1998;31:275–280. 18. Ellis SG, Vandormael MG, Cowley MJ, Di Sciascio G, Deligonul U, Topol EJ, Bulle TM, and the Multicenter Angioplasty Prognosis Study Group. Coronary morphology and clinical determinants of procedural outcome with angioplasty for multivessel coronary disease. Circulation 1990;82:1193–1202. 19. Lau KW, Gao W, Ding ZP, Kwok V. Single bailout stenting for threatened coronary closure complicating balloon angioplasty: acute and mid-term outcome. Coron Artery Dis 1996;7:327–333. 20. Lau KW, He Q, Ding ZP, Johan A. Safety and efficacy of angiographyguided stent placement in small native coronary arteries of , 3.0 mm in diameter. Clin Cardiol 1997;20:711–716.
BRIEF REPORTS
965
MBBS,
Zee-Pin Ding, MBBS, MMed, Abdullah Johan, Veronica Kwok, and Yean-Leng Lim
lthough conventional percutaneous transluminal coronary angioplasty (PTCA) has been used for A the treatment of chronic total occlusions for the past 2 decades, it is plagued by 2 major limitations. First, successful recanalization of chronic total occlusions is achieved in only approximately 60% of attempts (range 54% to 72%).1 The main cause of failure is the inability to pass a guidewire and newer devices, including a low-speed rotational angioplasty system2 and laser guidewire,3 through the occluded lesions. Second, after successful recanalization with PTCA, significantly higher rates of restenosis have been observed with these lesions than those associated with previously dilated subtotal stenoses.1,4,5 In contrast to PTCA, stent placement provides a greater immediate luminal gain, which in turn allows for more intimal hyperplasia before the onset of restenosis6 – 8 and counteracts vascular remodeling by providing a rigid endovascular scaffold.8,9 Thus, it is not surprising that, of the 2 techniques, stenting has been shown to yield superior mid-term angiographic and clinical results in the treatment of subtotal stenoses and chronic total occlusions.10 –17 However, what remains unclear is whether stenting of chronic total occlusions can negate the increased proclivity for restenosis compared with stenting of subtotal lesions. Accordingly, the primary purpose of the present study is to compare the restenosis rate of patients with chronic total occlusion and subtotal stenoses matched for certain important variables after initially successful intracoronary stent implantation. •••
From March 1993 to January 1998, 268 patients who did not sustain a myocardial infarction in the previous 2 weeks underwent successful intracoronary stent placement. Follow-up angiographic assessment was obtained in 231 patients (86.2%). Of these patients, 49 (21%) received stents for treatment of nonacute total occlusions, defined as complete interruption of the vessel with the presence of Thrombolysis in Myocardial Infarction trial (TIMI) grade 0 or 1 flow. The remaining 182 patients had stent implantation for treatment of subtotal stenoses. The frequency of restudy was similar in both patient groups. The patients with chronic total occlusion were matched manually on a patient-to-patient basis with those with subtotal stenoses by an investigator who was unaware of the From the National Heart Centre of Singapore, Singapore. Dr. Lau’s address is: Section in Charge, Research and Education, National Heart Centre, 3rd Hospital Avenue, Singapore 0316. Manuscript received August 4, 1998; revised manuscript received and accepted October 26, 1998. ©1999 by Excerpta Medica, Inc. All rights reserved.
RN,
follow-up outcome. The matching process was based on the following criteria: exact stent design used, expanded stent diameter (varies according to maximum inflated balloon size), stent length, and residual percent diameter stenosis after stent placement. The expanded stent diameter was matched to within a range of 60.3 mm, whereas the residual lesion severity was selected to within 15% diameter stenosis. Whenever possible, a match was also made for diabetes. A close match for 6 patients in the chronic total occlusion group could not be found; they were subsequently excluded from the study. The study population thus comprised 43 patients with chronic total occlusion (group 1) (13 with TIMI 0 flow and 30 with TIMI 1 flow) and 43 patients with subtotal stenoses (group 2). Their baseline characteristics (Table I) did not differ significantly; in particular, there was no difference in the proportion of diabetic patients in groups 1 and 2 (35% vs 28%; p 5 0.486). However, patients in group 1 tended to be older (58 vs 56 years), had a higher frequency of past myocardial infarction (63% vs 47%), and were more likely to have impaired left ventricular ejection fraction (35% vs 19%) than patients in group 2. All matched patients underwent single stent placements. Conventional PTCA was performed in other nonstented vessels in 9 patients in group 1 and in 12 patients in group 2. Informed written consent was obtained from all patients before intervention. Angiographic measurements were determined prospectively by calipers using selected cine frames at end-diastole, which showed the worse view without overlap and with the least degree of foreshortening, and by an author who was blinded to the follow-up angiographic result. The centered contrast-filled guide catheter was used as reference. Lesion morphology was classified according to the modified American Heart Association/ American Cardiology College grading system.18 Conventional PTCA and stenting were performed with angiographic guidance only.19,20 The indications for stent placement were classified into 3 categories: (1) bailout stenting for acute or threatened vessel closure (as defined previously19,20), (2) stenting for suboptimal angiographic result, and (3) elective stenting. Suboptimal result was defined as a residual stenosis .25% diameter stenosis after PTCA. After stent deployment, supplementary in-stent dilations were performed using a slightly oversized balloon (10% to 20% larger than the reference vessel size) with or without high-pressure inflations (.12 atm) to ensure uniform circumferential stent expansion and impaction and a residual target lesion ,25% diameter ste0002-9149/99/$–see front matter PII S0002-9149(98)01051-0
963
TABLE I Baseline Variables of Patients With Chronic Total Occlusions and Subtotal Stenoses Treated With Stent Placements
Age (yrs) Coronary risk factor Diabetes mellitus Hypertension Smoking Hyperlipidemia Past myocardial infarction Extent of CAD 1-vessel 2-vessel 3-vessel LVEF ,50%
Chronic Total Occlusions (n 5 43)
Subtotal Stenoses (n 5 43)
p Value
58 6 11
56 6 9
0.181
15 23 7 30 27
(35%) (53%) (16%) (70%) (63%)
12 20 11 28 20
(28%) (47%) (26%) (65%) (47%)
0.485 0.517 0.289 0.645 0.129
25 13 5 15
(58%) (30%) (12%) (35%)
22 10 11 8
(51%) (23%) (26%) (19%)
0.242
0.088
Values are presented as mean 6 SD or number. CAD 5 coronary artery disease; LVEF 5 left ventricular ejection fraction.
nosis. The size of the stents varied according to the diameter of the largest balloon used for the stenting procedure, with the latter parameter denoting the final expanded stent diameter. Patients were reviewed at 1 month and at 5 to 6 months to assess their functional and clinical status (death, myocardial infarction, revascularization, and stroke). To determine the true anatomic in-stent restenosis rate, patients were encouraged to undergo follow-up angiography at .3 months, or earlier if clinically indicated. Restenosis was defined as a stenosis .50% of the luminal diameter at follow-up. Data are expressed as mean 6 SD unless otherwise stated. Comparisons between continuous and categorical variables before and after stenting and between patient groups were made using Student’s t test and chi-square test. A p value ,0.05 was considered statistically significant. As per protocol, there was no observed difference in the stent design, stent length used, final stent size, or residual lesion diameter stenosis immediately after stent implantation in the 2 patient groups (Table II). The reference vessel size (2.9 6 0.3 vs 2.9 6 0.3 mm; p 5 0.718) also was similar. Indications for stenting, segment stented, and lesion morphology were well matched. Patients in group 1, however, were more likely to undergo stenting of the right coronary artery (40% vs 21%); this difference was not significant. Angiographic reassessment was performed at a mean of 4.9 6 1.5 and 5.1 6 2.4 months (p 5 0.668) in groups 1 and 2, respectively. The mean in-stent diameter stenosis was 41 6 33% and 35 6 33%, respectively (p 5 0.453). In-stent restenosis was detected in 14 patients in group 1 (32.5%) and in 12 patients in group 2 (27.9%) (p 5 0.638). There was no difference in the rate of restenosis between those with baseline TIMI 0 and TIMI 1 flow in group 1 (30% vs 38%, respectively; p 5 0.586). An occluded stented segment was found in 2 patients in group 1 (4.6%) and in 3 patients in group 2 (6.9%). Of the patients in group 1 who experienced in-stent restenosis, 11 un964 THE AMERICAN JOURNAL OF CARDIOLOGYT
VOL. 83
TABLE II Angiographic and Procedural Variables of the Two Patient Groups Chronic Total Occlusions (n 5 43) Stenting indication Bailout 9 (21%) Suboptimal 26 (60%) Elective 8 (19%) Vessel treated LAD 21 (49%) LCx 4 (9%) RCA 17 (40%) SVG 1 (2%) Segment treated Proximal 22 (51%) Mid-distal 21 (49%) Lesion morphology* A 0 (0%) B 40 (93%) C 3 (7%) Reference vessel diameter (mm) 2.9 6 0.3 Stent size (mm) 3.1 6 0.3 Stent length (mm) 17.4 6 6.1 Stent type Gianturco-Roubin 2 Palmaz-Schatz 6 Wiktor 3 Cordis 1 NIR 7 Multilink 15 Bestent 9 Lesions diameter stenosis (%) Baseline — Poststent 265 Follow-up 41 6 33 Restenosis rate (%) 14 (32.5%)
Subtotal Stenoses (n 5 43)
p Value
8 (19%) 30 (70%) 5 (12%)
0.577
26 5 9 3
(60%) (12%) (21%) (7%)
0.250
19 (44%) 24 (56%)
0.517
2 (5%) 37 (86%) 4 (9%) 2.9 6 0.3 3.1 6 0.3 16.6 6 5.3
0.323
2 6 3 1 7 15 9
0.718 0.740 0.522 1.00
89 6 8 NA 165 0.829 35 6 33 0.453 12 (27.9%) 0.638
Values are presented as mean 6 SD or number (%). *According to the American Heart Association/American College of Cardiology classification.18 LAD 5 left anterior descending artery; LCx 5 left circumflex artery; NA 5 not applicable; RCA 5 right coronary artery; SVG 5 saphenous vein graft.
derwent successful repeat PTCA, and 1 patient with triple-vessel disease was submitted for bypass surgery. Two remaining patients who had no symptoms and with 50% to 60% recurrent stenoses at the previously stented segments were treated medically. There were no deaths, myocardial infarctions, or strokes during follow-up. •••
Maintained patency of chronic total occlusions after initial successful recanalization is desirable, as it yields improvement in global and regional left ventricular function and avoids adverse left ventricular remodeling in patients with previous myocardial infarctions.15 Unfortunately, observational studies1,4,5 indicated that PTCA of lesions with this feature is associated with a dismal 6-month angiographic restenosis rate of 50% to 70%, which is substantially higher than that associated with PTCA of subtotal stenoses. In contrast, at least 6 recent studies12–17 with a reasonably high 5- to 6-month angiographic restudy rate in a total of 309 chronic total occlusions suggested that intracoronary stenting may significantly enhance the mid-term patency rate compared with MARCH 15, 1999
stand-alone PTCA; the average in-stent restenosis rate in these studies was 29% (range 20% to 40%), with a recurrent occlusion rate of 8%. In the Stenting in Chronic Coronary Occlusion (SICCO) trial14 involving 117 patients randomized to either Palmaz-Schatz stenting or PTCA, this discrepancy was confirmed; the angiographic restenosis rate was 31.6% for the stent group versus 73.7% for the PTCA group (p ,0.001). However, whether stent placement can negate the difference in the risk of restenosis between chronic total occlusions and subtotal stenoses remains unknown. Thus, to examine this aspect and to minimize the confounding factors that may influence the risk of restenosis, we performed manual case matching of several important clinical, angiographic, and stentrelated variables in a prospectively collected series of patients who underwent stent placement for the treatment of chronic total occlusions and subtotal stenoses. Our study indicates that there was no difference in either the 5-month mean in-stent diameter stenosis or the in-stent restenosis rate (32.6% for group 1 vs 27.9% for group 2; p 5 0.638). Furthermore, stent occlusion rate was found to be low in both groups. The present matched comparative study, to the best of our knowledge, is the first of its kind to clearly demonstrate that stent placement in chronic total occlusions is associated with a restenosis rate similar to that of stent placement in subtotal stenoses. Our findings, however, should be considered preliminary and require further verification from large, prospective randomized trials. 1. Meier B. “Occlusion angioplasty.” Light at the end of the tunnel or dead end? (editorial). Circulation 1992;85:1214 –1216. 2. Danchin N, Cassagnes J, Juilliere Y, Machecourt J, Bassand JP, Lablanche JM, Cherrier F. Balloon angioplasty versus rotational angioplasty in chronic coronary occlusions (The BAROCCO Study). Am J Cardiol 1995;75:330 –334. 3. Hamburger JN, Serruys PW, Scabra-Gomes R, Simon R, Kooken JJ, Fleck E, Mathey D, Sievert H, Rutsch W, Buchwald A, et al. Recanalization of total coronary occlusions using a laser guidewire (The European TOTAL Surveillance Study). Am J Cardiol 1997;80:1419 –1423. 4. Puma JA, Sketch MH, Tcheng JE, Harrington RA, Phillips HR, Stack RS,
Califf RM. Percutaneous revascularization of chronic total occlusions: an overview. J Am Coll Cardiol 1995;26:1–11. 5. Violaris AG, Melkert R, Serruys PW. Long-term luminal renarrowing after successful elective coronary angioplasty of total occlusions. A qunatitative angiographic analysis. Circulation 1995;91:2140 –2150. 6. Kuntz RE, Gibson M, Nobuyoshi M, Baim DS. Generalized model of restenosis after conventional balloon angioplasty, stenting and directional atherectomy. J Am Coll Cardiol 1993;21:15–25. 7. Kuntz RE, Safian RD, Levine MJ, Reis GJ, Diver DJ, Baim DS. Novel approach to the analysis of restenosis after the use of 3 new coronary devices. J Am Coll Cardiol 1992;19:1493–1499. 8. Lau KW, Sigwart U: Restenosis—an accelerated arteriopathy: pathophysiology, preventive strategies and research horizons. In: Edelman ER, ed. Molecular Interventions and Local Drug Delivery. London: W.B. Saunders Co. Ltd., 1995: 1–28. 9. Hoffman R, Mintz GS, Dussaillant GR, Popma JJ, Pichard AD, Salter LF, Kent KM, Griffin J, Leon MB. Patterns and mechanisms of instent restenosis: a serial intravascular ultrasound study. Circulation 1996;94:1247–1254. 10. Serruys PW, de Jaegere P, Kiemeneij F, Macaya C, Rutsch W, Heyndrickx G, Emanuelsson H, Marco J, Legrand V, Materne P, et al. A comparison of balloon-expandable-stent implantation with balloon angioplasty in patients with coronary artery disease. N Engl J Med 1994;331:489 – 495. 11. Fischman DL, Leon MB, Baim DS, Schatz RA, Savage MP, Penn I, Detre K, Veltri L, Ricci D, Nobuyoshi M, et al. A randomized comparison of coronarystent placement and balloon angioplasty in the treatment of coronary artery disease. N Engl J Med 1994;331:496 –501. 12. Medina A, Melian F, de Lezo JS, Pan M, Romero M, Hernandez E, Marrero J, Ortega JR, Parlovic D. Effectiveness of coronary stenting for the treatment of chronic total occlusion in angina pectoris. Am J Cardiol 1994;73:1222–1224. 13. Goldberg SL, Colombo A, Maiello L, Barrione M, Finci L, Almagor Y. Intracoronary stent insertion after balloon angioplasty for chronic total occlusions. J Am Coll Cardiol 1995;26:713–719. 14. Sirnes PA, Golf S, Myreng Y, Molstad P, Emanuelsson H, Albertsson P, Brekke M, Mangschau A, Endresen K, Kjekshus J. Stenting in Chronic Coronary Occlusion (SICCO): a randomized, controlled trial of adding stent implantation after successful angioplasty. J Am Coll Cardiol 1996;28:1444 –1451. 15. Belle EV, Blouard P, McFadden EP, Lablanche JM, Bauters C, Bertrand ME. Effects of stenting of recent or chronic coronary occlusions on late vessel patency and left ventricular function. Am J Cardiol 1997;80:1150 –1154. 16. Suttorp MJ, Mast G, Plokker T, Kelder JC, Ernst SMPG, Bal ET. Primary coronary stenting after successful balloon angioplasty of chronic total occlusions: a single-center experience. Am Heart J 1998;135:318 –322. 17. Rau T, Schofer J, Schluter M, Seidensticker A, Berger J, Mathey DG. Stenting of nonacute total coronary occlusions: predictors of late angiographic outcome. J Am Coll Cardiol 1998;31:275–280. 18. Ellis SG, Vandormael MG, Cowley MJ, Di Sciascio G, Deligonul U, Topol EJ, Bulle TM, and the Multicenter Angioplasty Prognosis Study Group. Coronary morphology and clinical determinants of procedural outcome with angioplasty for multivessel coronary disease. Circulation 1990;82:1193–1202. 19. Lau KW, Gao W, Ding ZP, Kwok V. Single bailout stenting for threatened coronary closure complicating balloon angioplasty: acute and mid-term outcome. Coron Artery Dis 1996;7:327–333. 20. Lau KW, He Q, Ding ZP, Johan A. Safety and efficacy of angiographyguided stent placement in small native coronary arteries of , 3.0 mm in diameter. Clin Cardiol 1997;20:711–716.
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