ORIGINAL PAPER Rel world smll vessel coronry rtery stenting: n nlysis ALLISON MORTON, THOMAS PAPADOPOULOS, CLARE WALES, ROBERT BOWES, STEPHEN CAMPBELL, DAVID OAKLEY, NIGEL WHEELDON, CHRISTOPHER NEWMAN, DAVID CROSSMAN, DAVID CUMBERLAND, JULIAN GUNN Abstrct The objective of this study ws to describe the context, procedurl outcome nd long-term results of contemporry smll vessel (SV) coronry rtery stenting. It ws set in tertiry crdiology centre. The study ws designed s retrospective nlysis of the procedurl nd long-term results in consecutive series of ptients undergoing implnttion of n SV stent (defined s < 2.5 mm) in 1999 2000. Of the 1,130 percutneous coronry interventions (PCIs) in the study period, 138 (12%) involved plcement of SV stents. Of these interventions 58% consisted of SV stents s sole tretment. Some 69% of ptients were mle nd their men ge ws 58 yers; 46% were hypertensive, 13% dibetic, 84% hypercholesterolemic nd 18% were smokers. Of these ptients 54% were in nginl clsses III nd IV. Of the SV stents fitted, 94% were 2.5 mm nd 6% were 2.0 mm. 75% of SV stents were implnted in min epicrdil vessels. The men follow-up for these ptients ws 17 months. Long-term symptomtic benefit ws chieved in 76%. The mjor dverse crdic events (MACE) rte ws 15%, comprising 1% cute myocrdil infrction (AMI) nd 14% re-pci. There were no deths. In conclusion, SV stenting in the modern er, in n unselected series of ptients, is performed in 12% of PCI Deprtment of Crdiology, Sheffield Teching Hospitls NHS Trust, Sheffield. Allison C Morton, Clinicl Reserch Fellow in Crdiology Thoms Ppdopoulos, Visiting Clinicl Fellow in Crdiology Clre Wles, Reserch Sister in Interventionl Crdiology Robert Bowes, Consultnt Crdiologist Stephen Cmpbell, Consultnt Crdiologist Dvid Okley, Consultnt Crdiologist Nigel Wheeldon, Consultnt Crdiologist Christopher Newmn, Senior Lecturer, Honorry Consultnt Crdiologist Dvid Crossmn, Professor of Crdiology Julin Gunn, Senior Lecturer, Honorry Consultnt Crdiologist Ampng Puteri Specilist Hospitl, Ampng, Selngor, Mlysi Dvid Cumberlnd, Consultnt in Crdiovsculr Intervention Correspondence to: Dr AC Morton, Crdiovsculr Reserch Group, Clinicl Sciences Centre, Northern Generl Hospitl, Herries Rod, Sheffield, S5 7AU. (emil:.c.morton@sheffield.c.uk) procedures. It comprises the sole tretment in 58% of these interventions. The mjority of SV stents re 2.5 mm nd re plced in min coronry rteries. Procedurl nd long-term results re excellent. These dt my inform the choice of tretment for ptients with SV disese nd my be useful in plnning studies in stenting SVs. Key words: smll vessel, coronry rtery, stent. Br J Crdiol (Acute Interv Crdiol) 2003;10(1):AIC 28 AIC 32 Introduction The use of stents for the tretment of stenoses in smll vessel (SV) coronry rteries remins controversil becuse the published dt revel disprte results. Erly stent versus blloon studies included only 10 13% vessels < 2.50 mm. 1,2 Subgroup nlysis showed tht the restenosis rte for SVs ws cceptble, lthough the numbers were smll: in the STRESS (Stent Restenosis Study) study, for vessels < 2.50 mm the restenosis rte ws 30% nd for vessels > 3 mm it ws 31.6%. 3 However, this result my be flwed by the smll numbers in the SV ctegory nd by the fct tht this ws not SV study the opertors lbelled the vessel s within the inclusion criteri of STRESS but quntittive ngiogrphy lbelled the vessel s smll (the opertors my hve been right). Akiym et l., in cohort of 1,298 ptients, reported restenosis rtes of 19.9% in vessels > 3 mm nd 32.6% in vessels < 3 mm (p=0.0001). 4 Kstrti et l., using univrite nlysis of 1,753 lesions, found tht reference dimeter < 3.08 mm conferred reltive risk of restenosis of 1.5 compred with lrger vessels. 5 A recent study by Koning et l. prospectively rndomised stent plcement nd POBA (plin old blloon ngioplsty) in vessels < 3 mm. Angiogrphic restenosis ws 21% in the stent group, compred with 47% in the POBA group (p=0.0001). 6 The production of second nd third genertion pre-mounted stents hs stimulted re-evlution of the efficcy of SV stenting. There hve been t lest eight rndomised trils of SV stents versus blloon ngioplsty. 1,2,6-13 The emerging messge from these trils, overll, is tht stenting is worthwhile in terms of cute nd long-term results. There hve lso been t lest six non-controlled series or registries. 14-19 Interestingly, in the SOPHOS study (Study of Phosphorylcholine coting On Stents), using the BiodivYsio stent AIC 28
Tble 1. Implnttion sites of SV nd non-sv stents Vessel SV stent group Non-SV stent group n=138 (%) n=992 (%) LAD 60 (44) 45 (46) Circumflex 25 (18) 188 (19) OM 11 (8) 99 (10) Digonl 15 (11) 109 (11) RCA 18 (13) 99 (10) PDA 6 (4) 30 (3) Vein grft/lima 3 (2) 10 (1) Key: SV = smll vessel; LAD = left nterior descending; OM = obtuse mrginl; RCA = right coronry rtery; PDA = posterior descending rtery; LIMA = left internl mmmry rtery. Tble 2. Chrcteristics of the lesions implnted with n SV stent (n=138) Lesion chrcteristic n (%) Eccentric 72 (48) Smooth 110 (74) Bifurcted 27 (18) Clcified 22 (15) Occluded 21 (14) Ostil 19 (13) Angulted 14 (9) Thrombotic 2 (1) Accessible 139 (93) (Biocomptibles), the restenosis rte ws 17.7% overll nd in vessels with reference dimeter 1.25 2.64 mm it ws only 20%. 19 These results re comprble to those of STRESS quoted bove, in tht the inclusion reference dimeter for the study ws > 3.0 mm. They suggest tht modern stents perform better thn the first genertion in the context of SVs. Despite this conflicting body of dt, the recent trend towrds stent implnttion hs extended to SVs. In the light of this, we decided to nlyse current clinicl prctice nd outcomes in stenting, in n unselected popultion of ptients, in single, tertiry interventionl centre with multiple opertors. Methods We retrospectively nlysed ll consecutive ptients undergoing percutneous coronry intervention (PCI) which included n SV stent (defined s < 2.5 mm blloon deployment with no upsizing) t the Northern Generl Hospitl, Sheffield, in the period July 1999 to October 2000. The ctheter lbortory nd hospitl records were exmined for procedurl dt nd in-hospitl events. Follow-up ws by questionnire nd telephone. Bseline demogrphic, clinicl nd ngiogrphic dt were collected. Locl ethics committee pprovl ws obtined. Percutneous intervention PCI ws crried out using stndrd techniques. Procedurl events, vessels treted nd stent sizes nd numbers were recorded. Success ws defined s ptent rtery with TIMI 3 flow. All ngiogrms were reviewed by one opertor (JG). Stndrd ntipltelet tretment for our institution ws used (spirin nd loding dose of clopidogrel followed by two weeks clopidogrel t mintennce dose nd indefinite spirin). Intrvenous heprin ws used during the procedure to keep the ctivted cogultion time bove 250 seconds nd bciximb ws used in selected unstble ptients. End points The end points of the study were mjor dverse crdic events (MACE), tht is, deth, non-ftl myocrdil infrction (MI), coronry rtery bypss grft (CABG) nd trget lesion or vessel revsculristion t long-term follow-up. MI ws defined s new presenttion with chest pin with either typicl electrocrdiogrphic findings or serum cretinine kinse level more thn twice the upper limit of norml. Enzymes were not routinely mesured, so smll subclinicl infrcts my hve been missed. Symptomtic sttus t followup ws lso mesured using simple index of sking the ptients if they were worse, the sme or better thn before the procedure. Sttistics Results re presented s men (SD) or s percentge of the totl unless otherwise stted. Comprisons between the SV group (one or more stents < 2.5 mm in dimeter) nd the non-sv group (no stent < 2.5 mm in dimeter) were mde with unpired Student s t tests. Significnce ws sought t the 5% level. Results Ptients Of the 1,130 PCIs in the study period, 138 (12%) included plcement of n SV stent nd these ptients mde up the study group. Bseline chrcteristics of the 138 were: 95 mle (69%); ge 58 + 9.6 yers; 63 hypertensive (46%); 18 dibetic (13%); 116 hypercholesterolemic (84%); 25 smokers (18%); nd four with documented cerebrovsculr disese (3%). Anginl clss, ccording to the Cndin Crdiovsculr Society clssifiction, ws s follows: clss 0, n=4 (3%); clss 1, n=7 (5%); clss 2, n=48 (35%); clss 3, n= 51 (37%); clss 4, n=24 (17%); nd cute myocrdil infrction (AMI), n=4 (3%). Vessels, lesions nd stents In the 138 ptients studied, 80 (58%) of the procedures consisted of SV stenting lone. The remining 42% comprised n SV stent with lrger stent or POBA in either the sme vessel or nother one. Some 94% of SV stents were deployed with 2.5 mm blloons nd 6% with 2.0 mm blloons. Almost ll the lesions (137) were new, nd one ws site of restenosis. Of the lesions 131 (95%) were stented electively nd seven (5%) were stented s bilout. Ten (7%) of the SV lesions were direct stented. VOLUME 10 ISSUE 1. FEBRUARY 2003 AIC 29
Figure 1. Exmples of SV stents being the sole tretment in min coronry rtery. ) Bseline ppernce of the LAD of 78-yer-old womn. b) Implnttion of 2.5 x 12 mm S660 stent (Medtronic). c) Finl result. d) Bseline ppernce of the rmus intermedius of 64-yer-old mn. e) Finl result fter implnttion of 2.5 x 25 mm Coroflex stent (B-Brun) b c d e Key: SV = smll vessel; LAD = left nterior descending Figure 2. Exmples of SV stents being used s djunct tretment with stndrd-sized stents. ) Bseline ppernce of dominnt RCA in 63-yer-old mn fter implnttion of 4.0 x 11 BiodivYsio stent (Biocomptibles) t the culprit lesion t the crux. b) Finl result fter implnttion of 2.5 x 18 mm BiodivYsio stent in the PDA. c) Bseline ppernce in the LAO cudl view of the LAD nd digonl rteries of 62-yer-old womn. d) Finl result fter implnttion of 3.5 x 13 mm Helistent (Hexcth) in the LAD nd 2.5 x 22 Helistent in the digonl c b d Key: SV = smll vessel; RCA = right coronry rtery; PDA = posterior descending rtery; LAD = left nterior descending The stents used were: BiodivYsio (Biocomptibles), n=119 (70%); S660 (Medtronic AVE), n=21 (12%); Coroflex (B-Brun), n=12 (7%); NIR (Boston), n=3 (2%); Sequence (Nycomed), n=3 (2%); nd others, n=12 (7%). Of the non-sv stents inserted, n=531 (54%) were 3.0 mm, n=388 (39%) 3.5 mm, nd n=73 (7%) > 4.0 mm. Tble 1 shows the vessels treted in the SV group. (Dt from the non-sv group re presented for comprison.) Tble 2 shows the chrcteristics of the lesions treted with SV stenting. The number of stents deployed per ptient ws 1.5 (0.6) in the SV group nd 1.3 (0.6) in the non-sv group (p=0.006). The length of the SV stents ws 10.2 (8.0) mm nd mximum deployment pressure ws 11.0 (2.6) tm. Of the 138 ptients, ngiogrms were vilble for review in 130. In these ptients, totl of 149 stents were inserted. Exmples of SV stent insertion nd the results chieved re shown in figures 1 nd 2. AIC 30
Procedurl events Of the 138 ptients, ngiogrphic success ws chieved in 100%. Two procedures (1%) were complicted by cute thrombus formtion. In the first cse, in 49-yer-old mn, thrombus ws noted distl to the stent t the end of the procedure. Abciximb ws used; the ptient mde n uneventful recovery without MI nd did not require trget vessel revsculristion (TVR). The second cse ws 51-yer-old mn with unstble ngin who underwent emergency PCI. Four stents were deployed in the right coronry rtery (3.0 x 18 mm, 3.0 x 9 mm, 3.0 x 11 mm, nd 2.5 x 9 mm). During the procedure, he hd chest pin nd inferior ST segment elevtion on the ECG. Angiogrphy showed thrombotic occlusion of the 3.0 x 18 mm stent, which ws resistnt to recnlistion. Abciximb ws not given becuse the ptient ws trnsferred for emergency CABG, which ws successful. Figure 3. Exmple of n pprent SV in 37-yer-old mn. ) A medium-sized vessel fter pre-dilttion, injection of intrcoronry nitrte nd implnttion of 3.0 x 15 mm Teneo stent (Biotronik) b) Contrst this ppernce with tht of truly SV in figure 1.2 b In-hospitl events There were no cses of in-hospitl deth or significnt ccess site bleeding. There were no cses of AMI or CABG other thn the two mentioned bove. Long-term follow-up Follow-up ws 17 (6) months. Symptomtic benefit ws chieved in 82% fter the procedure but this proportion fell to 76% t long-term follow-up. The six-month MACE rte ws 15%, comprising 1% (n=2) AMI nd 14% (n=20) re-pci. By 17 months, the MACE rte remined t 15%; no extr events hd occurred. The first cse of AMI ws 66-yer-old womn who presented to nother hospitl three weeks fter SV stenting (she hd hd 2.5 mm stent to the left nterior descending rtery), with sudden onset of chest pin, n old nterior infrct on the ECG nd cretinine kinse of 875 IU/L. The ECG bnormlities hd been present t the time of stenting. She ws treted conservtively. The second ptient ws 64-yer-old mn who underwent successful SV stenting to the left nterior descending rtery (with 2.5 mm stent). Three weeks lter he presented with n cute nterior MI nd underwent successful repet PCI to the sme vessel. Three weeks lter he presented with nother nterior infrct nd ws treted conservtively. He hd recently been dignosed with chronic lymphtic leukemi. Of the 20 (14%) SV ptients who underwent repet PCI, 14 involved revsculristion of the SV stent only, four revsculristion of the SV stent nd non-sv stent nd two revsculristion of different vessel. Of the repet PCI ptients, two were dibetic. Five of those ptients who required repet PCI to the smll vessel hd received two or more SV stents in the lesion during the originl procedure. Discussion This study reflects smll vessel stenting in the rel world, becuse the ptients comprised consecutive series with no exclusion or bis, nd the procedures were performed by eight opertors in the sme institution. The min findings were tht 12% of ll PCIs involve the stenting of wht the opertor considers to be SV. In 58% of these, the SV is the only trget vessel. In this series, 20% of ptients were unstble nd 13% were dibetic. Symptomtic benefit ws chieved in 82% but this proportion hd fllen to 76% t long-term follow-up. The long-term MACE rte ws 15%. In our study 75% of lesions were in the left nterior descending, circumflex or right coronry rtery. The remining 25% of lesions were in significnt brnches (digonl, mrginl or posterior descending rteries). The distribution of lesions between these vessels ws lmost identicl in the SV group compred with the non-sv group. This suggests tht most SV lesions re being considered for PCI using the sme criteri s non-sv lesions, nd only minority re prt of multivessel procedure in which SV stenting is n djunct tretment of smll brnches. Most opertors would, in the light of our dt nd those from the trils, 1,2,6-13 be prepred to stent 2.5 mm SVs. Very smll rteries (< 2.0 mm) might remin controversil, though in our study, 6% of SV stents were 2.0 mm (ll BiodivYsios) nd their MACE rte ws 0%. The stenting of very smll vessels such s these my be promising therpy for the future. On the other hnd, it could be rgued tht very smll vessels re not importnt in the first plce, nd tht restenosis is not ssocited with symptoms. In the six ptients who received 2.0 mm stent in our series, however, ll experienced n improvement in their symptoms fter stenting which ws mintined during followup; none of this smll group required TVR. De Feyter et l. hve constructed reference tble of the risk of restenosis fter stenting. This shows tht restenosis is dependent upon the stent length nd in-stent re on intrvsculr ultrsound (IVUS). 20 In so fr s the in-stent re of SV stents is, by definition, smller thn for non-sv stents, the restenosis rte for SV stents is likely to be higher. It is, therefore, importnt to VOLUME 10 ISSUE 1. FEBRUARY 2003 AIC 31
Key messges Definitions of smll vessels vry: we chose < 2.5 mm 12% of PCI procedures involve smll vessel stenting 75% of smll vessel stents re plced in the three min coronry rteries (rther then smll brnches) Long-term clinicl results (70% BiodivYsio smll vessel stents) re excellent (15% MACE t men of 17 months) mximise stent size in SVs whilst inflicting s little dmge s possible. The definition of wht comprises n SV involves more thn n rbitrry upper limit of lumen dimeter of 2.5 or 2.7 mm. In this study, we defined n SV s one in which stent < 2.5 mm ws implnted. True SVs my comprise only some of this group (figures 1 nd 2): others my be diffusely disesed lrger vessels with focl stenosis, rteries whose lumen is underfilled fter tight lesion or mildly disesed vessels prone to spsm (figure 3). The limittions of this study include the lck of rndomistion to POBA or stent, the use of different types of stent, differences in technique of the different opertors, sizing 'by eye' rther thn by quntittive ngiogrphy nd the lck of routine ngiogrphic follow-up. Nevertheless, this is indeed study of the contemporry prctice of SV stenting nd the clinicl results chieved. Conclusion Smll vessel coronry rtery stenting in the rel world is sfe, comprises n importnt proportion of PCI procedures nd is fesible nd effective in the long term. References 1. Serruys PW, de Jegere P, Kiemeneij F et l. A comprison of blloonexpndble-stent implnttion with blloon ngioplsty in ptients with coronry rtery disese. N Engl J Med 1994;331:489-95. 2. Fischmn DL, Leon MB, Bim DS et l. A rndomised comprison of coronry-stent plcement nd blloon ngioplsty in the tretment of coronry rtery disese. Stent Restenosis Study Investigtors. N Engl J Med 1994;331:496-501. 3. Svge MP, Fischmn DL, Rke R et l. Efficcy of coronry stenting versus blloon ngioplsty in smll coronry rteries. Stent Restenosis Study (STRESS) Investigtors. J Am Coll Crdiol 1998;31:307-11. 4. Akiym T, Mouss I, Reimers B et l. Angiogrphic nd clinicl outcome following coronry stenting of smll vessels; comprison with coronry stenting of lrge vessels. J Am Coll Crdiol 1998;32:1610-873. 5. Kstrti A, Elezi S, Dirschinger J et l. Influence of lesion length on restenosis fter coronry stent plcement. Am J Crdiol 1999;83:1617-22. 6. Koning R, Eltchninoff H, Commeu P et l. Stent plcement compred with blloon ngioplsty for smll coronry rteries: in-hospitl nd 6- month clinicl nd ngiogrphic results. Circultion 2001;104:1604-08. 7. Doucet S, Schlig MJ, Mthy CM et l. The SISA study: rndomised comprison of blloon ngioplsty nd stent to prevent restenosis in smll rteries (bstrct). J Am Coll Crdiol 2000;35:8A. 8. Kstrti A, Schomig A, Dirschinger J et l. A rndomised tril compring stenting with blloon ngioplsty in smll vessels in ptients with symptomtic coronry rtery disese. ISAR-SMART Study Investigtors. Intrcoronry Stenting or Angioplsty for Restenosis Reduction in Smll Arteries. Circultion 2000;102:2593-8. 9. Kleimn NS, Cliff RM. Results from lte-breking clinicl tril sessions t ACCIS 2000 nd ACC 2000. J Am Coll Crdiol 2000;36:310-25. 10. Moer R, Myreng Y, Mølstd P et l. Stenting in Smll Coronry Arteries (SISCA): rndomised comprison of heprin coted Be Stent nd blloon ngioplsty (bstrct). J Am Coll Crdiol 2001;37:46A-47A. 11. Prk SW, Lee CW, Hong JJ et l. Rndomised comprison of coronry stenting with optiml blloon ngioplsty for tretment of lesions in smll coronry rteries. Eur Hert J 2000;21:1785-9. 12. Grci E, Gomez-Recio M, Moreno R et l. Stent reduces restenosis in smll vessels: results of the RAP Study (bstrct). J Am Coll Crdiol 2001; 37:17A. 13. Svge MP, Fischmn DL, Rke R et l. A rndomised comprison of elective stenting nd blloon ngioplsty in the tretment of smll coronry rteries (bstrct). Circultion 1999;100:I-503. 14. Serruys PW, Emnuelsson H, vn der Giessen WJ et l. Heprin-coted Plmz-Schtz stents in humn coronry rteries: erly outcome of the Benestent II pilot study. Circultion 1996;93:412-22. 15. te Riele JAM, Piek JJ, Mudr H et l. Clinicl nd ngiogrphic results with the ACS Multi-Link DUET coronry stent system: the DUET study. Int J Crdiovsc Intervent 2000;3:97-104. 16. Rutsch W, Kiemeneji F, Colombo A et l. Clinicl nd ngiogrphic results with the NIR stent: first interntionl NIR endovsculr stent study. Int J Crdiovsc Intervent 2000;3:145-51. 17. Suryprnt H, Bolnd JL, Pieper M et l. Clinicl nd ngiogrphic results with the BeStent: the Registry for Optiml BeStent Evlution (ROSE) tril. Int J Crdiovsc Intervent 2000;3:21-8. 18. Emnuelsson H, Serruys P, vn der Giessen WJ et l. Clinicl nd ngiogrphic results with the Multi-Link coronry stent system: the West Europen Stent Tril (WEST). J Invs Crdiol 1998;10:12B-19B. 19. Bolnd JL, Corbeij H, vn der Giessen WJ et l. Multicentre evlution of the phosphorylcholine-coted BiodivYsio stent in short de novo coronry lesions: The SOPHOS study. Int J Crdiovsc Intervent 2000;3:215-25. 20. de Feyter PJ, Ky P, Disco C et l. Reference chrt derived from post-stent implnttion intrvsculr ultrsound predictors of 6-month expected restenosis on quntittive coronry ngiogrphy. Circultion 1999;100: 1777-83. AIC 32