Drug-eluting stents versus bare metal stents in saphenous vein graft disease :

1. Drug-elutingstents versus bare metal stents in saphenousveingraftdisease: insights from a meta-analysis of 7,090 patients E. NAVARESE (1), A. BUFFON(1), A. LUPI (2), M. SANSA (2), A. BONGO (2), S. DE SERVI (3) Catholic University of Sacred Heart, ROME, ITALY; Ospedale “Maggiore della Carità, NOVARA, ITALY; 3) Civic Hospital Legnano, Legnano, ITALY; Clinicaltrials.gov Identifier: NCT01036048

2. Background • Aortocoronary saphenous vein graft (SVG) disease represents the “Achilles’ heel” of CABG interventions due to SVG high failure rate • Drug-eluting stents (DES) are a major advance in interventional cardiology, but evidence for using these devices does not exist for many “off-label” indications • No clear indication is available about DES use in SVG disease, a common “off-label” indication for DES implantation in daily practice

3. Background the degeneration of SVG is quite a different phenomenon in comparison with native coronary artery atherosclerosis Histopathology of SVG degeneration a)Cross-section of an SVG implanted with a self-expanded metallic stent and developing late in-stent restenosis. The stent struts show a thick neointima developed within the stent lumen close to the struts (asterisk). The wires on the right-hand side (arrow) are close to a necrotic core and only a thin layer of healing neointima is observed in the lumen side of the stent (b) Atherosclerotic plaque and large thrombus protruding into the SVG lumen through the stent struts (asterisk). a) b) Ribichini, Histopathologyofsaphenousveingrafts, Clinical Science 2008

4. Aims and methods The aim of this work was to perform a meta-analysis on DES vs BMS in SVG disease Flow chart of the meta-analysis (N= 7090 patients) • Inclusion criteria were: 1) randomized and/or non randomized studies 2) studies reporting clinical outcomes as overall death and/or acute myocardial infarction and/or target vessel revascularization 3) follow up period longer than 6 months • Odds ratios (ORs) were computed from individual studies and pooled according to a fixed effect (e.g. inverse variance weighting) or random effect model in case of statistical heterogeneity

5. Qualitytableofincludedstudies Randomized studies: the quality was appraised according to the Cochrane Collaboration , estimating separately the risk of selection, performance, detection, and attrition bias (expressed as low risk of bias [A], moderate risk of bias [B], high risk of bias [C] Non-randomized studies: The Newcastle Ottawa Scale for non randomized studies assigns star for three area of study quality: selection, comparability and outcome

6. Results: mortality Favour DES Favour BMS

7. Results: myocardialinfarction Favour DES Favour BMS

8. Results: Target vessel Revascularization Favour DES Favour BMS

9. Results: Meta-regression for TVR

10. Discussion (1) • This meta-analysis offers an evidence summing up the whole literature from randomized and observational studies comparing DES vs BMS use in SVG disease • In the present analysis DES were found to significantly reduce rate ofTVR but did reduce neither mortality in the meta-analysis of randomized studies nor rate of overall MI • Meta-regressionhighlightedthatbenefitsfrom DES in the reductionofTVR are more substantial in olderSVGs

11. Discussion (2) Death MI the benefit from DES use could be largely diluted by acute coronary syndromes arising from other previously untreated coronary lesions • The opposite finding on mortality raised from the randomized and observational studies suggests that a definitive conclusion in favour to DES use in this setting cannot be drawn yet To exhaustively address these controversial findings, randomized trials powered for mortality and MI with adequate long-term follow up are warranted