***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: We performed a Monte Carlo study to evaluate the effect of the number of events per variable ( EPV ) analyzed in logistic regression analysis . The simulations were based on data from a cardiac trial of 673 patients in which 252 deaths occurred and seven variables were cogent predictors of mortality ; the number of events per predictive variable was ( 252/7 =) 36 for the full sample . For the simulations , at values of EPV = 2 , 5 , 10 , 15 , 20 , and 25 , we r and omly generated 500 sample s of the 673 patients , chosen with replacement , according to a logistic model derived from the full sample . Simulation results for the regression coefficients for each variable in each group of 500 sample s were compared for bias , precision , and significance testing against the results of the model fitted to the original sample . For EPV values of 10 or greater , no major problems occurred . For EPV values less than 10 , however , the regression coefficients were biased in both positive and negative directions ; the large sample variance estimates from the logistic model both overestimated and underestimated the sample variance of the regression coefficients ; the 90 % confidence limits about the estimated values did not have proper coverage ; the Wald statistic was conservative under the null hypothesis ; and paradoxical associations ( significance in the wrong direction ) were increased . Although other factors ( such as the total number of events , or sample size ) may influence the validity of the logistic model , our findings indicate that low EPV can lead to major problems AIMS Compared with bare metal stents , first-generation drug-eluting stents ( DES ) are associated with an increased risk of late restenosis and stent thrombosis ( ST ) . Whether this risk continues or attenuates during long-term follow-up remains unknown . METHODS AND RESULTS We extended the follow-up of 1012 patients [ sirolimus-eluting stent ( SES ) : N = 503 and paclitaxel-eluting stent ( PES ) : N = 509 ] included in the all-comers , r and omized Sirolimus-Eluting vs. Paclitaxel-Eluting Stents for Coronary Revascularization ( SIRTAX ) trial to 10 years . Follow-up was complete in 895 patients ( 88.4 % ) at 10 years . At 1 , 5 , and 10 years of follow-up , rates of ischaemia-driven target lesion revascularization ( ID-TLR ) were 8.1 % , 14.6 % and 17.7 % , respectively , and rates of ST were 1.9 % , 4.5 % and 5.6 % , respectively . The annual risks of ID-TLR and definite ST were significantly higher between 1 and 5 years as compared with the 5- to 10-year period [ ID-TLR : 1.8 % vs. 0.7%/year , hazard ratio ( HR ) 0.36 , 95 % confidence intervals ( 95 % CI ) 0.21 - 0.62 , P < 0.001 ; definite ST : 0.67 % vs. 0.23%/year , HR 0.31 , 95 % CI 0.13 - 0.75 , P = 0.01 ] . The attenuation of the risk of ID-TLR and ST beyond 5 years was independent of age . Major adverse events ( cardiac death , myocardial infa rct ion , and ID-TLR ) occurred in 33.7 % of SES- and 33.8 % of PES-treated patients ( P = 0.72 ) . CONCLUSIONS During long-term follow-up through 10 years , the annual risks of ID-TLR and definite ST significantly decreased beyond 5 years after first-generation DES implantation . These findings may have important implication s for secondary prevention after percutaneous coronary intervention with first-generation DES including long-term antiplatelet therapy . CLINICAL TRIAL REGISTRATION http://www . clinical trials.gov . Unique identifier : NCT00297661 BACKGROUND Data from r and omized controlled trials have shown that the ABSORB BVS is non-inferior to Cobalt Chromium everolimus-eluting stents at 2years . METHODS & RESULTS The EVERBIO II trial ( Comparison of Everolimus- and Biolimus-Eluting Coronary Stents with Everolimus-Eluting Bioresorbable Vascular Scaffold ) is a single-center , assessor-blind , r and omized controlled trial enrolling 240 patients with an allocation ration of 1:1:1 conducted at University and Hospital Fribourg , Switzerl and . The studied devices were an everolimus-eluting persistent polymer stent ( EES ) , a biolimus-eluting stent with bioabsorbable polymer ( BES ) and a fully bioresorbable vascular scaffold ( BVS ) . Clinical end points collected at 9months , 12months , and 2years , were academic research consortium defined composites , device thrombosis and target-vessel revascularization . Clinical follow-up at 2years was available in 96 % ( N=77 ) of patients in the EES group , in 100 % ( N=80 ) in the BES and 99 % ( N=77 ) in the BVS group . The device-oriented composite end point of cardiac death , target-vessel myocardial infa rct ion and target-lesion revascularization occurred in 13 ( 16 % ) patients treated with EES , in 7 ( 9 % ) patients treated with BES and in 16 ( 21 % ) patients treated with BVS . There was no significant difference when the metallic stents were compared to the BVS ( p=0.12 ) . There was one late scaffold thrombosis throughout the trial in the BVS group , and no definite stent thrombosis in either EES or BES treated patients . CONCLUSIONS The current analysis shows no significant differences with regard to clinical outcomes at 2years between BVS and the best-in-class metallic DES . Event rates were numerically higher in BVS-treated patients . However , when BVS were compared to BES alone , the occurrence of device related adverse events was significantly increased BACKGROUND In patients with coronary artery disease who receive metallic drug-eluting coronary stents , adverse events such as late target-lesion failure may be related in part to the persistent presence of the metallic stent frame in the coronary-vessel wall . Bioresorbable vascular scaffolds have been developed to attempt to improve long-term outcomes . METHODS In this large , multicenter , r and omized trial , 2008 patients with stable or unstable angina were r and omly assigned in a 2:1 ratio to receive an everolimus-eluting bioresorbable vascular ( Absorb ) scaffold ( 1322 patients ) or an everolimus-eluting cobalt-chromium ( Xience ) stent ( 686 patients ) . The primary end point , which was tested for both noninferiority ( margin , 4.5 percentage points for the risk difference ) and superiority , was target-lesion failure ( cardiac death , target-vessel myocardial infa rct ion , or ischemia-driven target-lesion revascularization ) at 1 year . RESULTS Target-lesion failure at 1 year occurred in 7.8 % of patients in the Absorb group and in 6.1 % of patients in the Xience group ( difference , 1.7 percentage points ; 95 % confidence interval , -0.5 to 3.9 ; P=0.007 for noninferiority and P=0.16 for superiority ) . There was no significant difference between the Absorb group and the Xience group in rates of cardiac death ( 0.6 % and 0.1 % , respectively ; P=0.29 ) , target-vessel myocardial infa rct ion ( 6.0 % and 4.6 % , respectively ; P=0.18 ) , or ischemia-driven target-lesion revascularization ( 3.0 % and 2.5 % , respectively ; P=0.50 ) . Device thrombosis within 1 year occurred in 1.5 % of patients in the Absorb group and in 0.7 % of patients in the Xience group ( P=0.13 ) . CONCLUSIONS In this large-scale , r and omized trial , treatment of noncomplex obstructive coronary artery disease with an everolimus-eluting bioresorbable vascular scaffold , as compared with an everolimus-eluting cobalt-chromium stent , was within the prespecified margin for noninferiority with respect to target-lesion failure at 1 year . ( Funded by Abbott Vascular ; ABSORB III Clinical Trials.gov number , NCT01751906 . ) BACKGROUND Percutaneous coronary intervention ( PCI ) is most commonly guided by angiography alone . Intravascular ultrasound ( IVUS ) guidance has been shown to reduce major adverse cardiovascular events ( MACE ) after PCI , principally by result ing in a larger postprocedure lumen than with angiographic guidance . Optical coherence tomography ( OCT ) provides higher resolution imaging than does IVUS , although findings from some studies suggest that it might lead to smaller luminal diameters after stent implantation . We sought to establish whether or not a novel OCT-based stent sizing strategy would result in a minimum stent area similar to or better than that achieved with IVUS guidance and better than that achieved with angiography guidance alone . METHODS In this r and omised controlled trial , we recruited patients aged 18 years or older undergoing PCI from 29 hospitals in eight countries . Eligible patients had one or more target lesions located in a native coronary artery with a visually estimated reference vessel diameter of 2·25 - 3·50 mm and a length of less than 40 mm . We excluded patients with left main or ostial right coronary artery stenoses , bypass graft stenoses , chronic total occlusions , planned two-stent bifurcations , and in-stent restenosis . Participants were r and omly assigned ( 1:1:1 ; with use of an interactive web-based system in block sizes of three , stratified by site ) to OCT guidance , IVUS guidance , or angiography-guided stent implantation . We did OCT-guided PCI using a specific protocol to establish stent length , diameter , and expansion according to reference segment external elastic lamina measurements . All patients underwent final OCT imaging ( operators in the IVUS and angiography groups were masked to the OCT images ) . The primary efficacy endpoint was post-PCI minimum stent area , measured by OCT at a masked independent core laboratory at completion of enrolment , in all r and omly allocated participants who had primary outcome data . The primary safety endpoint was procedural MACE . We tested non-inferiority of OCT guidance to IVUS guidance ( with a non-inferiority margin of 1·0 mm2 ) , superiority of OCT guidance to angiography guidance , and superiority of OCT guidance to IVUS guidance , in a hierarchical manner . This trial is registered with Clinical Trials.gov , number NCT02471586 . FINDINGS Between May 13 , 2015 , and April 5 , 2016 , we r and omly allocated 450 patients ( 158 [ 35 % ] to OCT , 146 [ 32 % ] to IVUS , and 146 [ 32 % ] to angiography ) , with 415 final OCT acquisitions analysed for the primary endpoint ( 140 [ 34 % ] in the OCT group , 135 [ 33 % ] in the IVUS group , and 140 [ 34 % ] in the angiography group ) . The final median minimum stent area was 5·79 mm2 ( IQR 4·54 - 7·34 ) with OCT guidance , 5·89 mm2 ( 4·67 - 7·80 ) with IVUS guidance , and 5·49 mm2 ( 4·39 - 6·59 ) with angiography guidance . OCT guidance was non-inferior to IVUS guidance ( one-sided 97·5 % lower CI -0·70 mm2 ; p=0·001 ) , but not superior ( p=0·42 ) . OCT guidance was also not superior to angiography guidance ( p=0·12 ) . We noted procedural MACE in four ( 3 % ) of 158 patients in the OCT group , one ( 1 % ) of 146 in the IVUS group , and one ( 1 % ) of 146 in the angiography group ( OCT vs IVUS p=0·37 ; OCT vs angiography p=0·37 ) . INTERPRETATION OCT-guided PCI using a specific reference segment external elastic lamina-based stent optimisation strategy was safe and result ed in similar minimum stent area to that of IVUS-guided PCI . These data warrant a large-scale r and omised trial to establish whether or not OCT guidance results in superior clinical outcomes to angiography guidance . FUNDING St Jude Medical BACKGROUND The first CE-approved bioresorbable vascular scaffold ( BVS ) is effective at treating simple lesions and stable coronary artery disease , but it has yet to be assessed versus the best-in-class drug-eluting stents ( DES ) . OBJECTIVES This study sought to compare the performance of a BVS with that of everolimus-eluting stents ( EES ) and biolimus-eluting stents ( BES ) in all-comer patients . METHODS The EVERBIO II ( Comparison of Everolimus- and Biolimus-Eluting Stents With Everolimus-Eluting Bioresorbable Vascular Scaffold Stents 
    Output:
    
INTERPRETATION BVS was associated with increased rates of composite device-oriented adverse events and device thrombosis cumulatively at 2 years and between 1 and 2 years of follow-up compared with EES .