***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: BACKGROUND Percutaneous treatment of patients with ST segment elevation myocardial infa rct ion ( STEMI ) has become the st and ard and default mode of management as recommended by the European Society of Cardiology guidelines for managing acute myocardial infa rct ion in patients presenting with STEMI . The choice of vascular access is made by the operator and has a potential impact on the safety and efficacy of the procedure and outcomes . AIM To underst and the influence of a radial approach on bleeding complications and angiographic success , we performed a prospect i ve , controlled r and omised trial . METHODS Patients were allocated to radial ( TR ) or femoral ( TF ) vascular access . The primary endpoints were major bleeding by the REPLACE-2 scale and minor bleeding by the EASY scale ( TR arm ) or the FEMORAL scale ( TF arm ) . Other outcomes included procedural data , in-hospital and long-term survival . RESULTS There were 103 patients analysed in total , 52 in the TR arm and 51 in the TF arm . The demographic and clinical baseline characteristics were well matched between the two study groups . The frequency of the primary endpoint was the same in both arms ( TR : 25.0 % vs. TF : 33.3 % , p = 0.238 ) . In per protocol analysis , there was a significant benefit of the TR approach among independent operators ( 17.4 % vs. 36.8 % , p = 0.038 ) . Major bleeding by the REPLACE-2 scale occurred in 4.2 % of patients ( TR : 5.8 % vs. TF : 3.9 % , p = 0.509 ) . There were no differences in terms of the rate of major cardiac adverse events , which happened in 10.7 % of the study population ( TR : 9.6 % vs. TF : 11.8 % , p = 0.48 ) . In the TF arm , there was a trend towards a higher risk of local bleedings ( TR : 22.4 % vs. TF : 37.7 % , p = 0.081 ) and a significantly higher frequency of local haematoma ( class III , EASY/FEMORAL ) ( TR : 0 % vs. TF : 9.8 % , p = 0.027 ) . CONCLUSIONS There were no significant differences between the TR and TF approaches in terms of clinical efficacy and patient safety . However , patients treated by independent operators might benefit from TR access . The overall complication risk of percutaneous coronary intervention treatment of STEMI patients remains low INTRODUCTION AND OBJECTIVES The right radial ( RR ) approach has been incorporated into daily clinical practice as a valid alternative to the femoral ( F ) approach . The left radial ( LR ) approach is seldom used and few data are available from r and omized studies comparing this approach with F and RR approaches . METHODS We r and omized 1005 consecutive patients referred to a tertiary-care hospital for cardiac catheterization to different approaches . Procedures were performed by three interventional cardiologists experienced in transradial catheterization . There were no exclusion criteria . The primary end-point was the percentage of procedures completed using the assigned approach . Secondary endpoints were the percentage completed in the absence of contraindications to any approach , the duration of the procedure , and the incidence of vascular complications . RESULTS More procedures were completed with the F approach ( LR , 71 % ; F , 92 % ; RR , 68 % ; P < .001 ) . The success rate in the absence of contraindications to any approach ( n=907 ) was greater with the F approach , with no difference between LR and RR approaches ( LR , 80 % ; F , 96 % ; RR , 82 % ; P < .001 ) . The canalization time was greater with the LR approach ( P < .001 ) , the time required for diagnosis was shorter with the F approach ( P < .001 ) and compression was faster with the radial approach ( P < .001 ) . There was no difference in the total duration of diagnostic procedures ( P=.22 ) or interventions ( P=.9 ) . The incidence of vascular complications was lower with the radial approach ( P=.03 ) . CONCLUSIONS The left radial approach is as valid an alternative to the femoral approach as the right radial approach Aims : The transradial ( TR ) approach has potentially lower complication rates than transfemoral ( TF ) approach coronary angiography . However , it may be technically more challenging , especially in elderly patients with alterations in vascular anatomy . We thus determined success rates , procedural data , and complication rates of TR angiography in comparison to the TF approach in elderly patients in a r and omized , prospect i ve trial . Methods and results : Four hundred consecutive patients ≥75 years with known or suspected coronary artery disease were included in the study . After exclusion of 93 patients with contraindications to the radial approach , 152 patients were r and omized to the TR and 155 to TF coronary angiography and intervention  . In 13 patients r and omized to TR , cross‐over to TF was necessary ( 9 % ) . Total examination time was significantly longer for the TR approach ( 18.1 vs. 15.0 min , P = 0.009 ) , but no difference was found for fluoroscopy time , number of catheters used , or amount of contrast agent . The rate of major complications ( bleeding requiring surgery or transfusion , stroke ) was 0 % for TR and 3.2 % for TF approach ( P < 0.001 ) . Minor complications occurred in 1.3 % versus 5.8 % of patients ( P < 0.001 ) . Conclusion : In elderly patients , TR coronary angiography and intervention has a high technical success rate and lower complication rates than the TF approach . © 2008 Wiley‐Liss , OBJECTIVES The purpose of this study was to assess whether transradial access for ST-segment elevation acute coronary syndrome undergoing early invasive treatment is associated with better outcome compared with conventional transfemoral access . BACKGROUND In patients with acute coronary syndrome , bleeding is a significant predictor of worse outcome . Access site complications represent a significant source of bleeding for those patients undergoing revascularization , especially when femoral access is used . METHODS The RIFLE-STEACS ( Radial Versus Femoral R and omized Investigation in ST-Elevation Acute Coronary Syndrome ) was a multicenter , r and omized , parallel-group study . Between January 2009 and July 2011 , 1,001 acute ST-segment elevation acute coronary syndrome patients undergoing primary /rescue percutaneous coronary intervention  were r and omized to the radial ( 500 ) or femoral ( 501 ) approach at 4 high-volume centers . The primary endpoint was the 30-day rate of net adverse clinical events ( NACEs ) , defined as a composite of cardiac death , stroke , myocardial infa rct ion , target lesion revascularization , and bleeding ) . Individual components of NACEs and length of hospital stay were secondary endpoints . RESULTS The primary endpoint of 30-day NACEs occurred in 68 patients ( 13.6 % ) in the radial arm and 105 patients ( 21.0 % ) in the femoral arm ( p = 0.003 ) . In particular , compared with femoral , radial access was associated with significantly lower rates of cardiac mortality ( 5.2 % vs. 9.2 % , p = 0.020 ) , bleeding ( 7.8 % vs. 12.2 % , p = 0.026 ) , and shorter hospital stay ( 5 days first to third quartile range , 4 to 7 days ] vs. 6 [ range , 5 to 8 days ] ; p = 0.03 ) . CONCLUSIONS Radial access in patients with ST-segment elevation acute coronary syndrome is associated with significant clinical benefits , in terms of both lower morbidity and cardiac mortality . Thus , it should become the recommended approach in these patients , provided adequate operator and center expertise is present . ( Radial Versus Femoral Investigation in ST Elevation Acute Coronary Syndrome [ RIFLE-STEACS ] ; NCT01420614 ) OBJECTIVES This study sought to compare and contrast use and radiation exposure using radial versus femoral access during cardiac catheterization of patients who had previously undergone coronary artery bypass graft ( CABG ) surgery . BACKGROUND Limited information is available on the relative merits of radial compared with femoral access for cardiac catheterization in patients who had previously undergone CABG surgery . METHODS Consecutive patients ( N = 128 ) having previously undergone CABG surgery and referred for cardiac catheterization were r and omized to radial or femoral access . The primary study endpoint was contrast volume . Secondary endpoints included fluoroscopy time , procedure time , patient and operator radiation exposure , vascular complications , and major adverse cardiac events . Analyses were by intention-to-treat . RESULTS Compared with femoral access , diagnostic coronary angiography via radial access was associated with a higher mean contrast volume ( 142 ± 39 ml vs. 171 ± 72 ml , p < 0.01 ) , longer procedure time ( 21.9 ± 6.8 min vs. 34.2 ± 14.7 min , p < 0.01 ) , greater patient air kerma ( kinetic energy released per unit mass ) radiation exposure ( 1.08 ± 0.54 Gy vs. 1.29 ± 0.67 Gy , p = 0.06 ) , and higher operator radiation dose ( first operator : 1.3 ± 1.0 mrem vs. 2.6 ± 1.7 mrem , p < 0.01 ; second operator 0.8 ± 1.1 mrem vs. 1.8 ± 2.1 mrem , p = 0.01 ) . Fewer patients underwent ad hoc percutaneous coronary intervention ( PCI )  in the radial group ( 37.5 % vs. 46.9 % , p = 0.28 ) and radial PCI procedures were less complex . The incidences of the primary and secondary endpoints was similar with femoral and radial access among PCI patients . Access crossover was higher in the radial group ( 17.2 % vs. 0.0 % , p < 0.01 ) and vascular access site complications were similar in both groups ( 3.1 % ) . CONCLUSIONS In patients who had previously undergone CABG surgery , transradial diagnostic coronary angiography was associated with greater contrast use , longer procedure time , and greater access crossover and operator radiation exposure compared with transfemoral angiography . ( RADIAL Versus Femoral Access for Coronary Artery Bypass Graft Angiography and Intervention [ RADIAL-CABG ] Trial ; NCT01446263 ) The transradial approach to coronary angiography is considered by some to be a route of choice , by others to be a route that should be used only where there are relative contraindications to the femoral approach . We present the largest series to date of patients in whom transradial coronary angiography was undertaken specifically because of contraindications to the femoral approach . Since 1995 , patients at this cardiothoracic center have been considered for a transradial approach to coronary angiography if there were relative contraindications to the femoral route . Data from 500 patients was prospect ively collected . Patients were aged 66 ± 9 years ; 72 % were male . Indications for the radial approach included peripheral vascular disease ( 305 ) , therapeutic anticoagulation ( 77 ) , musculoskeletal ( 59 ) , and morbid obesity ( 32 ) . Sixty‐eight patients ( 14 % ) required a radial procedure following a failed femoral approach . Access was right radial 291 ( 58 % ) , left radial 209 ( 42 % ) . Eighteen operators were involved , but two operators undertook 355 ( 71 % ) of the cases . Catheter gauge was 6 Fr ( n = 243 ; 49 % ) , 5 Fr ( 219 ; 43 % ) , and 4 Fr ( 29 ; 6 % ) . The procedure was successful in 463 cases [ 92.6 % ; 88.2 % for nonmajority vs. 94.4 % ( P < 0.05 ) for the two majority operators ] . Success in males ( 93.6 % ) significantly exceeded that in females ( 90.1 % ; P < 0.05 ) . In‐catheter‐laboratory duration was 45 ± 17 min ; fluoroscopy time , 7.5 ± 6 min ; radiation dose , 40 ± 23 CGy . The procedure was without incident in 408 cases ( 82 % ) . There were procedural difficulties in 18 % of cases , including radial artery spasm ( 12 % ) and vasovagal response ( 5 % ) . The incidence was higher with 6 Fr catheters ( 23 % ) than with 5/4 Fr ( 15 % ; P < 0.05 ) . Major procedural complications occurred in three cases : brachial artery dissection in one and cardiac arrest in two . Postprocedure major vascular complications numbered three : claudicant pain on h and grip in one , ischemic index finger ( with subsequent terminal phalanx amputation due to osteomyelitis ) in one , and ischemic h and for 4 hr in one . Patients with contraindications to the femoral approach form a high‐risk group . In these patients , transradial cardiac catheterization can be performed successfully and with a low risk of major complications . Minor adverse features remain frequent , occurr 
    Output:
    
INTERPRETATION Transradial access was associated with a small but significant increase in radiation exposure in both diagnostic and interventional procedures compared with transfemoral access .
Since differences in radiation exposure narrow over time , the clinical significance of this small increase is uncertain and is unlikely to outweigh the clinical benefits of transradial access .