Comparison of failure rates of crossing side branch with pressure vs. coronary guidewire: a meta-analysis Sameer Ather * , Chirag P. Bavishi † , Vikas Bhatia * , Navkaranbir S. Bajaj * and Massoud A. Leesar * * Division of Cardiology, University of Alabama at Birmingham, Birmingham, AL, USA, † Department of Medicine, Mount Sinai St Luke’s-Roosevelt Hospital Center, New York, NY, USA ABSTRACT Objectives The aim of this study was to compare the failure rates of crossing side branch (SB) with pressure guidewire vs. coronary guidewire after main vessel (MV) stenting in coronary bifurcation lesions (CBL). Background Percutaneous coronary intervention of CBL is technically difficult. The European Bifurcation Club recommends performing either fractional flow reserve (FFR) estimation of the SB or final kissing balloon inflation (FKBI) after the MV stenting when a significant SB ostial stenosis is present. Even though FFR is recommended in CBL, there is concern about SB crossing with pressure guidewire among interventionists. Materials and methods We undertook a comprehensive literature search to identify all relevant studies reporting the failure rates of SB crossing after MV stenting with either pressure or coronary guidewire. A random effects model was used to compare the failure rates between the two approaches. Results Our search identified six studies that reported failure rates of SB crossing with a pressure guidewire (n = 648) and 11 studies that reported failure rates of SB crossing with a coronary guide-wire (n = 2601). Estimated pooled failure rate was 3Á9% (95% CI: 1Á5% to 9Á6%) for inability to cross SB with pressure guidewire. Estimated pooled failure rate of SB crossing with coronary guidewire was 3Á1% (95% CI: 1Á5% to 6Á2%). There was no significant difference between the failure rates in the two groups (P = 0Á70). Conclusion The failure rates of SB crossing after MV stenting are low with both pressure and coronary guidewire procedures, with no significant difference between the two approaches. Keywords Coronary bifurcation, fractional flow reserve, kissing balloon inflation, wires. Eur J Clin Invest 2016; 46 (5): 448–459 Introduction Coronary bifurcation lesions (CBL) represent one of the most difficult technical challenges in percutaneous coronary inter- vention (PCI) [1,2]. Till date, no uniform strategy has been established for the optimal management of CBL, especially for the management of side branch (SB) stenosis [3–6]. Moreover, some patients with CBL develop apparent angio- graphic stenosis of the SB after main vessel (MV) stenting due to shifting of the carina towards the SB. Such patients may benefit from fraction flow reserve (FFR) estimation of SB that can help reduce the need for unnecessary PCI of the SB. The European Bifurcation Club states that FFR may be used in CBL involving the left main coronary artery. In contrast, European Bifurcation club does not advise routine SB FFR due to unknown validity when performed after MV stenting and also due to unknown increased risk of adverse events [7]. Thus, operators either perform SB FFR and subsequent SB PCI if FFR is significant, or perform FKBI on all angiographically significant ostial SB lesions to reduce functionally significant stenosis. Although, FKBI has been show to increase the MV stent area, especially in the proximal segment; FKBI may also cause stent asymmetry leading to variation of drug concentration in the vessel wall with a consequent increased incidence of neointimal hyperplasia [8,9]. These potential side effects may be the reason for the neutral results in recent trials comparing FKBI vs. no FKBI [10,11]. On the other hand, many operators believe that the success of crossing the SB with a pressure wire after MV stenting may be lower, compared with a coronary guide wire. This concern arises from the fact that one of the biggest chal- lenges in performing either FKBI or FFR of the SB is rewiring the SB after the MV stent implantation [12]. Till date, no sys- tematic review has assessed the failure rate of crossing the SB in CBL with pressure guide wire and compared it with the failure rate of crossing SB with coronary guide wire. Thus, in this study, we aim to compare the success rates of SB crossing with the pressure guide wire vs. coronary guide wire in CBL. 448 ª 2016 Stichting European Society for Clinical Investigation Journal Foundation DOI: 10.1111/eci.12620 ORIGINAL ARTICLE