Subintimal dissection/reentry techniques are increasingly being used for crossing coronary chronic total occlusions both antegradely (using a knucle wire or the Bridgepoint system) or retrogradely (using the controlled antegrade and retrograde tracking and dissection, and reverse controlled antegrade and retrograde tracking and dissection technique). Subintimal dissection/reentry techniques can increase procedural success rates, but their subsequent clinical outcomes are poorly studied, and they appear to be associated with high rates of in-stent restenosis and repeat target lesion revascularization. In the present review, we describe in detail the chronic total occlusions subintimal dissection/reentry techniques, clarify the related terminology and summarize the published studies in this area and the current gaps of knowledge.

Objectives We sought to evaluate the incidence, correlates, and clinical implications of periprocedural myocardial injury (PMI) during percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs). Background The risk of PMI during CTO PCI may be underestimated because systematic cardiac biomarker measurement was not performed in published studies. Methods We retrospectively examined PMI among 325 consecutive CTO PCIs performed at our institution between 2005 and 2012. Creatine kinase MB fraction (CK-MB) and troponin were measured before PCI and 8–12 and 18–24 hours after PCI in all patients. PMI was defined as CK-MB increase ≥3x upper limit of normal. Major adverse cardiac events (MACE) during mid-term follow-up was evaluated. Results Mean age was 64±8 years. The retrograde approach was used in 26.8% of all procedures. The technical and procedural success was 77.8% and 76.6%, respectively. PMI occurred in 28 patients (8.6%, 95% confidence intervals 5.8%, 12.2%), with symptomatic ischemia in 7 of those patients. The incidence of PMI was higher in patients treated with the retrograde compared to the antegrade approach (13.8% vs. 6.7%, p=0.04). During a median follow-up of 2.3 years, compared to patients without PMI those with PMI had higher incidence of MACE (hazard ratio=2.25, p=0.006). Patients with only asymptomatic PMI also had higher incidence of MACE on follow-up (HR=2.26, p=0.013). Conclusions Systematic measurement of cardiac biomarkers post CTO PCI demonstrates that PMI occurs in 8.6% of patients, is more common with the retrograde approach, and is associated with worse subsequent clinical outcomes during mid-term follow-up.

The GuideLiner catheter (Vascular Solutions, Minneapolis, MN) is a novel, rapid exchange catheter that allows deep vessel intubation. We describe 21 patients in whom the GuideLiner catheter [7 French (F) in 76% and 6F in 24%] was used to facilitate equipment delivery (n = 14) or vessel engagement (n = 7). Pressure dampening after GuideLiner catheter insertion was observed in 12 patients (57%). The procedure was successfully completed in 19 patients (90%) and one patient developed acute vessel closure, likely due to dissection. The GuideLiner catheter can facilitate complex coronary interventions but should be used with caution to minimize the risk for vessel injury.

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).