Clinical factors and Texas Heart PCI risk score correlate with SYNTAX score during patient selection for PCI or CABG

Background: “Mother–child technique” is applicable when the backup support of the guiding catheter is insufficient. We investigated the impact of the size of the mother guiding catheter on the catheter backup support using an in vitro coronary artery tree model. Methods: The backup support was measured for the 4-in-5, 4-in-6, 4-in-7, and 4-in-8 systems as well as for the 5-in-6, 5-in-7, and 5-in8 systems. Results: When a 4-Fr child catheter was advanced by 9 cm, the relative increase in the backup support was 174% in the 4-in-5 system; 203% in the 4-in-6, and 135% in the 4-in-7 (Pb.05 vs. the mother catheter alone). The increase with the 5-Fr child catheter was 289% in the 5-in-6 system, and 152% in the 5-in-7 (Pb.0001 vs. the mother catheter alone). However, the improvement did not reach statistical significance for either the 4-in-8 (115%) or the 5-in8 (112%) system (Fig. 1). Conclusions: The relative increase in the backup support of the mother–child system was inversely related to the size of the mother guiding catheter. Thus, the mother–child technique may be most useful for PCIs in which a small guiding catheter is used, such as transradial coronary interventions.