Complex antegrade and retrograde "Japanese style" PCI approaches can be applied in the U.S. practice environment with high technical success and low adverse event rates. Higher CTO-specific operator case volume is associated with improved technical success rates.

Background-Previous work on contrast-induced acute kidney injury (CI-AKI) has identified contrast volume as a risk factor and suggested that there is a maximum allowable contrast dose (MACD) above which the risk of CI-AKI is markedly increased. We hypothesized that there is a relationship between contrast volume and CI-AKI and that there might be reason to track incremental contrast volumes above and below the MACD limit. Methods and Results-Consecutive patients undergoing percutaneous coronary intervention (PCI) were prospectively enrolled from 2000 to 2008 (nϭ10 065). Patients on dialysis before PCI were excluded (nϭ155). MACD was defined as (5 mLϫbody weight [kg])/baseline serum creatinine [mg/dL]) and divided into categories in which 1.0 reflects the MACD limit: ՅMACD ratios (Ͻ0.5, 0.5 to 0.75, and 0.75 to 1.0) and ϾMACD (1.0 to 1.5, 1.5 to 2.0, and Ͼ2.0). CI-AKI was defined as a Ն0.3 (mg/dL) or Ն50% increase in serum creatinine from baseline or new dialysis. Multivariable regression was conducted to evaluate the effect of exceeding the MACD on CI-AKI.