A novel risk model including vascular access site for predicting 30-day mortality after primary PCI: The ALPHA score.

Background: The mortality benefit of transradial primary PCI has been shown by several studies. Previous risk models have not considered access site as a candidate predictor and many of them were developed using low risk populations of randomized trials. We conducted a prospective cohort study to construct and validate an admission risk model including access site as candidate variable for predicting 30-day mortality after primary PCI.

Methods: We analyzed data of 1255 patients using variables readily available at presentation. Predictor selection was based on backward logistic regression combined with bootstrap resampling. The model has been validated internally and temporally externally.

Results: Thirty-day mortality was independently associated with older age, faster heart rate, need for life support on or prior to admission, and femoral access while it was inversely related to systolic blood pressure. ROC curve analysis revealed high discriminatory power, which was preserved in the validation set (c-statistic: 0.88 and 0.87, respectively). For the new score the acronym ALPHA (Age, Life support, Pressure, Heart rate, Access site) has been coined. Compared with previous models, our score achieved the highest c-statistic (0.87) followed by the GRACE 2.0 (0.86), APEX-AMI (0.86), and CADILLAC (0.85) models, the other scoring systems (TIMI, Zwolle, and PAMI) performed less well. The ALPHA, GRACE 2.0, APEX-AMI, and CADILLAC models predicted 30-day mortality better than the PAMI score (p=0.005, 0.004, 0.01, and 0.02, respectively).

Conclusions: Using this tool, mortality risk may be precisely assessed at admission and patients who may benefit most from transradial access may be identified.