Abstract 3162: Dynamic mortality modeling in PCI-treated ST-elevation Myocardial Infarction: Implications for Clinical Decision Making
Background: Baseline factors predict adverse events after acute myocardial infarction (AMI), whereas dynamic risk modeling captures its evolving nature using continuous temporal profile updating. This refinement may guide medical decisions.
Methods: APEX AMI trial tested pexelizumab efficacy in 5745 STEMI pts undergoing primary PCI; no treatment effect was observed. Four multivariable Cox models predicted 90-day mortality from key time points: baseline, 30-min post-PCI, 24 hrs, 96 hrs. % ST-resolution 30-min post-PCI, TIMI Flow pre-and post-PCI were measured. Complications included shock, CHF, re-MI, recurrent ischemia, stroke, renal failure, severe bleeding and major cardiac rhythm disturbances. The relative covariate contribution was quantified as the % of the ∑individual X2’s.
Results: Ninety-day mortality was 4.7%; 22% and 40% of deaths occurred < 24 hrs and 4 days, respectively. The figure⇓ (left ) shows decreasing relative contributions of age, systolic BP/heart rate and other factors over time to 90d mortality, and incremental influence of in-hospital complications, TIMI flow and post-PCI ST-resolution. As time elapsed, the % of “low risk” pts increased. (Right panel) At 96 hrs, a possible early discharge point for low risk pts, 44.0% of survivors had been discharged. This discharge rate decreased with increasing risk: Low: 53.3%; Moderate: 35.3%; High: 20.4% (p < 0.001). If early discharge depended on risk, the remaining 46.7% of low risk pts might have been discharged early.
Conclusions: This novel approach demonstrates the dynamic nature of STEMI risk over time and may be used to guide early clinical decision-making.