Validation of AHA PREVENT in healthcare populations| JACC Deep Dive In this JACC Deep Dive, JACC Editor in Chief Harlan M. Krumholz, MD, SM, explores a study led by Dr. Pradeep Natarajan that evaluates how well the new AHA PREVENT risk equations predict cardiovascular events across four major U.S. health systems. The study found wide variation in performance—PREVENT was well-calibrated at Penn Medicine but significantly underestimated risk at Mass General Brigham and Vanderbilt, particularly among women and minority groups. Reviewers praised the importance and rigor of the work but raised key questions about model calibration, fairness in outcome comparisons, and whether truly "plug-and-play" risk tools are realistic across diverse healthcare environments.