The first time Dr. Nicholas Perricelli, a cardiologist at Harvard-affiliated Massachusetts General Hospital, explained HDL to a room full of skeptical patients, the lightbulb moment was palpable. “You’ve been chasing the wrong numbers,” he said, pointing to a blood panel where LDL (“bad” cholesterol) was near-perfect, yet HDL—his patient’s “good” cholesterol—hovered at a dangerously low […]