BACKGROUND: Lipid-lowering therapy (LLT) is underutilized for very high-risk atherosclerotic cardiovascular disease. PROMPT-LIPID (PRagmatic Trial of Messaging to Providers about Treatment of HyperLIPIDemia) sought to determine whether electronic health record (EHR) alerts improve 90-day LLT intensification in patients with very high-risk atherosclerotic cardiovascular disease. METHODS: PROMPT-LIPID was a pragmatic trial in which cardiovascular and internal medicine clinicians within Yale New Haven Health (New Haven, CT) were cluster-randomized to receive an EHR alert with individualized LLT recommendations or no alert for outpatients with very high-risk atherosclerotic cardiovascular disease and LDL-C (low-density lipoprotein cholesterol), ≥70 mg/dL. The primary outcome was 90-day LLT intensification (change to high-intensity statin and addition of ezetimibe or PCSK9i [proprotein subtilisin/kexin type 9 inhibitors]). Secondary outcomes included LDL-C level, proportion of patients with LDL-C of <70 or < 55 mg/dL, rate of major adverse cardiovascular events, ED visit incidence, and 6-month mortality. Results were analyzed using logistic and linear regression clustered at the provider level. RESULTS: The no-alert group included 47 clinicians and 1370 patients (median age, 71 years; 50.1% female, median LDL-C, 93 mg/dL); the alert group included 49 clinicians and 1130 patients (median age, 72 years; 47% female, median LDL-C 91, mg/dL). The primary outcome was observed in 14.1% of patients in the alert group as compared with 10.4% in the no-alert group. There were no differences in any secondary outcomes at 6 months. Among 542 patients whose clinicians (n=46) did not dismiss the EHR alert recommendations, LLT intensification was significantly greater (21.2% versus 10.4%, odds ratio, 2.33 [95% CI, 1.48–3.66]). CONCLUSIONS: With a real-time, targeted, individualized EHR alert as compared with usual care, the proportion of patients with atherosclerotic cardiovascular disease with LLT intensification was numerically higher but not statistically significant. Among clinicians who did not dismiss the alert, there was a > 2-fold increase in LLT intensification. EHR alerts, coupled with strategies to reduce clinician dismissal, may help address persistent gaps in LDL-C management. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04394715, https://www.clinicaltrials.gov/ct2/show/study/NCT04394715