Dissecting content profiles and information quality of myocardial infarction related short videos: a cross-platform cross-sectional investigation

Short video platforms have become key channels for public health information. However, the quality of myocardial infarction (MI)‑related health content across major Chinese platforms remains poorly characterized. This study characterized the content features, informational credibility, and dissemination patterns of MI-related videos on major short video platforms in China. A cross-sectional analysis was conducted from December 14 to 19, 2025, on TikTok, Rednote, and WeChat. Approximately 200 videos were initially retrieved for each platform. Two reviewers independently assessed videos using JAMA criteria, Global Quality Score (GQS), modified DISCERN, and the Patient Education Materials Assessment Tool (PEMAT). Multivariable robust‑Poisson regression and sensitivity analysis excluding top 1% engagement outliers were applied to handle over-dispersed engagement outcomes. Data were analyzed using R and GraphPad Prism. After exclusion criteria were applied, a total of 485 videos were analyzed. TikTok videos had significantly higher raw observed engagement metrics (likes, comments, collections) than those on WeChat and Rednote (all P < 0.001). Multivariable regression confirmed most of these platform‑related engagement differences, although the apparent sharing advantage of TikTok disappeared after outlier exclusion in sensitivity analysis. Rednote had a higher proportion of videos by junior and intermediate physicians ( P < 0.001). MI‑related educational videos were geographically concentrated in economically‑developed provinces. TikTok videos scored higher on JAMA but lower on GQS and DISCERN compared to other platforms; Rednote scored higher on DISCERN than WeChat. No significant differences were found between physician seniority groups on JAMA, GQS, DISCERN, or PEMAT understandability. However, junior and intermediate physicians scored higher on PEMAT actionability than senior physicians. MI-related video content varies in quality and engagement, with educational resources concentrated in developed regions. Findings underscore the need for stronger content governance and greater involvement of medical professionals in creating actionable health education to enhance public MI awareness.