Comparing closed and open large language models on pediatric cardiology board exam performance

Large language models (LLMs) have gained traction in medicine, but there is limited research comparing closed- and open-source models in subspecialty contexts. This study evaluated ChatGPT-4.0o and DeepSeek-R1 on a pediatric cardiology board-style examination to quantify their accuracy and discuss educational and clinical utility. ChatGPT-4.0o and DeepSeek-R1 were used to answer 88 text-based multiple choice questions across 11 pediatric cardiology subtopics from a Pediatric Cardiology Board Review textbook. DeepSeek-R1's processing time per question was measured. ChatGPT-4.0o and DeepSeek-R1 achieved 70% (62/88) and 68% (60/88) accuracy, respectively (p = 0.53). Subtopic accuracy was equal in 5 of 11 chapters, with each model outperforming its counterpart in 3 of 11. DeepSeek-R1's processing time negatively correlated with accuracy (r = -0.68, p = 0.02). ChatGPT-4.0o and DeepSeek-R1 were comparable in accuracy and approached the passing threshold on a pediatric cardiology board examination. While further development of LLMs is required for clinical integration into pediatric cardiology, these findings suggest the potential utility of these models as educational aids.