Discussion of the effectiveness of distance learning as a means of delivering higher education programs at classical universities has been ongoing for the past decade. The article presents the findings of a study of changes in academic performance of university students, covering the period from fall 2018 to fall 2023. This period included a rapid switch to online learning at Russian universities. Our study is based on a large dataset generated through the ERP system of the national university of science and technology MISIS (NUST MISIS). The dataset contains over 600,000 students' academic performance entries covering every subject and practical class, including the final assessments. In addition to the abovementioned dataset, the study also used a database of students' unified state examination (use) results. The results of use exams (taken during the final year of high school) determine the applicant's eligibility for admission to university programs. We evaluate the impact of an individual student's use results on their future academic performance at the undergraduate level. The study also analyzes the overall readiness of a university for distance learning at the time of the COVID-19 pandemic outbreak. Excel pivot tables were used as a statistical analysis tool; Shewhart charts were employed to analyze the academic performance trends. Our analysis confirmed the initial hypothesis--that there exists a potential negative impact of online learning on the academic performance of university students. The use of big data in learning analytics enhances the reliability of the results to the greatest extent possible.