This study investigated the 24-hour ambulatory blood pressure monitoring (ABPM) and Holter parameters for evaluating their prognostic significance of cardiovascular events including stroke in population without atrial fibrillation (AF).

Among 3,199 patients that underwent ABPM, 335 who also underwent Holter recordings were selected in a tertiary hospital. Seventeen patients who had been documented with AF on Holter monitoring or diagnosed with AF were excluded, and finally 318 patients were analyzed. The association between cardiovascular events and ABPM/Holter parameters was analyzed by a logistic regression model, and the risk factors were estimated by a Cox hazard model. Age, sex, and histories of cardiovascular disease were adjusted by a multivariable analysis, and the cut-off values were suggested by a Kaplan-Meyer analysis.

During the total follow-up (28.5±1.7 months), 13 (4.1%) stroke, 6 (1.9%) heart failure, and 12 (3.8%) acute coronary syndrome incidences were observed. In the univariate analysis of the ABPM parameters, an increment in the night systolic BP (hazard ratio=1.034, P=0.020) and night diastolic BP (hazard ratio=1.063, P=0.031) significantly elevated the risk of a stroke occurrence. According to the Kaplan-Meyer analysis, there was a significant difference in the stroke incidence between the groups divided by a cut-off value of the night systolic BP of 120 mmHg (P=0.014) and night diastolic BP of 75 mmHg (P=0.023).

In a population without AF, the nocturnal BP was a significant predictor of a stroke incidence. At this point, the cut-off value of mean 120/75 mmHg in 24 ABPM was advisable.

Ewha Womans University launched an on-campus Coronavirus disease-19 (COVID-19) response system called Ewha Safety Campus (ESC) Project in collaboration with the Seegene Inc. RT-PCR diagnostic tests for COVID-19 were proactively provided to the participants. This study examines the effectiveness of the on-campus testing strategy in controlling the reproduction number (R_t) and identifying student groups vulnerable to infection.

The ESC project was launched on March 2, 2022, with a pilot period from Feb 22 to March 1, 2022—the peak of the Omicron variant wave. We collected daily data on the RT-PCR test results of the students of Ewha Womans University from Mar 2 to Apr 30, 2022. We daily calculated R_t and compared it with that of the general population of Korea (women, people aged 20–29 years, and Seoul residents). We also examined the students vulnerable to the infection based on the group-specific R_t and positivity rate.

A lower R_t was observed about 2 weeks after the implementation of the ESC Project than that of the general population. The lower R_t persisted during the entire study period. Dormitory residents had a higher R_t. The positivity rate was higher in students who did not comply with quarantine guidelines and did not receive the second dose of the vaccine.

The study provides scientific evidence for the effectiveness of the on-campus testing strategy and different infection vulnerabilities of students, depending on dormitory residence, compliance with the quarantine guidelines, and vaccination.