The Effects of Daytime Variation on Short-term Outcomes of Patients Undergoing Off-Pump Coronary Artery Bypass Grafting

Abstract

Study objectiveTo evaluate the effects of time of operation on short-term outcomes of patients undergoing off-pump coronary artery bypass grafting (OPCAB). DesignRetrospective cohort study. SettingA single large-volume cardiovascular center. PatientsPatients undergoing elective OPCAB between September 2019 and July 2022. InterventionsPatients were divided into two groups according to the start time of surgery: morning (AM group, before 11am) and afternoon (PM group, after 11am). Propensity score matching (PSM) with a 1:1 matching ratio was used to create comparable cohorts. Measurements and Main resultsThe primary endpoint was the composite incidence of mortality and morbidities during hospitalization. Secondary endpoints included postoperative bleeding and transfusion, mechanical ventilation duration (MVD) and length of stay (LOS) in intensive care unit (ICU) and hospital. From a consecutive series of 1,039 patients, PSM yielded 317 well-matched pairs. There was no difference in the composite incidence of in-hospital mortality and morbidities between AM and PM groups (16.4% vs. 17.4%, P=0.832). However, patients in PM group were associated with less postoperative blood loss over the first 24 h (470 ml vs. 540 ml, P=0.002), decreased MVD (14 h vs. 16 h, P<0.001) and shorter LOS in ICU (46 h vs. 68 h, P=0.002) as compared to patients in AM group. ConclusionsThe current study suggested a lack of relevance regarding time of operation with in-hospital mortality and morbidities in patients undergoing OPCAB.