BACKGROUND Intra-operative tachycardia during noncardiac surgery has been associated with adverse postoperative outcomes. However, harm thresholds for tachycardia have not been uniformly defined. The definition of intraoperative tachycardia that best correlates with adverse postoperative outcomes remains unclear.OBJECTIVE We aimed to identify the definition of intraoperative tachycardia during noncardiac surgery that is associated with the best predictive ability for adverse postoperative outcomes.DESIGN A single-centre retrospective cohort analysis.SETTING Secondary care hospital, Afula, Israel.PATIENTS AND METHODS Adults who underwent elective or nonelective noncardiac surgery during 2015 to 2019. Five intra-operative heart rate (HR) cut-off values and durations were applied with penalised logistic regression modelling for the outcome measures.
MAIN OUTCOME MEASURESThe primary outcome was all-cause 30-day mortality; the secondary outcome was myocardial ischaemia or infarction (MI) within 30 days after noncardiac surgery.
RESULTSThe derivation and validation datasets included 6490 and 4553 patients, respectively. Altogether, all-cause 30-day mortality and MI rates averaged 2.1% and 3.2%, respectively. Only two definitions of intra-operative tachycardia were significantly associated with the outcome measures: HR ! 100 bpm for ! 30 min and HR ! 120 bpm for ! 5 min. The C-statistics of the base models without tachycardia exposure for all-cause 30-day mortality and MI were 0.75 (95% confidence interval, CI, 0.74 to 0.78) and 0.73 (95% CI, 0.72 to 0.76), respectively. The addition of intra-operative tachycardia exposure to the base models significantly improved their predictive performance. The highest area under the curve (AUC) was achieved when tachycardia was defined as an intra-operative HR ! 100 bpm for at least 30 min: AUC 0.81 (95% CI, 0.80 to 0.84) and AUC 0.80 (95% CI, 0.79 to 0.82) for all-cause 30-day mortality and MI, respectively.CONCLUSION Intra-operative tachycardia, defined as an intra-operative HR ! 100 bpm for at least 30 min, was associated with the highest predictive power for adverse postoperative outcomes.