Daytime variation does not impact outcome of cardiac surgery: Results from a diverse, multi-institutional cardiac surgery network

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

OBJECTIVE

To evaluate the effects of time of surgery on the short-term outcomes of patients undergoing off-pump coronary artery bypass grafting (OPCABG).

DESIGN

A retrospective cohort study.

SETTING

A single large-volume cardiovascular center.

PATIENTS

Patients undergoing elective OPCABG between September 2019 and July 2022.

INTERVENTIONS

Patients were divided into the following 2 groups according to the start time of surgery: morning (AM group, before 11 AM) and afternoon (PM group, after 11 AM). Propensity-score matching (PSM) with a 1:1 matching ratio was used to create comparable cohorts.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was the composite incidence of mortality and morbidities during hospitalization. Secondary endpoints included postoperative bleeding and transfusion, mechanical ventilation duration (MVD), and lengths of stay (LOS) in the 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 the AM and PM groups (16.4% v 17.4%, p = 0.832). However, patients in the PM group were associated with less postoperative blood loss over the first 24 hours (470 v 540 mL, p = 0.002), decreased MVD (14 v 16 hours, p < 0.001), and shorter LOS in ICU (46 v 68 hours, p = 0.002) compared to patients in AM group.

CONCLUSIONS

The current study suggested a lack of relevance regarding the time of surgery with in-hospital mortality and morbidities in patients undergoing OPCABG.

Morning or Afternoon Scheduling for Elective Coronary Artery Bypass Surgery: Influence of Longer Fasting Periods from Metabolic and Hemodynamic Perspectives

BACKGROUND

Prolonged preoperative fasting may worsen postoperative outcomes. Cardiac surgery has higher perioperative risk, and longer fasting periods may be not well-tolerated. We analysed the postoperative metabolic and hemodynamic variables in patients undergoing elective coronary artery bypass grafting (CABG) according to their morning or afternoon schedule.

METHODS

Single-centre retrospective study at University teaching hospital (1-year data collection from electronic medical records). Using a mixed-effects linear regression model adjusted for several covariates, we compared metabolic (lactatemia, pH, and base deficit [BD]) and haemodynamic values (patients on vasoactive support, and vasoactive inotropic score [VIS]) at 7 prespecified time-points (admission to intensive care, and 1st, 3rd, 6th, 12th, 18th, and 24th postoperative hours).

RESULTS

339 patients (n = 176 morning, n = 163 afternoon) were included. Arterial lactatemia and BD were similar (overall P = 0.11 and P = 0.84, respectively), while pH was significantly lower in the morning group (overall P < 0.05; mean difference -0.01). Postoperative urine output, fluid balance, mean arterial pressure, and central venous pressure were similar (P = 0.59, P = 0.96, P = 0.58 and P = 0.53, respectively). A subgroup analysis of patients with diabetes (n = 54 morning, n = 45 afternoon) confirmed the same findings. The VIS values and the proportion of patients on vasoactive support was higher in the morning cases at the 18th (P = 0.002 and p=0.04, respectively) and 24th postoperative hours (P = 0.003 and P = 0.04, respectively). Mean intensive care length of stay was 1.94 ± 1.36 days versus 2.48 ± 2.72 days for the afternoon and morning cases, respectively (P = 0.02).

CONCLUSIONS

Patients undergoing elective CABG showed similar or better metabolic and hemodynamic profiles when scheduled for afternoon surgery.

The effect of surgery started at different time point during the day on the clinical outcomes of mitral valve surgery

Background

The clinical prognosis of mitral valve surgery at morning, afternoon, and evening is not yet clear. The aim of the study is to investigate the impact of different time periods of surgery in the morning, afternoon and evening on the short-term and long-term results of mitral valve surgery.

Methods

From January 2018 to December 2020, 947 patients with mitral valve surgery in our department were selected. These patients were divided into 3 groups according to the starting time of surgery. Morning group (operation start time 8:00-10:30, n = 231), afternoon group (operation start time 12:00-14:30, n = 543), and evening group (operation start time 17:30-20:00, n = 173). The short-term and long-term results of the three groups were compared.

Results

There were no significant difference in the long-term mortality, long-term risk of stroke and reoperation. And there were no significant difference in in-hospital outcomes, including mortality, stroke, cardiopulmonary bypass time, aortic cross clamp time, mitral valve repair convert to mitral valve replacement, number of aortic cross clamp ≥2 times, unplanned secondary surgery during hospitalization (including thoracotomy hemostasis, thoracotomy exploration, redo mitral valve surgery, and debridement), intra-aortic balloon pump, extracorporeal membrane oxygenation, continuous renal replacement therapy, mechanical ventilation time, and intensive care unit length of stay.

Conclusion

There is no significant difference in the risk of short-term and long-term survival and adverse events after mitral valve surgery at different time periods in the morning, afternoon, and evening. Mitral valve surgery at night is safe.

Time-related variations in viability of random pattern skin flaps: An experimental study in rats

Chronobiological variations are in the fabric of life. The first ideas regarding the possible effects of circadian rhythm on surgical outcomes were published in the early 2000s. Some studies support and oppose this idea. The lack of experimental evidence in a controlled setting has led to this study. This study aimed to explore the chronobiological implications of surgical outcomes. The rats were divided into four groups. A random pattern dorsal skin flaps were elevated in all groups at six h intervals. Flap necrosis rates and melatonin, oxidant, and antioxidant factors were studied. Flap survival was better in the 06:00 h group. The flap necrosis was higher in the 18:00 h group. Some of the biochemical parameters displayed circadian variations. As an independent variable, the time of surgical intervention changed the flap survival rates. It should be noted that the study was held in a nocturnal animal model thus the pattern of flap survival can be in reversed fashion in a clinical scenario. This study is the first experimental evidence for "Chronosurgery" in a controlled setting. Further studies in all aspects of surgical disciplines are required.

Time-of-day discrepancy for the long-term surgical outcome of patients with aortic dissection

OBJECTIVES

It has been suggested that the time of day when cardiovascular surgery is performed may affect the surgery outcomes. This study investigated whether there was a difference in risk-adjusted mortality and morbidity outcomes between patients undergoing acute aortic dissection (AAD) during the day or the night.

METHODS

Consecutive patients who had undergone Stanford A AAD surgery were enrolled between 2016 and 2020. In the daytime group, surgery was performed between 08:00 and 20:00, and in the nighttime group between 20:00 and 8:00. The primary outcome was in-hospital overall mortality, and the secondary outcomes were overall mortality within a median follow-up time of 35.2 (17.0, 53.5) months and the occurrence of re-entry tears and major bleeding.

RESULTS

A total of 925 patients were enrolled. The primary outcome of in-hospital overall mortality did not differ significantly between patients who received daytime or nighttime surgery. Similarly, the secondary outcomes of overall mortality during the follow-up and incidence of re-entry tears and major bleeding did not differ significantly between the groups. Subgroup analysis was also performed according to the surgery type (modified triple-branched stent graft implantation or frozen elephant trunk implantation) and surgical approach (partial upper sternotomy or full median sternotomy) confirming that the time of surgery did not significantly influence the outcomes. Cox regression analysis showed that time from onset to admission (P = 0.036) and time from the onset to surgery (P = 0.045) were significant risk factors for increased mortality during follow-up.

CONCLUSIONS

The time of day when thoracotomy was performed did not significantly affect the clinical outcome and is therefore not a consideration for the improvement of outcome in Stanford A AAD patients.

Outcome differences between surgeons performing first and subsequent coronary artery bypass grafting procedures in a day: a retrospective comparative cohort study

BACKGROUND

With increasing surgical workload, it is common for cardiac surgeons to perform coronary artery bypass grafting (CABG) after other procedures in a workday. To investigate whether prior procedures performed by the surgeon impact the outcomes, we compared the outcomes between CABGs performed first versus those performed after prior procedures, separately for on-pump and off-pump CABGs as they differed in technical complexity.

METHODS

We conducted a retrospective cohort study of patients undergoing isolated CABG in China from January 2013 to December 2018. Patients were categorised as undergoing on-pump and off-pump CABGs. Outcomes of the procedures performed first in primary surgeons' daily schedule (first procedure) were compared with subsequent ones (non-first procedure). The primary outcome was an adverse events composite (AEC) defined as the number of adverse events, including in-hospital mortality, myocardial infarction, stroke, acute kidney injury and reoperation. Secondary outcomes were the individual components of the primary outcome, presented as binary variables. Mixed-effects models were used, adjusting for patient and surgeon-level characteristics and year of surgery.

RESULTS

Among 21 866 patients, 10 109 (16.1% as non-first) underwent on-pump and 11 757 (29.6% as non-first) off-pump CABG. In the on-pump cohort, there was no significant association between procedure order and the outcomes (all p>0.05). In the off-pump cohort, non-first procedures were associated with an increased number of AEC (adjusted rate ratio 1.29, 95% CI 1.13 to 1.47, p<0.001), myocardial infarction (adjusted OR (OR_adj) 1.43, 95% CI 1.13 to 1.81, p=0.003) and stroke (OR_adj 1.73, 95% CI 1.18 to 2.53, p=0.005) compared with first procedures. These increases were only found to be statistically significant when the procedure was performed by surgeons with <20 years' practice or surgeons with a preindex volume <700 cases.

CONCLUSIONS

For a technically challenging surgical procedure like off-pump CABG, prior workload adversely affected patient outcomes.

Time-of-Day and Clinical Outcomes After Surgical or Transcatheter Aortic Valve Replacement: Insights From the PARTNER Trials

BACKGROUND

Circadian rhythms may influence myocardial tolerance to ischemia-reperfusion phenomena occurring during cardiac procedures. While conflicting results exist on the effect of time-of-day on surgical aortic valve replacement (SAVR), afternoon procedures could be associated with a reduced risk of death, rehospitalization or periprocedural myocardial infarction, compared with morning procedures. We examined the impact of procedure time-of-day on outcomes after transcatheter aortic valve replacement (TAVR) or SAVR.

METHODS

We analyzed patients at intermediate- or high-surgical risk who underwent elective TAVR (n=4457) or SAVR (n=1129) in the PARTNER (Placement of Aortic Transcatheter Valve) 1 and 2 trials and registries according to time-of-day (morning versus afternoon) using the Kaplan-Meier event rates and multivariable Cox proportional hazards regression models. Sensitivity analysis was conducted using 1:1 propensity-score matching. The primary end point was all-cause death or rehospitalization at 2 years.

RESULTS

At 2 years, no difference was observed between patients operated in the morning versus the afternoon within the SAVR (32.3% versus 30.6%, adjusted hazard ratio, 1.08 [95% CI, 0.82-1.41], P=0.58) and TAVR cohorts (35.7% versus 35.4%, adjusted hazard ratio, 1.01 [95% CI, 0.89-1.14], P=0.86) with regards to the primary end point. Rates of periprocedural myocardial infarction were low and similar between morning and afternoon in SAVR (1.6% versus 1.0%, P=0.51) and TAVR (0.4% versus 0.4%, P=0.86), as were all other clinical end points. Similar results were observed in propensity-score matched analysis.

CONCLUSIONS

Procedure time-of-day was not associated with clinical outcomes after TAVR or SAVR. Registration: URL: https://www.clinicaltrials.gov; Unique identifiers: NCT00530894, NCT01314313, NCT03222141, and NCT03222128.

Practices and intravascular catheter infection during on- and off-hours in critically ill patients

Background

The potential relationship between intravascular catheter infections with their insertion during weekend or night-time (i.e., off-hours or not regular business hours) remains an open issue. Our primary aim was to describe differences between patients and catheters inserted during on- versus off-hours. Our secondary aim was to investigate whether insertions during off-hours influenced the intravascular catheter infectious risks.

Methods

We performed a post hoc analysis using the databases from four large randomized-controlled trials. Adult patients were recruited in French ICUs as soon as they required central venous catheters or peripheral arterial (AC) catheter insertion. Off-hours started at 6 P.M. until 8:30 A.M. during the week; at weekend, we defined off-hours from 1 P.M. on Saturday to 8.30 A.M. on Monday. We performed multivariable marginal Cox models to estimate the effect of off-hours (versus on-hours) on major catheter-related infections (MCRI) and catheter-related bloodstream infections (CRBSIs).

Results

We included 7241 patients in 25 different ICUs, and 15,208 catheters, including 7226 and 7982 catheters inserted during off- and on-hours, respectively. Catheters inserted during off-hours were removed after 4 days (IQR 2, 9) in median, whereas catheters inserted during on-hours remained in place for 6 days (IQR 3,10; p < 0.01) in median. Femoral insertion was more frequent during off-hours. Among central venous catheters and after adjusting for well-known risk factors for intravascular catheter infection, we found a similar risk between off- and on-hours for MCRI (HR 0.91, 95% CI 0.61–1.37, p = 0.65) and CRBSI (HR 1.05, 95% CI 0.65–1.68, p = 0.85). Among central venous catheters with a dwell-time > 4 or > 6 days, we found a similar risk for MCRI and CRBSI between off- and on-hours. Similar results were observed for ACs.

Conclusions

Off-hours did not increase the risk of intravascular catheter infections compared to on-hours. Off-hours insertion is not a sufficient reason for early catheter removal, even if femoral route has been selected.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00940-3.

Cardiac surgery in the afternoon is not associated with increased operative morbidity and mortality

BACKGROUND

Time of day for surgical procedures has been a topic of considerable controversy, with some suggesting that later operating times are associated with worse outcomes.

METHODS

All patients who underwent open cardiac surgery from 2011 to 2018 were included. Patients that had ventricular assist devices, heart transplant, transcatheter aortic valves, aortic dissections, and emergent operations were excluded. Primary outcomes included postoperative mortality and survival; secondary outcomes included postoperative complications and readmission.

RESULTS

The initial patient population consisted of 7883 patients who underwent index cardiac surgery. Following propensity matching (3:1), there were 2569 patients in the a.m. cohort (7-11 a.m.) and 860 patients in the p.m. cohort (3-11 p.m.). All baseline characteristics were matched to equivalent proportions. Total intensive care unit time following surgery was longer for the a.m. cohort (46.5 vs. 40.0 h; p<.001). Otherwise, there was no significant difference between cohorts including operative mortality (1.83% vs 2.21%; p= .48). On multivariable analysis, p.m. surgery was not significantly associated with 30 days mortality (hazard ratio [HR]: 0.96 [0.60, 1.53]; p= .86] or mortality over the study follow-up (HR: 0.87 [0.73, 1.03]; p= .10]. For propensity-matched cohorts, Kaplan-Meier survival at 30 days (97.9% vs. 97.4%; p= .44), 1 (93.4% vs  93.9%; p= .51), and 5 years (80.9% vs. 80.2%; p= .84) was not significantly different between cohorts.

CONCLUSION

Short- and long-term mortality, hospital readmission, and postoperative complications were not significantly different between patients that underwent cardiac surgery starting in the a.m. versus patients who had cases that started in the afternoon.

Daytime and outcomes after cardiac surgery: Systematic review and metaanalysis, insights from a large UK database review and post-hoc trial analysis

BACKGROUND

Several studies have suggested a variation of myocardial tolerance to ischaemia depending on the daytime of surgery. To test this hypothesis, we conducted a three-level analysis: metaanalysis, national patient-level dataset analysis and a post-hoc trial analysis.

METHODS

We first performed a systematic review and metaanalysis of available studies comparing clinical outcomes following cardiac surgery performed in the morning (am) versus afternoon (pm). Then, we interrogated the UK national adult cardiac surgery audit database (NACSA) and analysed the am or pm outcomes of patients undergoing non-emergency aortic valve replacement (AVR) or coronary artery bypass grafting (CABG). In a post-hoc analysis, we further investigated the effect of time of surgery on serum troponin release and ventricular myocardial biopsy adenine nucleotide metabolism.

RESULTS

A total of 18377 patients undergoing uncomplicated isolated CABG or isolated AVR on the same day am or pm were included in the metaanalysis. Meta-analytic estimates showed no difference in the risk of MI between patients operated in pm vs am (OR 1.02, 95% CI:0.79-1.32) and in the risk of mortality (OR 1.1, 95% CI:0.85-1.42). Outcomes of 91248 patients from the NACSA dataset were analysed according to the daytime of the procedure. Patient-level analysis showed no significant effect of daytime for both isolated AVR (p=0.094) and isolated CABG (p=0.425). Finally, we performed a post-hoc trial database analysis in 124 patients undergoing isolated AVR or CABG of serial cardiac troponin and nucleotides metabolism on ventricular myocardial biopsies. We found no significant diurnal changes in the perioperative cardiac troponin release or nucleotide metabolism in the AVR (p=0.30) or the CABG cohort (p=0.97).

CONCLUSION

The present three-level analysis found no evidence that daytime influences clinical outcomes and myocardial injury in patients undergoing cardiac surgery.

Daytime Variation of Clinical Outcome in Cardiac Surgery: A Propensity-Matched Cohort Study

OBJECTIVE

The purpose of the present study was to investigate the hypothesis of a nychthemeral variation in the tolerance to ischemia and reperfusion injury in adult cardiac surgeries.

DESIGN

Retrospective cohort study.

SETTING

A single academic center.

PARTICIPANTS

All patients undergoing nonemergent aortic valve replacement (AVR) ± coronary artery bypass graft between January 2012 and May 2018 were included. They were divided into two groups (morning and afternoon) according to the time of the day at the beginning of surgery. Propensity score matching estimated by multivariate logistic regression with a 1:1 matching ratio was performed to ensure that the two groups were comparable. This allowed obtaining 269 pairs, for a total of 538 patients.

INTERVENTION

The objective of the study was to assess whether there were differences in perioperative and postoperative outcomes between the morning and the afternoon groups.

RESULTS

There was no between-group difference in the primary composite endpoints, namely the occurrence of death, myocardial infarction, low cardiac output, and stroke during the 30 days following the surgery. Regarding cardiac biomarkers, there were no between-group differences for both postoperative evolution of troponin T plasma levels and the maximum postoperative troponin T plasma level.

CONCLUSION

These results did not support the hypothesis that the timing of the surgery could influence the tolerance to ischemia and reperfusion injury, at least in patients undergoing nonemergent AVR or a combined AVR with coronary artery bypass graft.