Association Between Preoperative Metformin Exposure and Postoperative Outcomes in Adults With Type 2 Diabetes

Safety of advanced laparoscopic hepatectomy for elderly patients: a Japanese nationwide analysis

BACKGROUND

Although basic laparoscopic hepatectomy (LH) has become the standard procedure for hepatectomy, the safety of advanced LH remains to be clarified, especially in elderly patients. We investigated the safety of advanced LH in elderly Japanese patients.

METHODS

Elderly patients (≥ 65 years) who underwent advanced LH between 2016 and 2021 were analyzed using a nationwide claims database in Japan. The perioperative outcomes of patients who underwent open hepatectomy (OH group) or LH (LH group) were compared using propensity score matching (PSM). The primary outcome was in-hospital mortality. The E-value method was performed to assess the strength of the outcome point estimates against possible unmeasured confounding factors.

RESULTS

Among 5,021 patients, eligible patients were classified into the OH (n = 4,152) and LH (n = 527) groups. The median patient age was 74 years in both groups. Hepatocellular carcinoma and metastatic liver tumors were the major indications for hepatectomy (OH: 52.5% versus 30.6%; LH: 60.7% versus 26.4%). After PSM, in-hospital mortality rates for OH and LH were 1.7 and 0.76%, respectively. The risk ratio was 0.45 (95% confidence interval, 0.16-1.25; E-value = 3.87). Compared with OH, LH was associated with a longer anesthesia time (411 versus 432 min), lower rate of blood product use (red blood concentrate: 33.5% versus 20.3%; fresh frozen plasma: 29.2% versus 17.1%), and shorter hospital stay (13 versus 12 days).

CONCLUSIONS

In elderly patients, the safety of advanced LH was similar to that of advanced OH, or might be better in Japan under the current policy of hospital accreditation.

Association between continued metformin use during hospital admission and hospital-acquired complications

AIMS

The safety of continuing metformin during a hospital admission has not been robustly demonstrated. We evaluated the association of continuing metformin in hospital with the risk for a hospital-acquired complication (HAC).

METHODS

This is a retrospective observational study of patients admitted to a medical or surgical ward. We considered those with diabetes who continued metformin (DM/MET group), those who discontinued metformin upon admission (DM/MET-STOP), and those with diabetes not on metformin just prior to and during admission (DM/NoMET). We prepared propensity score-matched (PSM) control groups from admitted patients without diabetes. The likelihood of a HAC was determined using a Kaplan-Meier survival analysis. A Cox proportional hazards model was employed to calculate the hazard ratio, adjusted for covariates.

RESULTS

Of the 4446 (14%) patients with diabetes, 3331 (10%) were prescribed metformin on admission, and it was continued in 2557 patients. HAC occurred in 5.5% of DM/MET group and 6.4% of the PSM control group. Continuation of metformin was associated with a lower likelihood of HAC, adjusted hazard ratio 0.85 (95% CI 0.69, 1.04), p = 0.117 compared to a PSM-matched control group without diabetes. The DM/NoMET and DM/MET-STOP groups had an increased risk for HAC, adjusted HR 1.77 (1.44, 2.18), p < 0.001 and 2.57 (2.10, 3.13), p < 0.001, as compared to their respective PSM control groups.

CONCLUSION

An individualized assessment to continue metformin during hospital admission was associated with a reduced likelihood of HAC, with the caveat that there was limited matching to non-diabetes controls. This finding warrants further exploration.

Adaptation of the Risk Analysis Index for Frailty Assessment Using Diagnostic Codes

Importance

Frailty is associated with adverse outcomes after even minor physiologic stressors. The validated Risk Analysis Index (RAI) quantifies frailty; however, existing methods limit application to in-person interview (clinical RAI) and quality improvement datasets (administrative RAI).

Objective

To expand the utility of the RAI utility to available International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) administrative data, using the National Inpatient Sample (NIS).

Design, Setting, and Participants

RAI parameters were systematically adapted to ICD-10-CM codes (RAI-ICD) and were derived (NIS 2019) and validated (NIS 2020). The primary analysis included survey-weighed discharge data among adults undergoing major surgical procedures. Additional external validation occurred by including all operative and nonoperative hospitalizations in the NIS (2020) and in a multihospital health care system (UPMC, 2021-2022). Data analysis was conducted from January to May 2023.

Exposures

RAI parameters and in-hospital mortality.

Main Outcomes and Measures

The association of RAI parameters with in-hospital mortality was calculated and weighted using logistic regression, generating an integerized RAI-ICD score. After initial validation, thresholds defining categories of frailty were selected by a full complement of test statistics. Rates of elective admission, length of stay, hospital charges, and in-hospital mortality were compared across frailty categories. C statistics estimated model discrimination.

Results

RAI-ICD parameters were weighted in the 9 548 206 patients who were hospitalized (mean [SE] age, 55.4 (0.1) years; 3 742 330 male [weighted percentage, 39.2%] and 5 804 431 female [weighted percentage, 60.8%]), modeling in-hospital mortality (2.1%; 95% CI, 2.1%-2.2%) with excellent derivation discrimination (C statistic, 0.810; 95% CI, 0.808-0.813). The 11 RAI-ICD parameters were adapted to 323 ICD-10-CM codes. The operative validation population of 8 113 950 patients (mean [SE] age, 54.4 (0.1) years; 3 148 273 male [weighted percentage, 38.8%] and 4 965 737 female [weighted percentage, 61.2%]; in-hospital mortality, 2.5% [95% CI, 2.4%-2.5%]) mirrored the derivation population. In validation, the weighted and integerized RAI-ICD yielded good to excellent discrimination in the NIS operative sample (C statistic, 0.784; 95% CI, 0.782-0.786), NIS operative and nonoperative sample (C statistic, 0.778; 95% CI, 0.777-0.779), and the UPMC operative and nonoperative sample (C statistic, 0.860; 95% CI, 0.857-0.862). Thresholds defining robust (RAI-ICD <27), normal (RAI-ICD, 27-35), frail (RAI-ICD, 36-45), and very frail (RAI-ICD >45) strata of frailty maximized precision (F1 = 0.33) and sensitivity and specificity (Matthews correlation coefficient = 0.26). Adverse outcomes increased with increasing frailty.

Conclusion and Relevance

In this cohort study of hospitalized adults, the RAI-ICD was rigorously adapted, derived, and validated. These findings suggest that the RAI-ICD can extend the quantification of frailty to inpatient adult ICD-10-CM-coded patient care datasets.

Preoperative beta blockers and other drugs in relation to anastomotic leakage after anterior resection for rectal cancer

AIM

Previous research has indicated that preoperative beta blocker therapy is associated with a decreased risk of complications after surgery for rectal cancer. This is thought to arise because of the anti-inflammatory activity of the drug. These results need to be reproduced and analyses extended to other drugs with such properties, as this information might be useful in clinical decision-making. The main aim of this work was to replicate previous findings of beta blocker use as a prognostic marker for postoperative leakage. We also investigated whether drug exposure might induce anastomotic leaks.

METHOD

This is a retrospective multicentre cohort study, comprising 1126 patients who underwent anterior resection for rectal cancer between 2014 and 2018. The use of any preoperative beta blocker was treated as the primary exposure, while anastomotic leakage within 12 months of surgery was the outcome. Secondary exposures comprised angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, statins and metformin. Using multivariable regression, we performed a replication analysis with a predictive aim for beta blockers only, while adjustment for confounding was done in more causally oriented analyses for all drugs. We estimated incidence rate ratio (IRR) and relative risk (RR) with 95% confidence intervals (CIs).

RESULTS

Anastomotic leakage occurred in 20.6% of patients. Preoperative beta blockers were used by 22.7% of the cohort, while the leak distribution was almost identical between exposure groups. In the main replication analysis, no association could be detected (IRR 0.95, 95% CI 0.68-1.33). In the causally oriented analyses, only metformin affected the risk of leakage (RR 1.59, 95% Cl 1.31-1.92).

CONCLUSION

While previous research has suggested that preoperative beta blocker use could be prognostic of anastomotic leakage, this study could not detect any such association. On the contrary, our results indicate that preoperative beta blocker use neither predicts nor causes anastomotic leakage after anterior resection for rectal cancer.

Favorable Antiviral Effect of Metformin on Severe Acute Respiratory Syndrome Coronavirus 2 Viral Load in a Randomized, Placebo-Controlled Clinical Trial of Coronavirus Disease 2019

BACKGROUND

Metformin has antiviral activity against RNA viruses including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The mechanism appears to be suppression of protein translation via targeting the host mechanistic target of rapamycin pathway. In the COVID-OUT randomized trial for outpatient coronavirus disease 2019 (COVID-19), metformin reduced the odds of hospitalizations/death through 28 days by 58%, of emergency department visits/hospitalizations/death through 14 days by 42%, and of long COVID through 10 months by 42%.

METHODS

COVID-OUT was a 2 × 3 randomized, placebo-controlled, double-blind trial that assessed metformin, fluvoxamine, and ivermectin; 999 participants self-collected anterior nasal swabs on day 1 (n = 945), day 5 (n = 871), and day 10 (n = 775). Viral load was quantified using reverse-transcription quantitative polymerase chain reaction.

RESULTS

The mean SARS-CoV-2 viral load was reduced 3.6-fold with metformin relative to placebo (-0.56 log10 copies/mL; 95% confidence interval [CI], -1.05 to -.06; P = .027). Those who received metformin were less likely to have a detectable viral load than placebo at day 5 or day 10 (odds ratio [OR], 0.72; 95% CI, .55 to .94). Viral rebound, defined as a higher viral load at day 10 than day 5, was less frequent with metformin (3.28%) than placebo (5.95%; OR, 0.68; 95% CI, .36 to 1.29). The metformin effect was consistent across subgroups and increased over time. Neither ivermectin nor fluvoxamine showed effect over placebo.

CONCLUSIONS

In this randomized, placebo-controlled trial of outpatient treatment of SARS-CoV-2, metformin significantly reduced SARS-CoV-2 viral load, which may explain the clinical benefits in this trial. Metformin is pleiotropic with other actions that are relevant to COVID-19 pathophysiology.

CLINICAL TRIALS REGISTRATION

NCT04510194.

Long-term outcome of adjuvant radiotherapy upon postoperative relapse of centrally located hepatocellular carcinoma: a real-world study

Despite that surgical resection is widely regarded as the most effective approach to the treatment of liver cancer, its safety and efficacy upon centrally located hepatocellular carcinoma (HCC) remain unsatisfactory. In consequence, seeking an integrated treatment, like combined with adjuvant radiotherapy, to enhance the prognosis of patients is of critical importance. By recruiting patients undergoing surgical resection for centrally located HCC ranging from June 2015 to 2020, they were divided into liver resection combined with adjuvant radiotherapy (LR + RT) and mere liver resection (LR) groups. The calculation of propensity score and model of Cox proportional hazards regression were utilized. 193 patients were recruited in aggregation, containing 88 ones undergoing LR + RT, while 105 handled with LR. RT was verified to be an independent factor of prognosis for relapse (HR 0.60). In propensity-score analyses, significant association existed between adjuvant radiotherapy and better disease-free survival (DFS) (Matched, HR 0.60; Adjustment of propensity score, HR 0.60; Inverse probability weighting, HR 0.63). The difference of DFS was apparent within two groups (p value = 0.022), and RT significantly down-regulated early relapse (p value < 0.05) in subgroup analysis. The calculation of E-value revealed robustness of unmeasured confounding. The combination of liver surgical resection with RT is safe and effective towards patients with centrally located HCC, which would notably enhance the prognosis and decrease the early relapse of HCC.

Long-term outcome of centrally located hepatocellular carcinoma treated by neoadjuvant radiotherapy and radical resection: a propensity score matched study

Objective

Centrally located hepatocellular carcinoma (HCC) typically presents challenges in surgical intervention and is associated with a bleak prognosis. In order to address this pressing issue, it is imperative to identify a comprehensive treatment approach, such as neoadjuvant radiotherapy (neoRT), that can enhance the prognosis of patients diagnosed with centrally located HCC.

Methods

Patients who had surgical resections for HCC between March 2015 and December 2020 were included in the study. Patients were assigned to either the neoRT combined with liver resection (neoRT+LR) group or the liver resection alone (LR) group. The study employed propensity-score analysis and Cox proportional-hazards regression models as research methodologies. Using the Kaplan-Meier method, overall survival (OS) and disease-free survival (DFS) were estimated in patients.

Results

During the study, 162 patients were enrolled, with 41 receiving neoRT+LR and 121 receiving LR. The duration of the median follow-up period was 45 months. The 1-year, 3-year, and 5-year OS rates were 95, 70, and 70% for patients in the neoRT+LR group, and 82, 64, and 54% for patients in the LR group, respectively. The 1-year, 3-year, 5-year DFS rates were 71, 53, and 37% for patients in the neoRT+LR group, and 52, 38, and 34% for patients in the LR group, respectively. A successful matching of 37 patients was achieved through propensity-score analysis. OS and DFS after matching analysis was statistically different between the two groups ( P=0.0099, P=0.034, respectively). neoRT was an independent prognostic factor for OS and DFS [hazard ratio (HR)=0.47, 95% CI: 0.24-0.93; HR=0.56, 95% CI: 0.34-0.92, respectively]. According to matching analysis, there were no statistically significant differences observed in terms of baseline characteristics, surgical safety, and complications between the groups.

Conclusion

Liver resection and neoRT can be advantageous for patients with centrally located HCC.

Metformin-associated lactic acidosis (MALA): Is it an underestimated entity? A retrospective, single-center case series

INTRODUCTION

Metformin is widely considered a first-line antiglycemic agent due to its cost-effectiveness and favorable adverse effect profile. However, its use is prohibited in patients with an estimated glomerular filtration rate <30 mL/min/1.73 m2 , due to the risk of potentially lethal metformin-associated lactic acidosis (MALA). We sought to evaluate MALA cases and outcomes at our institution.

METHODS

In this observational, retrospective case series, we reviewed our EMR for all patients who had a metformin level drawn between January 2013 and May 2022 to identify individuals who met the diagnostic criteria for MALA. We evaluated risk factors for MALA, the relationship between metformin level, blood pH, serum bicarbonate, and lactate level and clinical outcomes of ventilator dependency, renal replacement therapy requirement, renal recovery in acute kidney injury (AKI) patients, and survival.

FINDINGS

A total of 107 patients had metformin levels drawn, of which 19 patients met the diagnostic criteria for MALA. In our case series, MALA was primarily seen in AKI (15 patients) secondary to dehydration and sepsis, followed by end-stage renal disease (ESRD) (4 patients). Intubation was required in 17 patients, of whom 8 were successfully extubated after a mean duration of 14 days. Sixteen patients received renal replacement therapy (RRT). Intermittent hemodialysis (IHD) was performed in nine, continuous renal replacement therapy (CRRT) in four, and sequential therapy of IHD and CRRT in three patients. Seven patients, all in the AKI group (46.7%), died while all ESRD patients survived, accounting for an overall mortality rate of 36.8%. Among the eight surviving AKI patients, four had complete renal recovery with renal function returning to baseline, three had partial renal recovery, and one continued to require IHD at the time of discharge to a rehabilitation facility.

DISCUSSION

MALA may be an underrecognized entity. A high level of clinical suspicion leading to prompt and aggressive treatment with RRT may improve mortality rates. Provider and patient education is of paramount importance for safe use of metformin.

Clinical benefits of intraoperative radiotherapy for the recurrence of centrally located hepatocellular carcinoma with microvascular invasion

BACKGROUND

Although the efficacy and safety of intraoperative radiotherapy (IORT) in the treatment of malignant tumours, such as breast cancer, have been documented, it remains unclear whether this treatment is effective for centrally located hepatocellular carcinoma (HCC) with microvascular invasion (MVI).

AIMS

This study aimed to explore the efficacy and safety of IORT in the treatment of centrally located HCC with MVI.

METHODS AND RESULTS

Patients with centrally located HCC, who underwent surgery between January 2016 and January 2020, were enrolled. The patient cohort was then allocated to two groups: those who underwent IORT combined with liver resection (IORT+LR); or LR alone (LR). Propensity score matching and Cox proportional hazards regression analyses were performed. The Kaplan-Meier method was used to estimate recurrence-free survival (RFS), and the log-rank test was used to determine whether RFS differed between the groups. Subgroup analysis was performed to evaluate differences in RFS and early recurrence rates in patients with different MVI grades. E-values were generated to measure the sensitivity to unmeasured confounding factors. In total, 97 patients were enrolled, 27 of whom underwent IORT+LR and 70 underwent LR alone. The 1-, 3-, and 5-year RFS rates in the IORT+LR group were 66%, 50%, and 32%, respectively, whereas those in the LR group were 54%, 37%, and 26%, respectively. After matching analysis, 23 patients were successfully matched, and RFS was found to be significantly different between the two groups (p = .04). IORT was an independent prognostic factor for RFS (hazard ratio 0.46 [95% confidence interval 0.21-0.99]). In subgroup analysis, RFS between the IORT+LR and LR groups was significantly different in patients with MVI (M1 grade) (p = .0067). The postoperative early recurrence rate was significantly reduced with IORT (p < .05). No serious complications were reported in either group following surgery. Based on E-values, the results appeared to be robust against unmeasured confounding factors.

CONCLUSION

IORT+LR provided safe, feasible treatment for patients with centrally located HCC with MVI, along with an improvement in prognosis and lower early recurrence rates.

Prevalence and clinical relevance of liver dysfunction after thoracic surgery: a retrospective study

Postoperative elevation of serum aminotransferase or alkaline phosphatase levels after liver and heart surgeries has been widely reported. The prevalence and clinical significance of hypertransaminasemia/liver dysfunction after thoracic surgery remains largely unknown. Significant differences in surgical procedures between thoracic and extra-thoracic surgeries may suggest different risks of liver dysfunction. We retrospectively analyzed data from 224 consecutive patients who underwent thoracic surgery. Liver function tests were recorded the day before surgery, 12 h, 1 day, 5, and 10 days after the surgical procedure. Patients were studied to identify the frequency of hypertransaminasemia and/or hyperbilirubinemia and/or increase of INR levels. 37,5% of patients showed an increase in serum alanine aminotransferase (ALT) level after thoracic surgery, whereas an increase in gamma glutamyl transferase (GGT) serum levels of any grade was observed in 53,6% of patients. Approximately 83% of patients who experienced an increase in the serum GGT or ALT levels showed a grade 1 or 2 change. Operative time was associated with hypertransaminasemia in the univariate and multivariate analyses, whereas the use of metformin was associated with a lower risk of ALT increase.

Outpatient treatment of COVID-19 and incidence of post-COVID-19 condition over 10 months (COVID-OUT): a multicentre, randomised, quadruple-blind, parallel-group, phase 3 trial

BACKGROUND

Post-COVID-19 condition (also known as long COVID) is an emerging chronic illness potentially affecting millions of people. We aimed to evaluate whether outpatient COVID-19 treatment with metformin, ivermectin, or fluvoxamine soon after SARS-CoV-2 infection could reduce the risk of long COVID.

METHODS

We conducted a decentralised, randomised, quadruple-blind, parallel-group, phase 3 trial (COVID-OUT) at six sites in the USA. We included adults aged 30-85 years with overweight or obesity who had COVID-19 symptoms for fewer than 7 days and a documented SARS-CoV-2 positive PCR or antigen test within 3 days before enrolment. Participants were randomly assigned via 2 × 3 parallel factorial randomisation (1:1:1:1:1:1) to receive metformin plus ivermectin, metformin plus fluvoxamine, metformin plus placebo, ivermectin plus placebo, fluvoxamine plus placebo, or placebo plus placebo. Participants, investigators, care providers, and outcomes assessors were masked to study group assignment. The primary outcome was severe COVID-19 by day 14, and those data have been published previously. Because the trial was delivered remotely nationwide, the a priori primary sample was a modified intention-to-treat sample, meaning that participants who did not receive any dose of study treatment were excluded. Long COVID diagnosis by a medical provider was a prespecified, long-term secondary outcome. This trial is complete and is registered with ClinicalTrials.gov, NCT04510194.

FINDINGS

Between Dec 30, 2020, and Jan 28, 2022, 6602 people were assessed for eligibility and 1431 were enrolled and randomly assigned. Of 1323 participants who received a dose of study treatment and were included in the modified intention-to-treat population, 1126 consented for long-term follow-up and completed at least one survey after the assessment for long COVID at day 180 (564 received metformin and 562 received matched placebo; a subset of participants in the metformin vs placebo trial were also randomly assigned to receive ivermectin or fluvoxamine). 1074 (95%) of 1126 participants completed at least 9 months of follow-up. 632 (56·1%) of 1126 participants were female and 494 (43·9%) were male; 44 (7·0%) of 632 women were pregnant. The median age was 45 years (IQR 37-54) and median BMI was 29·8 kg/m2 (IQR 27·0-34·2). Overall, 93 (8·3%) of 1126 participants reported receipt of a long COVID diagnosis by day 300. The cumulative incidence of long COVID by day 300 was 6·3% (95% CI 4·2-8·2) in participants who received metformin and 10·4% (7·8-12·9) in those who received identical metformin placebo (hazard ratio [HR] 0·59, 95% CI 0·39-0·89; p=0·012). The metformin beneficial effect was consistent across prespecified subgroups. When metformin was started within 3 days of symptom onset, the HR was 0·37 (95% CI 0·15-0·95). There was no effect on cumulative incidence of long COVID with ivermectin (HR 0·99, 95% CI 0·59-1·64) or fluvoxamine (1·36, 0·78-2·34) compared with placebo.

INTERPRETATION

Outpatient treatment with metformin reduced long COVID incidence by about 41%, with an absolute reduction of 4·1%, compared with placebo. Metformin has clinical benefits when used as outpatient treatment for COVID-19 and is globally available, low-cost, and safe.

FUNDING

Parsemus Foundation; Rainwater Charitable Foundation; Fast Grants; UnitedHealth Group Foundation; National Institute of Diabetes, Digestive and Kidney Diseases; National Institutes of Health; and National Center for Advancing Translational Sciences.

Effects of metformin on acute respiratory distress syndrome in preclinical studies: a systematic review and meta-analysis

Introduction: In this study, we conducted a systematic review and meta-analysis to judge the effects of metformin on acute respiratory distress syndrome (ARDS) in a comprehensive and quantitative manner. Methods: We included studies that tested the effects of metformin on ALI or ARDS in in vivo studies. We excluded literature from which data could not be extracted or obtained. Electronic search was conducted to retrieve relevant literature from public databases, including PubMed, Web of Science, Embase, Scopus, and the Cochrane Central Register of Controlled Trials (inception to July 2023). Moreover, ProQuest Dissertations and Theses Global, Google Scholar, and Baidu scholar were inquired. Retrieved literature was screened and evaluated by pairs of reviewers independently according to pre-stated criteria. The Systematic Review Center for Laboratory Animal Experimentation risk of bias tool was used to evaluate the methodological quality of eligible literature. No restriction was exerted on publication status or language. Results: Fifteen preclinical studies were analyzed in this meta-analysis. Pooled results showed metformin effectively decreased pulmonary wet-to-dry weight ratios [SMD = -2.67 (-3.53 to -1.81), I2 = 56.6%], protein content [SMD = -3.74 (-6.76 to -0.72), I2 = 86.7%] and neutrophils [SMD = -3.47 (-4.69 to -2.26), I2 = 0%] in BALF, pulmonary malondialdehyde [SMD = -1.98 (-3.77 to -0.20), I2 = 74.2%] and myeloperoxidase activity [SMD = -3.15 (-4.79 to -1.52), I2 = 74.5%], lung injury scores [SMD = -4.19 (-5.65 to -2.74), I2 = 69.1%], and mortality at 24 h [RR = 0.43 (0.24-0.76), I2 = 0%] as well as 48 and 72 h. Conclusion: Metformin inhibited pulmonary inflammation and oxidative stress and improved experimental lung injury and survival rates in animal models of ARDS. Results from randomized controlled trials are needed.

Development and validation of the prediction model for mortality in patients with diabetic kidney disease in intensive care unit: a study based on medical information Mart for intensive care

We aimed to explore factors associated with mortality of diabetic kidney disease (DKD), and to establish a prediction model for predicting the mortality of DKD. This was a cohort study. In total, 1,357 DKD patients were identified from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database, with 505 DKD patients being identified from the MIMIC-III as the testing set. The outcome of the study was 1-year mortality. COX proportional hazard models were applied to screen the predictive factors. The prediction model was conducted based on the predictive factors. A receiver operating characteristic (ROC) curve with the area under the curve (AUC) was calculated to evaluate the performance of the prediction model. The median follow-up time was 365.00 (54.50,365.00) days, and 586 patients (43.18%) died within 1 year. The predictive factors for 1-year mortality in DKD included age, weight, sepsis, heart rate, temperature, Charlson Comorbidity Index (CCI), Simplified Acute Physiology Score (SAPS) II, and Sequential Organ Failure Assessment (SOFA), lymphocytes, red cell distribution width (RDW), serum albumin, and metformin. The AUC of the prediction model for predicting 1-year mortality in the training set was 0.771 [95% confidence interval (CI): 0.746-0.795] and the AUC of the prediction model in the testing set was 0.795 (95% CI: 0.756-0.834). This study establishes a prediction model for predicting mortality of DKD, providing a basis for clinical intervention and decision-making in time.

Metformin preconditioning protects against myocardial stunning and preserves protein translation in a mouse model of cardiac arrest

Cardiac arrest (CA) causes high mortality due to multi-system organ damage attributable to ischemia-reperfusion injury. Recent work in our group found that among diabetic patients who experienced cardiac arrest, those taking metformin had less evidence of cardiac and renal damage after cardiac arrest when compared to those not taking metformin. Based on these observations, we hypothesized that metformin's protective effects in the heart were mediated by AMPK signaling, and that AMPK signaling could be targeted as a therapeutic strategy following resuscitation from CA. The current study investigates metformin interventions on cardiac and renal outcomes in a non-diabetic CA mouse model. We found that two weeks of metformin pretreatment protects against reduced ejection fraction and reduces kidney ischemia-reperfusion injury at 24 h post-arrest. This cardiac and renal protection depends on AMPK signaling, as demonstrated by outcomes in mice pretreated with the AMPK activator AICAR or metformin plus the AMPK inhibitor compound C. At this 24-h time point, heart gene expression analysis showed that metformin pretreatment caused changes supporting autophagy, antioxidant response, and protein translation. Further investigation found associated improvements in mitochondrial structure and markers of autophagy. Notably, Western analysis indicated that protein synthesis was preserved in arrest hearts of animals pretreated with metformin. The AMPK activation-mediated preservation of protein synthesis was also observed in a hypoxia/reoxygenation cell culture model. Despite the positive impacts of pretreatment in vivo and in vitro, metformin did not preserve ejection fraction when deployed at resuscitation. Taken together, we propose that metformin's in vivo cardiac preservation occurs through AMPK activation, requires adaptation before arrest, and is associated with preserved protein translation.

Clinical Benefits of Neoadjuvant Radiotherapy on the Postoperative Recurrence of Centrally Located Hepatocellular Carcinoma: A Real-World Evidence Based on Phase II Clinical Trial

Objective

Although surgical resection is one of the most effective way to treat liver cancer, its efficacy and safety in treatment of centrally located hepatocellular carcinoma (HCC) remains elusive. Therefore, it is very important to find a comprehensive treatment mode, such as radical resection combined with neoadjuvant radiotherapy (neoRT).

Methods

The centrally located HCC patients who underwent radical resection from July 2015 to April 2021 were enrolled. According to whether the neoRT was implemented or not, these patients were allocated into neoadjuvant radiotherapy combined with liver resection (neoRT+LR) and liver resection alone (LR) group. The research method used propensity-score analysis and Cox proportional-hazards regression models. We generated an E-value to assess the sensitivity to unmeasured confounding. This study is a real-world, retrospective study based on phase II clinical trial.

Results

A total of 168 patients were enrolled, including 38 patients treating with neoRT+LR and 130 patients with LR. The 1-, 3-, 5-year disease free survival (DFS) rates were 74%, 55% and 39% in the neoRT+LR group, and 44%, 28%, and 24% in the LR group, respectively. Neoadjuvant radiotherapy was an independent prognostic factor for postoperative recurrence ([HR]0.42, 95% CI [0.25, 0.69]). There was significant association between neoRT+LR and longer disease-free survival (Match, [HR] 0.43, 95% CI [0.24, 0.76]; GenMatch, [HR] 0.32, 95% CI [0.23, 0.43]; Adjusted for propensity score, [HR] 0.41, 95% CI [0.23, 0.73]; Inverse probability weighting, [HR] 0.38, 95% CI [0.22, 0.65], respectively). DFS before and after matching analysis was statistically different in two groups (p-value=0.005, p-value=0.0024, respectively). Neoadjuvant radiotherapy can significantly reduce the postoperative early recurrence (p-value <0.05). E-value analysis suggested robustness to unmeasured confounding.

Conclusion

Liver resection combined with neoadjuvant radiotherapy was effective and safe for treatment of centrally located HCC patients, which improved the prognosis of patients and reduced the incidence of early recurrence.

Metformin plays an antitumor role by downregulating inhibitory cells and immune checkpoint molecules while activating protective immune responses in breast cancer

This study seeks to test the effect of metformin treatment on the outcomes of breast cancer in BALB/c mice bearing 4 T1 breast cancer cells. The survival rate and tumor size of mice were compared, as well as evaluation of the changes of immune cells in spleens and the microenvironment of tumors using flow cytometry and ELISA. Our results demonstrate that metformin prolongs mouse survival. A significant decrease in M2-like macrophages (F4/80⁺CD206⁺) was found in mice spleen treated with metformin. The treatment also inhibited monocytic myeloid-derived suppressor cells (M-MDSCs, CD11b⁺Gr-1⁺) and regulatory T cells (Tregs, CD4⁺CD25⁺Foxp3⁺). Metformin treatment resulted in an increase in the level of IFN-γ and a decrease in IL-10. Expression of the immune checkpoint molecule PD-1 on T cells was inhibited following treatment. Metformin enhances local antitumor activity in the tumor microenvironment, and our data supports the drug as a candidate for evaluation in the treatment of breast cancer.

The function, mechanisms, and clinical applications of metformin: potential drug, unlimited potentials

Metformin has been used clinically for more than 60 years. As time goes by, more and more miraculous effects of metformin beyond the clinic have been discovered and discussed. In addition to the clinically approved hypoglycemic effect, it also has a positive metabolic regulation effect on the human body that cannot be ignored. Such as anti-cancer, anti-aging, brain repair, cardiovascular protection, gastrointestinal regulation, hair growth and inhibition of thyroid nodules, and other nonclinical effects. Metformin affects almost the entire body in the situation taking it over a long period, and the preventive effects of metformin in addition to treating diabetes are also beginning to be recommended in some guidelines. This review is mainly composed of four parts: the development history of metformin, the progress of clinical efficacy, the nonclinical efficacy of metformin, and the consideration and prospect of its application.

Drainage of anorectal abscesses in the operating room is associated with a decreased risk of abscess recurrence and fistula formation

BACKGROUND

Timely incision and drainage (I&D) is first line management for anorectal abscesses. We aimed to define current practices in anorectal abscess management and identify factors associated with abscess recurrence and fistula formation.

METHODS

Index episodes of anorectal abscesses treated with I&D in 2014-2018 at a multi-hospital healthcare system were included. Association with one-year abscess recurrence or fistula formation was evaluated using Cox proportional hazard regression. Fistulae were captured only among patients without fistulae at the index operation.

RESULTS

A total of 458 patients met study criteria. One-year rate of abscess recurrence or fistula formation was 20.3%. When compared to bedside procedures, drainage in the operating room was associated with a reduced risk of either recurrence or fistula formation (aHR 0.20 [95%CI 0.114-0.367]).

CONCLUSIONS

Improved exposure and patient comfort in the operating room may allow more complete drainage contributing to decreased rates of abscess recurrence or fistula formation.

Improved long-term outcomes with catheter-directed therapies over medical management in patients with submassive pulmonary embolism-a retrospective matched cohort study

BACKGROUND

The benefit of catheter-directed therapy (CDT) for submassive pulmonary embolism (sPE) has been the subject of debate. We sought to determine the short- and long-term mortality and outcomes of CDT compared with anticoagulation for patients with sPE.

METHODS

We performed a single healthcare network, multihospital, retrospective cohort study of hospitalizations for sPE from 2012 to 2019. sPE was defined as the presence of right heart strain or elevated biomarkers (troponin I or B-type natriuretic peptide). Patients with massive PE and those who had undergone systemic thrombolysis were excluded. The sPE groups included therapeutic anticoagulation alone or anticoagulation plus CDT (ie, thrombolysis or suction thrombectomy). The primary outcome was mortality at 1, 3, and 5 years. The other measured outcomes included PE-related death, short term mortality (30 days and 3 and 6 months), 30-day treatment-related complications (eg, bleeding, transfusion, stroke), chronic thromboembolic pulmonary hypertension, and 6-minute walk test at 1 year. After 1:1 nearest-neighbor propensity score matching, Kaplan-Meier survival plots were generated, and the treatment groups were compared using log-rank testing. We used Cox multivariate analysis to evaluate the outcomes after clustering at the hospital level, generating matched hazard ratios (mHRs) with associated 95% confidence intervals (CIs).

RESULTS

Of 6746 sPE hospitalizations, the patients who had received CDT were younger (age, 58.9 ± 15.5 years vs 61.5 ± 17.4 years; P = .004), were more frequently White (92.5% vs 85.7%; P < .001), and had presented with a higher mean heart rate (104.6 bpm vs 94.9 bpm; P < .001), lower median systolic blood pressure (129 mm Hg vs 135 mm Hg; P < .001), and a greater incidence of right heart strain (79.2% vs 20.3%; P < .001). A total of 470 patients were matched, with 235 in the CDT group and 235 in the anticoagulation-only group. CDT was associated with a lower risk of mortality compared with anticoagulation at 1 year (7.6% vs 9.8%; mHR, 0.77; 95% CI, 0.65-0.92; P = .004), 3 years (11.1% vs 16.6%; mHR, 0.64; 95% CI, 0.55-0.73; P < .001), and 5 years (14.5% vs 19.1%; mHR, 0.71; 95% CI, 0.66-0.77; P < .001). Anticoagulation alone resulted in a greater incidence of PE-related deaths at 1, 3, and 5 years. The mortality at 30 days and 3 months was similar; however, CDT had resulted in better survival at 6 months (mHR, 0.81; 95% CI, 0.68-0.97; P = .02). No differences were found between the two groups in the incidence of bleeding complications at 30 days, development of chronic thromboembolic pulmonary hypertension, or the mean walking distance at 1 year.

CONCLUSIONS

CDT plus anticoagulation for sPE was associated with improved long-term survival compared with anticoagulation alone, with a lower incidence of PE-related death and a low complication rate. CDT should be considered for select patients with sPE given its survival benefit.

Outpatient treatment of Covid-19 with metformin, ivermectin, and fluvoxamine and the development of Long Covid over 10-month follow-up

Background

Long Covid is an emerging chronic illness potentially affecting millions, sometimes preventing the ability to work or participate in normal daily activities. COVID-OUT was an investigator-initiated, multi-site, phase 3, randomized, quadruple-blinded placebo-controlled clinical trial (NCT04510194). The design simultaneously assessed three oral medications (metformin, ivermectin, fluvoxamine) using two by three parallel treatment factorial assignment to efficiently share placebo controls and assessed Long Covid outcomes for 10 months to understand whether early outpatient treatment of SARS-CoV-2 with metformin, ivermectin, or fluvoxamine prevents Long Covid.

Methods

This was a decentralized, remotely delivered trial in the US of 1,125 adults age 30 to 85 with overweight or obesity, fewer than 7 days of symptoms, and enrolled within three days of a documented SARS-CoV-2 infection. Immediate release metformin titrated over 6 days to 1,500mg per day 14 days total; ivermectin 430mcg/kg/day for 3 days; fluvoxamine, 50mg on day one then 50mg twice daily through 14 days. Medical-provider diagnosis of Long Covid, reported by participant by day 300 after randomization was a pre-specified secondary outcome; the primary outcome of the trial was severe Covid by day 14.

Result

The median age was 45 years (IQR 37 to 54), 56% female of whom 7% were pregnant. Two percent identified as Native American; 3.7% as Asian; 7.4% as Black/African American; 82.8% as white; and 12.7% as Hispanic/Latino. The median BMI was 29.8 kg/m2 (IQR 27 to 34); 51% had a BMI >30kg/m2. Overall, 8.4% reported having received a diagnosis of Long Covid from a medical provider: 6.3% in the metformin group and 10.6% in the metformin control; 8.0% in the ivermectin group and 8.1% in the ivermectin control; and 10.1% in the fluvoxamine group and 7.5% in the fluvoxamine control. The Hazard Ratio (HR) for Long Covid in the metformin group versus control was 0.58 (95% CI 0.38 to 0.88); 0.99 (95% CI 0.592 to 1.643) in the ivermectin group; and 1.36 in the fluvoxamine group (95% CI 0.785 to 2.385).

Conclusions

There was a 42% relative decrease in the incidence of Long Covid in the metformin group compared to its blinded control in a secondary outcome of this randomized phase 3 trial.

Exploration of Residual Confounding in Analyses of Associations of Metformin Use and Outcomes in Adults With Type 2 Diabetes

IMPORTANCE

Metformin is often used as a first-line therapy for type 2 diabetes; however, frequent discontinuation with reduced kidney function and increased disease severity indicates that a comparison with any other group (eg, nonusers or insulin users) must address significant residual confounding concerns.

OBJECTIVES

To examine the potential for residual confounding in a commonly used observational study design applied to metformin and to propose a more robust study design for future observational studies of metformin.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study with a prevalent user design was conducted using an administrative claims database for Medicare Advantage beneficiaries in the US. Participants were categorized into 2 distinct cohorts: 404 458 individuals with type 2 diabetes and 81 791 individuals with prediabetes. Clinical history was observed in 2018, and end points were observed in 2019. Statistical analyses were conducted between May and December 2021.

EXPOSURES

Prevalent use (recent prescription and history of use on at least 90 of the preceding 365 days) of metformin or insulin but not both at the start of the observation period.

MAIN OUTCOMES AND MEASURES

Total inpatient admission days in 2019 and total medical spending (excluding prescription drugs) in 2019. Each of these measures was treated as a binary outcome (0 vs >0 inpatient days and top 10% vs bottom 90% of medical spending).

RESULTS

The study included 404 458 adults with type 2 diabetes (mean [SD] age, 74.5 [7.5] years; 52.7% female). A strong metformin effect estimate was associated with reduced inpatient admissions (odds ratio, 0.60; 95% CI, 0.58-0.62) and reduced medical expenditures (odds ratio, 0.57; 95% CI, 0.55-0.60). However, implementation of additional robust design features (negative control outcomes and a complementary cohort) revealed that the estimated beneficial effect was attributable to residual confounding associated with individuals' overall health, not metformin itself.

CONCLUSIONS AND RELEVANCE

These findings suggest that common observational study designs for studies of metformin in a type 2 diabetes population are at risk for consequential residual confounding. By performing 2 additional validation checks, the study design proposed here exposes residual confounding that nullifies the initially favorable claim derived from a common study design.

Association Between Time to Source Control in Sepsis and 90-Day Mortality

Importance

Rapid source control is recommended to improve patient outcomes in sepsis. Yet there are few data to guide how rapidly source control is required.

Objective

To determine the association between time to source control and patient outcomes in community-acquired sepsis.

Design, Setting, and Particpants

Multihospital integrated health care system cohort study of hospitalized adults (January 1, 2013, to December 31, 2017) with community-acquired sepsis as defined by Sepsis-3 who underwent source control procedures. Follow-up continued through January 1, 2019, and data analyses were completed March 17, 2022.

Exposures

Early (<6 hours) compared with late (6-36 hours) source control as well as each hour of source control delay (1-36 hours) from sepsis onset.

Main Outcomes and Measures

Multivariable models were clustered at the level of hospital with adjustment for patient factors, sepsis severity, resource availability, and the physiologic stress of procedures generating adjusted odds ratios (aOR) and 95% CI.

Results

Of 4962 patients with sepsis (mean [SD] age, 62 [16] years; 52% male; 85% White; mean [SD] Sequential Organ Failure Assessment score, 3.8 [2.5]), source control occurred at a median (IQR) of 15.4 hours (5.5-21.7) after sepsis onset, with 1315 patients (27%) undergoing source control within 6 hours. The crude 90-day mortality was similar for early and late source control (n = 177 [14%] vs n = 529 [15%]; P = .35). In multivariable models, early source control was associated with decreased risk-adjusted odds of 90-day mortality (aOR, 0.71; 95% CI, 0.63-0.80). This association was greater among gastrointestinal and abdominal (aOR, 0.56; 95% CI, 0.43-0.80) and soft tissue interventions (aOR, 0.72; 95% CI, 0.55-0.95) compared with orthopedic and cranial interventions (aOR, 1.33; 95% CI, 0.96-1.83; P < .001 for interaction).

Conclusions and Relevance

Source control within 6 hours of community-acquired sepsis onset was associated with a reduced risk-adjusted odds of 90-day mortality. Prioritizing the rapid identification of septic foci and initiation of source control interventions can reduce the number of avoidable deaths among patients with sepsis.

Preoperative Treatment of Severe Diabetes Mellitus and Hypertension Mitigates Healthcare Disparities and Prevents Adverse Postoperative Discharge to a Nursing Home

OBJECTIVE

To evaluate whether patients of Black race are at higher risk of losing the ability to live independently after surgery, and if a higher prevalence of severe diabetes mellitus and hypertension are contributing.

SUMMARY BACKGROUND DATA

It is unclear whether a patient's race predicts adverse discharge to a nursing home after surgery, and if preexisting diseases are contributing.

METHODS

368,360 adults undergoing surgery between 2007 and 2020 across two academic healthcare networks in New England were included. Patients of self-identified Black or White race were compared. The primary outcome was postoperative discharge to a nursing facility. Mediation analysis was used to examine the impact of preexisting severe diabetes mellitus and hypertension on the primary association.

RESULTS

10.3% (38,010/368,360) of patients were Black and 26,434 (7.2%) patients lost the ability to live independently after surgery. Black patients were at increased risk of postoperative discharge to a nursing facility (adjusted absolute risk difference [ARDadj] 1.9%;95%CI 1.6-2.2%;P<0.001). A higher prevalence of preexisting severe diabetes mellitus and hypertension in Black patients mediated 30.2% and 15.6% of this association. Preoperative medication-based treatment adherent to guidelines in patients with severe diabetes mellitus or hypertension mitigated the primary association (p-for-interaction<0.001). The same pattern of effect mitigation by pharmacotherapy was observed for the endpoint 30-day readmission.

CONCLUSIONS

Black race was associated with postoperative discharge to a nursing facility compared to White race. Optimized preoperative assessment and treatment of diabetes and hypertension improves surgical outcomes and provides an opportunity to the surgeon to help eliminate healthcare disparities.

Association of Metformin Use During Hospitalization and Mortality in Critically Ill Adults With Type 2 Diabetes Mellitus and Sepsis

OBJECTIVES

Whether metformin exposure is associated with improved outcomes in patients with type 2 diabetes mellitus and sepsis.

DESIGN

Retrospective cohort study.

SETTING

Patients admitted to ICUs in 16 hospitals in Pennsylvania from October 2008 to December 2014.

PATIENTS

Adult critical ill patients with type 2 diabetes mellitus and sepsis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We conducted a retrospective cohort study to compare 90-day mortality in diabetic patients with sepsis with and without exposure to metformin during hospitalization. Data were obtained from the electronic health record of a large healthcare system in Pennsylvania from October 2008 to December 2014, on patients admitted to the ICU at any of the 16 hospitals within the system. The primary outcome was mortality at 90 days. The absolute and adjusted odds ratio (OR) with 95% CI were calculated in a propensity score-matched cohort. Among 14,847 patients with type 2 diabetes mellitus and sepsis, 682 patients (4.6%) were exposed to metformin during hospitalization and 14,165 (95.4%) were not. Within a total of 2,691 patients subjected to propensity score-matching at a 1:4 ratio, exposure to metformin (n = 599) was associated with decreased 90-day mortality (71/599, 11.9% vs 475/2,092, 22.7%; OR, 0.46; 95% CI, 0.35-0.60), reduced severe acute kidney injury (50% vs 57%; OR, 0.75; 95% CI, 0.62-0.90), less Major Adverse Kidney Events at 1 year (OR, 0.27; 95% CI, 0.22-0.68), and increased renal recovery (95% vs 86%; OR, 6.43; 95% CI, 3.42-12.1).

CONCLUSIONS

Metformin exposure during hospitalization is associated with a decrease in 90-day mortality in patients with type 2 diabetes mellitus and sepsis.

Protection by metformin against severe Covid-19: an in-depth mechanistic analysis

Since the outbreak of Covid-19, several observational studies on diabetes and Covid-19 have reported a favourable association between metformin and Covid-19-related outcomes in patients with type 2 diabetes mellitus (T2DM). This is not surprising since metformin affects many of the pathophysiological mechanisms implicated in SARS-CoV-2 immune response, systemic spread and sequelae. A comparison of the multifactorial pathophysiological mechanisms of Covid-19 progression with metformin's well-known pleiotropic properties suggests that the treatment of patients with this drug might be particularly beneficial. Indeed, metformin could alleviate the cytokine storm, diminish virus entry into cells, protect against microvascular damage as well as prevent secondary fibrosis. Although our in-depth analysis covers many potential metformin mechanisms of action, we want to highlight more particularly its unique microcirculatory protective effects since worsening of Covid-19 disease clearly appears as largely due to severe defects in the structure and functioning of microvessels. Overall, these observations confirm that metformin is a unique, pleiotropic drug that targets many of Covid-19′s pathophysiology processes in a diabetes-independent manner.

Complications of degenerative lumbar spondylolisthesis and stenosis surgery in patients over 80 s: comparative study with over 60 s and 70 s. Experience with 678 cases

Purpose

Degenerative spondylolisthesis (DS) is a debilitating condition that carries a high economic burden. As the global population ages, the number of patients over 80 years old demanding spinal fusion is constantly rising. Therefore, neurosurgeons often face the important decision as to whether to perform surgery or not in this age group, commonly perceived at high risk for complications.

Methods

Six hundred seventy-eight elder patients, who underwent posterolateral lumbar fusion for DS (performed in three different centers) from 2012 to 2020, were screened for medical, early and late surgical complications and for the presence of potential preoperative risk factors. Patients were divided in three categories based on their age: (1) 60–69 years, (2) 70–79 years, (3) 80 and over. Multiple logistic regression was used to determine the predictive power of age and of other risk factors (i.e., ASA score; BMI; sex; presence or absence of insulin-dependent and -independent diabetes, use of anticoagulants, use of antiaggregants and osteoporosis) for the development of postoperative complications.

Results

In univariate analysis, age was significantly and positively correlated with medical complications. However, when controls for other risk factors were added in the regressions, age never reached significance, with the only noticeable exception of cerebrovascular accidents. ASA score and BMI were the two risk factors that significantly correlated with the higher numbers of complication rates (especially medical).

Conclusion

Patients of different age but with comparable preoperative risk factors share similar postoperative morbidity rates. When considering octogenarians for lumbar arthrodesis, the importance of biological age overrides that of chronological.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00701-022-05118-9.

Any Postoperative Surveillance Improves Survival after Endovascular Repair of Ruptured Abdominal Aortic Aneurysms

BACKGROUND

Endovascular aortic repair (EVAR) has advanced the care of patients with ruptured abdominal aortic aneurysms (rAAA) with improved early postoperative morbidity and mortality. However, this comes at the cost of a rigorous postoperative surveillance schedule to monitor for further aneurysmal degeneration. Adherence to surveillance recommendations is known to be poor in the elective setting, but has yet to be studied in the ruptured population. The aim of this study is to investigate predictors of incomplete surveillance after EVAR for rAAA (rEVAR) and examine how adherence impacts outcomes.

METHODS

This was a retrospective case control study of patients undergoing rEVAR at a multiple hospital single healthcare center (2003-2020). Patients were excluded if they underwent open conversion during their index hospitalization or died within 60 days of surgery. Follow-up was broadly categorized as complete surveillance (60-day postoperative visit and annually thereafter) or incomplete surveillance, comprising both patients with less than recommended surveillance (minimal surveillance) and completely lost to follow-up (LTF). Any follow-up was defined as patients with complete or minimal surveillance. We investigated predictors of complete versus incomplete surveillance by multivariate logistic regression. Secondary outcomes included overall survival and cumulative incidence of reintervention controlling for the competing risk of mortality, generating hazard ratios (HR) and subdistribution hazard ratios (SHR).

RESULTS

One-hundred and sixty patients (mean age 74 ± 10.1 years, 81.2% male) out of 673 total rAAA met study inclusion criteria. Complete surveillance was seen in 41.3% of our cohort, with the remainder with minimal surveillance (29.4%) or LTF (29.4%). Incomplete surveillance was associated with male sex (odds ratio [OR] 2.56; 95% CI 1.02-6.43), lack of a primary care provider (PCP; OR 0.20; 95% CI 0.04-0.99), and longer driving distance from home to treating hospital (OR 2.37; 95% CI 1.08-5.20). Survival was not different between complete and incomplete surveillance groups, however any follow-up conferred improved survival over LTF (HR 0.57; 95% CI 0.331-0.997; P = 0.049). Reintervention was associated with incomplete surveillance (SHR 0.29; 95% CI 0.11-0.75), and discharge to a facility (SHR 0.25; 95% CI 0.067-0.94).

CONCLUSIONS

Incomplete surveillance was observed in over 50% of patients who underwent rEVAR and was associated with male sex, lack of PCP, and longer driving distance. Any follow-up conferred a survival benefit, yet incomplete surveillance was associated with a lower risk of reintervention. Targeted strategies to prevent LTF, and less stringent, personalized follow-up plans that may confer similar survival benefit with better patient adherence should be investigated.

Metformin Protects Against Cardiac and Renal Damage in Diabetic Cardiac Arrest Patients

INTRODUCTION

Metformin is a first-line diabetic therapy that improves survival in a wide number of ischemic pathologies. We tested the association of metformin with markers of cardiac and renal injury in diabetic post-arrest patients.

METHODS

We performed a retrospective analysis of clinical outcomes in diabetic cardiac arrest patients with and without metformin therapy at a single academic medical center. We used generalized linear models to test the independent association of metformin, insulin, and other hypoglycemic agents with peak 24-hour serum creatinine and peak 24-hour serum troponin.

RESULTS

Metformin prescription at the time of SCA was independently associated with lower 24-hour peak serum troponin and lower 24-hour peak serum creatinine when compared to non-metformin patients.

CONCLUSION

Metformin pretreatment may offer cardiac and renal protection for diabetic patients during sudden cardiac arrest.

Serum Galectin-3 levels and all-cause and cardiovascular mortality in maintenance hemodialysis patients: a prospective cohort study

Background

Higher serum galectin-3 levels are related to adverse outcomes in different disease states. However, the association of galectin-3 with mortality in the maintenance hemodialysis (HD) population has not been fully described. Thus, we aimed to assess the predictive significance of galectin-3 for all-cause and cardiovascular (CV) mortality through a Chinese maintenance HD population.

Methods

A prospective cohort study was conducted in five hundred and six patients with end-stage renal disease who underwent hemodialysis at Dalian Central Hospital before December 31, 2014. Serum galectin-3 levels were measured at baseline and classified as high (> 8.65 ng/ml) or low (≤ 8.65 ng/ml) according to the “X-tile” program. Primary and secondary outcomes were all-cause and CV mortality, respectively. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated by the Cox proportional hazards regression models.

Results

During the median follow-up of 60 months, there were 188 all-cause deaths and 125 CV deaths. Compared with maintenance HD population with galectin-3 ≤ 8.65 ng/ml, the adjusted HR for all-cause mortality among those with galectin-3 >  8.65 ng/ml was 1.59 (CI: 0.96–2.65, p = 0.07). Furthermore, multivariable analysis showed that maintenance HD patients with galectin-3 >  8.65 ng/ml had a 2.13-fold higher risk of CV death than those with galectin-3 ≤ 8.65 ng/ml (HR = 2.13, 95% CI 1.07–4.26).

Conclusion

Galectin-3 is an independent predictor of CV mortality in maintenance HD patients.

Perspectives of metformin use in endometrial cancer and other gynaecological malignancies

Insulin resistance and hyperinsulinemia play a key role in type 1 endometrial cancer pathogenesis. Most of these cancers develop on a background of overweight or type 2 diabetes mellitus (T2DM). One of the medications widely used in the treatment of T2DM is biguanide derivative, metformin, which exerts promising anticancer properties principally through activation of adenosine monophosphate kinase (AMPK) and inhibition of mammalian target of rapamycin (mTOR) pathways. Many epidemiological studies on diabetic patients show potential preventative role of metformin in endometrial cancer patients, but data regarding its therapeutic role is still limited. So far, most of attention has been paid to the concept of metformin use in fertility sparing treatment of early-stage cancer. Another investigated alternative is its application in patients with primary advanced or recurrent disease. In this review we present the latest data on clinical use of metformin in endometrial cancer patients and potential underlying mechanisms of its activity. Finally, we present some most important clinical information regarding metformin efficacy in other gynaecological malignancies, mainly breast and ovarian cancer.

Impact of Metformin Use on Survival in Patients Undergoing Liver Resection for Colorectal Cancer Metastases

INTRODUCTION

Resection of colorectal liver metastases provides the best chance for survival in patients with Stage IV colorectal cancer; however, hepatic recurrence is frequent and the main cause of death. Multiple epidemiological studies have documented an association between metformin and anti-neoplastic effects in a variety of cancers. Given the vast literature, we evaluated the incidence on recurrence and survival of patients on metformin who undergo surgery for colorectal liver metastasis (CRLM).

METHODS

We selected 270 consecutive patients with known CRLM who underwent hepatic metastases resection at our institution between January 1st 2012 and December 31st 2019. Patients were divided based on their use of metformin (n = 62) or no metformin (n = 208). Adjusted analysis of recurrence-free (RFS) and overall survival (OS) was performed.

RESULTS

Patients on metformin had significantly longer RFS (HR: .44, 95% CI: .26-.75, P < .002; Median RFS: 49 months vs 33 months) and OS (HR .60, 95% CI .31-.97, P < .048, Median OS: 72 months vs 60 months). Additional factors associated with shorter RFS on univariate analysis included the following: CEA > 200 ng/ml (HR: 2.23, 95% CI 1.21-4.03, P < .010), positive liver margin (HR: 3.70, 95% CI 2.27-6.03, P < .001), and >1 tumor (HR: 1.98, 95% CI 1.26-3.09, P < .003). Liver margin remained a significant factor for predicting shorter OS (HR: 4.99, 95% CI 2.49-10.0, P < .001).

CONCLUSION

In this study, we found that patients with CRLM on metformin have prolonged RFS and OS postliver resection. Further prospective randomized trials need to be carried out to evaluate the anti-neoplastic effect of metformin in diabetic and non-diabetic cancer patients.

[Perioperative Management of Long-term Antidiabetic Therapy in Patients with Diabetes Mellitus]

Drug therapy, as well as diabetes technology, e.g. insulin pumps or sensor glucose measurement, have developed enormously in recent years. Their use differs according to the type of diabetes, secondary or concomitant diseases, and individual factors and target values. In the perioperative phase, diabetic patients are generally at increased risk of complications, including a derailment of glucose metabolism, an increased rate of cardiovascular events, worsening of preexisting renal insufficiency, and increased incidence of wound infections. In addition, drug class-specific side effects of antidiabetic therapy may occur. The prevalence of diabetes patients in anesthesiology is high and will continue to increase. In Germany, more than 8 million people are estimated to live with diabetes mellitus. The rate of new cases is about 600 000 per year. The distinction between type 1 and type 2 diabetes mellitus is essential. Diabetes therapy is becoming increasingly individualized; combination therapies are becoming more common. Therefore, the management of long-term medication should also be individualized. Substance-specific side effects or adverse effects, especially of oral antidiabetic agents, must be considered in the care of patients, e.g. euglycemic diabetic ketoacidosis under SGLT-2 inhibitors is a relevant problem. Insulin therapy is also evolving; knowledge of new preparations and of insulin pump therapy facilitates perioperative management. Both hypoglycemia and hyperglycemia, possibly with ketoacidosis, must be avoided. The purpose of this article is to provide an overview of the management of long-term medication in patients with diabetes mellitus.

The Epidemiology of Extremity Threat and Amputation Following Vasopressor-dependent Sepsis

RATIONALE

Extremity threat and amputation following sepsis is a well-publicized and devastating event. However, there is a paucity of data exists surrounding theabout the epidemiology of extmreityextremity threat following sepsis onset.

OBJECTIVES

We aim toTo estimate the incidence of extremity threat with or without surgical amputation in community sepsis.

METHODS

Multihospital Rretrospective cohort study of adults with Sepsis-3 hospitalized at XX14 academic and community sites from 2013 to 2017. Vasopressor-dependent sepsis was identified by administration epinephrine, norepinephrine, phenylephrine, vasopressin, or dopamine for >1 hour during the 48 hours before to 24 hours following sepsis onset. Outcomes included the incidence of extremity threat, defined as acute onset ischemia, with or without amputation in the 90 days following sepsis onset. The association between extremity threat, and demographics, comorbid conditions, and, and time-varying sepsis treatment factorss were evaluated using a Cox-proportional hazards model.

RESULTS

Among 24,365 adults with sepsis, 12,060 (54%) were vasopressor-dependent (mean±standard deviation SD age, 64±16 years; male, 6,548 [54%]; sequential organ failure assessment (SOFA), 10±4). Of these, 231 (2%) patients had a threatened extremity with 26 undergoing 37 amputations, a risk of 2.2 (95% CI: 1.4-3.2) per 1,000, and 205 not undergoing amputation, a risk of 17.0 (95% CI: 14.8-19.5) per 1,000. 95% of the total 37Most amputations occurred in lower extremities (95%), a median (interquartile range) of 16 (6.3-4039.9) days after sepsis onset. Compared to patients with no extremity threat, patients with threat had a higher sequential organ failure assessmentSOFA score (11±4 vs 10±4; P < 0.001), serum lactate (4.6 mmol/L [2.4-8.7] vs 3.1 [1.7-6.0]; P < 0.001), and more bacteremia (n = 37 [37%??] vs n = 2,087 [26%]; P < 0.001) at sepsis onset. Peripheral vascular disease, congestive heart failure, sequential organ failure assessmentSOFA score, and norepinephrine equivalents were significantly associated with the risk of extremity threat.

CONCLUSIONS

The evaluation of a threatened extremity resulting in surgical amputation occurred in 2 per 1,000 patients with vasopressor-dependent sepsis.

Association of Smoking With Postprocedural Complications Following Open and Endovascular Interventions for Intermittent Claudication

Importance

Smoking is a key modifiable risk factor in the development and progression of peripheral artery disease, which often manifests as intermittent claudication (IC). Smoking cessation is a first-line therapy for IC, yet a minority of patients quit smoking prior to elective revascularization.

Objective

To assess if preprocedural smoking is associated with an increased risk of early postprocedural complications following elective open and endovascular revascularization.

Design, Setting, and Participants

This retrospective cohort study used nearest-neighbor (1:1) propensity score matching of 2011 to 2019 data from the Veterans Affairs Surgical Quality Improvement Program, including all cases with a primary diagnosis of IC and excluding emergent cases, primary procedures that were not lower extremity revascularization, and patients with chronic limb-threatening ischemia within 30 days of the intervention. All data were abstracted June 18, 2020, and analyzed from July 26, 2020, to June 30, 2021.

Exposures

Preprocedural cigarette smoking.

Main Outcomes and Measures

Any and organ system-specific (ie, wound, respiratory, thrombosis, kidney, cardiac, sepsis, and neurological) 30-day complications and mortality, overall and in prespecified subgroups.

Results

Of 14 350 included cases of revascularization, 14 090 patients (98.2%) were male, and the mean (SD) age was 65.7 (7.0) years. A total of 7820 patients (54.5%) were smoking within the preprocedural year. There were a total of 4417 endovascular revascularizations (30.8%), 4319 hybrid revascularizations (30.1%), and 5614 open revascularizations (39.1%). A total of 1594 patients (11.1%) had complications, and 57 (0.4%) died. Among 7710 propensity score-matched cases (including 3855 smokers and 3855 nonsmokers), 484 smokers (12.6%) and 34 nonsmokers (8.9%) experienced complications, an absolute risk difference (ARD) of 3.68% (95% CI, 2.31-5.06; P < .001). Compared with nonsmokers, any complication was higher for smokers following endovascular revascularization (26 [4.3%] vs 52 [2.1%]; ARD, 2.19%; 95% CI, 0.77-3.60; P = .003), hybrid revascularization (204 [17.3%] vs 163 [14.1%]; ARD, 3.18%; 95% CI, 0.23-6.13; P = .04), and open revascularization (228 [15.4%] vs 153 [10.3%]; ARD, 5.18%; 95% CI, 2.78-7.58; P < .001). Compared with nonsmokers, respiratory complications were higher for smokers following endovascular revascularization (20 [1.7%] vs 6 [0.5%]; ARD, 1.17%; 95% CI, 0.35-2.00; P = .009), hybrid revascularization (33 [2.8%] vs 10 [0.9%]; ARD, 1.93%; 95% CI, 0.85-3.02; P = .001), and open revascularization (32 [2.2%] vs 19 [1.3%]; ARD, 0.89%; 95% CI, 0-1.80; P = .06). Wound complications and graft failure were higher for smokers compared with nonsmokers following open interventions (wound complications: 146 [9.9%] vs 87 [5.8%]; ARD, 4.05%; 95% CI, 2.12-5.99; P < .001; graft failure: 33 [2.2%] vs 11 [0.7%]; ARD, 1.50%; 95% CI, 0.63-2.37; P = .001). In a sensitivity analysis, compared with active smokers (n = 5173; smoking within 2 weeks before the procedure), the risk of any complication was decreased by 65% for never smokers (n = 1197; adjusted odds ratio, 0.45; 95% CI, 0.34-0.59) and 29% for former smokers (n = 4755; cessation more than 1 year before the procedure; adjusted odds ratio, 0.71; 95% CI, 0.61-0.83; P = .001 for interaction).

Conclusions and Relevance

In this cohort study, more than half of patients with IC were smoking prior to elective revascularization, and complication risks were higher across all modalities of revascularization. These findings stress the importance of smoking cessation to optimize revascularization outcomes.

Association Between Black Race, Clinical Severity, and Management of Acute Pulmonary Embolism: A Retrospective Cohort Study

Background

Existing evidence indicates Black patients have higher incidence of pulmonary embolism (PE) and PE‐related mortality compared with other races/ethnicities, yet disparities in presenting severity and treatment remain incompletely understood.

Methods and Results

We retrospectively queried a multihospital healthcare system for all hospitalizations for acute PE (2012–2019). Of 10 329 hospitalizations, 8743 met inclusion criteria. Black patients (14.3%) were significantly younger (54.6±17.8 versus 63.1±16.6 years; P<0.001) and more female (56.1% versus 51.6%; P=0.003) compared with White patients. Using ordinal regression, Black race was significantly associated with higher PE severity after matching 1:3 on age and sex (1210:3264; odds ratio [OR], 1.08; 95% CI, 1.03–1.14), adjusting for clinical (OR, 1.13; 95% CI, 1.01–1.27), and socioeconomic (OR, 1.05; 95% CI, 1.05–1.35) characteristics. Among intermediate and high‐severity PE, Black race was associated with a decreased risk of intervention controlling for the competing risk of mortality and censoring on hospital discharge. This effect was modified by PE severity (P value <0.001), with a lower and higher risk of intervention for intermediate and high‐severity PE, respectively. Race was not associated with in‐hospital mortality (OR, 0.84; 95% CI, 0.69–1.02).

Conclusions

Black patients hospitalized with PE are younger with a higher severity of disease compared with White patients. Although Black patients are less likely to receive an intervention overall, this differed depending on PE severity with higher risk of intervention only for life‐threatening PE. This suggests nuanced racial disparities in management of PE and highlights the complexities of healthcare inequalities.

Impact of Bamlanivimab Monoclonal Antibody Treatment on Hospitalization and Mortality Among Nonhospitalized Adults With Severe Acute Respiratory Syndrome Coronavirus 2 Infection

BACKGROUND

Monoclonal antibody treatment may prevent complications of coronavirus disease 2019 (COVID-19). We sought to quantify the impact of bamlanivimab monoclonal antibody monotherapy on hospitalization and mortality among outpatients at high risk of COVID-19 complications.

METHODS

In this observational study we compared outpatients who received bamlanivimab monoclonal antibody from December 9, 2020 to March 3, 2021 to nontreated patients with a positive polymerase chain reaction or antigen test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the same period who were eligible for monoclonal antibody treatment. The primary outcome was 28-day hospitalization or all-cause mortality, and the secondary outcome was hospitalization or emergency department visit without hospitalization. The risk-adjusted odds of study outcomes comparing bamlanivimab treated and untreated patients was determined using 1:5 propensity matching and multivariable logistic regression.

RESULTS

Among 232 patients receiving bamlanivimab matched with 1160 comparator patients, the mean age was 67 years, 56% were female, and 196 (14%) of patients experienced hospitalization or mortality. After adjustment for propensity to receive treatment, bamlanivimab treatment was associated with a significantly reduced risk-adjusted odds of hospitalization or mortality within 28 days (odds ratio [OR], 0.40; 95% confidence interval [95% CI], 0.24-0.69; P < .001). Bamlanivimab treatment was also associated with a significantly lower risk adjusted odds of hospitalization or emergency department visit without hospitalization (OR, 0.54; 95% CI, 0.35-0.82; P = .004). The results were most strongly associated with patients age 65 years and older.

CONCLUSIONS

Bamlanivimab monoclonal antibody monotherapy was associated with reduced hospitalizations and mortality within 28 days among outpatients with mild to moderate COVID-19.Use of bamlanivimab monotherapy for outpatients with mild to moderate COVID-19 infection was associated with reductions in hospitalizations and mortality within 28 days. Benefit was strongest in those age 65 years or older.

[Treatment of diabetes mellitus in perioperative medicine-an update]

Patients with diabetes who undergo a surgical intervention have an increased risk of metabolic derailment, anesthesiological complications, postoperative infections and cardiovascular events. The treatment of diabetes mellitus is subject to a continuous further development due to pharmaceutical and technical innovations. This article presents the implications of the current concepts of diabetes treatment for perioperative medicine, particularly the changes due to new oral antidiabetic agents and insulin pump treatment. Some of the currently available guidelines are discussed with respect to the care of diabetes patients in childhood and adulthood in connection with an operation. Finally, possible perspectives in the field of monitoring and treatment of diabetes patients are discussed.

Metformin Use Is Associated with Fewer Complications in Patients with Type-2 Diabetes Undergoing Total Knee Arthroplasty: A Propensity Score-Matched Analysis

BACKGROUND

Diabetes is a well-established risk factor for complications following total knee arthroplasty (TKA), and the incidence of type-2 diabetes is increasing. Metformin is considered first-line therapy for type-2 diabetes and has been shown to reduce all-cause mortality and to possess anti-inflammatory properties. The impact of metformin use as it relates to outcomes following TKA is unknown. The purpose of this study was to investigate this relationship.

METHODS

This is a retrospective cohort study using the Truven MarketScan database. Adult patients undergoing unilateral, primary TKA were identified. We included only patients with a preoperative diagnosis of type-2 diabetes and established 2 cohorts based on metformin status. Propensity score matching was performed to match patients who used metformin to those who did not (1-to-1). Patients were matched on factors including age, sex, insulin status, other diabetic medications, comorbidities, complexity of diabetes, and smoking status. Regression analysis was then performed on matched cohorts to examine 90-day outcomes. A subgroup analysis was performed on 1-year revision rates.

RESULTS

After matching, there were 32,186 patients in both the metformin group and the no-metformin group, resulting in a total of 64,372 included patients. Baseline characteristics were similar between groups. Regression analysis, performed on matched cohorts, demonstrated that the no-metformin group had increased odds of readmission (odds ratio [OR], 1.09 [95% confidence interval (CI), 1.04 to 1.15]; p < 0.001), emergency department presentation (OR, 1.09 [95% CI, 1.04 to 1.14]; p < 0.001), extended length of stay (OR, 1.12 [95% CI, 1.06 to 1.15]; p < 0.001), periprosthetic joint infection (OR, 1.30 [95% CI, 1.13 to 1.50]; p < 0.001), deep vein thrombosis (OR, 1.17 [95% CI, 1.09 to 1.26]; p < 0.001), acute kidney injury (OR, 1.21 [95% CI, 1.09 to 1.33]; p < 0.001), hypoglycemic events (OR, 1.25 [95% CI, 1.01 to 1.54]; p = 0.039), and 1-year revision (OR, 1.16 [95% CI, 1.01 to 1.33]; p = 0.033).

CONCLUSIONS

Metformin use in patients with type-2 diabetes undergoing TKA appears to be associated with lower odds of multiple complications and resource utilization parameters, including periprosthetic joint infection and 1-year revision rates. Given the frequency with which TKA is performed in patients with type-2 diabetes, this knowledge has the potential to improve optimization protocols and outcomes in this group of patients.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Outcomes After Sentinel Lymph Node Biopsy and Radiotherapy in Older Women With Early-Stage, Estrogen Receptor-Positive Breast Cancer

IMPORTANCE

Overtreatment of early-stage breast cancer with favorable tumor biology in older patients may be harmful without affecting recurrence and survival. Guidelines that recommend deimplementation of sentinel lymph node biopsy (SLNB) (Choosing Wisely) and radiotherapy (RT) (National Comprehensive Cancer Network) have been published.

OBJECTIVE

To describe the use rates and association with disease recurrence of SLNB and RT in older women with breast cancer.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study obtained patient and clinical data from an integrated cancer registry and electronic health record of a single health care system in Pennsylvania. The cohort was composed of consecutive female patients 70 years or older who were diagnosed with early-stage, estrogen receptor-positive, ERBB2 (formerly HER2)-negative, clinically node-negative breast cancer from January 1, 2010, to December 31, 2018, who were treated at 15 community and academic hospitals within the health system.

EXPOSURES

Sentinel lymph node biopsy and adjuvant RT.

MAIN OUTCOMES AND MEASURES

Primary outcomes were 5-year locoregional recurrence-free survival (LRFS) rate and disease-free survival (DFS) rate after SLNB and after RT. Secondary outcomes included recurrence rate, subgroups that may benefit from SLNB or RT, and use rate of SLNB and RT over time. Propensity scores were used to create 2 cohorts to separately evaluate the association of SLNB and RT with recurrence outcomes. Cox proportional hazards regression model was used to estimate hazard ratios (HRs).

RESULTS

From 2010 to 2018, a total of 3361 women 70 years or older (median [interquartile range {IQR}] age, 77.0 [73.0-82.0] years) with estrogen receptor-positive, ERBB2-negative, clinically node-negative breast cancer were included in the study. Of these women, 2195 (65.3%) received SLNB and 1828 (54.4%) received adjuvant RT. Rates of SLNB steadily increased (1.0% per year), a trend that persisted after the 2016 adoption of the Choosing Wisely guideline. Rates of RT decreased slightly (3.4% per year). To examine patient outcomes and maximize follow-up time, the analysis was limited to cases from 2010 to 2014, identifying 2109 patients with a median (IQR) follow-up time of 4.1 (2.5-5.7) years. In the propensity score-matched cohorts, no association was found between SLNB and either LRFS (HR, 1.26; 95% CI, 0.37-4.30; P = .71) or DFS (HR, 1.92; 95% CI, 0.86-4.32; P = .11). In addition, RT was not associated with LRFS (HR, 0.33; 95% CI, 0.09-1.24; P = .10) or DFS (HR, 0.99; 95% CI, 0.46-2.10; P = .97). Subgroup analysis showed that stratification by tumor grade or comorbidity was not associated with LRFS or DFS. Low absolute rates of recurrence were observed when comparing the groups that received SLNB (3.5%) and those that did not (4.5%) as well as the groups that received RT (2.7%) and those that did not (5.5%).

CONCLUSIONS AND RELEVANCE

This study found that receipt of SLNB or RT was not associated with improved LRFS or DFS in older patients with ER-positive, clinically node-negative breast cancer. Despite limited follow-up time and wide 95% CIs, this study supports the continued deimplementation of both SLNB and RT in accordance with the Choosing Wisely and National Comprehensive Cancer Network guidelines.

Metformin Benefits: Another Example for Alternative Energy Substrate Mechanism?

Since the UK Prospective Diabetes Study (UKPDS), metformin has been considered the first-line medication for patients with newly diagnosed type 2 diabetes. Though direct evidence from specific trials is still lacking, several studies have suggested that metformin may protect from diabetes- and nondiabetes-related comorbidities, including cardiovascular, renal, neurological, and neoplastic diseases. In the past few decades, several mechanisms of action have been proposed to explain metformin's protective effects, none being final. It is certain, however, that metformin increases lactate production, concentration, and, possibly, oxidation. Once considered a mere waste product of exercising skeletal muscle or anaerobiosis, lactate is now known to act as a major energy shuttle, redistributed from production sites to where it is needed. Through the direct uptake and oxidation of lactate produced elsewhere, all end organs can be rapidly supplied with fundamental energy, skipping glycolysis and its possible byproducts. Increased lactate production (and consequent oxidation) could therefore be considered a positive mechanism of action of metformin, except when, under specific circumstances, metformin and lactate become excessive, increasing the risk of lactic acidosis. We are proposing that, rather than considering metformin-induced lactate production as dangerous, it could be considered a mechanism through which metformin exerts its possible protective effect on the heart, kidneys, and brain and, to some extent, its antineoplastic action.

Pharmacological preconditioning protects from ischemia/reperfusion-induced apoptosis by modulating Bcl-xL expression through a ROS-dependent mechanism

Myocardial ischemia/reperfusion (I/R) injury is a frequent perioperative threat, with numerous strategies developed to limit and/or prevent it. One interesting axis of research is the anesthetic preconditioning (APc) agent's hypothesis (such as sevoflurane, SEV). However, APc's mode of action is still poorly understood and volatile anesthetics used as preconditioning agents are often not well suited in clinical practice. Here, in vitro using H9C2 cells lines (in myeloblast state or differentiated toward cardiomyocytes) and in vivo in mice, we identified that SEV-induced APc is mediated by a mild induction of reactive oxygen species (ROS) that activates Akt and induces the expression of the anti-apoptotic protein B-cell lymphoma-extra large (Bcl-xL), therefore protecting cardiomyocytes from I/R-induced death. Furthermore, we extended these results to human cardiomyocytes (derived from induced pluripotent stem - IPS - cells). Importantly, we demonstrated that this protective signaling pathway induced by SEV could be stimulated using the antidiabetic agent metformin (MET), suggesting the preconditioning properties of MET. Altogether, our study identified a signaling pathway allowing APc of cardiac injuries as well as a rational for the use of MET as a pharmacological preconditioning agent to prevent I/R injuries.

Association between metformin use on admission and outcomes in intensive care unit patients with acute kidney injury and type 2 diabetes: A retrospective cohort study

PURPOSE

Acute kidney injury (AKI) occurs in more than half of intensive care unit patients. Effective prevention and treatment strategies for AKI remain limited. We aimed to assess AKI-related mortality in patients with diabetes who were metformin and non-metformin users.

MATERIALS AND METHODS

We included patients with AKI and type 2 diabetes (T2DM) from the Medical Information Mart for Intensive Care database. The 30-day mortality, neutrophil-to-lymphocyte ratio, and length of hospital stay were compared between patients with and without metformin prescriptions. We used multivariable Cox proportional hazards regression, propensity score analysis, and an inverse probability-weighting model to ensure the robustness of our findings.

RESULTS

We included 4328 patients with AKI and T2DM (998 and 3330 patients were metformin and non-metformin users, respectively). The overall 30-day mortality was 14.2% (613/4328); it was 15.7% (523/3330) and 9.0% (90/998) for non-metformin and metformin users, respectively. In the inverse probability-weighting model, metformin use was associated with 37% lower 30-day mortality (HR = 0.63, 95% CI: 0.50-0.80, p < 0.0001).

CONCLUSIONS

Metformin use may be associated with reduced risk-adjusted mortality in patients with AKI and T2DM. Further randomized controlled trials are needed to clarify this association.

Strategies to Promote ResiliencY (SPRY): a randomised embedded multifactorial adaptative platform (REMAP) clinical trial protocol to study interventions to improve recovery after surgery in high-risk patients

INTRODUCTION

As the population ages, there is interest in strategies to promote resiliency, especially for frail patients at risk of its complications. The physiological stress of surgery in high-risk individuals has been proposed both as an important cause of accelerated age-related decline in health and as a model testing the effectiveness of strategies to improve resiliency to age-related health decline. We describe a randomised, embedded, multifactorial, adaptative platform (REMAP) trial to investigate multiple perioperative interventions, the first of which is metformin and selected for its anti-inflammatory and anti-ageing properties beyond its traditional blood glucose control features.

METHODS AND ANALYSIS

Within a multihospital, single healthcare system, the Core Protocol for Strategies to Promote ResiliencY (SPRY) will be embedded within both the electronic health record (EHR) and the healthcare culture generating a continuously self-learning healthcare system. Embedding reduces the administrative burden of a traditional trial while accessing and rapidly analysing routine patient care EHR data. SPRY-Metformin is a placebo-controlled trial and is the first SPRY domain evaluating the effectiveness of three metformin dosages across three preoperative durations within a heterogeneous set of major surgical procedures. The primary outcome is 90-day hospital-free days. Bayesian posterior probabilities guide interim decision-making with predefined rules to determine stopping for futility or superior dosing selection. Using response adaptative randomisation, a maximum of 2500 patients allows 77%-92% power, detecting >15% primary outcome improvement. Secondary outcomes include mortality, readmission and postoperative complications. A subset of patients will be selected for substudies evaluating the microbiome, cognition, postoperative delirium and strength.

ETHICS AND DISSEMINATION

The Core Protocol of SPRY REMAP and associated SPRY-Metformin Domain-Specific Appendix have been ethically approved by the Institutional Review Board and are publicly registered. Results will be publicly available to healthcare providers, patients and trial participants following achieving predetermined platform conclusions.

TRIAL REGISTRATION NUMBER

NCT03861767.