CANCARE RESEARCH
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An automated research-discovery feed. Summaries are based on published abstracts and are not clinical recommendations.
Postoperative infections after cardiac surgery with cardiopulmonary bypass - incidence, performance of diagnostic procedures, and predictive factors.
Clinical takeaway Postoperative infection was associated with higher mortality after cardiac surgery with bypass. Common inflammatory markers showed poor diagnostic performance, limiting their usefulness for distinguishing infection from postoperative inflammation.
Summary & abstract
Study summary
This bidirectional cohort included 1,222 patients undergoing cardiac surgery with cardiopulmonary bypass; postoperative infections during hospitalisation and/or later occurred in 17.3%. Compared with uninfected patients, those with infection had higher 90-day mortality (3.8% versus 1.5%, p=0.045) and 1-year mortality (5.7% versus 2.7%, p=0.032). CRP, white blood cell count, and temperature performed poorly for infection detection, despite peak CRP and peak temperature being independent predictors. Peak temperature occurred on postoperative day 5 in infected patients versus day 2 in those without infection.
Study limitation: The observational comparison cannot establish causality; infected patients had more comorbidities and underwent more complex procedures.
Published abstract
OBJECTIVES: Cardiac surgery using cardiopulmonary bypass (CPB) induces a systemic inflammatory response that affects common inflammatory markers, including C-reactive protein (CRP), white blood cell count (WBC), and body temperature, complicating postoperative diagnosis of infections. The objective of this study was to assess the incidence of postoperative infections and evaluate the performance of clinically used biomarkers. DESIGN: This was a bidirectional cohort study including patients undergoing cardiac surgery with CPB between 1st of February 2020 and 22nd of September 2021. Patients with postoperative infection were compared to patients without. Multivariable logistic regression was used to identify independent predictors of postoperative infections. Receiver operating characteristic (ROC) curves evaluated the diagnostic ability of current biomarkers to detect infection. RESULTS: A total of 1,222 patients were included. The incidence of postoperative infections (during hospitalisation and/or late infection) was 17.3%. Patients with postoperative infection had more comorbidities, underwent more complex procedures, and had higher mortality (90-day mortality 3.8% vs 1.5%, p = 0.045; 1-year mortality 5.7% vs 2.7%, p = 0.032). CRP, WBC, and temperature performed poorly in detecting postoperative infection, although peak CRP (OR 1.069, p < 0.001) and peak temperature (OR 2.408, p = 0.005) were independent predictors of postoperative infection. Peak temperature occurred on postoperative day 5 in infected patients versus day 2 in those without infection. CONCLUSION: Postoperative infections following cardiac surgery with CPB remain common and are associated with increased postoperative complications and mortality. Common inflammatory biomarkers perform poorly in detecting infection. Improved diagnostic tools are needed to facilitate early detection and treatment.
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Evaluation of Four-Factor Prothrombin Complex Concentrate Dosing for Major Bleeding Following Cardiac Surgery.
Clinical takeaway This small observational comparison does not establish equivalent effectiveness or safety between dosing strategies. The numerical thromboembolic difference is inconclusive and warrants further study.
Summary & abstract
Study summary
This retrospective review compared 4F-PCC at 25 versus 12.5 units/kg after a cardiac-surgery dosing protocol change, including 31 and 11 patients, respectively. The primary endpoint, receiving at least three packed red blood cell transfusions within 24 hours, occurred in 15 versus three patients (P = .299). Thromboembolic events within 14 days occurred in 22.6% versus 0%, respectively (P = .161), leaving considerable uncertainty about this numerical difference. No statistically significant differences were reported in additional haemostatic agent use, hospital length of stay or mortality.
Study limitation: The small, unequal groups and retrospective comparison following a protocol change limit precision and causal interpretation.
Published abstract
Four-factor prothrombin concentrate complex (4F-PCC) may be used for significant bleeding following cardiac surgery but the optimal dosing has not been established. The purpose of this study was to compare two dosing strategies of 4F-PCC in cardiac surgery patients. This retrospective chart review evaluated 4F-PCC dosing of 25 units/kg compared to 12.5 units/kg in cardiac surgery patients following a protocol change for 4F-PCC dosing. The primary outcome was major bleeding, defined as the number of patients receiving ≥3 packed red blood cell (PRBC) transfusions within 24 h of 4F-PCC administration. Secondary outcomes included other surrogate markers for bleeding (eg, Use of other blood products and hemostatic agents), thrombotic events within 14 days of surgery, hospital length of stay, and all-cause mortality. A total of 42 patients were included (31 patients in the 25 units/kg group and 11 patients in the 12.5 units/kg group). There was no difference in the number of patients that received ≥3 PRBC transfusions between the two groups with 15 patients (47.4%) in 25 units/kg group and 3 patients (27.3%) in 12.5 units/kg (P = .299). Additionally, no difference was observed in amount of additional hemostatic agents administered, hospital length of stay or mortality between the two groups. A higher rate of thromboembolic events was observed among patients receiving 25 units/kg vs 12.5 units/kg (22.6% vs 0%, P = .161). Reduced dosing of 4F-PCC from 25 units/kg to 12.5 units/kg following cardiac surgery resulted in no difference in clinical or effectiveness outcomes.
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Preoperative levels of biomarkers of coagulation to predict massive bleeding after surgical repair for acute type A aortic dissection: a retrospective cohort study.
Clinical takeaway Preoperative APTT was associated with massive postoperative bleeding after type A dissection repair. Its usefulness for prospective risk stratification remains unvalidated.
Summary & abstract
Study summary
This single-center retrospective cohort included 474 patients undergoing surgery for acute type A aortic dissection between January 2005 and May 2023. Massive postoperative bleeding occurred in 87 patients (18%), who were compared with 387 patients without massive bleeding. In multivariable analysis, preoperative APTT above 34.5 seconds was associated with massive bleeding (OR 2.95, 95% CI 1.60–5.47). Higher preoperative creatinine, hypertension, and longer cardiopulmonary bypass duration were also independently associated with bleeding. Patients with massive bleeding experienced more postoperative complications.
Study limitation: The retrospective, single-center design limits generalizability, and the abstract does not report the definition of massive bleeding or predictive performance.
Published abstract
BACKGROUND: Acute type A aortic dissection is a highly emergent condition with a high mortality rate. The condition poses an imminent risk of serious complications such as coagulopathy with massive bleeding. This increases the risk of mortality even after surgical repair. Procoagulant drugs are routinely administered but some patients still suffer postoperative massive bleeding that can be fatal. The study aimed to investigate whether massive bleeding after surgical treatment for type A aortic dissection can be predicted preoperatively through routine coagulation tests such as APTT, PT (INR), fibrinogen, D-dimer, and platelets. METHODS: The study was a retrospective, single-center, cohort study performed at a tertiary cardiac surgery unit. A total of 474 patients who underwent surgery for type A aortic dissection at our department between January 2005 and May 2023 were included in the study. Of these, 87 patients had massive postoperative bleeding after surgery for type A aortic dissection and were compared to 387 patients who did not have massive postoperative bleeding. Uni- and multivariable analyses were performed using logistic regression. The multivariable model included predictors of massive bleeding. Bleeding-related routine lab variables were then forced into the model. RESULTS: Patients with massive bleeding (18%) had higher preoperative activated partial thromboplastin time (APTT) (33 s vs 29 s, p<0.01), and creatinine (97 µmol/L vs 87 µmol/L, p<0.01), as well as lower preoperative platelet counts (172 × 109/L vs 187 × 109/L, p=0.03) compared to patients without massive bleeding. Patients with massive bleeding also had longer duration of cardiopulmonary bypass (CPB) (221 min vs 170 min, p<0.01) and suffered more postoperative complications. Multivariable logistic regression identified preoperative APTT per mmol increment (OR 1.04 (95% CI 1.01-1.07, p=0.01), preoperative APTT > 34.5 s (OR 2.95 (95% CI 1.60-5.47), p<0.01), preoperative creatinine > 82.5 µmol/L (OR 2.16 (95% CI 1.15-4.06), p=0.02), hypertension (OR 1.83 (95% CI 1.01-3.32), p<0.05) and CPB time per 10 min increment (OR 1.09 (95% CI 1.05-1.13, p<0.01)) as independent predictors of massive bleeding. CONCLUSION: Preoperative APTT exceeding 34.5 s was independently associated with massive bleeding after type A aortic dissection repair and may, pending prospective validation, help identify patients who could potentially benefit from earlier hemostatic intervention.
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Exploratory Sex-Stratified Associations of Postoperative Visual and Auditory Hallucinations After Cardiac Surgery: Insights from the VAACS Study.
Clinical takeaway Hallucinations were reported during the first week after cardiac surgery in both sexes. The exploratory associations do not establish causation or justify changes to perioperative medication use.
Summary & abstract
Study summary
A prospective cohort followed 1,331 adults undergoing isolated coronary bypass or valve surgery at 10 Palestinian centers for postoperative hallucinations through day 7. Visual hallucinations occurred in 155 patients (11.6%) and auditory hallucinations in 92 (6.9%), with similar rates in males and females. In exploratory sex-stratified models, postoperative noradrenaline requirement was associated with auditory hallucinations among females (adjusted HR 4.35, 95% CI 2.18–8.68), but this model included only 22 events. The authors emphasized that these findings require confirmation in studies incorporating structured delirium assessment.
Study limitation: Sex-stratified associations are hypothesis-generating; the female auditory-hallucination model included only 22 events, and structured delirium assessment is needed.
Published abstract
Background Postoperative hallucination experiences are distressing but under-recognized complications of cardiac surgery. This study investigated whether sex differences exist in their incidence and in the factors associated with postoperative visual and auditory hallucination experiences. Methods We conducted a prospective multicenter cohort study of 1,331 adults (1,000 males and 331 females) undergoing isolated coronary artery bypass grafting or isolated valve surgery at 10 cardiac surgery centers in the West Bank, Palestine (September 2022-May 2025). Postoperative visual (VH) and auditory hallucination (AH) experiences were assessed using daily QPE interviews through postoperative day 4, followed by clinical checks or telephone follow-up through day 7, with QPE-based confirmation of newly reported experiences. Sex-stratified multivariable Cox proportional hazards models evaluated associated factors within an exploratory, hypothesis-generating framework. This study was conducted as part of the VAACS Study (https://www.isrctn.com/ISRCTN18368253). Results Within the first postoperative week, 155 patients (11.6%) experienced visual hallucination experiences (11.2% of males vs. 13.0% of females), and 92 (6.9%) experienced auditory hallucination experiences (7.0% vs. 6.6%). Among males, lower body mass index (adjusted HR 0.91; 95% CI 0.83-0.99; P = 0.034), higher EuroSCORE II (adjusted HR 1.03; 95% CI 1.02-1.04; P < 0.001), higher serum creatinine (adjusted HR 1.21; 95% CI 1.15-1.27; P < 0.001), and postoperative blood transfusion (adjusted HR 1.65; 95% CI 1.20-2.28; P = 0.002) were associated with visual hallucination experiences. Among females, higher EuroSCORE II (adjusted HR 1.05; 95% CI 1.04-1.06; P < 0.001) and longer postoperative ventilation duration (adjusted HR 0.93; 95% CI 0.89-0.97; P < 0.001) were associated with visual hallucination experiences. Higher EuroSCORE II (adjusted HR 1.07; 95% CI 1.04-1.10; P < 0.001) and longer postoperative ventilation duration (adjusted HR 0.91; 95% CI 0.83-0.99; P = 0.029) were associated among males; intraoperative fentanyl exposure did not reach statistical significance (adjusted HR 0.51; 95% CI 0.26-1.02; P = 0.057). Among females, lower age (adjusted HR 0.98; 95% CI 0.97-1.00; P = 0.007), higher EuroSCORE II (adjusted HR 1.08; 95% CI 1.07-1.10; P < 0.001), and postoperative noradrenaline requirement (adjusted HR 4.35; 95% CI 2.18-8.68; P < 0.001) were associated with auditory hallucination experiences; this model included only 22 events. Conclusions Postoperative hallucination experiences captured by the QPE occurred at similar rates in male and female patients after cardiac surgery, but exploratory sex-stratified association patterns differed by hallucination modality. These findings should be interpreted irrespective of delirium status and require confirmation in future studies incorporating structured delirium assessment.
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The association between cardiac surgery - associated acute kidney injury and elevated liver function tests. A single-center cohort study.
Clinical takeaway Admission liver enzymes offered limited discrimination for postoperative kidney injury. The stronger predictive signal for renal replacement therapy at 12 hours warrants further validation before clinical application.
Summary & abstract
Study summary
This single-center cohort included 3,415 adult cardiac surgery patients over six years and evaluated liver enzymes as predictors of postoperative acute kidney injury. Overall, 65.4% developed acute kidney injury, 37.4% had stage ≥2 injury, and 3.8% received renal replacement therapy. Admission AST normalized to the upper limit of normal showed weak discrimination for acute kidney injury: AUC 0.587 (95% CI 0.570–0.604). AST measured 12 hours after ICU admission was the strongest reported predictor of renal replacement therapy, with an AUC of 0.751 (95% CI 0.733–0.768).
Study limitation: The single-center observational design limits generalizability and cannot establish that liver enzyme elevations cause kidney injury.
Published abstract
INTRODUCTION: Acute kidney injury after cardiac surgery (CSA-AKI) is common and associated with worse outcome. Venous congestion contributes to CSA-AKI and liver dysfunction. We hypothesized that elevated liver enzymes may serve as early markers for CSA-AKI. METHODS: In a single-center cohort study we included adult cardiac surgery patients during a 6-year period. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured at ICU admission, 12 h and 24 h. The primary objective was to assess whether liver enzymes at ICU admission, normalized to their upper limits of normal (ULN), predicted CSA-AKI. Secondary outcomes included prediction of CSA-AKI severity, use of renal replacement therapy (RRT), and the association between central venous pressure (CVP) and liver enzymes. RESULTS: Among 3415 patients, 65.4% developed CSA-AKI, 37.4% had AKI stage ≥2 and 3.8% received RRT. AST/ULN and ALT/ULN at ICU admission predicted CSA-AKI [AUC-ROC (95% CI; resp. 0.587 (0.570-0.604); 0.534 (0.517-0.551); both p < 0.001)], with AST performing better (p < 0.001). The discriminating power of AST/ULN and ALT/ULN at ICU admission for AKI ≥2 were respectively AUC-ROC (95% CI); 0.594 (0.577-0.610) and 0.541 (0.524-0.585) (both p < 0.001). AST/ULN 12 h after ICU admission was the strongest predictor for RRT [AUC-ROC (95% CI; 0.751 (0.733-0.768); p < 0.001)], with a 4-fold increased RRT risk when AST exceeded 1.6 times the ULN. AST and ALT 24 h post ICU admission were weakly associated with CVP (respectively: R2 = 0.007; p = 0.003 and ALT: R2 = 0.006; p = 0.004). CONCLUSION: AST activity may have potential as a predictor of CSA-AKI and use of RRT, although liver enzymes demonstrated a weak association with CSA-AKI.
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Physiological response following inhaled nitric oxide administration during one-lung ventilation in minimally invasive cardiac surgery: an exploratory prospective cohort study.
Clinical takeaway Nitric oxide administration was followed by improved oxygenation in this selected surgical cohort. These physiological observations do not establish comparative efficacy or patient-centred benefit.
Summary & abstract
Study summary
This exploratory prospective cohort enrolled 63 consecutive patients undergoing minimally invasive cardiac surgery and evaluated physiological responses to inhaled nitric oxide. Thirty patients (47.6%) received nitric oxide for post-bypass hypoxemia with pulmonary hypertension during one-lung ventilation. After administration, PaO2/FiO2 increased from 70 [61–80] to 85 [72–102] (P=0.011), while mean pulmonary artery pressure did not change significantly, from 24 [23–26] to 25 [22–28] mmHg (P=0.564). Female sex, higher body mass index, and longer bypass time were associated with nitric oxide initiation in multivariable analysis.
Study limitation: The small exploratory cohort lacked a randomized comparator and reported physiological responses rather than patient-centred outcomes.
Published abstract
OBJECTIVE: This study aimed to evaluate the physiological responses following inhaled nitric oxide (iNO) administration in patients with one-lung ventilation (OLV)-related hypoxemia accompanied by pulmonary hypertension in minimally invasive cardiac surgery (MICS). METHODS: This exploratory prospective cohort study enrolled 63 consecutive patients who underwent MICS. Patients who developed post-cardiopulmonary bypass (CPB) OLV-related hypoxemia with pulmonary hypertension received iNO. The evaluation included changes in PaO2/FiO2 and mean pulmonary artery pressure (mPAP). Additionally, multivariable logistic regression analysis was performed to examine clinical factors associated with iNO initiation. RESULTS: Overall, 30 patients (47.6%) received iNO. PaO2/FiO2 significantly increased following iNO administration (70 [61-80] to 85 [72-102], P = 0.011), while mPAP remained unchanged (24 [23-26] to 25 [22-28] mmHg, P = 0.564). Multivariable analysis identified female sex (odds ratio [OR]: 5.00), higher body mass index (OR: 1.36), and prolonged CPB time (OR: 1.03) as associated factors for iNO initiation (area under the curve: 0.822). All patients with a second aortic clamp or pre-CPB hypoxemia met the initiation criteria and received iNO. CONCLUSIONS: Post-CPB OLV-related hypoxemia accompanied by pulmonary hypertension occurs frequently during MICS. The observed increase in oxygenation following iNO administration suggests its potential utility for respiratory management in MICS, warranting future large-scale, multicenter investigations.
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Comparable rates of severe primary graft dysfunction after heart transplantation in recipients with prior LVAD or other cardiac surgery: The burden of surgical reentry.
Clinical takeaway Prior surgical history may help contextualize graft dysfunction risk after transplantation. These findings do not establish equivalence between LVAD and other prior-surgery recipients or prove that surgical reentry causes the excess risk.
Summary & abstract
Study summary
A retrospective registry cohort compared severe primary graft dysfunction after heart transplantation in 3,406 recipients with durable LVADs, other prior cardiac surgery, or no prior surgery. Severe graft dysfunction occurred in 11.1% versus 10.9% of LVAD and other prior-surgery recipients (adjusted OR 0.81, 95% CI 0.50–1.32), versus 4.2% without prior surgery (LVAD adjusted OR 2.17, 95% CI 1.50–3.13). Mortality at 180 days was 8.5% in both prior-surgery groups (adjusted HR 0.98, 95% CI 0.58–1.65), versus 4.2% without prior surgery (LVAD adjusted HR 2.13, 95% CI 1.46–3.13).
Study limitation: Retrospective registry comparisons remain vulnerable to residual confounding; the contribution of surgical reentry cannot be isolated causally.
Published abstract
INTRODUCTION: The use of durable left ventricular assist device (dLVAD) as a bridge to heart transplantation (HTx) is a risk factor for severe primary graft dysfunction (sPGD). Whether the intrinsic properties of the device itself or mediastinal reentry at the time of HTx are responsible for this deadly complication remains unknown. METHODS: We conducted a retrospective cohort study using the United Network for Organ Sharing database from September 2023 through May 2025 comparing patients with a dLVAD to those with prior non-dLVAD cardiac surgery and no prior cardiac surgery. The primary outcome was development of severe PGD; secondary outcomes included non-sPGD complications and 180-day survival. Multivariable logistic regression, multivariable Cox models, and propensity score matching were used for analysis. RESULTS: In sum, 3,406 patients were included. A total of 219 (6.4%) recipients experienced sPGD. Rates were similarly elevated among those with dLVAD and prior non-dLVAD cardiac surgery (11.1 vs 10.9%, adjusted odds ratio (aOR) 0.81 [95% CI 0.50-1.32]) but significantly higher than those with no prior surgery (11.1 vs 4.2%, aOR 2.17 [95% CI 1.50-3.13]). Rates of post-operative dialysis were similar between dLVAD and prior non-dLVAD cardiac surgery (21.5 vs 22.5%, aOR 0.93, [95% CI 0.65-1.33]), but significantly higher than those with no prior surgery (21.5 vs 13.7%, aOR 1.83 [95% CI 1.44-2.32]). 180-day mortality was comparable between dLVAD and prior non-dLVAD cardiac surgery (8.5 vs 8.5%, adjusted hazard ratio (aHR) 0.98 [95% CI 0.58-1.65]) but significantly higher than those with no prior cardiac surgery (8.5 vs 4.2%, aHR 2.13 [95% CI 1.46-3.13]). Propensity score matching confirmed these results. CONCLUSIONS: Recipients bridged with dLVAD display phenotypic similarity to those with prior non-dLVAD cardiac surgery postoperatively, indicating that mediastinal reentry likely plays a large role in the pathophysiology of sPGD in bridging with dLVAD.
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Incidence and Predictors of Acute Kidney Injury Among Postoperative Cardiac Surgery Patients in Tanzania.
Clinical takeaway Early postoperative AKI was common in this Tanzanian cardiac-surgery cohort. The reported associations identify potential risk markers but do not establish that modifying transfusion or bypass practices would reduce AKI.
Summary & abstract
Study summary
A prospective study of 177 cardiac-surgery patients at Tanzania’s National Cardiac Institute assessed AKI using serum creatinine changes at 24, 48, and 72 hours postoperatively. Postoperative AKI occurred in 53%, with stage I accounting for 72.9% of cases. In adjusted analyses, blood transfusion was associated with AKI (adjusted prevalence ratio 3.63, 95% CI 1.15–11.41), as was cardiopulmonary bypass exceeding 240 minutes (3.80, 95% CI 1.57–9.18). Diabetes and ASA IV status were also associated with AKI, while female sex was associated with lower AKI prevalence.
Study limitation: This single-centre observational study cannot establish causality; patient ages are unspecified, and several adjusted estimates have wide confidence intervals.
Published abstract
INTRODUCTION: Cardiac surgery-associated acute kidney injury (CSA-AKI) is a severe postoperative complication linked to increased morbidity and mortality. Data on the incidence and predictors of CSA-AKI in sub-Saharan Africa, including Tanzania, are limited. This study aimed to determine the incidence and predictors of AKI in patients who underwent cardiac surgery at Tanzania's National Cardiac Institute. METHODS: This prospective study included 177 patients. AKI was defined using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria based on serum creatinine (SCr) changes at 24, 48, and 72 h postoperatively. The patients' clinical profiles were collected and analyzed using SPSS version 27.0 (IBM Corp., Armonk, NY, USA). Chi-square tests and modified Poisson regression were used to identify associated factors at 95% confidence intervals (CIs), with P < 0.05. RESULTS: The prevalence of postoperative AKI was 53%, with the majority of patients presenting with AKI stage I (72.9%). In the multivariable analysis, diabetes mellitus (Adjusted Prevalence Ratio (aPR )1.32, 95% CI 1.02-1.70; P = 0.038), American Society of Anesthesiologists (ASA) IV status (aPR 1.39, 95% CI 1.10-1.76; P = 0.007), blood transfusion (transfusion: aPR 3.63, 95% CI 1.15-11.41; P = 0.027), triple components (aPR 3.41, 95% CI 1.08-10.78; P = 0.037), and prolonged cardiopulmonary bypass (CPB) time of 181-240 min (aPR 3.53, 95% CI 1.51-8.25; P = 0.004) and > 240 min (aPR 3.80, 95% CI 1.57-9.18; P = 0.003) were independent predictors of AKI. Female sex was independently associated with a lower prevalence of AKI (aPR 0.66, 95% CI 0.50-0.88; P = 0.004). Patients who developed AKI had significantly longer stays in the intensive care unit (ICU) (aPR 2.39, 95% CI 1.39-4.12; P = 0.002). CONCLUSION: The prevalence of CSA-AKI is remarkably high in this setting, posing a significant clinical burden. Key preoperative and intraoperative predictors were also identified. These results reinforce the importance of perioperative patient optimization, strategies to minimize CPB exposure, transfusion practice optimization, and surveillance of high-risk patients.
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Oxygen delivery during cardiopulmonary bypass and postoperative mortality: A retrospective cohort study.
Clinical takeaway Lower oxygen delivery during bypass was associated with worse postoperative outcomes. These findings support further investigation but do not establish that increasing oxygen delivery improves survival.
Summary & abstract
Study summary
This single-center retrospective cohort included 4,358 adults undergoing cardiac surgery with cardiopulmonary bypass in 2018–2024. Thirty-day mortality was 1.7% (75 deaths). Each 10 ml/min/m² decrease in indexed oxygen delivery was associated with higher mortality odds (adjusted OR 1.16, 95% CI 1.09–1.23). Adjusted mortality was 1.69% (95% CI 1.32–2.05%) at the 25th oxygen-delivery percentile versus 0.74% (95% CI 0.41–1.07%) at the 75th percentile. Lower oxygen delivery was also associated with acute kidney injury and longer ICU and hospital stays; no statistically significant association with stroke was observed.
Study limitation: The retrospective, single-center design leaves residual confounding possible despite multivariable adjustment and limits causal interpretation.
Published abstract
BACKGROUND: Oxygen delivery during cardiopulmonary bypass reflects the balance between pump flow, hemoglobin concentration, and arterial oxygenation and is a key determinant of tissue oxygen transport. While inadequate oxygen delivery has been linked to postoperative organ dysfunction, its association with mortality remains unclear. METHODS: We conducted a retrospective cohort study including 4,358 adult patients undergoing cardiac surgery with cardiopulmonary bypass at a tertiary center between 2018 and 2024. Time-weighted average indexed oxygen delivery (DO2i) was calculated from pump flow, arterial oxygen saturation, hemoglobin concentration, and body surface area. The primary outcome was 30-day mortality. Secondary outcomes included postoperative acute kidney injury (AKI), stroke, and intensive care unit (ICU) and hospital length of stay. Associations were evaluated using multivariable regression models adjusted for demographic, clinical, and procedural factors. RESULTS: Lower intraoperative DO2i was associated with higher 30-day mortality. Overall, 75 patients (1.7%) died within 30 days. Each 10 ml · min -1 · m -2 decrease in DO2i was associated with increased odds of mortality (adjusted odds ratio [ORadj] 1.16; 95% CI 1.09-1.23; P < 0.001). The adjusted 30-day mortality was 1.69% (95% CI 1.32-2.05%) at the 25th percentile of DO2i (226.2 ml · min⁻¹ · m⁻²), compared with 0.74% (95% CI 0.41-1.07%) at the 75th percentile (295.6 ml · min⁻¹ · m⁻²). Lower DO2i was also associated with AKI (ORadj 1.05; 95% CI 1.03-1.07; P < 0.001), longer ICU (adjusted incidence rate ratio [IRRadj] 1.02; 95% CI 1.01-1.03; P < 0.001) and hospital length of stay (IRRadj 1.01; 95% CI 1.01-1.02; P < 0.001), but not with stroke (ORadj 1.00; 95% CI 0.95-1.06; P = 0.877). CONCLUSIONS: Patients receiving lower intraoperative DO2i during cardiopulmonary bypass had a higher risk of postoperative mortality, AKI, and prolonged recovery. These findings support the clinical relevance of oxygen delivery during bypass and provide a rationale for future mechanistic and interventional studies.
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Intraoperative Goal-Directed Perfusion Improves Outcomes in Left Ventricular Assist Device Explant Heart Transplantation.
Clinical takeaway Cumulative oxygen extraction burden may be a prognostic marker in LVAD-explant transplantation. This observational analysis does not establish that targeting it improves renal outcomes or survival.
Summary & abstract
Study summary
This single-centre observational study evaluated cumulative oxygen extraction burden during cardiopulmonary bypass in 110 adult LVAD-explant heart transplant recipients, comparing groups defined by median burden. After inverse probability weighting, higher burden was associated with postoperative renal replacement therapy (OR 4.16, 95% CI 1.35–12.83) and 2-year mortality (HR 7.61, 95% CI 1.49–38.73). Higher burden was also associated with lower immediate postoperative cardiac index and greater vasoactive inotrope requirements. These findings link intraoperative oxygen extraction burden with adverse postoperative outcomes in this transplant population.
Study limitation: Single-centre observational data remain vulnerable to residual confounding, and wide confidence intervals indicate substantial uncertainty in effect magnitude.
Published abstract
Left ventricular assist device (LVAD) explant heart transplantation represents a metabolically vulnerable population with an increased risk for renal failure and mortality. Oxygen extraction ratio (O2ER), which integrates oxygen delivery and tissue oxygen demand, may provide a physiologic marker of cumulative metabolic stress during cardiopulmonary bypass (CPB). Adult LVAD-explant heart transplant recipients at a single center from October 2021 to June 2025 were analyzed using continuous perfusion data captured during CPB. Oxygen extraction ratio was calculated continuously, and cumulative oxygen extraction burden was quantified as the area above an O2ER threshold of 0.20. Patients were stratified by median O2ER burden. Among 110 patients, a higher intraoperative O2ER burden was associated with increased postoperative renal replacement therapy (odds ratio [OR], 4.16; 95% confidence interval [CI], 1.35-12.83) and increased 2-year mortality (hazard ratio [HR], 7.61; 95% CI, 1.49-38.73) after inverse probability weighting adjustment. A higher O2ER burden was also associated with a lower immediate postoperative cardiac index and increased vasoactive inotrope requirements. Donor hypertension, recipient diabetes, static storage modality, and a lower intraoperative oxygen delivery index were associated with an increased O2ER burden. These findings suggest that cumulative oxygen extraction during CPB reflects intraoperative metabolic stress and may represent a physiologically integrated perfusion target in LVAD-explant heart transplantation.
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Perioperative temporary microaxial left ventricular assist device support in patients with low ejection fraction undergoing coronary artery bypass grafting.
Clinical takeaway These findings describe survival after CABG with temporary microaxial support in a selected high-risk population. Without a comparator group, they do not establish a survival benefit from support.
Summary & abstract
Study summary
This retrospective study examined 111 high-risk patients undergoing CABG with Impella 5.5 or LD temporary microaxial pump support during the same hospitalization between April 2018 and January 2025. Patients receiving ECMO were excluded, and the cohort had a mean age of 69 years. Support was planned in 30% (33/111) and unplanned in 70% (78/111). Survival was 89.2% (99/111) at 30 days and 74.8% (83/111) at one year. Mortality did not differ significantly by concomitant procedures or between the 2018–2020 and 2021–2025 operative periods.
Study limitation: The retrospective, supported-only cohort lacks a comparison group without microaxial support, limiting causal interpretation of survival outcomes.
Published abstract
PURPOSE: Despite advances in mechanical circulatory support (MCS), outcomes in high-risk coronary artery bypass grafting (CABG) with low ejection fraction (EF) remain unclear. We evaluate short-term outcomes associated with temporary microaxial flow pump (TMFP) support in high-risk patients undergoing CABG during the same hospitalization. METHODS: This retrospective study reviewed 111 patients who underwent CABG with Impella 5.5 or LD TMFP support during the same hospitalization between April 2018 and January 2025. Patients receiving extracorporeal membrane oxygenation (ECMO) were excluded. Baseline demographics, procedural characteristics, and postoperative outcomes were collected. Statistical analyses were performed using R version 4.4.0 with significance defined as p < 0.05. RESULTS: The cohort (n = 111) had a mean age of 69 years and was 75% male (83/111). Comorbidities documented prior to index hospitalization included hypertension (85%, 94/111), diabetes mellitus (57%, 63/111), coronary artery disease (CAD) (47%, 52/111), and at least one prior cardiac surgery or intervention (31%, 34/111). Support was planned in 30% (33/111) of cases and unplanned in 70% (78/111). 30-day survival was 89.2% (99/111) and 1-year survival of 74.8% (83/111). No statistically significant differences in mortality were observed according to performance of concomitant procedures or operative time periods (2018-2020 vs. 2021-2025). CONCLUSION: In high-risk low-EF patients undergoing CABG, TMFP support during the same hospitalization was associated with acceptable 30-day and 1-year survival outcomes among patients considered unsuitable for PCI and/or advanced therapies at the time of surgery. Mortality was not significantly different among patients undergoing concomitant procedures or between planned vs. unplanned TMFP placement. These findings support TMFP's growing role in complex coronary surgeries and warrant further studies to define optimal application and surgical candidacy.
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Predictors of extubation failure during ongoing VA-ECMO support after cardiac surgery.
Clinical takeaway Extubation failure was common in this postoperative VA-ECMO cohort and associated with adverse outcomes. These findings identify potential risk markers, rather than establish criteria for extubation decisions.
Summary & abstract
Study summary
This retrospective single-centre study included 186 adults extubated during ongoing VA-ECMO after cardiac surgery. Unplanned reintubation within seven days occurred in 44 patients (23.6%), mainly because of acute respiratory failure or neurological impairment. Extubation failure was associated with fewer ventilator-free days, longer ICU stay, and higher short- and long-term mortality. Renal replacement therapy during ICU stay was independently associated with failure (adjusted odds ratio 3.209, 95% confidence interval 1.418–7.467); older age and massive intraoperative transfusion were also associated with failure, while effective post-extubation cough was associated with success.
Study limitation: The retrospective, single-centre design limits generalisability and cannot establish whether extubation failure caused the associated adverse outcomes.
Published abstract
BACKGROUND: As earlier extubation strategies expand during VA-ECMO support, data on predictors of extubation failure remain scarce. OBJECTIVES: We aimed to identify factors associated with extubation failure in cardiac surgery patients extubated during ongoing VA-ECMO support. METHODS: We conducted a retrospective single-center study including all adult patients extubated while receiving VA-ECMO between January 2016 and December 2020. The primary outcome was extubation failure, defined as unplanned reintubation within 7 days. Secondary outcomes included ventilator-free days, ICU and hospital length of stay, and mortality at 28 days and 1 year. RESULTS: A total of 186 patients were included. Median VA-ECMO duration was 9 days [6-14]. Extubation failure occurred in 44 patients (23.6%), mainly due to acute respiratory failure or neurological impairment. Extubation failure was associated with fewer ventilator-free days, longer ICU stay, and higher short- and long-term mortality. In multivariable analysis, older age (aOR 1.053, 95% CI 1.017-1.094; p = 0.006), renal replacement therapy during ICU stay (aOR 3.209, 95% CI 1.418-7.467; p = 0.006), and massive intraoperative transfusion (aOR 4.091, 95% CI 1.753-10.212; p = 0.002) were independently associated with extubation failure, whereas effective post-extubation cough was associated with success (aOR 0.116, 95% CI 0.033-0.368; p < 0.001). CONCLUSIONS: Extubation failure during ongoing VA-ECMO was frequent and associated with adverse outcomes. Markers of global vulnerability and airway protection may be more informative than conventional respiratory and hemodynamic parameters when assessing the risk of extubation failure in this population.
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