Michael Z. L. Zhu

Late right heart failure (LRHF) following left ventricular assist device (LVAD) implantation remains an under-recognized complication with significant impact on patient outcomes. We conducted a retrospective cohort study of 183 consecutive LVAD patients at our institution between 2010 and 2024. LRHF was defined according to the 2020 Mechanical Circulatory Support Academic Research Consortium criteria. Clinical, echocardiographic, and perioperative parameters were analyzed with group comparisons and logistic regression, whereas outcomes were evaluated using Kaplan–Meier and competing-risk analyses. LRHF occurred in 17% of patients at a median of 8.8 months following LVAD implantation. Patients with LRHF had larger preoperative right ventricular (RV) basal diameters. Early right heart failure (ERHF) and RV basal diameter were independently associated with LRHF development. LRHF patients had significantly longer intensive care unit and hospital stays, higher rates of chest re-exploration, acute kidney injury, ventricular arrhythmias, and significantly more heart failure-related readmissions. Although overall survival was lower among LRHF patients, it did not reach statistical significance ( p = 0.06). In conclusion, LRHF remains a frequent and morbid complication after LVAD implantation. Early recognition of RV dysfunction may help identify patients at risk of developing LRHF.

OBJECTIVES: A best evidence topic was written according to a structured protocol described in ICVTS. The question addressed was ‘In patients with vasoplegic syndrome following cardiac surgery with cardiopulmonary bypass, does adjunctive methylene blue improve outcomes including reduced mortality, morbidity and vasopressor requirements?’ METHODS: Ovid Medline was searched using a reported search algorithm. Articles that represented the best evidence to answer the clinical question were selected, tabulated and discussed. RESULTS: Seven articles were selected: 4 randomized controlled trials and 3 observational studies. Studies were single centre with sample sizes ranging from 30 to 120 patients. Two studies reported a significant reduction in mortality among patients who received adjunctive methylene blue for post-cardiopulmonary bypass (CPB) vasoplegic syndrome compared with placebo or standard therapy. Four studies reported improved haemodynamic stability and reduced vasopressor requirements following methylene blue. No studies reported methylene blue-related adverse events or worse outcomes compared to controls or standard therapy. There was significant heterogeneity among the included studies in terms of the timing and dosage of methylene blue therapy as well as the definition of vasoplegic syndrome. CONCLUSIONS: The summation of the best available evidence, which was limited to small clinical trials and observational studies, suggests that the adjunctive administration of methylene blue for refractory post-CPB vasoplegic syndrome is safe and may provide benefits in terms of improved haemodynamic stability, reduction in vasopressor requirements and reduced mortality. Questions surrounding the optimal timing of methylene blue administration, as prophylactic, adjunctive, or rescue therapy for vasoplegic syndrome, require further investigation.

Summary: A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was ‘For patients with malignant pleural effusion is chemical pleurodesis with povidone-iodine as effective, safe and well tolerated as talc pleurodesis for prevention of recurrent malignant pleural effusions?’. A total of 124 papers were found during the search, of which 8 represented the best evidence to answer the clinical question. The authors, journal, date, country of publication, patient group studied, study type, relevant outcomes and results of these papers were tabulated. At present, medical-grade talc is the most commonly used agent for chemical pleurodesis due to its high success rate, extensive history of clinical use and well-known side-effect profile. However, studies using povidone-iodine seek to establish it as a readily available,low-cost alternative to talc that can be easily administered through an intercostal catheter at the bedside. The summation of available evidence suggests that povidone-iodine is a safe, well-tolerated and equally efficacious agent for pleurodesis in the setting of malignant pleural effusion, when compared to talc.

Background: Infective endocarditis (IE) is a morbid condition with high mortality. We investigated predictors of in‐hospital mortality and embolic phenomena in a contemporary Australasian cohort.Methods: We identified all patients with IE admitted between January 2017 and 30th April 2020 (40 months). Patient characteristics, risk factors and clinical outcomes were retrospectively collected and analysed.Results: One hundred and seventy‐two consecutive patients (mean age: 56.8 ± 17.9 years, male: 63%, 114/172) were included. Causative organisms were Staphylococcus aureus (44%, 75/172), Enterococcus faecalis (15%, 26/172), Streptococcus mitis (6%, 10/172) and Staphylococcus epidermidis (3%, 6/172). In‐hospital mortality was 15% (25/172). Embolic complications were found among 57% (98/172) of patients, the most common being stroke (23%, 40/172), septic pulmonary emboli (17%, 29/172), splenic and/or renal emboli (17%, 26/172) and peripheral limb emboli (15%, 25/172). Sixty (35%, 60/172) patients underwent cardiac surgery. On multivariable analysis, independent predictors of in‐hospital mortality were: increased age (odds ratio: 1.064, per year older, P = 0.001), ICU admission independent of cardiac surgery (OR 9.81, P < 0.001), moderate or severe LV impairment (OR 5.19, P = 0.012) and any sign of embolic phenomena to limbs (OR 5.02, P = 0.006). Multivariable predictors of embolic complications were S. aureus bacteraemia (OR 3.22, P = 0.001) and large vegetation >10 mm (OR 3.04, P = 0.002).Conclusion: We demonstrate predictors of in‐hospital mortality and embolic phenomena in our cohort. Though age remains a consistent predictor of mortality, surprisingly, signs of embolic phenomena to the limbs was established as an independent predictor of mortality. The mechanism of this is unclear and warrants further evaluation.

Background: Veno-arterial extracorporeal membrane oxygenation (VA ECMO) is increasingly utilized in patients with cardiogenic shock due to improved technology and outcomes. Peripheral VA ECMO offers several advantages over central ECMO and is becoming increasingly popular. However, when configured via the femoral vessels, retrograde flow to the descending aorta and arch of aorta competes with antegrade ventricular output and can be associated with a watershed phenomenon and increased risk of neurologic and visceral injury. Case summary: In this case series, we report three patients who were supported with peripheral VA ECMO for cardiogenic shock. All three were successfully weaned from peripheral VA ECMO; however, they had developed bilateral lower limb paralysis. Magnetic resonance imaging revealed spinal cord infarction in all three patients. All patients subsequently succumbed to multiorgan failure and did not survive to hospital discharge. Discussion: The use of mechanical circulatory support, in particular, peripheral ECMO, has escalated with advances in technology, better understanding of cardiac physiology and improving outcomes. Spinal cord infarction is a rare but serious complication of peripheral VA ECMO support with only a few case reports published. Further studies are needed to identify the exact cause and prevention of this rare but often terminal complication. Through this series of three patients supported on peripheral VA ECMO complicated by spinal cord infarction, we review previously published reports, analyse possible mechanisms, and propose alternate management strategies to be considered in patients at risk.

A best evidence topic was written according to a structured protocol. The question addressed was: ‘Does continuation of antifibrotics before lung transplantation (LTx) influence post-transplant outcomes in patients with idiopathic pulmonary fibrosis (IPF) with regard to mortality, bronchial anastomotic dehiscence, reoperation for bleeding and wound complications, primary graft dysfunction or longer-term survival and allograft rejection?’ A total of 261 articles were found using the reported search strategy, of which 7 represented the best evidence to answer the clinical question. Six out of 7 studies demonstrated equivalent post-transplant survival among IPF patients on antifibrotics before LTx compared with controls. Five out of 6 studies showed no increase in the risk of major bleeding, wound or bronchial anastomotic complications. One bi-institutional study found a higher incidence of early bronchial anastomotic dehiscence, but this difference was not statistically significant after longer term follow-up. In a study that only included IPF patients who underwent single LTx, a lower incidence of grade 3 primary graft dysfunction was reported in the antifibrotic group compared with controls. Overall, to date, only small (N < 40 in the antifibrotic group), non-risk-adjusted, retrospective observational studies have been published. Notwithstanding, the summation of available evidence suggests that, in IPF patients, continuation of antifibrotic therapy before LTx is likely safe, and the rates of perioperative bleeding, wound or bronchial anastomotic complications, as well as 30-day and 1-year survival, are similar to patients not on antifibrotics before LTx.

Background Acute kidney injury (AKI) is common after cardiac surgery requiring cardiopulmonary bypass. Renal hypoxia may precede clinically detectable AKI. We compared the efficacy of two indices of renal hypoxia, (i) intraoperative urinary oxygen tension (UPO₂) and (ii) the change in plasma erythropoietin (pEPO) during surgery, in predicting AKI. We also investigated whether the performance of these prognostic markers varies with preoperative patient characteristics. Methods In 82 patients undergoing on-pump cardiac surgery, blood samples were taken upon induction of anesthesia and upon entry into the intensive care unit. UPO₂ was continuously measured throughout surgery. Results Thirty-two (39%) patients developed postoperative AKI. pEPO increased during surgery, but this increase did not predict AKI, regardless of risk of postoperative mortality assessed by EuroSCORE-II. For patients categorized at higher risk by EuroSCORE-II >1.98 (median score for the cohort), UPO₂ ≤10 mmHg at any time during surgery predicted a 4.04-fold excess risk of AKI (p = .04). However, UPO₂ did not significantly predict AKI in lower-risk patients. UPO₂ significantly predicted AKI in patients who were older, had previous myocardial infarction, diabetes, lower preoperative serum creatinine, or shorter bypass times. pEPO and UPO₂ were only weakly correlated. Conclusions Intraoperative change in pEPO does not predict AKI. However, UPO₂ shows promise, particularly in patients with higher risk of operative mortality. The disparity between these two markers of renal hypoxia may indicate that UPO₂ reflects medullary oxygenation whereas pEPO reflects cortical oxygenation.