Dismal prognosis of patients with operative indication without surgical intervention in active left-sided infective endocarditis

Introduction

Around 25% of patients with left-sided infective endocarditis and operative indication do not undergo surgery. Baseline characteristics and outcomes are underreported. This study describes characteristics and outcomes of surgical candidates with surgical intervention or medical treatment only.

Methods

Retrospective analysis of ongoing collected data from a single-center from an observational cohort of patients with infective endocarditis (ENVALVE). Kaplan-Meier estimates for survival was calculated. Factors associated with survival were assessed using a bivariable Cox model. To adjust for confounding by indication, uni- and multivariable logistic regression for the propensity to receive surgery were adjusted.

Results

From January 2018 and December 2021, 154 patients were analyzed: 116 underwent surgery and 38 received medical treatment only. Surgical candidates without surgery were older (70 vs. 62 years, p = 0.001). They had higher preoperative risk profile (EuroSCORE II 14% (7.2-28.6) vs. 5.8% (2.5-20.3), p = 0.002) and more comorbidities. One patient was lost-to-follow-up. Survival analysis revealed a significant higher one-year survival rate among patients following surgery (83.7% vs. 15.3% in the non-surgical group; log-rank test <0.0001). In the final multivariable adjusted model, surgery was less likely among patients with liver cirrhosis [OR = 0.03 (95% CI 0.00-0.30)] and with hemodialysis [OR = 0.014 (95% CI 0.00-0.47)].

Conclusion

Patients with left-sided infective endocarditis who do not undergo surgery despite an operative indication are older, have more comorbidities and therefore higher preoperative risk profile and a low 1-year survival. The role of the Endocarditis Team may be particularly important for the decision-making process in this specific group.

Hyperoxia-induced deterioration of diastolic function in anaesthetised patients with coronary artery disease - Randomised crossover trial

Background

There are no current recommendations for oxygen titration in patients with stable coronary artery disease. This study investigates the effect of iatrogenic hyperoxia on cardiac function in patients with coronary artery disease undergoing general anaesthesia.

Methods

Patients scheduled for elective coronary artery bypass graft surgery were prospectively recruited into this randomised crossover clinical trial. All patients were exposed to inspired oxygen fractions of 0.3 (normoxaemia) and 0.8 (hyperoxia) in randomised order. A transoesophageal echocardiographic imaging protocol was performed during each exposure. Primary analysis investigated changes in 3D peak strain, whereas secondary analyses investigated other systolic and diastolic responses.

Results

There was no statistical difference in systolic function between normoxaemia and hyperoxia. However, the response in systolic function to hyperoxia was dependent on ventricular function at normoxaemia. Patients with a normoxaemic left ventricular (LV) global longitudinal strain (GLS) poorer than the derived cut-off (>-15.4%) improved with hyperoxia (P<0.01), whereas in patients with normoxaemic LV-GLS <-15.4%, LV-GLS worsened with transition to hyperoxia (P<0.01). The same was seen for right ventricular GLS with a cut-off at -24.1%. Diastolic function worsened during hyperoxia indicated by a significant increase of averaged E/e' (8.6 [2.6]. vs 8.2 [2.4], P=0.01) and E/A ratio (1.4 (0.4) vs 1.3 (0.4), P=0.01).

Conclusions

Although the response of biventricular systolic variables is dependent on systolic function at normoxaemia, diastolic function consistently worsens under hyperoxia. In coronary artery disease, intraoperative strain analysis may offer guidance for oxygen titration.

Clinical trial registration

NCT04424433.

Twenty-five year experience with aortic valve-sparing root replacement in a single teaching center

Objectives

Aortic valve-sparing root replacement (AVSRR) is a technically demanding procedure. In experienced centers it offers excellent short- and long-term results, making the procedure an attractive alternative for aortic root replacement especially in young patients. The aim of this study was to analyze long-term results of AVSRR using the David operation in our institution over the last 25 years.

Methods

This is a single-center retrospective analysis of outcomes of David operations performed in a teaching institution not running a large AVSRR-program. Pre-, intra- and postoperative data were collected from the institutional electronic medical record system. Follow-up data were collected through direct contact of the patients and their cardiologists/primary care physicians.

Results

Between 02/1996 and 11/2019, 131 patients underwent David operation in our institution by a total of 17 different surgeons. Median age was 48 (33–59), 18% were female. Elective surgery was performed in 89% of the cases, 11% were operated as emergency in the setting of an acute aortic dissection. Connective tissue disease was present in 24% and 26% had a bicuspid aortic valve. At hospital admission 61% had aortic regurgitation grade ≥3, 12% were in functional NYHA-class ≥III. 30-day mortality was 2%, 97% of the patients were discharged with aortic regurgitation ≤2. In 10-year follow-up, 15 (12%) patients had to be re-operated because of root-related complications. Seven patients (47%) received a transcatheter aortic valve implantation, 8 (53%) required surgical replacement of the aortic valve or a Bentall-De Bono operation. Estimated reoperation-free survival at 5 and 10 years was 93.5% ± 2.4% and 87.0% ± 3.5%, respectively. Subgroup analysis showed no differences in reoperation-free survival for patients presenting with a bicuspid valve or preoperative aortic regurgitation ≥3. However a preoperative left ventricular end diastolic diameter of ≥5.5 cm was associated with worse outcome.

Conclusion

David operations can be performed with excellent perioperative and 10-year follow-up outcomes in centers not running large AVSRR-programs.

Mitochondrial Damage-associated Molecular Patterns as Potential Biomarkers in DCD Heart Transplantation: Lessons From Myocardial Infarction and Cardiac Arrest

Heart transplantation with donation after circulatory death (DCD) has become a real option to increase graft availability. However, given that DCD organs are exposed to the potentially damaging conditions of warm ischemia before procurement, new strategies for graft evaluation are of particular value for the safe expansion of DCD heart transplantation. Mitochondria-related parameters are very attractive as biomarkers because of their intimate association with cardiac ischemia-reperfusion injury. In this context, a group of mitochondrial components, called mitochondrial damage-associated molecular patterns (mtDAMPs), released by stressed cells, holds great promise. mtDAMPs may be released at different stages of DCD cardiac donation and may act as indicators of graft quality. Because of the lack of information available for DCD grafts, we consider that relevant information can be obtained from other acute cardiac ischemic conditions. Thus, we conducted a systematic review of original research articles in which mtDAMP levels were assessed in the circulation of patients with acute myocardial infarction and cardiac arrest. We conclude that 4 mtDAMPs, ATP, cytochrome c, mitochondrial DNA, and succinate, are rapidly released into the circulation after the onset of ischemia, and their concentrations increase with reperfusion. Importantly, circulating levels of mtDAMPs correlate with cardiac damage and may be used as prognostic markers for patient survival in these conditions. Taken together, these findings support the concept that mtDAMPs may be of use as biomarkers to assess the transplant suitability of procured DCD hearts, and ultimately aid in facilitating the safe, widespread adoption of DCD heart transplantation.

Sutureless versus rapid deployment aortic valve replacement: results from a multicentric registry

BACKGROUND

To compare clinical and hemodynamic in-hospital outcomes of patients undergoing sutureless versus rapid deployment aortic valve replacement (SURD-AVR) in the large population of the Sutureless and Rapid Deployment International Registry (SURD-IR).

METHODS

We examined 4695 patients who underwent isolated or combined SURD-AVR. The "sutureless" Perceval valve was used in 3133 patients and the "rapid deployment" Intuity in 1562. Potential confounding factors were addressed by the use of propensity score matching. After matching, 2 well-balanced cohorts of 823 pairs (isolated SURD-AVR) and 467 pairs (combined SURD-AVR) were created.

RESULTS

Patients who received Perceval and Intuity valves showed similar in-hospital mortality and rate of major postoperative complications. Perceval was associated shorter cross clamp and cardiopulmonary bypass time. In the isolated SURD-AVR group, patients receiving Perceval were more likely to undergo anterior right thoracotomy incision. Postoperative transvalvular gradients were significantly lower for the Intuity valve compared to those of the Perceval valve, either in isolated and combined SURD-AVR. The Intuity valve was associated with a lower rate of postoperative mild aortic regurgitation.

CONCLUSIONS

Our results confirm the safety and efficacy of SURD-AVR regardless of the valve type. The Perceval valve was associated with reduced operative times and increased anterior right thoracotomy incision. The Intuity valve showed superior hemodynamic outcomes and a lower incidence of postoperative mild aortic regurgitation.

Study design for a randomized crossover study investigating myocardial strain analysis in patients with coronary artery disease at hyperoxia and normoxemia prior to coronary artery bypass graft surgery (StrECHO-O2)

BACKGROUND

Supplemental oxygen (O₂) is used routinely during anesthesia. In the treatment of acute myocardial infarction, it has been established that hyperoxia is to be avoided, whereas information on benefit and risk of hyperoxia in patients with stable coronary artery disease (CAD) remain scarce, especially in the setting of general anesthesia. This study will compare the immediate effects of normoxemia and hyperoxia on cardiac function, with a primary focus on changes in peak longitudinal left-ventricular strain, in anesthetized stable chronic CAD patients using peri-operative transesophageal echocardiography (TEE).

METHODS

A single-center randomized cross-over clinical trial will be conducted, enrolling 106 patients undergoing elective coronary artery bypass graft surgery. After the induction of anesthesia and prior to the start of surgery, cardiac function will be assessed by 2D and 3D TEE. Images will be acquired at two different oxygen states for each patient in randomized order. The fraction of inspired oxygen (F_IO₂) will be titrated to a normoxemic state (oxygen saturation of 95-98%) and adjusted to a hyperoxic state (F_IO₂ = 0.8). TEE images will be analyzed in a blinded manner for standard cardiac function and strain parameters.

CONCLUSION

By using myocardial strain assessed by TEE, early and subtle signs of biventricular systolic and diastolic dysfunction can be promptly measured intraoperatively prior to the onset of severe signs of ischemia. The results may help anesthesiologists to better understand the effects of F_IO₂ on cardiac function and potentially tailor oxygen therapy to patients with CAD undergoing general anesthesia.

Effects of graft preservation conditions on coronary endothelium and cardiac functional recovery in a rat model of donation after circulatory death

BACKGROUND

Use of cardiac grafts obtained with donation after circulatory death (DCD) could significantly improve donor heart availability. As DCD hearts undergo potentially deleterious warm ischemia and reperfusion, clinical protocols require optimization to ensure graft quality. Thus, we investigated effects of alternative preservation conditions on endothelial and/or vascular and contractile function in comparison with the current clinical standard.

METHODS

Using a rat DCD model, we compared currently used graft preservation conditions, St. Thomas n°2 (St. T) at 4°C, with potentially more suitable conditions for DCD hearts, adenosine-lidocaine preservation solution (A-L) at 4°C or 22°C. Following general anesthesia and diaphragm transection, hearts underwent either 0 or 18 min of in-situ warm ischemia, were explanted, flushed and stored for 15 min with either St. T at 4°C or A-L at 4°C or 22°C, and then reperfused under normothermic, aerobic conditions. Endothelial integrity and contractile function were determined.

RESULTS

Compared to 4°C preservation, 22°C A-L significantly increased endothelial nitric oxide synthase (eNOS) dimerization and reduced oxidative tissue damage (p < 0.05 for all). Furthermore, A-L at 22°C better preserved the endothelial glycocalyx and coronary flow compared with St. T, tended to reduce tissue calcium overload, and stimulated pro-survival signaling. No significant differences were observed in cardiac function among ischemic groups.

CONCLUSIONS

Twenty-two-degree Celsius A-L solution better preserves the coronary endothelium compared to 4°C St. T, which likely results from greater eNOS dimerization, reduced oxidative stress, and activation of the reperfusion injury salvage kinase (RISK) pathway. Improving heart preservation conditions immediately following warm ischemia constitutes a promising approach for the optimization of clinical protocols in DCD heart transplantation.

Minimally invasive access type related to outcomes of sutureless and rapid deployment valves

OBJECTIVES

Minimally invasive surgical techniques with optimal outcomes are of paramount importance. Sutureless and rapid deployment aortic valves are increasingly implanted via minimally invasive approaches. We aimed to analyse the procedural outcomes of a full sternotomy (FS) compared with those of minimally invasive cardiac surgery (MICS) and further assess MICS, namely ministernotomy (MS) and anterior right thoracotomy (ART).

METHODS

We selected all isolated aortic valve replacements in the Sutureless and Rapid Deployment Aortic Valve Replacement International Registry (SURD-IR, n = 2257) and performed propensity score matching to compare aortic valve replacement through FS or MICS (n = 508/group) as well as through MS and ART accesses (n = 569/group).

RESULTS

Postoperative mortality was 1.6% in FS and MICS patients who had a mean logistic EuroSCORE of 11%. Cross-clamp and cardiopulmonary bypass (CPB) times were shorter in the FS group than in the MICS group (mean difference 3.2 and 9.2 min; P < 0.001). Patients undergoing FS had a higher rate of acute kidney injury (5.6% vs 2.8%; P = 0.012). Direct comparison of MS and ART revealed longer mean cross-clamp and CPB times (12 and 16.7 min) in the ART group (P < 0.001). The postoperative outcome revealed a higher stroke rate (3.2% vs 1.2%; P = 0.043) as well as a longer postoperative intensive care unit [2 (1-3) vs 1 (1-3) days; P = 0.009] and hospital stay [11 (8-16) vs 8 (7-12) days; P < 0.001] in the MS group than in the ART group.

CONCLUSIONS

According to this non-randomized international registry, FS resulted in a higher rate of acute kidney injury. The ART access showed a lower stroke rate than MS and a shorter hospital stay than all other accesses. All these findings may be related to underlying patient risk factors.

Hypothermic, oxygenated perfusion (HOPE) provides cardioprotection via succinate oxidation prior to normothermic perfusion in a rat model of donation after circulatory death (DCD)

In donation after circulatory death (DCD), cardiac grafts are subjected to warm ischemia in situ, prior to a brief period of cold, static storage (CSS) at procurement, and ex situ, normothermic, machine perfusion (NMP) for transport and graft evaluation. Cold ischemia and normothermic reoxygenation during NMP could aggravate graft injury through continued accumulation and oxidation, respectively, of mitochondrial succinate, and the resultant oxidative stress. We hypothesized that replacing CSS with hypothermic, oxygenated perfusion (HOPE) could provide cardioprotection by reducing cardiac succinate levels before NMP. DCD was simulated in male Wistar rats. Following 21 minutes in situ ischemia, explanted hearts underwent 30 minutes hypothermic storage with 1 of the following: (1) CSS, (2) HOPE, (3) hypothermic deoxygenated perfusion (HNPE), or (4) HOPE + AA5 (succinate dehydrogenase inhibitor) followed by normothermic reperfusion to measure cardiac and metabolic recovery. After hypothermic storage, tissue ATP/ADP levels were higher and succinate concentration was lower in HOPE vs CSS, HNPE, and HOPE + AA5 hearts. After 60 minutes reperfusion, cardiac function was increased and cellular injury was decreased in HOPE compared with CSS, HNPE, and HOPE + AA5 hearts. HOPE provides improved cardioprotection via succinate oxidation prior to normothermic reperfusion compared with CSS, and therefore is a promising strategy for preservation of cardiac grafts obtained with DCD.

Cardiac Graft Assessment in the Era of Machine Perfusion: Current and Future Biomarkers

Heart transplantation remains the treatment of reference for patients experiencing end‐stage heart failure; unfortunately, graft availability through conventional donation after brain death is insufficient to meet the demand. Use of extended‐criteria donors or donation after circulatory death has emerged to increase organ availability; however, clinical protocols require optimization to limit or prevent damage in hearts possessing greater susceptibility to injury than conventional grafts. The emergence of cardiac ex situ machine perfusion not only facilitates the use of extended‐criteria donor and donation after circulatory death hearts through the avoidance of potentially damaging ischemia during graft storage and transport, it also opens the door to multiple opportunities for more sensitive monitoring of graft quality. With this review, we aim to bring together the current knowledge of biomarkers that hold particular promise for cardiac graft evaluation to improve precision and reliability in the identification of hearts for transplantation, thereby facilitating the safe increase in graft availability. Information about the utility of potential biomarkers was categorized into 5 themes: (1) functional, (2) metabolic, (3) hormone/prohormone, (4) cellular damage/death, and (5) inflammatory markers. Several promising biomarkers are identified, and recommendations for potential improvements to current clinical protocols are provided.

Long-term outcome of patients with Marfan syndrome with previous aortic surgery but native aortic roots

OBJECTIVES

The goal of this study was to report the long-term outcomes of patients with Marfan syndrome who had aortic surgery on any aortic segment except for the replacement of the aortic root itself.

METHODS

An observational retrospective single-centre study was conducted with 115 Marfan syndrome patients who underwent 189 major aortic interventions from 1995 until 2018. Patients without aortic root replacement were identified and aortic root growth was analysed over time.

RESULTS

Eleven of 115 patients (9.5%) did not have aortic root replacement during a follow-up of 10.5 [standard deviation (SD) 5.7] years and a mean age at last follow-up of 53.9 (SD 13.4) years. Patients without root replacement did not suffer less frequently from any type of acute aortic dissection (type A 27% vs 25%, P = 0.999; type B 36% vs 25%, P = 0.474). Patients with native aortic roots did not undergo fewer aortic interventions than those with aortic root replacement [12/11, mean 1.09 (SD 0.54) operations/patient vs 177/104, mean 1.7 (SD 1.3); P = 0.128]. Progression of the aortic root dimension was 0.5 (SD 0.3) mm/year in the group of patients with native aortic roots.

CONCLUSIONS

Current data suggest that 10% of patients with Marfan syndrome with previous aortic surgery will be free from aortic root replacement until the sixth decade of life.

Minimally invasive aortic valve replacement with sutureless and rapid deployment valves: a report from an international registry (Sutureless and Rapid Deployment International Registry)†

OBJECTIVES

The impact of sutureless and rapid deployment (SURD) valves on the clinical outcomes of patients undergoing minimally invasive aortic valve replacement (MI-AVR) has still to be defined. The aim of this study was to assess clinical characteristics and in-hospital results of patients receiving SURD-AVR through less invasive approaches in the large population of the Sutureless and Rapid Deployment International Registry (SURD-IR).

METHODS

Of the 1935 patients who received primary isolated SURD-AVR between 2009 and 2018, a total of 1418 (73.3%) underwent MI interventions and were included in this analysis. SURD-AVR was performed using upper ministernotomy in 56.4% (n = 800) of cases and anterior right thoracotomy in 43.6% (n = 618). Perceval S was implanted in 1011 (71.3%) patients and Edwards Intuity or Intuity Elite in 407 (28.7%) patients.

RESULTS

Overall in-hospital mortality and stroke rates were 1.7% and 2%, respectively. A definitive pacemaker implantation was reported in 9% of cases and significantly decreased over the observational period, from 20.6% to 5.6% (P = 0.002). The Perceval valve was associated with shorter operative times and was more frequently implanted in patients receiving anterior right thoracotomy incision. The Intuity valve was preferred in younger patients and revealed superior postoperative haemodynamic results.

CONCLUSIONS

SURD-AVR was largely performed through less invasive approaches and can be considered as a primary indication in MI surgery. In the SURD-IR cohort, MI SURD-AVR using both Perceval and Intuity valves appeared a safe and reproducible procedure associated with promising early results.

Operative outcome of patients at low, intermediate, high and 'very high' surgical risk undergoing isolated aortic valve replacement with sutureless and rapid deployment prostheses: results of the SURD-IR registry

OBJECTIVES

The ideal strategy for the treatment of severe aortic valve stenosis in patients of varying risk categories has become a debated topic in the last years: should the transcatheter or surgical approach be adopted? The aim of this study was to evaluate the outcomes of low-, intermediate-, high- and very high-risk patients undergoing sutureless, rapid deployment aortic valve replacement.

METHODS

From 2007 to 2017, data on a total of 3651 patients were collected from the Sutureless and Rapid Deployment Aortic Valve Replacement International Registry (SURD-IR). Of these, 2057 patients who underwent primary isolated aortic valve replacement were considered for this analysis and classified as being at low (EuroSCORE <5; n = 500), intermediate (EuroSCORE 5-10; n = 901), high (EuroSCORE 11-20; n = 500) and very high (EuroSCORE >20; n = 156) preoperative risk.

RESULTS

Overall, a less invasive approach was used in 74.1% of patients and represented the most frequent (>50%) approach in all risk categories. The Perceval prosthesis was used more frequently than other devices, especially in patients at high and very high risk. Hospital mortality was 1.6%, 0.8%, 1.9% and 2.7% in low-, intermediate-, high- and very high-risk patients, respectively, with no significant differences among subgroups. Similarly, postoperative complication rates were similar across the different risk categories.

CONCLUSIONS

Surgical aortic valve replacement using sutureless, rapid deployment biological valve prostheses is associated with excellent results and represents a safe and effective treatment option for patients with severe aortic valve stenosis. This seems to be particularly true in patients with a higher risk profile.

Sutureless and rapid deployment implantation in bicuspid aortic valve: results from the sutureless and rapid-deployment aortic valve replacement international registry

Background

Benefits of sutureless and rapid deployment (SURD) bioprostheses in bicuspid aortic valves (BAV) are controversial. The aim of this study is to report the outcomes of patients undergoing aortic valve replacement (AVR) for BAV from the Sutureless and Rapid-Deployment Aortic Valve Replacement International Registry (SURD-IR).

Methods

Of the 4,636 patients who received primary isolated SURD-AVR between 2007 and 2018, 191 (4.1%) BAV patients underwent AVR with SURD valve.

Results

Overall 30-day mortality was 1.6%. The Intuity valve was implanted in 53.9% of cases, whereas the Perceval was implanted in 46.1%. Rate of stroke for isolated AVR was 4.2%. No case of endocarditis, thromboembolism, myocardial infarction, valve dislocation or structural valve deterioration was reported in the early phase. Rate of pacemaker implantation and moderate-severe aortic regurgitation (AR) were 7.9% and 3.7%, respectively.

Conclusions

BAV is not considered a contraindication for the implantation of SURD valves. However, detailed information of aortic root geometry as well as the knowledge of some technical considerations are mandatory for a good outcome.

Current trends of sutureless and rapid deployment valves: an 11-year experience from the Sutureless and Rapid Deployment International Registry

OBJECTIVES

Current evidence on sutureless and rapid deployment aortic valve replacement (SURD-AVR) is limited and does not allow for the assessment of the clinical impact and the evolution of procedural and clinical outcomes of this new valve technology. The Sutureless and Rapid Deployment International Registry (SURD-IR) represents a unique opportunity to evaluate the current trends and outcomes of SURD-AVR interventions.

METHODS

Data from 3682 patients enrolled between 2007 and 2018 were analysed. Patients were divided according to the date of surgery into 6 equal groups and by the type of intervention: isolated SURD-AVR (n = 2472) and combined SURD-AVR (n = 1086).

RESULTS

Across the 11-year study period, significant changes occurred in patient characteristics including a decrease in age and in estimated surgical risk. Less invasive approaches for isolated SURD-AVR increased considerably from 49.4% to 85.5%. The overall in-hospital mortality rate was 1.6% and 3.9% in isolated and combined procedures, respectively, with no change over time. The rate of perioperative stroke decreased significantly (from 4% to 0.5%), as did the rates of postoperative pacemaker implantation (from 12.8% to 5.9%) and aortic regurgitation (from 17.8% to 2.7%).

CONCLUSIONS

The present study provides a comprehensive analysis of the current trends and results of SURD-AVR interventions. The most notable changes over time were the increasing implantation of SURD valves in a younger population, with more frequent utilization of less invasive techniques. SURD-AVR demonstrated remarkable improvements in clinical outcomes with a significant reduction in the rates of stroke, pacemaker implantation and postoperative aortic regurgitation.

Heart Transplantation With Donation After Circulatory Death

Heart transplantation remains the preferred option for improving quality of life and survival for patients suffering from end-stage heart failure. Unfortunately, insufficient supply of cardiac grafts has become an obstacle. Increasing organ availability with donation after circulatory death (DCD) may be a promising option to overcome the organ shortage. Unlike conventional donation after brain death, DCD organs undergo a period of warm, global ischemia between circulatory arrest and graft procurement, which raises concerns for graft quality. Nonetheless, the potential of DCD heart transplantation is being reconsidered, after reports of more than 70 cases in Australia and the United Kingdom over the past 3 years. Ensuring optimal patient outcomes and generalized adoption of DCD in heart transplantation, however, requires further development of clinical protocols, which in turn require a better understanding of cardiac ischemia-reperfusion injury and the various possibilities to limit its adverse effects. Thus, we aim to provide an overview of the knowledge obtained with preclinical studies in animal models of DCD heart transplantation, to facilitate and promote the most effective and efficient advancement in preclinical research. A literature search of the PubMed database was performed to identify all relevant preclinical studies in DCD heart transplantation. Specific aspects relevant for DCD heart transplantation were analyzed, including animal models, graft procurement and storage conditions, cardioprotective approaches, and graft evaluation strategies. Several potential therapeutic strategies for optimizing graft quality are identified, and recommendations for further preclinical research are provided.

Minimally Invasive Redo Aortic Valve Replacement: Results From a Multicentric Registry (SURD-IR)

BACKGROUND

Reoperation for aortic valve replacement can be challenging and is usually associated with an increased risk for complications and mortality. The study aim was to report the results of a multicenter cohort of patients who underwent minimally invasive reoperative aortic valve replacement with a sutureless or rapid-deployment prosthesis.

METHODS

From 2007 to 2018 data from 3651 patients were retrospectively collected from the Sutureless and Rapid-Deployment Aortic Valve Replacement International Registry. Of them, 63 patients who had previously undergone cardiac surgery represented the study population. In-hospital clinical and echocardiographic outcomes were recorded.

RESULTS

Mean age of the selected 63 patients was 75.3 ± 7.8 years and logistic EuroSCORE 10.1. Surgery was performed by ministernotomy in 43 patients (68.3%) and by anterior right thoracotomy in 20 (31.7%); 31 patients (49.2%) received the Perceval valve (Livanova PLC, London, UK) and 32 (50.8%) the Intuity valve (Edwards Lifesciences, Irvine, CA). Mean cross-clamp time was 57.8 ± 23.2 minutes and cardiopulmonary bypass time 95.0 ± 34.3 minutes. Neither conversion to full sternotomy nor in-hospital deaths occurred. Postoperative events were ischemic cerebral events in 3 patients (4.8%), need for pacemaker implantation in 2 (3.6%), bleeding requiring reoperation in 5 (8.9%), and dialysis in 1 (1.6%). Median intensive care unit stay was 1 day, and median length of hospital stay was 10 days. On echocardiographic evaluation 1 patient showed a significant postoperative aortic regurgitation.

CONCLUSIONS

Minimally invasive reoperative aortic valve replacement with a sutureless or rapid-deployment prosthesis is a safe and feasible treatment strategy, resulting in fast recovery and improved postoperative outcome with no mortality and an acceptable complication rate.

Adding vancomycin to perioperative prophylaxis decreases deep sternal wound infections in high-risk cardiac surgery patients

OBJECTIVES

Perioperative prophylaxis with cephalosporins reduces sternal wound infections (SWIs) after cardiac surgery. However, more than 50% of coagulase-negative staphylococci, an important pathogen, are cephalosporin resistant. The aim of this study was to determine the impact of adjunctive vancomycin on SWIs in high-risk patients.

METHODS

We conducted a pre- and postintervention study in an academic hospital. Preintervention (2010-2011), all patients received prophylaxis with 1.5 g of cefuroxime for 48 h. During the intervention period (2012-2013), high-risk patients additionally received 1 g of vancomycin. High-risk status was defined as body mass index ≤18 or ≥ 30 kg/m2, reoperation, renal failure, diabetes mellitus, chronic obstructive pulmonary disease or immunosuppressive medication. Time series analysis was performed to study SWI trends and logistic regression to determine the effect of adding vancomycin adjusting for high-risk status.

RESULTS

A total of 3902 consecutive patients (n = 1915 preintervention and n = 1987 postintervention) were included, of which 1493 (38%) patients were high-risk patients. In the high-risk group, 61 of 711 (8.6%) patients had SWI before and 30 of 782 (3.8%) patients after the intervention. Focusing on deep SWI (DSWI), 33 of 711 (4.6%) patients had DSWI before and 13 of 782 (1.7%) patients afterwards; the absolute risk difference of 2.9% yielded a number-needed-to-treat of 34 to prevent 1 DSWI. Corrected for high-risk status, adding vancomycin significantly reduced the overall SWI rate (odds ratio 0.42, 95% confidence interval 0.26-0.67; P < 0.001) and the subset of DSWI (odds ratio 0.30, 95% confidence interval 0.14-0.62; P = 0.001). The rate of SWI in low-risk patients remained unchanged.

CONCLUSIONS

Adding vancomycin to standard antibiotic prophylaxis in high-risk patients significantly reduced DSWI after cardiac surgery.

Cardioprotective reperfusion strategies differentially affect mitochondria: Studies in an isolated rat heart model of donation after circulatory death (DCD)

Donation after circulatory death (DCD) holds great promise for improving cardiac graft availability; however, concerns persist regarding injury following warm ischemia, after donor circulatory arrest, and subsequent reperfusion. Application of preischemic treatments is limited for ethical reasons; thus, cardioprotective strategies applied at graft procurement (reperfusion) are of particular importance in optimizing graft quality. Given the key role of mitochondria in cardiac ischemia-reperfusion injury, we hypothesize that 3 reperfusion strategies-mild hypothermia, mechanical postconditioning, and hypoxia, when briefly applied at reperfusion onset-provoke mitochondrial changes that may underlie their cardioprotective effects. Using an isolated, working rat heart model of DCD, we demonstrate that all 3 strategies improve oxygen-consumption-cardiac-work coupling and increase tissue adenosine triphosphate content, in parallel with increased functional recovery. These reperfusion strategies, however, differentially affect mitochondria; mild hypothermia also increases phosphocreatine content, while mechanical postconditioning stimulates mitochondrial complex I activity and reduces cytochrome c release (marker of mitochondrial damage), whereas hypoxia upregulates the expression of peroxisome proliferator-activated receptor-gamma coactivator (regulator of mitochondrial biogenesis). Characterization of the role of mitochondria in cardioprotective reperfusion strategies should aid in the identification of new, mitochondrial-based therapeutic targets and the development of effective reperfusion strategies that could ultimately facilitate DCD heart transplantation.

Acute Pulmonary Embolectomy Three Days following a Coronary Artery Bypass Graft Procedure

Pulmonary embolism is very rarely reported early after cardiac surgery, most probably due to full heparinisation during cardiopulmonary bypass. We report a 66-year-old man without thromboembolic history who presented three days after a coronary artery bypass grafting procedure with acute dyspnoea and haemodynamic instability. A CT scan confirmed paracentral bilateral pulmonary embolism requiring an urgent and successful embolectomy. Review of the literature confirms that pulmonary embolism may occur in up to 3% of post-cardiopulmonary bypass patients.

The possibility of pulmonary embolism must be taken into consideration in post-cardiopulmonary bypass patients with acute onset of chest pain and respiratory insufficiency.

Mitochondrial integrity during early reperfusion in an isolated rat heart model of donation after circulatory death-consequences of ischemic duration

BACKGROUND

Cardioprotection and graft evaluation after ischemia-reperfusion (IR) are essential in facilitating heart transplantation with donation after circulatory death. Given the key role of mitochondria in IR, we aimed to investigate the tolerance of cardiac mitochondria to warm, global ischemia and to determine the predictive value of early reperfusion mitochondria-related parameters for post-ischemic cardiac recovery.

METHODS

Isolated, working rat hearts underwent 0, 21, 24, 27, 30, or 33 minutes of warm, global ischemia, followed by 60 minutes of reperfusion. Functional recovery (developed pressure × heart rate) was determined at 60 minutes of reperfusion, whereas mitochondrial integrity was measured at 10 minutes of reperfusion.

RESULTS

Functional recovery at 60 minutes of reperfusion decreased with ≥ 27 minutes of ischemia vs no ischemia (n = 7-8/group; p < 0.01). Cytochrome c, succinate release, and mitochondrial Ca²⁺ content increased with ≥ 27 minutes of ischemia vs no ischemia (p < 0.05). Ischemia at ≥ 21 minutes decreased mitochondrial coupling, adenosine 5'-triphosphate content, mitochondrial Ca²⁺ retention capacity, and increased oxidative damage vs no ischemia (p < 0.05). Reactive oxygen species (ROS) from reverse electron transfer increased with 21 and 27 minutes of ischemia vs no ischemia and 33 minutes of ischemia (p < 0.05), whereas ROS from forward electron transfer increased only with 33 minutes of ischemia vs no ischemia (p < 0.05). Mitochondrial coupling and adenosine 5'-triphosphate content correlated positively and cytochrome c, succinate, oxidative damage, and mitochondrial Ca²⁺ content correlated negatively with cardiac functional recovery (p < 0.05).

CONCLUSIONS

Mitochondrial dysfunction occurs with shorter periods of ischemia than cardiac dysfunction. Mitochondrial coupling, ROS emission from reverse electron transfer, and calcium retention are particularly sensitive to early reperfusion injury, reflecting potential targets for cardioprotection. Indicators of mitochondrial integrity may be of aid in evaluating suitability of donation after circulatory death grafts for transplantation.