Transatlantic analysis of patient profiles and mid-term survival after isolated coronary artery bypass grafting: a head-to-head comparison between the European DuraGraft Registry and the US STS Registry

Introduction: Although cardiovascular surgery societies in Europe and the USA constantly strive for the exchange of knowledge and best practices in coronary artery bypass grafting (CABG), the available evidence on whether such efforts result in similar patient outcomes is limited. Therefore, in the present analysis, we sought to compare patient profiles and overall survival outcomes for up to 3 years between large European and US patient cohorts who underwent isolated CABG.

Methods: Patients from the European DuraGraft Registry (n = 2,522) who underwent isolated CABG at 45 sites in eight different European countries between 2016 and 2019 were compared to randomly selected patients from the US STS database who were operated during the same period (n = 294,725). Free conduits (venous and arterial grafts) from the DuraGraft Registry patients were intraoperatively stored in DuraGraft, an endothelial damage inhibitor, before anastomosis, whereas grafts from the STS Registry patients in standard-of-care solutions (e.g., saline). Propensity score matching (PSM) models were used to account for differences in patient baseline and surgical characteristics, using a primary PSM with 35 variables (2,400 patients matched) and a secondary PSM with 25 variables (2,522 patients matched, sensitivity analysis). The overall survival for up to 3 years after CABG was assessed as the primary endpoint.

Results: The comparison of patient profiles showed significant differences between the European and US cohorts. The European patients had more left main disease, underwent more off-pump CABG, and received more arterial grafts together with more complete arterial grafting procedures. In contrast, the US patients received more distal anastomoses with more saphenous vein grafts (SVGs) that were mainly harvested endoscopically. Such differences, however, were well balanced after PSM for the mortality comparison. Mortality comparison at 30 days, 12 months, and 24 months between the European and US patients was 2.38% vs. 1.96%, 4.32% vs. 4.79%, and 5.38% vs. 6.96%, respectively. At 36 months, the mortality was significantly lower in the European patients than that of their US counterparts (7.37% vs. 9.65%; p-value = 0.016). The estimated hazard ratio (HR) was 1.29 (95% CI 1.05-1.59).

Conclusion: This large-scale transatlantic comparative analysis shows that there are some significant differences in patient profiles between large cohorts of European and US patients. These differences were adjusted by using PSM for the mortality analysis. No significant difference in mortality was detected between groups through 2 years, but survival was significantly better in the European DuraGraft Registry patients at 3 years post-CABG.

Outcomes following heart valve surgery in patients with infective endocarditis and preoperative septic cerebral embolism: insights from the CAMPAIGN study group

Objectives: This study aimed to analyse the impact of preoperative septic cerebral embolism on early and late postoperative outcomes in patients with infective endocarditis undergoing valve surgery.

Methods: Retrospective multicentric study based on the Clinical Multicentric Project for Analysis of Infective Endocarditis in Germany (CAMPAIGN) registry comprising patients with infective endocarditis who underwent valve surgery between 1994 and 2018 at 6 German centres. Patients were divided into 2 groups for statistical comparison according to the presence or absence of preoperative septic cerebral embolism. Propensity score matching was performed for adjusted comparisons of postoperative outcomes. Primary outcomes were 30-day mortality and estimated 5-year survival.

Results: A total of 4917 patients were included in the analysis, 3909 (79.5%) patients without and 1008 (20.5%) patients with preoperative septic cerebral embolism. Patients with preoperative septic cerebral embolism had more baseline comorbidities. Mitral valve endocarditis (44.1% vs 33.0% P < 0.001), large vegetations >10 mm (43.1% vs 30.0%, P < 0.001), and Staphylococcus species infection (42.3% vs 21.3%, P < 0.001) were more frequent in the cerebral embolism group. Among patients with preoperative cerebral embolism, 286 (28.4%) patients had no stroke signs (silent stroke). After matching (1008 matched pairs), there was no statistically significant difference in 30-day mortality (20.1% vs 22.8%; P = 0.14) and 5-year survival (47.8% vs 49.1%; stratified log-rank P = 0.77) in patients with and without preoperative cerebral embolism, respectively.

Conclusions: Preoperative septic cerebral embolism in patients with infective endocarditis requiring valve surgery does not negatively affect early or late mortality; therefore, it should not play a major role in deciding if surgery is to be performed.

Sex-related differences in patients with infective endocarditis requiring cardiac surgery: insights from the CAMPAIGN Study Group

Objectives: Sex-related differences play a role in cardiovascular disease-related outcomes. There is, however, a knowledge gap regarding sex-specific differences in patients with infective endocarditis (IE)-requiring surgical treatment. This study aims to analyse sex-related differences in the clinical presentation, treatment and clinical outcomes of patients with IE-requiring surgical treatment from the multicentric Germany-wide CAMPAIGN registry.

Methods: Patients with IE who underwent cardiac surgery between 1994 and 2018 at six German centres were retrospectively analysed. Outcomes were compared based on patients’ sex. Primary outcomes were 30-day mortality and mid-term survival.

Results: A total of 4917 patients were included in the analysis (1364 female [27.7%] and 3553 male [72.3%]). Female patients presented with more comorbidities and higher surgical risk (EuroScore II 12.0% vs 10.0%, P < 0.001). The early postoperative course of female patients was characterized by longer ventilation times (20.0 h vs 16.0 h; P = 0.004), longer intensive care unit stay (4.0 days vs 3.0 days; P < 0.001), and more frequent new-onset dialysis (265 [20.3%] vs 549 [16.3%]; P = 0.001). The 30-day mortality was 13.8% and 15.5% in female and male patients, respectively (P = 0.06). The estimated mid-term survival was significantly higher amongst male patients (56.1% vs 45.4%; Log-rank P < 0.001). Female sex was an independent predictor of mid-term mortality (HR 1.2 [95% CI 1.0-1.4], P = 0.01).

Conclusions: Male patients more frequently undergo cardiac surgery for IE. However, female patients have a higher surgical risk profile and subsequently an increased early postoperative morbidity, but with similar 30-day mortality compared with male patients. The estimated mid-term survival is lower amongst female patients.

Preventing Sheep Carotid Artery Spasm for Vascular Graft Surgery and Computed Tomography Angiography

The development of small-diameter vascular grafts requires testing in large animal models before advancing to clinical trials. Vascular graft interposition implantation in sheep carotid arteries (CAs) is the most widely used model, but ovine CAs are prone to severe spasm following surgical manipulation, potentially impairing graft performance assessment. There is paucity in the literature on reducing sheep CA spasm using effective vasodilator therapeutic protocols. In this study, four healthy Merino cross White Suffolk wethers (1-2 years, 52.1 ± 0.8 kg) underwent CT angiography and CA graft surgery. CT angiography using iodinated contrast agent was performed with innominate artery access through the CA or ascending aortic arch access through the femoral artery. Sheep then underwent right CA sham surgery or left CA vascular graft implantation. A variety of vasodilators, including papaverine, sodium nitroprusside, verapamil, and their combination, were tested for preventing or treating CA spasms intraoperatively. Blood flow was reassessed immediately after CA surgery using CT angiography. The results showed that innominate artery access through the CA for CT angiography in sheep induced presurgical CA spasm with reduced arterial flow. Conversely, ascending aortic arch access through the femoral artery for CT angiography did not cause CA spasm and maintained arterial flow. During CA graft surgery, surgical trauma induced CA spasm, which was prevented by localized intra-arterial administration of vasodilators papaverine hydrochloride and verapamil before significant surgical manipulation.

Cellular heterogeneity of pluripotent stem cell-derived cardiomyocyte grafts is mechanistically linked to treatable arrhythmias

Preclinical data have confirmed that human pluripotent stem cell-derived cardiomyocytes (PSC-CMs) can remuscularize the injured or diseased heart, with several clinical trials now in planning or recruitment stages. However, because ventricular arrhythmias represent a complication following engraftment of intramyocardially injected PSC-CMs, it is necessary to provide treatment strategies to control or prevent engraftment arrhythmias (EAs). Here, we show in a porcine model of myocardial infarction and PSC-CM transplantation that EAs are mechanistically linked to cellular heterogeneity in the input PSC-CM and resultant graft. Specifically, we identify atrial and pacemaker-like cardiomyocytes as culprit arrhythmogenic subpopulations. Two unique surface marker signatures, signal regulatory protein α (SIRPA)+CD90CD200+ and SIRPA+CD90CD200, identify arrhythmogenic and non-arrhythmogenic cardiomyocytes, respectively. Our data suggest that modifications to current PSC-CM-production and/or PSC-CM-selection protocols could potentially prevent EAs. We further show that pharmacologic and interventional anti-arrhythmic strategies can control and potentially abolish these arrhythmias.

Systematic review and meta-analysis of two decades of reported outcomes for robotic coronary artery bypass grafting

Background: Despite the well-documented safety and feasibility of robotic coronary artery bypass grafting (CABG), widespread adoption of this approach remains limited by its steep learning curve, high procedural costs and paucity of data on longer-term efficacy. This current meta-analysis aims to provide a systematic overview of the outcomes of robot-assisted CABG, with a focus on long term graft patency and freedom from major adverse cardiac and cerebrovascular events (MACCE).

Methods: A systematic literature search of three electronic databases was conducted for studies reporting outcomes of robotic-assisted CABG, and were grouped based on whether patients underwent robot-assisted minimally invasive direct coronary artery bypass (RA-MIDCAB), totally endoscopic coronary artery bypass (TECAB) or were mixed. Perioperative and mid-to-long term results from included studies were pooled using meta-analysis of proportion or means in a random effects model.

Results: In the quantitative analysis, thirty-nine eligible studies included 6,152 patients who underwent RA-MIDCAB, 1,729 patients who underwent TECAB and 21,642 patients who underwent either form of robot-assisted CABG. A high level of heterogeneity was observed amongst baseline characteristics. Perioperative mortality and complication rates were low. Conversion rate to full sternotomy overall was less than 3.2% [95% confidence interval (CI): 2.1-5.2%, I2=39%]. At a mean follow-up duration of 5.2 years, overall graft patency was 96% for both RA-MIDCAB and TECAB, and freedom from major adverse cardiac events (MACE) or MACCE was 83.2% (95% CI: 72.0-90.4%; I2=90%) for RA-MIDCAB and 91.6% (95% CI: 86.6-94.9%; I2=76%) for TECAB.

Conclusions: Robot-assisted CABG is observed to have acceptable perioperative and mid-to-long term outcomes with promising overall graft patency.

Predictors of surgical intervention in first episode primary spontaneous pneumothorax requiring chest drain insertion

Background: Primary spontaneous pneumothorax occurs in patients with no underlying lung disease and guidelines recommend chest tube drainage for the first episode, with surgical intervention reserved for recurrent episodes, persistent air leak or failure of lung re-expansion. Modern surgical management is associated with reduced length of hospital stay and superior freedom from recurrence compared with chest tube drainage alone. The objective of this study was to identify risk factors for failed chest tube drainage in patients who present with first episode primary spontaneous pneumothorax.

Methods: A retrospective analysis of patients who presented to Royal Prince Alfred Hospital, Australia with first episode PSP and underwent chest tube insertion was performed. Patient demographics and size of pneumothorax were examined in relation to the primary outcome, a composite of failed chest tube drainage and recurrent ipsilateral pneumothorax.

Results: Fifty-five patients underwent chest tube drainage for first episode primary spontaneous pneumothorax between 1st January 2017 and 31st December 2020. Complete lung collapse on admission chest x-ray was associated with an increased risk of the primary outcome (63% versus 19%, OR 7.3 [96% CI 2.0-27.4), P = 0.004).

Conclusion: This small retrospective study found that patients that undergo chest drain insertion for first episode primary spontaneous pneumothorax who present with complete lung collapse on admission are at high risk of requiring pleurodesis and therefore may benefit from early surgical referral.

Comparison of modified Del Nido and Custodiol® cardioplegia in minimally invasive mitral valve surgery

Objectives: In this study, we evaluated if modified Del Nido cardioplegia delivers comparable cardiac protection in comparison to Custodiol® in patients undergoing isolated minimally invasive mitral valve repair.

Methods: From January 2018 to October 2021, all patients undergoing non-emergent isolated minimally invasive mitral valve repair were included in this study. The cardioplegia was chosen at the surgeons’ discretion. The primary end points of this study were peak postoperative cardiac enzyme levels. Secondary end points were in-hospital mortality, hospital stay, occurrence of cardiac arrhythmias, pacemaker implantations, postoperative lactate and sodium levels and postoperative incidence of renal failure requiring dialysis.

Results: A total of 355 patients were included in this study. The mean age of patients was 57. After propensity score matching, a total of 156 pairs were identified. There was no difference in cross-clamp time between both groups. Postoperative creatine kinase levels were higher in patients receiving Custodiol on the 1st and 2nd postoperative days. Creatine kinase isoenzyme MB levels were higher in patients receiving Custodiol on the 2nd postoperative day (0.5 ± 0.2 vs 0.4 ± 0.1 µmol/l s; P < 0.001). Postoperative Troponin T concentrations were similar between both groups. Maximum lactate concentrations were higher in patients receiving Custodiol on the day of surgery (2.4 ± 1.9 vs 2.0 ± 1.1 mmol/l; P = 0.04). The overall hospital stay was longer in patients receiving Del Nido cardioplegia (10.6 ± 3.2 vs 8 ± 4.1 days; P < 0.01).

Conclusions: Modified Del Nido cardioplegia based on Ionosteril® solution offers equivalent protection compared to Custodiol for isolated minimally invasive mitral valve repair.

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