Julia Stein

Background: Surgically implanted microaxial flow pumps (mAFP) are increasingly used for cardiogenic shock treatment. Standard mAFP explantation is performed bedside with a shortening of the vascular prosthesis, which may represent a potential source of infection in future. We analyzed the impact of gentamicin‐impregnated collagen sponge (GICS) application in the wound during mAFP explantation on the incidence of prosthetic graft infections. Methods: Between 01/2020 and 07/2024, 235 patients underwent bedside full‐support mAFP explantation at our institution. Since 11/2022, GICS has been routinely applied in 115 patients, while 120 previously were treated without it. Results: In the GICS‐group, after a median follow‐up of 221 [24; 351] days, 17 (14.8%) patients developed graft infection, resulting in 0.23 events per patient year (EPPY); surgery was necessary in 16 patients (13.9%). In the control group, after a median follow‐up of 399 [113; 654] days, infection occurred in 14 (11.7%) cases, 0.10 EPPY; surgical removal of the graft was necessary in 12 (10%). The GICS‐groups presented an increased risk for graft infections: sHR 2.49 [1.11; 5.59], p = 0.027. After propensity score matching for relevant demographic parameters, there was no significant difference in the risk reduction of total graft infections sHR 1.92 [0.79; 4,72], p = 0.15. Conclusions: Local application of GICS did not reduce the risk of access site infections in patients undergoing bedside explantation of mAFP from the graft surgically anastomosed to an axillary artery.

Objectives: External compression of the outflow graft causing obstruction (eOGO) is a potentially lethal complication in patients on long‐term mechanical circulatory support with the HeartMate 3 (HM3, Abbott) left ventricular assist device (LVAD). This complication results from the build‐up of gelatinous substance between the bend relief and outflow graft and can be resolved by percutaneous intervention, surgery, or transplantation. This single‐centre follow‐up study evaluated the suitability of percutaneous intervention as a treatment strategy and long‐term outcomes of eOGO patients in terms of laboratory, LVAD, and quality‐of‐life parameters. Methods: On October 31, 2024, a search of the implantation centre's electronic database identified HM3 patients diagnosed with eOGO. Individual patient data concerning 31 cases was analyzed. A quality‐of‐life survey was conducted using the short version of the Kansas City Cardiomyopathy Questionnaire (KCCQ‐12). Results: The patient cohort had a median support time to eOGO diagnosis of 1219 days [976, 1917] and a post‐treatment follow‐up of 686 days [447, 1003]. 64.5% of patients ( n = 20) underwent percutaneous intervention showing immediate LVAD flow improvement of 0.5 L/min post‐intervention ( p = 0.04). Of eight post‐interventional survey respondents, 62.5% ( n = 5) were assigned a fair‐excellent health status according to the KCCQ‐12. Conclusions: Percutaneous intervention is a suitable treatment strategy for eOGO, resolving low flow and providing satisfactory long‐term quality of life outcomes. Given the increasing eOGO incidence after 1 year of support and overall mortality of 29.0%, clinicians should remain on high alert for this complication. We suggest computed tomography (CT) imaging be considered early on when eOGO is suspected.

Introduction: Left ventricular assist devices (LVAD) have become an established therapy for end‐stage heart failure over the last three decades. In currently available devices, the blood flow is estimated using a power consumption algorithm. In this study, intraoperative direct LVAD flow measurement with an ultrasonic flow probe was analyzed. Methods: As part of our routine evaluation of optimal LVAD flow, intraoperative direct flow measurement at the outflow graft was performed using a 14‐mm ultrasonic flow probe. Direct LVAD flow measurements were performed at different speed levels: 4400 rpm, 4800 rpm, 5200 rpm, and the optimal flow setting before chest closure. In twenty consecutive patients who underwent a durable LVAD implantation via median sternotomy in our institution between January and April 2025, direct flow measurement was compared with the estimated flow provided by the device. Results: Median age was 63 [60;68] years, 17 (85%) were male, 8 (40%) had a history of acute myocardial infarction. Temporary mechanical circulatory support with a microaxial flow pump was necessary in 8 (40%) patients prior to durable LVAD implantation. Destination therapy was indicated in 12 (60%) cases. Mean flows at 4400 rpm were 2.9 ± 0.3 and 3.4 ± 0.4 L/min calculated by the pump and measured by the probe, respectively. Mean difference between the measurements was 0.56 L/min (95% CI [0.40, 0.70], p < 0.001). Mean flows at 4800 rpm were 3.5 ± 0.3 and 4.1 ± 0.5 L/min, respectively. Mean difference between the measurements was 0.55 L/min (95% CI [0.33, 0.77], p < 0.001). Mean flows at 5200 rpm were 4.2 ± 0.3 and 4.7 ± 0.5 L/min, respectively. Mean difference between the measurements was 0.53 L/min (95% CI [0.40, 0.70], p = 0.001). Mean optimal speed for patients was 5400 rpm, mean difference between the measurements was 0.49 L/min (95% CI [0.23, 0.74], p = 0.001). Conclusion: LVAD flow measured with an ultrasonic flow probe shows significantly higher results (approximately +0.5 L/min) compared to the flow estimated by the device. The difference remains constant at different LVAD speed modes. Intraoperative flow measurement employing an ultrasonic flow probe is a valuable tool for hemodynamic evaluation during implantation of a durable LVAD.

Background: The HeartMate 3 (HM3, Abbott) left ventricular assist device (LVAD) is the only commercially available option considered suitable for long-term circulatory support. External compression of the outflow graft causing obstruction (eOGO) is a serious adverse event affecting patients on long-term support. The obstruction occurs due to the accumulation of gelatinous substance between the bend relief and outflow graft. This systematic review evaluated all available studies with regard to the diagnosis and therapy of eOGOs. Methods: A systematic literature review and analysis of individual patient data was performed using MEDLINE/PubMed following PRISMA guidelines. Original works dating up to 31 October 2024 were considered. Results: Twenty-four publications that met the inclusion criteria were identified, providing individual data from 113 patients with a median support time to eOGO diagnosis of 809 days [588, 1095] and follow-up after treatment of 365 days [33, 605]. eOGO severity classification was performed on 108 patients according to our grading system. For treatment, most patients underwent surgery (n = 38) or stenting (n = 29). A hazard ratio of 0.75 [0.28, 2.03] was calculated for the surgical group versus the stenting group (p = 0.570). Conclusions: Concerning 30-day mortality, we did not find a significant difference between the eOGO severity of survivors and non-survivors. We found no significant differences in outcome between patients with differing eOGO severity and treatment strategy, namely stenting and surgery. Due to an increase in eOGO incidence after one year of support, we propose that clinicians monitor their patients for this complication when support time surpasses one year.

Background: Driveline infections (DLI) are a serious complication in patients with left ventricular assist devices (LVAD). Apart from the differentiation between superficial and deep DLI, there is no consensus on the classification of the severity of DLI. Little is known about risk factors and typical bacteria causing DLI in centrifugal‐flow LVADs.Methods: In this single‐center study with 245 patients, DLI were classified by their local appearance using a modification of a score suggested by the Sharp Memorial group. The driveline exit site was inspected routinely every 6 months.Results: Severe DLI were detected in 34 patients (15%) after 6 months and in 24 patients (22%) after 24 months. The proportion of patients with DLI increased significantly during the follow‐up (p = 0.0096). The most common bacteria in local smears were Corynebacterium, coagulase‐negative Staphylococcus, and Staphylococcus aureus. Fifty‐nine patients were hospitalized more than once for DLI. In these patients, S. aureus was the most common bacterium. It was also the most common bacterium in blood cultures. Higher BMI, no partnership, and a HeartMate 3 device were identified as risk factors for DLI in a multivariable cause‐specific Cox regression.Conclusion: This study is a standardized analysis of DLI in a large cohort with centrifugal‐flow LVADs.

Impact of prior sternotomy on survival and allograft function after heart transplantation: a single-center matched analysisPrior sternotomy versus primary heart transplantEditorialE. Potapov, J. SteinIn the presented study, the authors showed that prior sternotomy in heart transplant candidates does not impact survival after heart transplantation (reference). The analysis was performed between 106 propensity score-matched pairs (212 patients).The results of published studies are contradictory and confusing. The small, single-center study published by Sert D, 2020, showed an increased early mortality in HTx recipients with prior sternotomy1, with no increased bleeding risk and a similar 4-year survival. In contrast, yet another single-center study with a similar design –no sternotomy vs. VAD-supported vs. prior sternotomy other than for VAD– published by Gaffey in 2015 showed no differences regarding early and long-term mortality, but a significantly higher risk of postoperative bleeding and a greater use of blood products2. A further single-center study with a comparable number of patients published in 2018 by Still S yet again showed that HTx recipients with prior sternotomy required more blood transfusions and showed an increased incidence in postoperative pneumonia, wound infection, and longer hospital stays. A stepwise multivariable regression model identified prior sternotomy as a predictor of primary graft dysfunction with a subsequently higher short-term and 1-year mortality3. However, in these studies the impact of confounding variables was not eliminated.Having said that, the presented study attempts to overcome imbalances in confounding variables by comparing survival and complications between propensity score-matched patient groups. The matching procedure was based on established risk factors including recipients’ baseline characteristics, donor age, sex mismatch, risk scores, ECLS, PVR, serum creatinine, and serum bilirubin, and ultimately produced 106 matched pairs. However, the benefit of balanced confounders is achieved at the cost of a reduced number of patients and therefore less power to detect differences between patient groups. The lack of significant differences in this study cannot merely be explained by a low power, but is instead due to the similarity of effects: Authors report a 30-day mortality of 5.7 % for prior sternotomy vs. 7.5 % for first-time sternotomy and no impact of prior sternotomy on long-term survival with an HR of 0.87 [95% CI: 0.57, 1.56]. Contradicting the above-mentioned studies, these results do not even come close to indicating a trend towards worse long- and short-term survival for patients with prior sternotomy. This also holds true for long-term survival in the unmatched population of 131 patients with and 381 patients without redo surgery.Now how about a larger registry-based analysis? An analysis based on the UNOS database comprising 11,266 patients showed that prior sternotomy was associated with an excess 3.3 % mortality and higher morbidity within the first 60 days after heart transplantation, as measured by the frequency of dialysis, drug-treated infections, and strokes. Conditional 5-year survival after 60 days is unaffected by prior sternotomy4. Five years later, another group performed an analysis of the same UNOS database (meanwhile comprising 14,730 patients) and showed again that prior sternotomy is a risk factor for worse survival after cardiac transplantation, mainly due to an increased early postoperative mortality5.Why are we interested in knowing the effect of prior sternotomy on post-transplant outcomes? Since a prospective, randomized study is not possible due to ethical reasons, we have to rely on retrospective analyses. From a practical perspective, a comparison is meaningless – patients with prior sternotomy would never be refused for HTx due to this fact alone, even if we knew that morbidity and mortality in these patients may be higher.In our opinion, such an analysis may be performed to identify and support the advantages of less invasive LVAD implantation regarding the outcome of later HTx, as was performed in a first analysis of 46 patients (sic!, the lowest number of patients among the discussed studies) published by Riebandt J, 20216. The study showed that patients supported with LVAD implanted via full sternotomy required more packed red blood cells with no increased risk of bleeding, and subsequently developed more donor-specific antibodies, however, without any impact on short- and long-term survival, similar to the studies discussed above2,3.However, the virgin chest is not comparable to that of patients supported with an LVAD implanted via a less invasive approach, even if no7 or partial sternotomy8 is performed. In either of the groups the pericardium remains intact. Regardless of the technique used, the left pleura is opened, as is the pericardium around the ascending aorta and the apex of the right and left ventricles, and the graft is placed into the pericardial space, causing adhesions making any efforts to suggest, that the HTx in the “virgin chest”is similar to that after less invasive LVAD implantation not appropriate.Finally, the authors should nonetheless be congratulated on their outstanding surgical experience and the resulting very good outcomes in HTx – better than in the majority of centers worldwide.References1. Sert DE, Kervan Ü, Kocabeyoğlu SS, et al. Early and long-term results of heart transplantation with reoperative sternotomy. Turk gogus kalp damar cerrahisi dergisi 2020;28:120-6.2. Gaffey AC, Phillips EC, Howard J, et al. Prior Sternotomy and Ventricular Assist Device Implantation Do Not Adversely Impact Survival or Allograft Function After Heart Transplantation. The Annals of thoracic surgery 2015;100:542-9.3. Still S, Shaikh AF, Qin H, et al. Reoperative sternotomy is associated with primary graft dysfunction following heart...

Background: The literature on outcomes of patients requiring durable mechanical circulatory support (MCS) after extra-corporeal life support (ECLS) is limited. The aim of this study was to investigate the impact of preoperative ECLS cannulation on postoperative outcome after durable MCS implantation. Methods: The durable MCS after ECLS registry is a multicenter retrospective study that gathered data on consecutive patients who underwent durable MCS implantation after ECLS between January 2010 and August 2018 in eleven high volume European centers. Patients who underwent the implantation of total artificial heart, pulsatile pumps, or first-generation pumps after ECLS were excluded from the analysis. The remaining patients were divided into two groups; central ECLS group (cECLS) and peripheral ECLS group (pECLS). A 1:1 propensity score analysis was performed to identify two matched groups. The outcome of these two groups was compared. Results: A total of 531 durable MCS after ECLS were implanted during this period. The ECLS cannulation site was peripheral in 87% (n=462) and central in 13% (n=69) of the patients. After excluding pulsatile pumps and total artificial heart patients, a total of 494 patients remained (pECLS =434 patients, cECLS =60 patients). A 1:1 propensity score analysis resulted in 2 matched groups (each 55 patients) with median age of 54 years (48–60 years) in cECLS group and 54 years (43–60 years) in pECLS group. HeartWare HVAD (Medtronic, Minneapolis, MN) was implanted in the majority of the patients (cECLS =71% vs. pECLS =76%, P=0.67). All postoperative morbidities were comparable between the groups. The thirty-day, one year and long-term survival was comparable between the groups (P=0.73). Conclusions: The cannulation strategy of ECLS appears to have no impact on the post-operative outcome after durable MCS implantation.

Microaxial LVADs are increasingly used for cardiogenic shock treatment. We compared the short-term outcome of patients supported with different microaxial devices for cardiogenic shock. A retrospective propensity score-adjusted analysis was performed in cardiogenic shock patients treated with either the Impella CP (n=64) or the Impella 5.0/5.5 (n=62) at two tertiary cardiac care centers between 1/14 and 12/19. Patients in the Impella CP group were significantly older (69.6±10.7 vs 58.7±11.9 years, p=0.001), more likely in an INTERMACS level 1 (76.6% vs 50%, p=0.003) and post CPR (36% vs 13%, p=0.006). The unadjusted 30-day survival was significantly higher in Impella 5.0/5.5 group (58% vs 36%, p=0.021, odds ratio (OR) for 30-day survival on Impella 5.0/5.5 was 3.68 (95% CI [1.46-9.90], p=0.0072). After adjustment, the 30-day survival was similar for both devices (OR 1.23, 95% CI [0.34-4.18], p=0.744). Lactate levels above 8 mmol/L and preoperative CPR were associated with a significant mortality increase in both cohorts (OR=10.7, 95% CI [3.45-47.34], p<0.001; OR=13.2, 95% CI [4.28-57.89], p<0.001, respectively). Both Impella devices offer a similar effect with regards to survival in cardiogenic shock patients. Preoperative CPR or lactate levels exceeding 8 mmol/L immediately before implantation have a poor prognosis on Impella CP and Impella 5.0/5.5.