Interstitial Pulmonary Fibrosis and Extensive Dendriform Ossification with Persistent Viral Load: A Rare Presentation of Post-COVID-19 Condition in Need of Lung Transplantation.

The incidence, presentation, and predisposing factors of post-acute sequelae of COVID-19 (PASC) are currently poorly understood. Lung explants may provide a rare insight into terminal SARS-CoV-2-associated lung damage and its pathophysiology. A 62-year-old man presented with progressively worsening respiratory symptoms after recovering from mild COVID-19 3 months earlier. No underlying pulmonary comorbidities were reported. A chest CT revealed bilateral extensive ground-glass and reticular opacities, suspicious of pulmonary fibrosis. Despite initial high-dose glucocorticoid therapy, the interstitial lung disease progressed, and after exhausting all viable therapeutic options, bilateral lung transplantation was successfully conducted. Histological analysis revealed extensive end-stage interstitial fibrosis with diffuse dendriform ossification and bronchiolar and transitional cell metaplasia. Signs of interstitial remodeling such as an increased interstitial collagen deposition, a pathological accumulation of CD163+/CD206+ M2-polarized macrophages with an increased expression of phosphorylated ERK, and an increased density of CD105+ newly formed capillaries were observed. qRT-PCR and immunohistochemistry for SARS-CoV-2 N-protein in the endothelium of medium-sized vessels confirmed a persistence of SARS-CoV-2. Our findings highlight a highly unusual presentation of SARS-CoV-2-associated lung fibrosis, implying that incomplete viral clearance in the vascular compartment may play a vital pathophysiological role in the development of PASC.

Upper Hemi-Sternotomy Provides Benefit for Patients with Isolated or Combined Mitral Valve Surgery.

Background and objectives: Certain clinical and anatomical conditions are absolute or relative contraindications for safe mitral valve surgery via the right mini-thoracotomy access. It is uncertain whether patients with these contraindications may benefit from the less invasive approach via upper hemi-sternotomy compared to standard full sternotomy. Materials and methods: Out of 2052 mitral valve surgery patients, operated from 6/04 through 2/19, 1535 were excluded due to the different criteria for eligibility to both approaches. Out of these, 350 received full sternotomy and 167 upper hemi-sternotomy. After propensity score matching, 164 pairs were analyzed for operative variables, postoperative complications and 30-day and one-year survival. Results: Upper hemi-sternotomy was associated with a survival benefit of 30 days (99.4% vs. 82.1%; p < 0.001) and one-year (93.9% vs. 79.9% p < 0.001, HR 0.26, 95% CI 0.14-0.49). Cardiopulmonary bypass and aortic cross-clamp times were comparable in both groups. Upper hemi-sternotomy resulted in less low cardiac output syndrome (18.9% vs. 31.1%; p = 0.011); ventilation time (8 vs. 13 h; p < 0.001), length of intensive care stay (1 vs. 2 days; p < 0.001) and total hospital stay (8 vs. 9 days; p < 0.001) were shorter in the upper hemi-sternotomy group. Conclusion: In patients undergoing mitral valve surgery, upper hemi-sternotomy is associated with short- and mid-term survival benefits as well as lower postoperative complication rates compared to full sternotomy. Hence, the less invasive upper hemi-sternotomy can be a valid approach in patients with contraindications for right mini-thoracotomy.

Impact of donor lung quality on post-transplant recipient outcome in the Lung Allocation Score era in Eurotransplant - a historical prospective study.

The aim of this study was to investigate whether there is an impact of donation rates on the quality of lungs used for transplantation and whether donor lung quality affects post-transplant outcome in the current Lung Allocation Score era. All consecutive adult LTx performed in Eurotransplant (ET) between January 2012 and December 2016 were included (N = 3053). Donors used for LTx in countries with high donation rate were younger (42% vs. 33% ≤45 years, P < 0.0001), were less often smokers (35% vs. 46%, P < 0.0001), had more often clear chest X-rays (82% vs. 72%, P < 0.0001), had better donor oxygenation ratios (20% vs. 26% with PaO2 /FiO2  ≤ 300 mmHg, P < 0.0001), and had better lung donor score values (LDS; 28% vs. 17% with LDS = 6, P < 0.0001) compared with donors used for LTx in countries with low donation rate. Survival rates for the groups LDS = 6 and ≥7 at 5 years were 69.7% and 60.9% (P = 0.007). Lung donor quality significantly impacts on long-term patient survival. Countries with a low donation rate are more oriented to using donor lungs with a lesser quality compared to countries with a high donation rate. Instead of further stretching donor eligibility criteria, the full potential of the donor pool should be realized.

Mitral Valve Surgery via Partial Upper Sternotomy: Closing the Gap between Conventional Sternotomy and Right Lateral Minithoracotomy.

BACKGROUND: Minithoracotomy (MT) has gained broad acceptance for mitral valve surgery (MVS) in the last decade. In the presence of defined limitations of MT, however, full sternotomy (FS) is still widely preferred. We assume that the less investigated partial upper sternotomy (PS) will permit the gap between MT and FS in MVS to be closed. The purpose of this study is to investigate a valid less invasive alternative to MT for isolated MVS or multivalve surgery. METHODS: This retrospective analysis includes data on 1,639 patients, who underwent either isolated or combined primary MVS at our department from May 2011 to August 2017. Out of these, 663 patients were operated via MT access. One-hundred three patients had been judged as not suitable for MT but feasible for PS approach in which 53.4% (n = 55) had isolated MVS and 46.6% patients (n = 48) underwent multivalve surgery. Concomitant myocardial revascularization was performed in 2.9% of the study patients (n = 3). RESULTS: Operative, 90-day, and 1-year mortality in the PS-cohort was 0, 1.0% (n = 1), and 3.3% (n = 3), respectively. During a median follow-up time of 1,115 days (interquartile range 398-1806), all-cause mortality was 5.8% (n = 6). Operative times for cardiopulmonary-bypass and cross-clamping were 167 minutes (140-198) and 107 minutes (93-132), respectively. Median length of stay at the intensive care unit and hospital was 1 (1-2) and 7 days (7-10), respectively. CONCLUSION: The presented results demonstrate that there is a cohort of patients, who are not candidates for MT in MVS but may be operated successfully by an alternative less invasive approach.

Lung allocation score: the Eurotransplant model versus the revised US model - a cross-sectional study.

Both Eurotransplant (ET) and the US use the lung allocation score (LAS) to allocate donor lungs. In 2015, the US implemented a new algorithm for calculating the score while ET has fine-tuned the original model using business rules. A comparison of both models in a contemporary patient cohort was performed. The rank positions and the correlation between both scores were calculated for all patients on the active waiting list in ET. On February 6th 2017, 581 patients were actively listed on the lung transplant waiting list. The median LAS values were 32.56 and 32.70 in ET and the US, respectively. The overall correlation coefficient between both scores was 0.71. Forty-three per cent of the patients had a < 2 point change in their LAS. US LAS was more than two points lower for 41% and more than two points higher for 16% of the patients. Median ranks and the 90th percentiles for all diagnosis groups did not differ between both scores. Implementing the 2015 US LAS model would not significantly alter the current waiting list in ET.

Clinical usefulness of gene-expression profile to rule out acute rejection after heart transplantation: CARGO II.

AIMS: A non-invasive gene-expression profiling (GEP) test for rejection surveillance of heart transplant recipients originated in the USA. A European-based study, Cardiac Allograft Rejection Gene Expression Observational II Study (CARGO II), was conducted to further clinically validate the GEP test performance. METHODS AND RESULTS: Blood samples for GEP testing (AlloMap(®), CareDx, Brisbane, CA, USA) were collected during post-transplant surveillance. The reference standard for rejection status was based on histopathology grading of tissue from endomyocardial biopsy. The area under the receiver operating characteristic curve (AUC-ROC), negative (NPVs), and positive predictive values (PPVs) for the GEP scores (range 0-39) were computed. Considering the GEP score of 34 as a cut-off (>6 months post-transplantation), 95.5% (381/399) of GEP tests were true negatives, 4.5% (18/399) were false negatives, 10.2% (6/59) were true positives, and 89.8% (53/59) were false positives. Based on 938 paired biopsies, the GEP test score AUC-ROC for distinguishing ≥3A rejection was 0.70 and 0.69 for ≥2-6 and >6 months post-transplantation, respectively. Depending on the chosen threshold score, the NPV and PPV range from 98.1 to 100% and 2.0 to 4.7%, respectively. CONCLUSION: For ≥2-6 and >6 months post-transplantation, CARGO II GEP score performance (AUC-ROC = 0.70 and 0.69) is similar to the CARGO study results (AUC-ROC = 0.71 and 0.67). The low prevalence of ACR contributes to the high NPV and limited PPV of GEP testing. The choice of threshold score for practical use of GEP testing should consider overall clinical assessment of the patient's baseline risk for rejection.

Performance of gene-expression profiling test score variability to predict future clinical events in heart transplant recipients.

BACKGROUND: A single non-invasive gene expression profiling (GEP) test (AlloMap®) is often used to discriminate if a heart transplant recipient is at a low risk of acute cellular rejection at time of testing. In a randomized trial, use of the test (a GEP score from 0-40) has been shown to be non-inferior to a routine endomyocardial biopsy for surveillance after heart transplantation in selected low-risk patients with respect to clinical outcomes. Recently, it was suggested that the within-patient variability of consecutive GEP scores may be used to independently predict future clinical events; however, future studies were recommended. Here we performed an analysis of an independent patient population to determine the prognostic utility of within-patient variability of GEP scores in predicting future clinical events. METHODS: We defined the GEP score variability as the standard deviation of four GEP scores collected ≥315 days post-transplantation. Of the 737 patients from the Cardiac Allograft Rejection Gene Expression Observational (CARGO) II trial, 36 were assigned to the composite event group (death, re-transplantation or graft failure ≥315 days post-transplantation and within 3 years of the final GEP test) and 55 were assigned to the control group (non-event patients). In this case-controlled study, the performance of GEP score variability to predict future events was evaluated by the area under the receiver operator characteristics curve (AUC ROC). The negative predictive values (NPV) and positive predictive values (PPV) including 95 % confidence intervals (CI) of GEP score variability were calculated. RESULTS: The estimated prevalence of events was 17 %. Events occurred at a median of 391 (inter-quartile range 376) days after the final GEP test. The GEP variability AUC ROC for the prediction of a composite event was 0.72 (95 % CI 0.6-0.8). The NPV for GEP score variability of 0.6 was 97 % (95 % CI 91.4-100.0); the PPV for GEP score variability of 1.5 was 35.4 % (95 % CI 13.5-75.8). CONCLUSION: In heart transplant recipients, a GEP score variability may be used to predict the probability that a composite event will occur within 3 years after the last GEP score. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT00761787.

Isolated annuloplasty in elderly patients with secondary mitral valve regurgitation: short- and long-term outcomes with a less invasive approach.

Background: Long-term outcomes of elderly and frail patients with secondary mitral valve regurgitation (MR) are inconclusive. Especially in patients with co-morbidities such as atherosclerosis who are suffering from heart failure, optimal medical therapy (OMT) is the preferred therapy relative to surgical or percutaneous interventions. It remains challenging to identify the most successful therapy to improve symptoms and increase life expectancy. To reduce surgical trauma for these patients, minimally invasive mitral valve surgery (MIMVS) was developed; this has shown promising medium-term results, but there is still a lack of evidence regarding long-term results. The aim of this investigation was to describe the long-term outcomes of less invasive mitral valve surgery (MVS) in elderly patients. Methods: In this longitudinal retrospective analysis, 67 patients (aged ≥70 years) with secondary MR who underwent MV repair ± tricuspid valve repair (TVR) were identified. MVS was performed via minithoracotomy (MT) in most cases (n = 54); in patients with contraindications for MIMVS, partial upper sternotomy (PS) was the preferred route for surgical access (n = 13). The appropriate access route was chosen according to the patient's clinical condition and comorbidities. We analyzed reoperation-free long-term survival, combined operative success (lack of residual MR, conversion to MV replacement, or larger thoracic incisions), and perioperative safety (at 30 days: mortality, re-thoracotomy, ECMO, pacemaker implantation, dialysis, longer ventilation, stroke, myocardial infarction). In a subgroup analysis, we compared long-term survival in MVS patients with and without TVR. Results: The median age of patients (62.7% female) was 74 years (interquartile range: 72-76 years), with a median EuroSCORE2 of 2.8% (1.5%-4.6%) and N-terminal pro-brain natriuretic peptide plasma levels of 1,434 ng/L (1035-2149 ng/L). The median follow-up period was 5.6 years (2.7-8.5 years). The reoperation-free long-term survival rate up to 10 years was 66.2%. Combined operative success and perioperative safety were achieved in 94% and 76% of patients, respectively. Additional TVR was performed in 56.7% of patients, without any significant difference in survival rates compared to the group without TVR (p = 0.417; HR 1.473, 95% CI 0.578-3.757). Conclusion: Less invasive MV repair for secondary MR shows excellent operative success and safety in selected patients. Freedom from significant MR and from the need for reoperation indicates long-lasting efficacy. These results should be considered in heart team discussions regarding allocation of patients to surgical mitral procedures.

Partial Upper Sternotomy is a Safe Alternative in Mitral Annulus Decalcification.

In patients with major annulus calcifications (MAC) requiring en-bloque decalcification anterolateral minithoracotomy is not suitable for safe and reproducible mitral valve surgery (MVS) procedures. In these cases, full sternotomy (FS) is still the preferred approach. Alternatively, less invasive MVS via partial upper sternotomy (PS) and transseptal access can be used in experienced centers. After reviewing the records of 1741 patients, who were treated with either isolated MVS or combined procedures, we identified 32 patients who had undergone en-bloque decalcification for MAC. The 2 techniques (PS-group n = 17, FS-cohort n = 15) were presented in terms of 1-year mortality as well as intra- and perioperative outcome. In the PS group, the age was 60.06 ± 7.56 patients, 64.7% were female and had a STS Predicted Risk of Mortality (PROM) score of 1.01 ± 1.06. In the FS group the patients (53.3% female) mean age was 58.47 ± 14.45 and had a STS PROM score 2.35 ± 2.73%. Rates of mitral repair were in the PS and FS cohort 64.7% and 46.7%, respectively. One-year mortality for PS-MVS was 5.9% (n = 1) and 20% (n = 3) for FS-MVS. The cardiopulmonary bypass (FS: 181.60 ± 49.99 minutes, PS: 192.83 ± 77.32 minutes and the cross-clamp times (FS: 119.67 ± 46.06, PS: 136.94 ± 54.37 minutes). The observed ventilation times in the PS and FS group were 5 hours (IQR 3.5-9) and 10 hours (IQR 5-15), respectively. A permanent pacemaker implantation was not necessary in any patient. In patients with MAC and en-bloque decalcification PS seems to be a safe access and might be a valid less invasive alternative to minithoracotomy.

Predictors of safety and success in minimally invasive surgery for degenerative mitral disease.

OBJECTIVES: The aim of this study was to identify predictors of periprocedural success and safety in minimally invasive mitral valve surgery and to determine the impact of pathology localization and repair technique on reoperation-free survival. METHODS: We isolated 686 patients (mean age 60.5, standard deviation 12.3 years, 69.4% male) who underwent surgery for mitral valve prolapse between 2002 and 2020 in a single institution. Patients with concomitant disease, redo or mitral pathology other than degenerative mitral disease were excluded from the analysis. Periprocedural safety was defined as: freedom from perioperative death, myocardial infarction, stroke, use of extracorporeal membrane oxygenation or reoperation for bleeding. Operative success was defined as: successful primary mitral repair without conversion to replacement or to larger thoracic incisions, without residual mitral regurgitation > mild at discharge or reoperation within 30 days. Predictors for perioperative success and safety were identified using univariable and multivariable analyses. The impact of prolapse localization and repair technique on reoperation-free survival was assessed by Cox regression. RESULTS: The mitral repair rate and the need for concomitant tricuspid repair were 94.6% and 16.5%, respectively. Perioperative mortality occurred in 5 patients (0.7%). The criteria for perioperative safety and success were met in 646/686 (94.2%) and 648/686 (94.5%) patients, respectively. The absence of tricuspid disease requiring repair was the only independent predictor of safety in this cohort [hazard ratio (HR) 0.460 (0.225-0.941), P = 0.033]. The only independent predictor of operative success was the use of chordal replacement [0.27 (0.09-0.83), P = 0.022]. Reoperation-free survival was 98.5%, 94.5% and 86.9% at 1, 5 and 10 years, respectively. Posterior leaflet pathology demonstrated a higher reoperation-free survival as compared to other localizations (log-rank P = 0.002). The localization of leaflet pathology but not the repair method was an independent predictor for reoperation-free survival (HR 1.455, 95% confidence interval 1.098-1.930; P = 0.009). CONCLUSIONS: In minimally invasive mitral surgery for degenerative disease, chordal replacement yields higher rates of periprocedural success than leaflet resection. Posterior leaflet pathology is an independent predictor of reoperation-free survival.

Donor hypo- and hypernatremia are predictors for increased 1-year mortality after cardiac transplantation.

Donor hypernatremia is known to be associated with initial graft dysfunction in liver transplantation. Controversial data exist regarding the impact of sodium dysregulation on patient survival after heart transplantation (HTX). The aim of this study was to investigate the influence of donor sodium levels on survival in a large cohort of heart transplant recipients from the Eurotransplant registry. From 1997 to 2005, all consecutive adult HTX performed in the Eurotransplant region were included into this study (n = 4641 patients). Multivariate analysis was applied to investigate possible clinical predictors for 1-year post-transplant survival after cardiac transplantation (donor sodium levels, donor age, donor cause of death, recipient age, primary disease, urgency status, cold ischemia time). In multivariate analysis, recipients receiving a donor heart with serum sodium level lower than 130 mmol/l or higher than 170 mmol/l had a 1.25-fold higher risk for 1-year post-transplant mortality than patients with normal donor sodium ranges (P = 0.007). Other independent risk factors for impaired 1-year survival were recipient age, the indication for transplantation and the urgency status of the recipient. Our study demonstrates that hyponatremia as well as hypernatremia show a strong U-shaped correlation with poor survival after cardiac transplantation. Accurate donor management to avoid electrolyte disorder seems to be crucial for ensuring good quality of donor hearts.

Thromboembolic complications during weaning from right ventricular assist device support.

We report on two patients who experienced life-threatening thromboembolic complications during prolonged weaning from Levitronix CentriMag right ventricular assist device support. Right ventricular assist device flow in both patients was reduced below 2 L/min for a period of 72 or 36 h to closely monitor patients' hemodynamics and echocardiography because the extent of right ventricular recovery was difficult to assess. Thrombus formation occurred despite adjusting the heparin dosage to achieve partial prothrombin time values between 60 and 70 s. Periods of reduced flow during Levitronix CentriMag support must be kept short, and an additional bolus dose of heparin should be considered.

Successful administration of levosimendan in a patient with low-gradient low-output aortic stenosis.

Aortic valve replacement in patients suffering from low-gradient aortic stenosis and congestive heart failure is associated with high operative mortality, and the perioperative use of inotropes is common. Levosimendan is a calcium sensitizer with positive inotropic and vasodilatory effects and has been developed for treatment of decompensated heart failure. Although its use in patients with low-gradient aortic stenosis is not established, we hypothesized that it might have beneficial effects on outcome after aortic valve replacement. We report on a high-risk operation in a 73-year-old man with low-gradient aortic stenosis, congestive heart failure and coronary artery disease. Levosimendan was administered perioperatively (0.1 mg/kg/min 16 hours prior to the operation without a loading dose) and allowed rapid recovery of the patient, who required only brief treatment in the intensive care unit. No levosimendan-specific adverse events were observed, in particular no hypotension. The excellent postoperative result was maintained after the patient was discharged from hospital.

Effect of a Home-Based Palliative Care Program on Healthcare Use and Costs.

OBJECTIVES: To evaluate the nonclinical outcomes of a proactive palliative care program funded and operated by a health system for Medicare Advantage plan beneficiaries. DESIGN: Observational, retrospective study using propensity-based matching. SETTING: A health system in southern California. PARTICIPANTS: Individuals who received the intervention between 2007 and 2014 (n = 368) were matched with 1,075 comparison individuals within each of four disease groups: cancer, chronic obstructive pulmonary disease, heart failure, and dementia. All were known to be dead at the time of the retrospective study, were Medicare Advantage beneficiaries, and had 2 years of usage data before death. Median age at death for each disease group was older than 80. INTERVENTION: Home- and clinic-based palliative care (PC) services provided by a multidisciplinary team. MEASUREMENTS: Outcomes included hospital costs, other healthcare costs, readmission rates, hospital admissions and bed days, intensive care unit use in final 30 days of life, and death within 30 days of an admission. RESULTS: Intervention participants in all four disease groups had less hospital use and lower hospital costs nonintervention participants, which drove lower overall healthcare costs. In the final 6 months of life, healthcare costs for the intervention groups stayed largely the same from month to month, whereas costs for comparison participants increased dramatically. CONCLUSION: In the context of an alternative payment model in which the provider was "at risk" of bearing the costs of care, a proactive PC program helped to avoid the escalation in hospital use and costs commonly seen in the final months of life.

Early detection and successful therapy of fulminant chlamydia pneumoniae myocarditis.

We report a case involving a young female patient with Chlamydia pneumoniae myocarditis who required assist device therapy for acute heart failure. Early diagnosis was provided by endomyocardial biopsy, and tailored antibiotic therapy facilitated quick recovery of myocardial function. This is the first case to report detecting C pneumoniae as the pathogen responsible for fulminant myocarditis while the patient was still alive and to report long-term follow-up data.

Cardiac transplantation complicated by acute thrombotic occlusion of the right coronary artery.

We report the case of a 63-year-old male patient undergoing cardiac transplantation due to fourth time aortic valve endocarditis. The postoperative course was complicated by thrombotic occlusion of the right coronary artery (RCA) causing acute right ventricular myocardial infarction, which required extracorporeal membrane oxygenation. The RCA could be reopened by catheter-based intervention and the patient stabilized. In order to avoid further immobilization, a right ventricular assist device was implanted and an aortocoronary bypass to the RCA was performed. After that, the patient stabilized progressively, could be weaned from the assist device, and was discharged home 6 weeks after transplantation. On coronary angiography, which is routinely performed 4 to 6 weeks after transplantation, a fistula from the RCA to the right ventricle was detected which was treated conservatively. Five months after transplantation, the patient is in good clinical condition without signs of recurrent endocarditis. This case shows that intense interdisciplinary cooperation of cardiac specialists allows the successful management of very complex patients in serious clinical conditions.

Factors influencing intensive care unit length of stay after surgery for acute aortic dissection type A.

BACKGROUND: Operative mortality after acute aortic dissection type A is still high, and prolonged stay at the intensive care unit is common. Little has been documented about factors influencing the intensive care unit length of stay. The aim of this study was to determine such variables. METHODS: During a 10-year period, 67 patients (47 male, 20 female) were operated on for acute aortic dissection type A. In 42 patients (63%), an ascending aortic replacement was performed, 23 patients (34%) underwent a Bentall procedure, and 2 patients (3%) received a valve-sparing David type of operation. In 14 of these cases (20%), an additional partial or total arch replacement was performed. RESULTS: Hospital mortality was 9 of 67 (14%). Median postoperative intensive care unit length of stay was 5 days (range, 1 to 72 days). Intensive care unit stay was in univariate analysis significantly influenced by the following factors: age (p = 0.008), body mass index (p = 0.039), cardiopulmonary bypass time (p = 0.018), aortic cross-clamp time (p = 0.031), postoperative low cardiac output syndrome (p < 0.001), and postoperative lactate levels (p = 0.01). By multivariate analysis, age (p = 0.012), cardiopulmonary bypass time (p = 0.037), and the presence of a postoperative low cardiac output syndrome (p < 0.001) significantly influenced intensive care unit stay. CONCLUSIONS: Stay in the intensive care unit after operation for acute aortic dissection type A seems to be determined by age, cardiopulmonary bypass time, and the postoperative presence of a low cardiac output syndrome.

Effects of intracoronary shunts on coronary endothelial coating in the human beating heart.

BACKGROUND: Local occlusion of coronary arteries during beating heart revascularization leads to injury of the arterial wall especially disturbing the integrity of the endothelium. The aim of this study was to elucidate the effects of intracoronary shunts versus local occlusion with elastic silicone loops on the beating heart in human coronary arteries by scanning electron microscopy. METHODS: Coronary arteries of patients with dilated cardiomyopathy (n = 4) or ischemic heart disease (n = 8) undergoing heart transplantation were locally occluded either with a silicone loop or with a shunt inserted after arteriotomy. Unmanipulated segments of the coronary arteries served as controls. Integrity of the endothelial lining was observed with scanning electron microscopy. RESULTS: Scanning electron microscopy revealed a statistically significant higher injury after shunting compared with controls (p < 0.001) and vessel loop occlusion (p < 0.001). There was no difference between both patient groups according to control specimens or after manipulation. CONCLUSIONS: From this investigation we conclude that insertion of intracoronary shunts during beating heart surgery leads to severe endothelial denudation in human coronary arteries. Therefore, at present we recommend using intracoronary shunts selectively in cases in which critical ischemia or technical difficulties as a result of anatomic conditions are expected during anastomosis and avoiding routine shunt insertion into coronary arteries during beating heart revascularization.