A comparison between minimized extracorporeal circuits and conventional extracorporeal circuits in patients undergoing aortic valve surgery: is 'minimally invasive extracorporeal circulation' just low prime or closed loop perfusion ?

INTRODUCTION: Even though results have been encouraging, an unequivocal conclusion on the beneficial effect of minimally invasive extracorporeal circulation (MiECC) in patients undergoing aortic valve surgery cannot be derived from previous publications. Long-term outcomes are rarely reported and a significant decrease in operative mortality has not been shown. Most studies have a limited number of patients and are underpowered. They merely report on short-term results of a heterogeneous intraoperative group using different types of ECC system in aortic valve surgery. The aim of the present study was to determine whether MiECC systems are more beneficial than conventional extracorporeal systems (CECC) with regard to mortality, hospital stay and inflammation and with only haemodilution and blood-air interface as differences. METHODS: We retrospectively analysed data regarding mortality, hospital stay and inflammation in patients undergoing isolated aortic valve surgery. Forty patients were divided into two groups based on the type of extracorporeal system used; conventional (n=20) or MiECC (n=20). RESULTS: Perioperative blood product requirements were significantly lower in the MiECC group (MiECC: 0.2±0.5 units vs CECC: 0.9±1.2 units, p=0.004). No differences were seen postoperatively regarding mortality (5% vs 5%, p=0.99), total length of hospital stay (10.6±7.2 days (MiECC) vs 12.1±5.9 days (CECC), p=0.39) or inflammation markers (CRP: MiECC: 7.09±13.62 mg/L vs CECC: 3.4±3.2 mg/L, p=0.89). CONCLUSION: MiECC provides circulatory support that is equally safe and feasible as conventional extracorporeal circuits. No differences in mortality, hospital stay or inflammation markers were observed.

Cardiac atrial appendage stem cells engraft and differentiate into cardiomyocytes in vivo: A new tool for cardiac repair after MI.

BACKGROUND: This study assessed whether autologous transplantation of cardiac atrial appendage stem cells (CASCs) preserves cardiac function after myocardial infarction (MI) in a minipig model. METHODS AND RESULTS: CASCs were isolated from right atrial appendages of Göttingen minipigs based on high aldehyde dehydrogenase activity and expanded. MI was induced by a 2h snare ligation of the left anterior descending coronary artery. Upon reperfusion, CASCs were intramyocardially injected under NOGA guidance (MI-CASC, n=10). Non-transplanted pigs (MI, n=8) received sham treatment. 3D electromechanical mapping (EMM) and cardiac MRI were performed to assess left ventricular (LV) function. MI pigs developed LV dilatation at 2 months (2M), while in the MI-CASC group volumes remained stable. Global LV ejection fraction decreased by 16 ± 8% in MI animals vs 3 ± 10% in MI-CASC animals and regional wall thickening in border areas was better preserved in the MI-CASC group. EMM showed decreased viability and wall motion in the LV for both groups POST-MI, whereas at 2M these parameters only improved in the MI-CASC. Substantial cell retention was accompanied by cardiomyogenic differentiation in 98±1% of the transplanted CASCs, which functionally integrated. Second harmonic generation microscopy confirmed the formation of mature sarcomeres in transplanted CASCs. Absence of cardiac arrhythmias indicated the safety of CASC transplantation. CONCLUSION: CASCs preserve cardiac function by extensive engraftment and cardiomyogenic differentiation. Our data indicate the enormous potential of CASCs in myocardial repair.

Elective reconstruction of the ascending aorta for aneurysmal disease restores normal life expectancy. An analysis of risk factors for early and late mortality.

OBJECTIVE: We investigated the survival of patients who had undergone elective reconstruction of the ascending aorta for degenerative aneurysms. The long-term survival was compared to an age- and sex-matched case-control population. An analysis of risk factors, influencing survival was made. METHODS AND RESULTS: From May 1998 to January 2012, 72 patients underwent elective reconstruction of the ascending aorta for degenerative disease at the department of Cardiothoracic Surgery of the Jessa Hospital, Hasselt, Belgium. Sixty patients were treated with Bentall procedures, whereas 12 received valve-sparing procedures. The average age of the patient group was 65.5 years (range 24-80), with 64% males. Thirty-day mortality was 9.7% (consistent with calculated Euroscore II: 9.2%). The long-term survival was 80.9% at 3, 5 and 10 years. No deaths occurred between 3 and 10 years postoperatively. In an age- and sex case-matched Belgian population, 3-, 5- and 10-year survival were 95.7%, 94.7% and 85.2%, respectively. Long-term survival was not significantly different between both groups. Poor NYHA class at the time of surgery (P = 0.041) and COPD (P = 0.028) had a significant impact on global survival. Valve-sparing operations provide similar long-term survival, avoiding thrombo-embolic complications. CONCLUSIONS: Reconstruction of the ascending aorta for degenerative aneurysmal disease restores normal life expectancy, compared with an age- and sex-matched case-control population. Early mortality is consistent with the Euroscore II risk calculation. Whereas late survival progressively declines in the average population, it remains constant in the treated group after 3 years. COPD and poor functional class significantly impair survival. Valve-sparing procedures confer a similar long-term survival as valve replacement.

The cardiac atrial appendage stem cell: a new and promising candidate for myocardial repair.

AIMS: Considerable shortcomings in the treatment of myocardial infarction (MI) still exist and therefore mortality remains high. Cardiac stem cell (CSC) therapy is a promising approach for myocardial repair. However, identification and isolation of candidate CSCs is mainly based on the presence or absence of certain cell surface markers, which suffers from some drawbacks. In order to find a more specific and reliable identification and isolation method, we investigated whether CSCs can be isolated based on the high expression of aldehyde dehydrogenase (ALDH). METHODS AND RESULTS: An ALDH(+) stem cell population, the cardiac atrial appendage stem cells (CASCs), was isolated from human atrial appendages. CASCs possess a unique phenotype that is clearly different from c-kit(+) CSCs but that seems more related to the recently described cardiac colony-forming-unit fibroblasts. Based on immunophenotype and in vitro differentiation studies, we suggest that CASCs are an intrinsic stem cell population and are not mobilized from bone marrow or peripheral blood. Indeed, they possess a clonogenicity of 16% and express pluripotency-associated genes. Furthermore, compared with cardiosphere-derived cells, CASCs possess an enhanced cardiac differentiation capacity. Indeed, differentiated cells express the most important cardiac-specific genes, produce troponin T proteins, and have an electrophysiological behaviour similar to that of adult cardiomyocytes (CMs). Transplanting CASCs in the minipig MI model resulted in extensive cardiomyogenic differentiation without teratoma formation. CONCLUSION: We have identified a new human CSC population able to differentiate into functional CMs. This opens interesting perspectives for cell therapy in patients with ischaemic heart disease.

Mesenchymal stem cells or cardiac progenitors for cardiac repair? A comparative study.

In the past, clinical trials transplanting bone marrow-derived mononuclear cells reported a limited improvement in cardiac function. Therefore, the search for stem cells leading to more successful stem cell therapies continues. Good candidates are the so-called cardiac stem cells (CSCs). To date, there is no clear evidence to show if these cells are intrinsic stem cells from the heart or mobilized cells from bone marrow. In this study we performed a comparative study between human mesenchymal stem cells (hMSCs), purified c-kit(+) CSCs, and cardiosphere-derived cells (CDCs). Our results showed that hMSCs can be discriminated from CSCs by their differentiation capacity towards adipocytes and osteocytes and the expression of CD140b. On the other hand, cardiac progenitors display a greater cardiomyogenic differentiation capacity. Despite a different isolation protocol, no distinction could be made between c-kit(+) CSCs and CDCs, indicating that they probably derive from the same precursor or even are the same cells.

Human bone marrow stem cells co-cultured with neonatal rat cardiomyocytes display limited cardiomyogenic plasticity.

BACKGROUND AIMS: This study investigated whether neonatal rat cardiomyocytes (NRCM), when co-cultured, can induce transdifferentiation of either human mesenchymal stromal cells (MSC) or hematopoietic stem cells (HSC) into cardiomyocytes. Stem cells were obtained from patients with ischemic heart disease. METHODS: Ex vivo-expanded MSC or freshly isolated HSC were used to set-up a co-culture system between NRCM and MSC or HSC. 5-azacytidin (5-aza) or dimethylsulfoxide (DMSO) was used as differentiation-inducing factor. Co-cultured stem cells were separated from NRCM by flow sorting, and cardiac gene expression was analyzed by reverse transcriptase-polymerase chain reaction. Cellular morphology was analyzed by immunofluorescence and transmission electron microscopy (TEM). RESULTS: Co-culturing MSC induced expression of troponin T and GATA-4. However, no expression of alpha-actinin, myosin heavy chain or troponin I was detected. In the case of HSC, only expression of troponin T could be induced. Immunofluorescence and TEM confirmed the absence of sarcomeric organization in co-cultured MSC and HSC. Adding 5-aza or DMSO to the co-cultures did not influence differentiation. CONCLUSIONS: This in vitro co-culture study obtained no convincing evidence of transdifferentiation of either MSC or HSC into functional cardiomyocytes. Nevertheless, induction of troponin T was observed in MSC and HSC, and GATA-4 in MSC. However, no morphologic changes could be detected by immunofluorescence or by TEM. These data could explain why only limited functional improvement was reported in clinical stem cell trials.

Amyloidoma of the chest wall: a rare entity.

Amyloidoma (tumoral amyloidosis) is defined as a solitary localized tumor-like deposit of amyloid, in the absence of systemic amyloidosis. Amyloidoma is the least common presentation of tissue amyloid deposition, reported in many anatomic sites including the respiratory, genitourinary and gastrointestinal tracts, as well as the central nervous system, skin, breast and soft tissue. Amyloidoma of the chest wall is extremely rare, and to date only one case has been reported in literature. The authors present a case of a chest wall tumor that causes local destruction, being an amyloidoma on histopathologic examination. It was treated with wide local excision, with no recurrence during almost two years of follow-up. A search for occult systemic disease is recommended and was also performed.

Aortic valve lymphoma presenting as acute coronary syndrome.

Primary cardiac lymphoma is a very rare tumor which commonly affects the right atrium, although any chamber may be affected. Over the past few decades, the incidence of the lesion has increased, due mainly to growing numbers of immunocompromised patients, either HIV-related or iatrogenic. Because of this rapid evolution, the situation represents an oncologic emergency, and therefore early diagnosis and treatment are crucial. Although MRI is the most sensitive modality, open biopsy remains the 'gold standard' for reaching the diagnosis. However, the overall prognosis is poor. Herein is presented a case of a large B-cell non-Hodgkin lymphoma involving only the aortic valve.

Acute thrombosis of an abdominal aortic aneurysm following intra-aortic balloon pumping.

Acute thrombosis of an abdominal aortic aneurysm is a rare but devastating surgical emergency. We present the first case of a patient with sudden thrombosis of an AAA delayed (more than 24 h) after removal of an intra-aortic balloon pump. Treatment options include open surgical repair, axillobifemoral grafting or endovascular aortic repair. The patient received an aorto-bifemoral graft. The associations between intra-aortic balloon pump counter-pulsation and abdominal aortic thrombosis are discussed.

Recovery of regional but not global contractile function by the direct intramyocardial autologous bone marrow transplantation: results from a randomized controlled clinical trial.

BACKGROUND: Recent trials have shown that intracoronary infusion of bone marrow cells (BMCs) improves functional recovery after acute myocardial infarction. However, whether this treatment is effective in heart failure as a consequence of remodeling after organized infarcts remains unclear. In this randomized trial, we assessed the hypothesis that direct intramyocardial injection of autologous mononuclear bone marrow cells during coronary artery bypass graft (CABG) could improve global and regional left ventricular ejection fraction (LVEF) at 4-month follow-up. METHODS AND RESULTS: Twenty patients (age 64.8+/-8.7; 17 male, 3 female) with a postinfarction nonviable scar, as assessed by thallium (Tl) scintigraphy and cardiac magnetic resonance imaging (MRI), scheduled for elective CABG, were included. They were randomized to a control group (n =10, CABG only) or a BMC group (CABG and injection of 60.10(6)+/-31.10(6) BMC). Primary end points were global LVEF change and wall thickening changes in the infarct area from baseline to 4-month follow-up, as measured by MRI. Changes in metabolic activity were measured by Tl scintigraphy and expressed as a score with a range from 0 to 4, corresponding to percent of maximal myocardial Tl uptake (4 indicates <50%, nonviable scar; 3, 50% to 60%; 2, 60% to 70%; 1, 70% to 80%; 0>80%). Global LVEF at baseline was 39.5+/-5.5% in controls and 42.9+/-10.3% in the BMC group (P=0.38). At 4 months, LVEF had increased to 43.1+/-10.9% in the control group and to 48.9+/-9.5% in the BMC group (P=0.23). Systolic thickening had improved from -0.6+/-1.3 mm at baseline to 1.8+/-2.6 mm at 4 months in the cell-implanted scars, whereas nontreated scars remained largely akinetic (-0.5+/-2.0 mm at baseline compared with 0.4+/-1.7 mm at 4 months, P=0.007 control versus BMC-treated group at 4 months). Defect score decreased from 4 to 3.3+/-0.9 in the BMC group and to 3.7+/-0.4 in the control group (P=0.18). CONCLUSIONS: At 4 months, there was no significant difference in global LVEF between both groups, but a recovery of regional contractile function in previously nonviable scar was observed in the BMC group.

Midterm follow-up after off-pump versus on-pump coronary artery bypass grafting. Results from a case-matched study.

OBJECTIVE: Early survival in off-pump coronary artery bypass (OPCAB) patients is reported to be as good as that of conventional coronary artery bypass grafting (CABG). However, it remains unknown whether midterm cardiac outcome after off-pump surgery is similar to that for the on-pump procedure. METHODS AND RESULTS: One hundred OPCAB patients (67.8 (9.3) y) were compared to a case-matched contemporary group of CABG patients (69.4 (8.8) y). In-hospital and midterm outcome data are presented. Follow-up was 100% complete. The mean number of distal anastomoses per patient was 1.9 (0.8) and 2.4 (1.0) in the OPCAB and CABG group, respectively. Grafting according to treatment plan was 100% in both groups. Peak creatine kinase muscle-brain and cardiac troponin I (cTnI) release were similar in the overall groups, but the cTnI release in the 25 most recently operated patients was significantly lower in the OPCAB group (4.8 (9.1) ng/ml vs. 14.0 (20.5) ng/ml, p = 0.04). Duration of mechanical ventilation, ICU stay and hospital stay were shorter in the OPCAB group. The incidence of atrial fibrillation was similar. There were no differences in in-hospital complications. The actuarial survival at 1, 3 and 5 years was 88% (C.I. 81.6 to 94.3), 78% (C.I. 66.1 to 90.2) and 78% (C.I. 66.1 to 90.2) in the OPCAB and 90% (C.I. 84.0 to 95.9), 84% (C.I. 74.6 to 92.5) and 68% (C.I. 44.7 to 90.6) in the CABG group (log rank p-value = 0.96). Event-free survival at 1, 3, 5 years was 85% (C.I. 77.8 to 91.9), 71 % (C.I. 57.4 to 84.2) and 71 % (C.I. 57.4 to 84.2) in the OPCAB and 85% (C.I. 77.8 to 91.9), 72% (C.I. 61.1 to 82.7) and 58% (C.I. 37.2 to 78.8) in the CABG group (log rank p-value = 0.63). Recurrence of angina (3%) and need for reintervention (2%) in the OPCAB group were low. CONCLUSIONS: OPCAB surgery is a safe and reproducible technique, yielding short-and midterm outcomes comparable to conventional CABG.

Penetrating pediatric cardiac trauma caused by fall on a pencil with normal echocardiography.

A toddler, age 2, presented with a penetrating cardiac trauma caused by a fall on a pencil. This case showed a normal echocardiography. However, during removal of the pencil, signs of cardiac tamponade were noticeable. Thus, a normal echocardiography is no guarantee to exclude a possible penetrating cardiac injury.