Performance of the EuroSCORE II Model in Predicting Short-Term Mortality of General Cardiac Surgery: A Single-Center Study in Taiwan.

Background: The latest European System for Cardiac Operative Risk Evaluation (EuroSCORE) II is a well-accepted risk evaluation system for mortality in cardiac surgery in Europe. Objectives: To determine the performance of this new model in Taiwanese patients. Methods: Between January 2012 and December 2014, 657 patients underwent cardiac surgery at our institution. The EuroSCORE II scores of all patients were determined preoperatively. The short-term surgical outcomes of 30-day and in-hospital mortality were evaluated to assess the performance of the EuroSCORE II. Results: Of the 657 patients [192 women (29.22%); age 63.5 ± 12.68 years], the 30-day mortality rate was 5.48%, and the in-hospital mortality rate was 9.28%. The discrimination power of this new model was good in all populations, regardless of 30-day mortality or in-hospital mortality. Good accuracy was also noted in different procedures related to coronary artery bypass grafting, and good calibration was noted for cardiac procedures (p value > 0.05). When predicting surgical death within 30 days, the EuroSCORE II overestimated the risk (observed to expected: 0.79), but in-hospital mortality was underestimated (observed to expected: 1.33). The predictive ability [area under the curve (AUC) of the receiver operating characteristic (ROC) curve] and calibration of the EuroSCORE II for 30-day mortality (0.792) and in-hospital mortality (0.825) suggested that in-hospital mortality is a better endpoint for the EuroSCORE II. Conclusions: The new EuroSCORE II model performed well in predicting short-term outcomes among patients undergoing general cardiac surgeries. For short-term outcomes, in-hospital mortality was better than 30-day mortality as an indicator of surgical results, suggesting that it may be a better endpoint for the EuroSCORE II.

A Facile Fabrication of Biodegradable and Biocompatible Cross-Linked Gelatin as Screen Printing Substrates.

This study focuses on preparation and valuation of the biodegradable, native, and modified gelatin film as screen-printing substrates. Modified gelatin film was prepared by crosslinking with various crosslinking agents and the electrode array was designed by screen-printing. It was observed that the swelling ratio of C-2, crosslinked with glutaraldehyde and EDC/NHS (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide) was found to be lower (3.98%) than that of C-1 (crosslinked with only glutaraldehyde) (8.77%) and C-0 (without crosslinking) (28.15%). The obtained results indicate that the swelling ratios of both C-1 and C-2 were found to be lower than that of C-0 (control one without crosslinking). The Young's modulus for C-1 and C-2 was found to be 8.55 ± 0.57 and 23.72 ± 2.04 kPa, respectively. Hence, it was conveyed that the mechanical strength of C-2 was found to be two times higher than that of C-l, suggesting that the mechanical strength was enhanced upon dual crosslinking in this study also. The adhesion study indicates that silver ink adhesion on the gelation surface is better than that of carbon ink. In addition, the electrical response of C-2 with a screen-printed electrode (SPE) was found to be the same as the commercial polycarbonate (PC) substrate. The result of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay suggested that the silver SPE on C-2 was non-cytotoxic toward L929 fibroblast cells proliferation. The results indicated that C-2 gelatin is a promising material to act as a screen-printing substrate with excellent biodegradable and biocompatible properties.

Angiogenesis-promoting effect of LIPUS on hADSCs and HUVECs cultured on collagen/hyaluronan scaffolds.

Angiogenesis refers to blood vessel formation through endothelial cell migration and proliferation. Angiogenesis is crucial and beneficial for wound healing and tissue regeneration. In the current study, we prepared porous collagen and collagen/hyaluronan (Col/HA) scaffolds composed of collagen (7 mg/mL) and hyaluronan (HA) (0.5 w%, 1 w%, and 1.5 w%) as culture vehicles for coculture of human adipose-derived stem cells (hADSCs) and human umbilical vein endothelial cells (HUVECs). These scaffolds were combined with low-intensity pulsed ultrasound (LIPUS) to investigate and evaluate angiogenesis in the coculture cell/scaffold constructs in vitro and in vivo. Scaffold porosity decreased (from 74.4% to 60.7%) and readily degraded after addition of various ratios of HA. The porous scaffolds all had high water content (~98%) and similar mechanical properties. The hADSCs alone and hADSCs cocultured with HUVECs exhibited stable proliferative profiles on the Col/HA scaffolds; furthermore, LIPUS significantly enhanced cell growth on the collagen and Col/0.5HA scaffolds by approximately 1.85- and 1.5-fold, respectively, compared with the cells that did not receive LIPUS treatment. In vivo immunohistochemistry results indicated stronger immunofluorescent CD31 presence and vascular endothelial cadherin messenger RNA expression in the hADSCs/HUVECs coculture/scaffold implantation in rats that received LIPUS treatment compared with those that received no such treatment. Our results demonstrated that the hADSCs/HUVECs cocultured on fabricated collagen and Col/HA scaffolds combined with LIPUS treatment had angiogenesis-promoting capability and therapeutic potential when angiogenesis is demanded.

In vitro and in vivo study of the application of volvox spheres to co-culture vehicles in liver tissue engineering.

Volvox sphere is a biomimetic concept of a natural Volvox, wherein a large outer sphere contains smaller inner spheres, which can encapsulate cells and provide a double-layer three-dimensional environment for culturing cells. This study simultaneously encapsulated rat mesenchymal stem cells (MSCs) and AML12 hepatocytes in volvox spheres and extensively evaluated the effects of various culturing modes on cell functions and fates. The results showed that compared with a static flask culture, MSCs encapsulated in volvox spheres differentiated into hepatocyte-like cells with a 2-fold increase in albumin (ALB) expression and a 2.5-fold increase in cytokeratin 18 expression in a dynamic bioreactor. Moreover, the restorative effects of volvox spheres encapsulating cells on retrorsine-exposed CCl4-induced liver injuries in rats were evaluated. The data presented significant reductions in AST and ALT levels after the implantation of volvox spheres encapsulating both MSCs and AML12 hepatocytes in vivo. In contrast to the negative control group, histopathological analysis demonstrated liver repair and formation of the new liver tissue in groups implanted with volvox spheres containing cells. These results demonstrate that liver cells implanted with volvox spheres encapsulating both MSCs and AML12 hepatocytes promote liver repair and liver tissue regeneration in liver failure caused by necrotizing agents such as retrorsine and CCl4. Hence, volvox spheres encapsulating MSCs and liver cells can be a promising and clinically effective therapy for liver injury. STATEMENT OF SIGNIFICANCE: In this study, we used a volvox sphere, which is a unique design that mimics the natural Volvox, that consists of a large outer sphere that contains smaller inner spheres, which provide a three-dimensional environment to culture cells. The purpose of this study is to co-culture mesenchymal stem cells (MSCs) and AML12 liver cells in volvox spheres and evaluate two different culture methods, dynamic bioreactor and static culture flask,on the cultured cells. In addition, we aimed to evaluate the restorative effects of volvox spheres encapsulating MSCs and/or AML12 liver cells on rats with retrorsine-exposed CCl4-induced liver injuries. The results showed that MSCs encapsulated in volvox spheres differentiated into hepatocyte-like cells with a 2-fold increase in albumin expression and a 2.5-fold increase in cytokeratin 18 expression ina dynamic bioreactor. Moreover, the data presented significant reductions in AST and ALT levels after the implantation of volvox spheres encapsulating both MSCs and AML12 hepatocytes in vivo. In contrast to the negative control group, histopathological analysis demonstrated liver repair and formation of new liver tissue in groups implanted with volvox spheres containing cells. These results demonstrate that liver cells implanted with volvox spheres encapsulating both MSCs and AML12 hepatocytes promote liver repair and liver tissue regeneration in liver failure caused by necrotizing agents such as retrorsine and CCl4. Hence, volvox spheres encapsulating MSCs and liver cells can be a promising and clinically effective therapy for liver injury.

Young Adult Patent Ductus Arteriosus Treated with Endovascular Stent Grafting.

Endovascular stent-grafting is an alternative treatment for adult patent ductus arteriosus (PDA), especially in elderly patients. Regarding young adults, endovascular therapy is a reasonable choice if the landing zone is sufficient. In this study, we report on a young adult with PDA successfully treated with endovascular stent-grafting.

Targeted Delivery of Hyaluronan-Immobilized Magnetic Ceramic Nanocrystals.

Effective cancer therapy relies on delivering the therapeutic agent precisely to the target site to improve the treatment outcome and to minimize side effects. Although surgery, chemotherapy, and radiotherapy are the standard methods commonly used in clinics, hyperthermia has been developed as a new and promising strategy for cancer therapy. In this study, magnetic bioceramic hydroxyapatite (mHAP) nanocrystals have been developed as heat mediator for intracellular hyperthermia. Hyaluronic acid (HA) modified mHAP nanocrystals are synthesized by a wet chemical precipitation process to achieve active targeting. The results demonstrate that the HA targeting moiety conjugated by a poly(ethylene glycol) (PEG) spacer arm is successfully immobilized on the surface of mHAP. The HA-modified mHAP possesses relatively good biocompatibility, an adequate biodegradation rate and superparamagnetic properties. The HA-modified mHAP could be localized and internalized into HA receptor-overexpressed malignant cells (e.g., MDA-MB-231 cell) and used as the heat generating agent for intracellular hyperthermia. The results from this study indicate that biocompatible HA-modified mHAP shows promise as a novel heat mediator and a specific targeting nanoagent for intracellular hyperthermia cancer therapy.

In vitro and in vivo evaluation of the effect of nano-sized collagen molecules and nicotinamide on mesenchymal stem cell differentiation.

Advances and improvements in mesenchymal stromal/stem cells (MSCs) and cell replacement therapies have been promising approaches to treat diabetes mellitus (DM) since their potent capacities for differentiation into various functional cells match the demands of tissue repair and regeneration. The aim of this study is to examine the effects of nano-sized type I collagen molecules in combination with nicotinamide (NCT) and exendin-4 (EX4) on MSC differentiation into insulin-secreting cells in vitro and to evaluate their reparative effects against type 2 diabetes mellitus (T2DM) in vivo. Differentiation of MSCs in the presence of NCT, nano-sized type I collagen molecules and EX4 was represented with insulin production and Nkx6.1/PDX-1 mRNA expression assessed by insulin secretion assay and quantitative RT-PCR. Histopathological and glycosylated haemoglobin (HbA1) analysis was performed to assess reparative effects against T2DM in the rat model. The results revealed that MSCs showed increased differentiation into insulin-secreting cells with higher mRNA expression for Nkx6.1 and early PDX-1 in the presence of NCT and nano-sized type I collagen molecules. Addition of nano-sized type I collagen fibrils increased morphologically islet-like clusters in differentiated cells. T2DM rats reverted to their normal HbA1 values and exhibited structurally repaired islets in the pancreas implanted with NCT/nano-sized collagen I molecule/EX4-incubated differentiated cells. In short, the combined recipe showed reparative actions on the destructive islet of Langerhans in the pancreas coupled with glucoregulatory effects in T2DM rats in vivo. Therefore, MSCs incubated with NCT/EX4 and nano-sized collagen I molecules could be a potential therapy for retrieval of destructed islets and could efficiently regulate blood glucose in T2DM.

Nano-sized collagen I molecules enhanced the differentiation of rat mesenchymal stem cells into cardiomyocytes.

The aim of this study was to investigate the ability of nano-sized collagen I molecules (nanoparticles or nanofibrils) and a 5-azacytidine (5-aza) treatment to enhance the differentiation of rat mesenchymal stem cells (MSCs) toward a cardiomyogenic phenotype in vitro. Second passaged MSCs were cocultured with nano-sized collagen I molecules for 24 h and then treated with 10 µM 5-aza for 24 h. The results demonstrated that the size of the cells increased significantly and acquired a flattened, triangular-shaped morphology after treatment with nano-sized collagen I molecules and 5-aza. The cells are connecting with adjoining cells by forming myotube-like structures. Additional treatment of the MSCs with nano-sized collagen I fibrils significantly increased two transcription factors GATA-4 (12.6-fold increase) and Nkx2.5 (4.8-fold increase) expressions compared with MSC groups treated only with 5-aza at 3-day culturing. Furthermore, MSCs pretreated with nano-sized collagen fibrils significantly increased the expressions of cardiac genes of troponin I, ß-myosin heavy chain, and cardiac α-actin compared with MSC groups treated only with 5-aza (all, p < 0.01 or better). These results indicate that culturing MSCs with nano-sized collagen I molecules, which may act as scaffolds or soluble protein ingredients, leads to alterations in gene expression and affects the differentiation fate induced with 5-aza.

Treatment strategies for acute coronary syndrome with severe mitral regurgitation and their effects on short- and long-term prognosis.

Mitral regurgitation (MR) of even mild severity affects the prognosis of patients with acute coronary syndrome (ACS). The present study retrospectively analyzed 1,142 patients with ACS and MR of varying severity. Of the 95 patients with severe MR, 57 (60%) underwent primary percutaneous coronary intervention only and 38 (40%) underwent coronary artery bypass grafting (CABG) and mitral valve replacement (MVR). The severity of MR was significantly associated with the risk of heart failure but not with in-hospital or long-term mortality. In patients with severe MR, in-hospital mortality was no greater in those treated with CABG and MVR than in those treated with percutaneous coronary intervention alone. However, the incidence of long-term hard events (heart failure and all-cause mortality) was lower in those who had received the combined treatment. Multivariate analysis showed that, compared to percutaneous coronary intervention alone, CABG combined with MVR at the acute phase of ACS resulted in a significantly improved prognosis (odds ratio 0.172, 95% confidence interval 0.046 to 0.649, p = 0.009), even after adjusting for age, left ventricular filling pressure, and ejection fraction. In conclusion, the severity of MR in patients with ACS is associated with long-term heart failure events. Even at the acute phase of ACS, CABG combined with MVR results in an acceptable in-hospital mortality rate. The combined strategy also reduced the long-term hard events.

Left atrial expansion index for predicting atrial fibrillation and in-hospital mortality after coronary artery bypass graft surgery.

BACKGROUND: Atrial fibrillation (AF), a common complication after coronary artery bypass graft surgery (CABG), is associated with prolonged hospital stay. This prospective study assessed the accuracy of left atrial parameters and additional preoperative characteristics for predicting post-CABG AF and in-hospital mortality. METHODS: A total of 197 patients without hemodynamic-significant valvular problems, who received isolated CABG, were enrolled. Echocardiography was performed before CABG. RESULTS: Compared with patients without post-CABG AF, those with post-CABG AF were older (71 vs 64 years, p<0.0001), had a higher incidence of CABG during index hospitalization of acute myocardial infarction and preoperative respiratory failure requiring ventilator support, lower left ventricular ejection fraction (0.41 vs 0.48, p<0.0001), lower left atrial expansion index (52.2% vs 93.3%, p<0.0001), and higher left ventricular filling pressure (24.2 vs 19.1 mm Hg, p<0.0001). Multivariate analysis of preoperative variables showed that independent predictors of AF included age (odds ratio [OR], 1.064; 95% confidence interval [CI], 1.022 to 1.107 per 1-year increase; p 0.002), maximal indexed left atrial volume (OR, 1.026; 95% CI, 1.002 to 1.051 per 1 mL/m2 increase; p 0.037) and left atrial expansion index (OR, 0.981; 95% CI, 0.962 to 0.998 per 1% increase; p 0.029). The left atrial expansion index was also significantly associated with in-hospital mortality (OR, 0.982; 95% CI, 0.951 to 0.996 per 1% increase; p 0.042). Incidence of post-CABG AF in patients with left atrial expansion index less than 120% progressively increased as left atrial expansion index decreased. CONCLUSIONS: Left atrial expansion index independently predicts post-CABG AF and in-hospital mortality.

Evaluation of bone growth using artificial bone substitute (osteoset) and platelet gel mixtures: a preliminarily study in dogs.

Platelet gels (PG), activated by bovine thrombin (BT), have increasingly been used in orthopedic surgery. However, BT may induce immunological reactions and carry potential viral and prion risks. To avoid these side effects, thrombin derived from human plasma (human thrombin, HT) is becoming the preferred platelet activator to prepare PG. However, limited experience and data on the clinical benefits of HT-generated PG (HTPG) in orthopedic surgery is reported. Consequently, we designed and performed a series of studies in dogs to compare the impacts of promotion of bone growth by an artificial bone substitute (Osteoset) in combination with HTPG or without it in the spinal repair experiments. X-ray observations and histological studies were performed at predetermined periods post-operation. The preliminary results revealed the preparation of HTPG was easy and required less than 30 minutes. HTPG was capable of embedding the artificial bone substitute Osteoset to prepare a sticky and easily manipulated composite for the application into spinal defect. We found HTPG exhibited enhancement of grafting capacity in consolidation of bone mass. After 12 weeks, tissue reconstruction reached approximately 80% of the injury defects when treated by HTPG/Osteoset combination, but only 30 approximately 40% in the absence of HTPG. The physiological activity of artificial bone substitute combined with PG activated by HT may therefore open beneficial prospects for more successful and safer bone formation in spine procedures in the near future.

Percutaneous management of acutely thrombosed hemodialysis grafts: the double balloon occlusion technique.

OBJECTIVES: The aim of this article is to introduce a new technique, named the "double balloon occlusion technique" (DBOT), for the salvage of acutely thrombosed grafts and to demonstrate its safety and efficacy. BACKGROUND: Acute thrombosis is recognized as the most common factor of acute graft failures. A suitably percutaneous technique should be devised to remove thrombi safely and effectively. Care should also be taken to prevent possible thromboembolic complications during procedures. Mainly composed of two balloons, the percutaneous DBOT has been developed to meet the clinical needs. METHODS: Thirty-two patients with graft failures undergoing the DBOT were recruited between May 2007 and May 2008. The DBOT is itemized in the text and a practical case undergoing successful DBOT is also demonstrated. RESULTS: Of the 32 DBOT treatments, the procedural success rate was 100% (32/32). The clinical success rate was 94% (30/32). One complicated case with severe hematoma resulting from a balloon-induced graft rupture received surgery, although the graft outflow restored. The mean procedure time was 92 minutes. Three patients died and two patients were lost within the 3-month follow-up. The 3-month graft patency rate was 70% (19/27). CONCLUSION: The DBOT has the potential to be operated safely and effectively. Preliminary results had high success rates and patency rates. With basic devices, it may serve as an option to rescue thrombosed grafts. More data are needed to identify its clinical role.

Main pulmonary artery aneurysm.

Pulmonary artery aneurysm is a rare lesion of the thoracic cavity. Different etiologies have been reviewed, but idiopathic lesions without other symptoms are seldom reported. Usually, surgical interventions are suggested, but the long-term outcomes are not well established. Here, we report a 24-year-old man with main pulmonary artery aneurysm who successfully underwent aneurysmectomy and polytetrafluoroethylene vascular graft replacement. The postoperative course was uneventful, and the following image study revealed normal size of the great vessels.

Tissue Doppler velocity is not totally preload-independent: a study in a uremic population after hemodialysis.

OBJECTIVES: The aim of this study was to investigate the changes of regional tissue Doppler velocity after volume removal following regular hemodialysis (HD) in uremic patients. Is tissue Doppler velocity really preload-independent? BACKGROUND: Diastolic dysfunction was divided into four stages: normal pattern, abnormal relaxation pattern, pseudonormalization pattern, and restrictive pattern. Pulse wave Doppler and color Doppler echocardiography were important diagnostic tools for these forms of diastolic dysfunction. However, they were preload-dependent and sometimes there was confusion between the normal pattern and the pseudonormalization pattern. Tissue Doppler echocardiography was promising for problems in diastolic dysfunction and appeared to be preload-independent. However, there are still some disputes over this point. METHODS: Ninety-three uremic patients receiving regular HD were included in the study. There were 45 males and 48 females aged 59 +/- 14 years. The mean volume removed after HD was 2.3 +/- 0.9 kg. The mean heart rates before and after HD were 77 +/- 11 and 76 +/- 12 beats per minute, respectively (p = 0.73). All patients received complete transthoracic echocardiography examinations before and after HD. The studies included cardiac chamber size, left ventricular systolic performance, pulse wave Doppler echocardiographic data of mitral inflow and the right upper pulmonary vein including peak velocity of early diastolic E wave, E wave time velocity integral (TVI-E), peak velocity of late diastolic A wave, A wave TVI, systolic phase of pulmonary vein (S wave TVI), early diastolic phase of pulmonary vein (D wave TVI) and atrial contraction phase of pulmonary vein (Ar wave TVI). Pulsed tissue Doppler echocardiography (TDE) was performed and a 4-mm sample volume was placed at the 6 corners of the mitral annulus including septal, lateral, anterior, inferior, anteroseptal and posterior corners. Five to ten cardiac cycles were recorded and the data were averaged. Measurements performed included peak velocity of systolic phase (Sa), early diastolic phase (Ea), late diastolic phase (Aa), Ea/Aa ratio and time from the beginning of electrocardiogram Q wave to the beginning of Sa (Q-Sa time). The same measurements were repeated after HD. RESULTS: After HD, left atrium diameter and left ventricular internal dimensions at end diastole became smaller. There were significant reductions for mitral peak E wave velocity, TVI-E, peak A wave velocity and E/A ratio. As for the pulmonary vein, systolic phase of pulmonary vein and early diastolic phase of pulmonary vein decreased significantly. Peak Ar wave did not change significantly. For TDE, Sa and Aa did not change but Ea did decrease. CONCLUSION: After HD, there is a significant reduction of intravascular effective volume. No significant change is found for myocardial peak systolic velocity and peak late diastolic velocity. However, there is a significant reduction of myocardial early diastolic phase peak velocity. This suggests that TDE is not completely preload-independent; at least, it is phase-dependent within each cardiac cycle.

Coculture of endothelial and smooth muscle cells on a collagen membrane in the development of a small-diameter vascular graft.

In this study, we have evaluated the feasibility of developing a biodegradable collagenous small diameter vascular graft of 2mm diameter and 1cm length. In brief, bi-layer type I collagen membrane was fabricated under vacuum suction and lyophilization methods. The smooth muscle cells were inoculated into the lower side of the porous membrane, while endothelial cells were seeded onto upper smooth side of the membrane. After cultured for 7 days, the vascular substitute was either harvested for in vitro examination or in vivo implanted in the subcutaneous layer for biocompatibility test. The tubular vascular prosthesis was then used as a temporary absorbable guide that served as an in vivo vascular graft to promote the complete regeneration of rat inferior vena cava. After implantation for 12 weeks, a thin continuous layer of endothelial cells and smooth muscle cells were lined with the vascular lumen and tunic media, respectively. Histology results showed that there were no signs of significant thrombogeneity and intima hyperplasia. This tissue engineered vascular substitute not only had enough tensile strength and good biocompatibility, but also advanced vascular regeneration. In the future, we suggest that this biodegradable vascular substitute will provide with the possibility in application on small diameter prosthetic grafts in artificial blood vessels.

Bolus injection of adenosine before cardioplegic induction improves postischemic global function in coronary artery bypass grafting.

BACKGROUND: Alternative strategies to optimize preexisting cardioplegia during myocardial preservation are currently under extensive investigation. Adenosine, an endogenous purine nucleoside, has been approved for its cardioprotective potential against ischemic-reperfusion injury. Yet, little information is available with respect to the use of adenosine for cardioplegic induction in humans. The purpose of the present study was, therefore, to assess the clinical relevance of intra-aortic administration of adenosine following aortic cross-clamping with respect to the exertion of additional protection in routine coronary artery bypass surgery. METHODS: Thirty patients to receive elective coronary artery bypass grafting under cardiopulmonary bypass (CPB) were prospectively randomized into two study groups. Immediate after aortic cross-clamping and just before the application of modified St. Thomas cardioplegic (20 mL/kg), adenosine solution (250 microg/kg) was injected into the aortic root in the study group (n = 15), while the same amount of normal saline injection was administered in the control group (n = 15). Anesthesia was carried out in all patients in a similar fashion, and all the surgeries were performed by the same team. Homodynamic change, cardiac enzyme assay, and post-bypass inotropic supplementation were recorded throughout the study period to evaluate the extent of myocardial ischemic injury. RESULTS: The mean time to asystole after aortic cross-clamping was significantly shorter for the adenosine group compared with the control group (8.1 +/- 5.9 vs. 79.0 +/- 35.3 sec, respectively; P< 0.01). To compare with the baseline value, the mean cardiac index immediately post CPB and 24 hours postoperatively was increased significantly for the adenosine group (from 2.1 +/- 0.6 to 2.6 +/- 0.6 and 3.2 +/- 0.6 L/min/m2, respectively; P < 0.05), as contrasted with the control group (from 2.3 +/- 0.5 to 2.0 +/- 0.4 and 2.5 +/- 0.4 L/min/m2). Further, the requirement for inotropic support after CPB and postoperative troponin I release were significantly less in the adenosine group. There appeared no adverse effects associated with adenosine administration. CONCLUSIONS: Immediate administration of 250 microg/kg adenosine via the aortic root following aortic cross-clamping could optimize the myocardial protective effect of conventional cardioplegia, quicken cardiac standstill, and offer better postoperative myocardial performance after CPB.