Direct Transcatheter Valve Deployment via Sternotomy for Complex Aortic Valve Reoperation.

Reoperative aortic valve replacement is associated with increased morbidity. Valve-in-valve transcatheter aortic valve replacement offers a less invasive alternative to traditional reoperation. However, cases of valve failure after valve-in-valve transcatheter aortic valve replacement represent a complex surgical challenge. We present a case requiring a complex reoperative aortic valve replacement due to structural valve deterioration after multiple previous valve-in-valve transcatheter aortic valve replacements. We performed removal of 3 previous valve-in-valve transcatheter aortic valves, bioprosthetic leaflet excision, and intentional bioprosthetic fracture under direct vision for annular enlargement. This facilitated direct insertion of a new transcatheter aortic valve for expedient and successful management of recurrent aortic stenosis in a very high-risk patient. Creative use of leaflet excision, intentional bioprosthetic fracture, and insertion of a new transcatheter aortic valve under direct vision, proved efficient and successful in a high-risk patient with few surgical options.

TLR4 Expression Is Associated with Left Ventricular Dysfunction in Patients Undergoing Coronary Artery Bypass Surgery.

INTRODUCTION: Toll-like receptor 4 (TLR4) is an innate immune receptor expressed in immune cells and the heart. Activation of the immune system following myocardial ischemia causes the release of proinflammatory mediators that may negatively influence heart function. AIM: The aim of this study is to determine whether TLR4 is activated in peripheral monocytes and heart tissue taken from patients with varying degrees of myocardial dysfunction caused by coronary artery diseases and scheduled for coronary artery bypass graft (CABG) surgery before 12 months following operation. METHODS AND RESULTS: Patients (n = 44) undergoing CABG surgery having left ventricular ejection fraction ≤ 45% ('reduced EF', n = 20) were compared to patients with preserved EF >45% ('preserved EF' group, n = 24). 'Reduced EF' patients exhibited increased TLR4 expression in monocytes (2.78±0.49 vs. 1.76±0.07 rMFI, p = 0.03). Plasma levels of C-reactive protein, microRNA miR-320a, brain natriuretic peptide (pro BNP) and NADPH oxidase (NOX4) were also significantly different between the 'preserved EF' and 'reduced EF'groups. Elevated TLR4 gene expression levels in the right auricle correlated with those of EF (p<0.008), NOX4 (p<0.008) and miR320, (p<0.04). In contrast, no differences were observed in peripheral monocyte TLR2 expression. After CABG surgery, monocyte TLR4 expression decreased in all patients, reaching statistical significance in the 'reduced EF' group. CONCLUSION: TLR4 is activated in peripheral monocytes and heart tissue obtained from patients with ischemic heart disease and reduced left ventricular function. Coronary revascularization decreases TLR4 expression. We therefore propose that TLR4 plays a pathogenic role and may serve as an additional marker of ischemic myocardial dysfunction.

[Large pericardial cyst in a young woman presenting with fever abdominal pain and diarrhea].

Pericardial cysts are rare mediastinal abnormalities occurring in 1 in 100,000 persons. Most pericardial cysts are congenital but may also be acquired. Their presence poses a diagnostic challenge, distinguishing them from other intracardiac and mediastinal lesions. We describe an unusual presentation of a large pericardial cyst which was diagnosed during the evaluation of prolonged fever, abdominal pain and diarrhea. This case emphasizes that the evaluation and treatment of a pericardial cyst should be based on clinical judgment and should be managed on a case by case basis.

Two-year outcomes for patients with severe symptomatic aortic stenosis treated with transcatheter aortic valve implantation.

Transcatheter aortic valve implantation (TAVI) is an emerging technique for the treatment of severe symptomatic aortic stenosis. Little has been reported about the use of different devices and multiple catheter-based options and anesthetic techniques in the same institution. We report the long-term clinical experience in treating patients with severe symptomatic aortic stenosis using TAVI. We analyzed the outcomes of 153 TAVI-treated patients who were followed for ≤2 years. All patients were at very high risk of surgical valve replacement. The Medtronic-CoreValve device was used in 59.5% and the Edwards-SAPIEN device in 40.5% of the patients. The primary end point was death from any cause during follow-up. The mean ± SD patient age was 81.1 ± 6 years, and 62% of the patients were women. The procedural success rate was 97.4%. At 30 days of follow-up, the all-cause mortality was 3.9%. Two-year follow-up data were obtained for 108 patients, with 85.5% survival of treated patients. The 30-day stroke rate was 3.9%. No significant differences in mortality were found when angioplasty was performed before or during TAVI compared with TAVI alone. Multivariate analysis showed that increased baseline creatinine (hazard ratio 1.55, 95% confidence interval 1.01 to 2.42, p = 0.049) and increased logistic European System for Cardiac Operative Risk Evaluation score (hazard ratio 1.03, 95% confidence interval 1.01 to 1.06, p = 0.048) predicted all-cause mortality. In conclusion, the clinical outcome of TAVI is favorable. The use of both procedural devices and multiple techniques in the same institution is feasible and potentially desirable.

Elevated level of pro-inflammatory eicosanoids and EPC dysfunction in diabetic patients with cardiac ischemia.

BACKGROUND: Circulating endothelial progenitor cells (EPCs) are recruited from the blood system to sites of ischemia and endothelial damage, where they contribute to the repair and development of blood vessels. Since numerous eicosanoids including leukotrienes (LTs) and hydroxyeicosatetraenoic acids (HETEs) have been shown to exert potent pro-inflammatory activities, we examined their levels in chronic diabetic patients with severe cardiac ischemia in conjunction with the level and function of EPCs. RESULTS: Lipidomic analysis revealed a diabetes-specific increase (p<0.05) in inflammatory and angiogenic eicosanoids including the 5-lipoxygenase-derived LTB (4.11±1.17 vs. 0.96±0.27 ng/ml), the lipoxygenase/CYP-derived 12-HETE (117.08±35.05 vs. 24.34±10.03 ng/ml), 12-HETrE (17.56±4.43 vs. 4.15±2.07 ng/ml), and the CYP-derived 20-HETE (0.32±0.04 vs. 0.06±0.05 ng/ml) the level of which correlated with BMI (p=0.0027). In contrast, levels of the CYP-derived EETs were not significantly (p=0.36) different between these two groups. EPC levels and their colony-forming units were lower (p<0.05) with a reduced viability in diabetic patients compared with non-diabetics. EPC function (colony-forming units (CFUs) and MTT assay) also negatively correlated with the circulating levels of HgA1C. CONCLUSION: This study demonstrates a close association between elevated levels of highly pro-inflammatory eicosonoids, diabetes and EPC dysfunction in patients with cardiac ischemia, indicating that chronic inflammation impact negatively on EPC function and angiogenic capacity in diabetes.

Clinical profile and outcome of patients with severe aortic stenosis at high surgical risk: single-center prospective evaluation according to treatment assignment.

BACKGROUND: The study sought to assess the clinical profile, outcome, and predictors for mortality of "real-world" high-risk severe aortic stenosis patients according to the mode of treatment assigned. METHODS: Patients were referred to a dedicated clinic for meticulous screening and multidisciplinary team assessment and 343 were finally assigned treatment (age 81.3 ± 7.2 years, 42.3% men): transcatheter aortic valve replacement (TAVR) with the Edwards SAPIEN or CoreValve device, 100 (29.2%); surgical aortic valve replacement (SAVR), 61 (17.8%); balloon valvuloplasty (as definitive therapy), 27 (7.9%); medication only, 155 (45.2%). No patient was lost to follow-up. RESULTS: The balloon valvuloplasty group had a significantly higher 1-month mortality rate (18.5%) than the TAVR group (3%, P = 0.006) and medical therapy group (3.9%; P = 0.004), without significant difference from the SAVR group (11.5%, P = 0.5). One-year cumulative survival was significantly higher in the TAVR group (92%) than in the other groups (SAVR 71%, balloon valvuloplasty 61.5%, medication 65%; all P < 0.001). Among survivors, 1-year rates of high functional class (NYHA I/II) were as follows: TAVR, 84.6%; SAVR, 63.3%; balloon valvuloplasty, 18.2%; medication, 21.4% (TAVR vs. SAVR, P = 0.04; SAVR vs. balloon valvuloplasty or medical therapy, P = 0.01). On multivariate regression analysis, renal failure (hazard ratio [HR] = 5.3, P < 0.001), not performing TAVR (HR = 4.9, P < 0.001), and pulmonary pressure (10 mm Hg, HR = 1.2, P = 0.02) were independent predictors of 1-year mortality. CONCLUSIONS: TAVR, performed in carefully selected high-risk patients, is associated with an excellent survival rate and high functional class. Patients treated with another of the available modalities, including SAVR, had a worse outcome, regardless of which alternative treatment they receive.

Exercise training improves cardiac function and attenuates arrhythmia in CPVT mice.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a lethal ventricular arrhythmia evoked by physical or emotional stress. Recessively inherited CPVT is caused by either missense or null-allele mutations in the cardiac calsequestrin (CASQ2) gene. It was suggested that defects in CASQ2 cause protein deficiency and impair Ca(2+) uptake to the sarcoplasmic reticulum and Ca(2+)-dependent inhibition of ryanodine channels, leading to diastolic Ca(2+) leak, after-depolarizations, and arrhythmia. To examine the effect of exercise training on left ventricular remodeling and arrhythmia, CASQ2 knockout (KO) mice and wild-type controls underwent echocardiography and heart rhythm telemetry before and after 6 wk of training by treadmill exercise. qRT-PCR and Western blotting were used to measure gene and protein expression. Left ventricular fractional shortening was impaired in KO (33 ± 5 vs. 51 ± 7% in controls, P < 0.05) and improved after training (43 ± 12 and 51 ± 9% in KO and control mice, respectively, P = nonsignificant). The exercise tolerance was low in KO mice (16 ± 1 vs. 29 ± 2 min in controls, P < 0.01), but improved in trained animals (26 ± 2 vs. 30 ± 3 min, P = nonsignificant). The hearts of KO mice had a higher basal expression of the brain natriuretic peptide gene. After training, the expression of natriuretic peptide genes markedly decreased, with no difference between KO and controls. Exercise training was not associated with a change in ventricular tachycardia prevalence, but appeared to reduce arrhythmia load, as manifested by a decrease in ventricular beats during stress. We conclude that, in KO mice, which recapitulate the phenotype of human CPVT2, exercise training is well tolerated and could offer a strategy for heart conditioning against stress-induced arrhythmia.

[Transcatheter aortic-valve implantation].

Aortic valve stenosis is associated with severe morbidity and death within several years of symptom onset, and its accepted treatment is surgical aortic valve replacement. However, many affected patients are not referred for surgery because of old age and significant comorbidities. In recent years, an alternative treatment approach has been developed, transcatheter aortic-valve implantation. In this review we would like to describe this treatment modality and to present several cases performed in our center.

Endothelial progenitor cell function inversely correlates with long-term glucose control in diabetic patients: association with the attenuation of the heme oxygenase-adiponectin axis.

BACKGROUND: Endothelial progenitor cells (EPCs) are attenuated, both in number and functionality, in animal models of chronic cardiovascular and metabolic disorders. This effect has subsequently been linked to the aggravation of long-term morbidity and mortality associated with such disorders. The objective was to examine EPC number and survival in chronic diabetic vs nondiabetic patients in conjunction with the examination of their redox, inflammatory, and antioxidant defense system (Nrf2 genes) status in serum and visceral fat. METHODS: Visceral adipose tissue from diabetic and nondiabetic patients undergoing coronary artery bypass graft surgery was analyzed for Nrf2-dependent genes. Oxidative stress was evaluated using thiobarbituric acid-reactive substance assay (TBARS). Peripheral blood, collected 1 day prior to surgery, was evaluated for inflammatory cytokines and EPCs. RESULTS: When compared with controls (P < 0.05), results of the thiobarbituric acid-reactive substance assay were higher in diabetic patients. Although Nrf2-dependent antioxidant proteins (thioredoxin-1 [Trx-1], nicotinamide adenine dinucleotide phosphate [NAD(P)H] quinone oxidoreductase [NQO1], glutathione S-transferase [GST]) were upregulated, heme oxygenase (HO-1) and adiponectin protein expression were lower in the diabetic group (P < 0.05). Serum levels of bilirubin were lower (P < 0.005) while the levels of inflammatory cytokines were higher in diabetic patients (P < 0.05). EPC levels and their colony forming units were significantly lower (P < 0.05) with reduced viability in diabetic patients as compared with nondiabetic patients. CONCLUSIONS: These results demonstrate for the first time that in diabetic patients, there is an inadequate heme oxygenase-adiponectin axis response, which could compromise the compensatory antioxidant and anti-inflammatory effects consequently contributing toward EPC dysfunction in these patients.

Distal left anterior descending coronary artery obstruction: a rare complication of transapical aortic valve implantation.

Apical complications are considered the "Achilles' heel" of transapical aortic valve implantation, in which laceration and hemorrhage are potentially fatal. We describe the case of a rare complication of the transapical aortic valve implantation procedure, where after apical closure, tension on a distal coronary segment resulted in flow obstruction. Clinicians should be alert to the possibility of distal left anterior descending artery obstruction when ischemia following a transapical procedure is suspected. The exact location of sheath insertion during "transapical" aortic valve implantation is usually apicolateral. A more apical insertion should be avoided since the apex is a relatively weak region and there could be an increased risk of coronary avulsion or apical ventricular septal defect. Nevertheless, a too-lateral insertion could diminish the sheath orientation toward the left ventricular outflow tract and the sheath could also be entrapped with mitral valve chordae. Surgeons should be aware of these factors when deciding on the exact sheath insertion site during tranaspical procedures.

The value of intraoperative transesophageal echocardiography in patients undergoing aortic valve replacement.

BACKGROUND AND AIM OF THE STUDY: While the role of intraoperative transesophageal echocardiography (IOTEE) in valve repair surgery is well documented, its value in patients undergoing valve replacement is debatable. The study aim was to assess the impact of IOTEE on the management of a large cohort of patients referred for aortic valve replacement (AVR). METHODS: The departmental echocardiography database for patients undergoing AVR with IOTEE between April 1999 and September 2006 at the authors' institution was reviewed. Patients with a diagnosis of infective endocarditis, aortic dissection, or those in whom a composite graft was implanted, were excluded from the study. RESULTS: The study group included 604 patients (319 males, 285 females; mean age 70 +/- 11 years) who underwent AVR for either predominant aortic stenosis (n = 520; 86.1%) or aortic regurgitation (n = 84; 13.9%). Pre-pump IOTEE was performed in 440 patients (72.8%), and post-pump IOTEE in 586 (97.0%). Overall major preoperative findings influencing the operative plan were found in 106 of the 440 patients (24.1%); decisions regarding the mitral valve were the most frequent. The post-pump study revealed unexpected findings requiring a second pump run in 20 patients (3.4%), of whom nine cases (1.5%) applied to the replaced aortic prostheses (paravalvular leak in five patients, coronary obstruction by an aortic bioprosthesis in two, and detection and closure of a pseudoaneurysm in the mitral-aortic fibrosa and incompetent bioprosthesis in one patient each). Eleven patients (1.8%) required a second pump run because of failed mitral/tricuspid repair or hemodynamic compromise. CONCLUSION: The main use of a routine application of IOTEE among patients undergoing AVR was to detect additional lesions preoperatively, and technical failures postoperatively.

Transcatheter aortic and mitral valve implantations for failed bioprosthetic heart valves.

BACKGROUND: Restoring degenerated bioprosthetic valves by transcatheter valve implantation may obviate the need for redo surgery in carefully selected patients. We present our initial experience with valve-in-valve (VIV) procedures for failed aortic and mitral bioprosthetic valves. METHODS: Data were collected for all patients who underwent VIV procedures at a tertiary medical center (n = 6). Findings were analyzed and compared with those for transcatheter valve implantation in native valves at the same center during the last 3 years (n = 84). RESULTS: Six patients of mean age 78.3 ± 13.8 years (range, 51-87) underwent VIV procedures with the CoreValve (n = 4) or Edwards-SAPIEN device (n = 2). Four (66%) had a failed prosthetic aortic valve, and 2 (33%) had a failed prosthetic mitral valve. Regurgitation accounted for valve failure in 83.3% of the VIV group versus 1.2% of the comparison group (p < 0.001). Procedural success and 30-day survival rates were 100%. Patient functional class improved significantly from 0% class I/II, 50% class III, and 50% class IV before the procedure to 66% class I, 33% class II, and 0% class III/IV after (p < 0.001). CONCLUSION: This preliminary experience demonstrates that in carefully selected cases, transcathether valve implants can be safely and effectively deployed in stenotic and/or regurgitant degenerated bioprosthetic valves. Further evaluations in larger series are needed.

Toll-like receptor 4 stimulation initiates an inflammatory response that decreases cardiomyocyte contractility.

Toll-like receptors (TLRs) have been identified as primary innate immune receptors for the recognition of pathogen-associated molecular patterns by immune cells, initiating a primary response toward invading pathogens and recruitment of the adaptive immune response. TLRs, especially Toll-like receptor 4 (TLR4), can also be stimulated by host-derived molecules and are expressed in the cardiovascular system, thus acting as a possible key link between cardiovascular diseases and the immune system. TLR4 is involved in the acute myocardial dysfunction caused by septic shock and myocardial ischemia. We used wild-type (WT) mice, TLR4-deficient (TLR4-knockout [ko]) mice, and chimeras that underwent myeloablative bone marrow transplantation to dissociate between TLR4 expression in the heart (TLR4-ko/WT) and the immunohematopoietic system (WT/TLR4-ko). Following lipopolysaccharide (LPS) challenge (septic shock model) or coronary artery ligation, myocardial ischemia (MI) model, we found WT/TLR4-ko mice challenged with LPS or MI displayed reduced cardiac function, increased myocardial levels of interleukin-1ß and tumor necrosis factor-α, and upregulation of mRNA encoding TLR4 prior to myocardial leukocyte infiltration. The cardiac function of TLR4-ko or WT/TLR4-ko mice was less affected by LPS and demonstrated reduced suppression by MI compared with WT. These results suggest that TLR4 expressed in the cardiomyocytes plays a key role in this acute phenomenon.

Retrosternal percutaneous tracheostomy: an approach for predictably impossible classic tracheostomy.

Percutaneous tracheostomy is a routine procedure in intensive care units. In cases of very low position of the larynx, cervical spine deformation, morbid obesity, or neck tumor, performance of the classic tracheostomy is inapplicable. Retrosternal approach to tracheostomy in such 20 patients is herein reported. After preoperative neck computerized tomography to define the neck anatomy, a small suprasternal incision followed by a short retrosternal tissue dissection to expose the trachea was done; the trachea was then catheterized at the level of the 2nd ring in the usual tracheostomy manner. The immediate and late (≥6 months) outcomes were similar to that of the standard tracheostomy. Thus, percutaneous retrosternal tracheostomy is safe in patients with abnormal positioning of the trachea or neck constitution. It is a bedside applicable technique, that, however, requires caution to avoid hazardous vascular complications.

Optimizing catecholaminergic polymorphic ventricular tachycardia therapy in calsequestrin-mutant mice.

BACKGROUND: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a lethal arrhythmia provoked by physical or emotional stress and mediated by spontaneous Ca(2+) release and delayed after-depolarizations. Beta-adrenergic blockers are the therapy of choice but fail to control arrhythmia in up to 50% of patients. OBJECTIVE: To optimize antiarrhythmic therapy in recessively inherited CPVT caused by calsequestrin (CASQ2) mutations. METHODS: Murine heart rhythm telemetry was obtained at rest, during treadmill exercise, and after injection of epinephrine. The protocol was repeated after injection of different antiarrhythmic drugs. Results were then validated in human patients. RESULTS: Adult CASQ2 mutant mice had complex ventricular arrhythmia at rest and developed bidirectional and polymorphic ventricular tachycardia on exertion. Class I antiarrhythmic agents (procainamide, lidocaine, flecainide) were ineffective in controlling arrhythmia. Propranolol and sotalol attenuated arrhythmia at rest but failed to prevent VT during sympathetic stimulation. The calcium channel blocker verapamil showed a dose-dependent protection against CPVT. Verapamil was more effective than the dihydropyridine L-type Ca(2+) channel blocker nifedipine, and its activity was markedly enhanced when combined with propranolol. Human patients homozygous for CASQ2(D307H) mutation, remaining symptomatic despite chronic ß-blocker therapy, underwent exercise testing according to the Bruce protocol with continuous electrocardiogram recording. Verapamil was combined with propranolol at maximum tolerated doses. Adding verapamil attenuated ventricular arrhythmia and prolonged exercise duration in five of 11 patients. CONCLUSION: Verapamil is highly effective against catecholamine-induced arrhythmia in mice with CASQ2 mutations and may potentiate the antiarrhythmic activity of ß-blockers in humans with CPVT2.

Primary cardiac valve tumors.

To assess the prevalence, characteristics, and outcome of surgical treatment of primary cardiac valve tumors in a single center, we reviewed our experience in 6 women and 1 man, aged 49 to 76 years (mean, 64.7 years) who presented between 1999 and 2006. In one patient, the diagnosis of cardiac valve tumor was made incidentally on transesophageal echocardiography during aortocoronary bypass surgery. The others had clinical symptoms: angina or myocardial infarction in 3, congestive heart failure in 2, dyspnea and cerebrovascular ischemia in 1 patient each. Four of the 7 tumors were benign, and 3 were malignant. All patients survived the operation and recovered uneventfully. Midterm follow-up was available in all patients. Two patients with malignant tumors were considered unsuitable for adjuvant therapy by the oncologist; both died during follow-up from local tumor recurrence. All 5 survivors were categorized at the last follow-up as functional class I, with normal exercise tolerance. Excellent early and midterm surgical results can be obtained in patients with benign cardiac valve tumors, but the prognosis for those with a malignant tumor is poor.

Cardiomyocyte Toll-like receptor 4 is involved in heart dysfunction following septic shock or myocardial ischemia.

Toll-like receptors are expressed in immune cells and cardiac muscle. We examined whether the cardiac Toll-like receptor 4 (TLR4) is involved in the acute myocardial dysfunction caused by septic shock and myocardial ischemia (MI). We used wild type mice (WT), TLR4 deficient (TLR4-ko) mice and chimeras that underwent myeloablative bone marrow transplantation to dissociate between TLR4 expression in the heart (TLR4-ko/WT) and the immunohematopoietic system (WT/TLR4-ko). Mice were injected with lipopolysaccharide (LPS) (septic shock model) or subjected to coronary artery ligation (MI model) and tested in vivo and ex vivo, for function, histopathology proinflammatory cytokine and TLR4 expression. WT mice challenged with LPS or MI displayed reduced cardiac function, increased myocardial levels of IL-1 beta and TNF-alpha and upregulation of mRNA encoding TLR4 prior to myocardial leukocyte infiltration. TLR4 deficient mice sustained significantly smaller infarctions as compared to control mice at comparable areas at risk. The cardiac function of TLR4-ko mice was not affected by LPS and demonstrated reduced suppression by MI compared to WT. Chimeras deficient in myocardial TLR4 were resistant to suppression induced by LPS and the heart function was less depressed, compared to the TLR4-ko, following MI in the acute phase (4h). In contrast, hearts of chimeras deficient in immunohematopoietic TLR4 expression were suppressed both by LPS and MI, exhibiting increased myocardial cytokine levels, similar to WT mice. We concluded that cardiac function of TLR4-ko mice and chimeric mice expressing TLR4 in the immunohematopoietic system, but not in the heart, revealed resistance to LPS and reduced cardiac depression following MI, suggesting that TLR4 expressed by the cardiomyocytes themselves plays a key role in this acute phenomenon.

The effect of cardiac angiography timing, contrast media dose, and preoperative renal function on acute renal failure after coronary artery bypass grafting.

OBJECTIVE: Our objective was to assess the effect of the timing of cardiac angiography, contrast media dose, and preoperative renal function on the prevalence of acute renal failure after cardiac surgery. METHODS: Data on 395 consecutive patients who underwent coronary artery bypass grafting were prospectively collected. Creatinine clearance was estimated by the Cockcroft-Gault equation. Patients were divided into 3 groups according to the time between cardiac angiography and surgery (group A, < or = 1 day; group B, > 1 day and < or = 5 days; group C, > 5 days). Patients who underwent a salvage operation or were receiving dialysis before surgery were excluded. Acute renal failure was defined as 25% decrease from baseline of estimated creatinine clearance and estimated creatinine clearance of 60 mL/min or less on postoperative day 3. Owing to differences in preoperative characteristics between groups, propensity score analysis was used to adjust those differences. RESULTS: Acute renal failure developed in 13.6% of patients. Hospital mortality was 3.3% and was higher in patients in whom acute renal failure developed (22%) versus those in whom it did not (0.3%; P < .001). Multivariable analysis identified preoperative estimated creatinine clearance of 60 mL/min or less (odds ratio [OR], 7.1), operation within 24 hours of catheterization (OR = 3.7), use of more than 1.4 mL/kg of contrast media (OR = 3.4), lower hemoglobin level (OR = 1.3), older age (OR = 1.1), and lower weight (OR = 0.95) as independent predictors of postoperative acute renal failure. Analysis of interaction between contrast dose and time of surgery revealed that high contrast dose (>1.4 mL/kg) predicted acute renal failure if surgery was performed up to 5 days after angiography. CONCLUSIONS: Whenever possible, coronary bypass grafting should be delayed for at least 5 days in patients who received a high contrast dose, especially if they also have preoperative reduced renal function.

Adenosine A3 receptor-mediated cardioprotection against doxorubicin-induced mitochondrial damage.

Cardiotoxicity associated with doxorubicin (DOX) treatment limits the therapeutic efficiency of this drug against cancer. 2-Chloro-N(6)-(3-iodobenzyl)adenosine-5'-N-methyluronamide (Cl-IB-MECA), a selective agonist of A(3) adenosine receptor (A(3)R), reduces DOX toxicity in newborn rat cultured cardiomyocytes. The study's aim was to determine whether the protection demonstrated by Cl-IB-MECA attenuates cardiac depression in vivo. In addition, we wished to examine whether this protective pathway affects the sarcoplasmic reticulum (SR) calcium uptake and release, as well as intramitochondrial Ca(2+) accumulation induced by DOX. Rats were injected every alternate day (6 times) with (1) saline, (2) 2.5mg/kg i.p. DOX, (3) 33 microg/kg i.v. Cl-IB-MECA, (4) DOX+Cl-IB-MECA. Left ventricular functions were assessed by invasive (pressure) and non-invasive (echocardiography) techniques at the end of the injection period and 4 weeks later. Cytosolic and intramitochondrial calcium levels were measured with indo-1 and rhod-2 probes. SR Ca(2+) content was determined by exposing cultured rat cardiomyocytes to caffeine. Echocardiography data demonstrate left ventricular wall thinning (23%), an increase in the end systolic dimension (170%) and decreased fractional shortening (35+/-5% vs. 54+/-5%, p<0.01) in DOX-treated animals, compared to the control group. DOX increased Ca(2+) levels in the cytosol and in mitochondria by diminishing the SR Ca(2+) uptake. Pretreatment with Cl-IB-MECA attenuated left ventricular dysfunction, improved SR calcium storage capacity and prevented mitochondrial Ca(2+) overload. We conclude that the adenosine A(3) receptor agonist is effective in vivo against DOX cardiotoxicity via the restoration of Ca(2+) homeostasis and prevention of mitochondrial damage that occurs as a result of Ca(2+) overload.

Video-assisted pericardial fenestration for effusions after cardiac surgery.

Delayed-onset pericardial effusion following cardiac surgery can give rise to significant morbidity due to its presentation as well as management by traditional surgical techniques. An institutional experience of a video-assisted thoracoscopic technique to create a pericardial window, with the advantages of a minimally invasive approach combined with excellent visualization in such patients, was reviewed. A retrospective analysis was conducted on all patients undergoing video-assisted thoracoscopic for delayed pericardial effusion after cardiac surgery from January 2001 to January 2006 at our center. Seven patients with echocardiographically diagnosed delayed tamponade underwent video-assisted thoracoscopy; 5 were receiving anticoagulants after valve replacement, and 2 had undergone heart transplantation. Pericardial windows were created under general anesthesia and single-lung ventilation using 2 to 3 trocars. Mean operative time was 45 min. There were no complications of the thoracoscopic technique. Video-assisted thoracoscopic creation of a pericardial window is safe and effective treatment for loculated pericardial effusions secondary to cardiac surgery.