Influence of angiogenesis by implantation of bone marrow mononuclear cells in the rat ischemic heart.

Bone marrow implantation (BMI) enhances angiogenesis in several animal models of ischemic diseases, and it is currently applied in the clinical treatment of humans. However, the mechanisms of this effect have not yet been fully described. Rat bone marrow mononuclear cells (BM-MNCs) were obtained by Histopaque density gradient centrifugation and injected directly into the ischemic myocardium of the test rats (BMI group), which were then examined and compared with the groups that received surgery only (Controls) or surgery and an injection of phosphate buffered saline (PBS group). Cardiac function was evaluated by echocardiography, and neovascularization was examined both histologically and immunohistochemically before, 1 day after, and 7 or 28 days after the operation. BM-MNCs were analyzed by fluorescence staining for the endothelial cell marker CD31 and alkaline phosphatase (ALP). The mechanisms of angiogenesis were examined by gene expression analysis. In the BMI group, cardiac function parameters at 7 days after operation were significantly improved and the number of capillaries in the myocardium was significantly larger than that in the PBS and Control groups. Gene analysis showed the expression of 12 genes in the BMI group 7 days after operation. The implantation of BM-MNCs into the myocardiumin cases of acute infarction enhances cytoprotection and angiogenesis by affecting gene expression.

Effects of nicorandil preconditioning on membrane dystrophin.

OBJECTIVE: Dystrophin is an integral membrane protein that stabilizes the sarcolemmal membrane integrity, and its loss may be involved in the mechanism of ischemia and reperfusion injury. It has been reported that ischemic preconditioning is related to the preservation of membrane dystrophin during ischemia and reperfusion. Preconditioning with nicorandil, a mitochondrial K(ATP) channel opener, may attenuate the injury by preventing a disturbance in the level of this membrane-associated protein. METHODS: The isolated rat hearts were subjected to 60 min of cardioplegic arrest, followed by 60 min of reperfusion. The hearts were divided into the following three groups according to the drugs given before cardioplegic arrest. The control group received saline intravenously 30 min before heart isolation. The nicorandil group received nicorandil (0.3 mg/kg) intravenously 30 min before isolation. The 5-HD group received 5-hydroxydecanoate (1 mg/kg) intravenously, a mitochondrial K(ATP) channel blocker, 5 min before nicorandil administration. Cardiac function, myocardial metabolism, dystrophin distribution and protein levels of dystrophin were assessed before and after cardioplegic arrest. RESULTS: The nicorandil group showed significantly better cardiac function and a significant reduction in creatine kinase release during reperfusion. After 60 min of cardioplegic arrest, dystrophin, which was distributed predominantly in the sarcolemmal membrane before ischemia, was translocated to the costameric cytoskeleton in all groups. During reperfusion, the level of membrane dystrophin remained decreased in the majority of cardiomyocytes in the control and 5-HD groups, whereas it was restored to nearly the baseline level in the nicorandil group. The immunoblot analysis supported this result. CONCLUSIONS: Depletion of sarcolemmal membrane dystrophin occurred during cardioplegic arrest and reperfusion. Nicorandil preconditioning may attenuate ischemia and reperfusion injury by maintaining the membrane structural integrity.

Dysfunction of an ATS valve in the aortic position: the first reported case caused by pannus formation.

A 64-year-old woman underwent aortic valve replacement with a 21-mm Advancing The Standard (ATS) open-pivot mechanical heart valve for bicuspid aortic valve stenosis. In addition to the appearance of a new cardiac murmur, echocardiography performed 3 years after surgery showed a high pressure gradient across the ATS valve and a reduction in the valve orifice area. Cineradiography of the valve revealed restricted leaflet opening. Subsequent multidetector-row computed tomography clearly demonstrated pannus overgrowth on the inflow aspect of the ATS valve. During a repeat operation, subvalvular overgrown pannus was confirmed and the ATS valve was replaced with a bioprosthetic valve. This is the first reported case of prosthetic valve dysfunction resulting from pannus formation in a patient with an ATS valve in the aortic position.

P-wave signal-averaged electrocardiogram for predicting atrial arrhythmia after cardiac surgery.

BACKGROUND: Atrial arrhythmias (AF) are usually benign, but occur frequently after cardiac surgery. P-wave signal-averaged electrocardiogram has been used to characterize atrial conduction delay as a marker of risk of AF during sinus rhythm. METHODS: Ninety-five patients undergoing either primary isolated coronary artery bypass grafting or aortic valve replacement were enrolled. The duration and the root mean square voltage for the last 20 ms of filtered (40 to 300 Hz) P-wave of the spatial magnitude were recorded before surgery. Any episode of postoperative atrial fibrillation, atrial flutter, or paroxysmal atrial fibrillation lasting longer than 1 hour was considered as AF. RESULTS: Twenty-eight patients (29%) exhibited AF 3.0 +/- 2.3 days after surgery. The P-wave duration recorded with P-wave signal-averaged electrocardiogram was significantly prolonged in patients with AF (135 +/- 14 ms versus 127 +/- 9 ms; p = 0.002). Patients with AF more often had dilated left atrium (p = 0.003), left ventricular hypertrophy (p = 0.03), and advanced age (p = 0.02). Logistic regression analysis identified the following three variables as predictive of AF: P-wave duration of 135 ms or greater (p = 0.02; odds ratio, 3.5), patients 70 years of age and older (p = 0.03; odds ratio, 3.2), and left atrial dimension of 35 mm or greater (p = 0.03; odds ratio, 3.2). If a patient had two or more of these three risk factors, the occurrence of AF was predicted with a sensitivity of 75%, specificity of 76%, positive predictive accuracy of 57%, and negative predictive accuracy of 88%. CONCLUSIONS: The prolonged P-wave duration recorded with P-wave signal-averaged electrocardiogram, together with advanced age and left atrial enlargement, is a potent and independent predictor of AF after cardiac surgery. Patients with these risk factors may benefit from prophylactic antiarrhythmic treatment.

Cardiac operations in cirrhotic patients.

It is well recognized that morbidity and mortality rates after cardiac operations with cardiopulmonary bypass in patients with cirrhosis are significantly higher than those in the general cardiac surgical population. Several contributing factors peculiar to cirrhosis, such as compromised nutritional status, increased susceptibility to infections, and impaired coagulopathy, may be responsible for the poor prognosis. It is empirically agreed that cardiac operations using cardiopulmonary bypass are contraindicated in patients with advanced cirrhosis. However, the population of cirrhotic patients who are referred for cardiac operations is still small and definitive indications for surgical interventions remain unknown. Moreover, cirrhotic patients have many distinctive anatomical and physiological features that influence postoperative course considerably. In this article, we reviewed the literature with special reference to its clinical features and clinical outcomes after cardiac surgery that would help cardiac surgeons to decide therapeutic modality. Further understanding of the unique condition, careful patient selection and intensive postoperative care are required to improve the clinical outcome in cirrhotic patients undergoing cardiopulmonary bypass. Recent developments in minimally invasive procedures, such as off-pump coronary artery bypass grafting, however, may enable us to treat patients with advanced cirrhosis safely.

Clinical outcome after cardiac operations in patients with cirrhosis.

BACKGROUND: To evaluate the clinical outcome after cardiac operations in patients with cirrhosis, a retrospective study was undertaken. METHODS: Between 1989 and 2003, 18 patients with cirrhosis who underwent cardiac operations were identified. Their preoperative status and postoperative clinical results were assessed. RESULTS: Ten patients were classified as having Child-Pugh class A cirrhosis, 7 as having class B cirrhosis, and 1 as having class C cirrhosis. Fifteen of 18 patients underwent cardiac surgery using cardiopulmonary bypass, and the remaining 3 patients with class B cirrhosis received coronary artery bypass grafting without cardiopulmonary bypass. In patients undergoing cardiopulmonary bypass, 60% of those with class A cirrhosis and 100% of those with class B cirrhosis and class C cirrhosis had postoperative major complications, including infection, respiratory failure, renal failure, bleeding, and gastrointestinal disorder. One of 3 patients (33%) with class B cirrhosis undergoing coronary artery bypass grafting without cardiopulmonary bypass had major complications. The overall postoperative mortality rate was 17%. Hospital mortality of patients with class A cirrhosis, class B cirrhosis, and class C cirrhosis undergoing cardiopulmonary bypass was 0%, 50%, and 100%, respectively. None of 3 patients with class B cirrhosis undergoing coronary artery bypass grafting without cardiopulmonary bypass died in this study. CONCLUSIONS: Although the incidence of major complications was high, patients with Child-Pugh class A cirrhosis tolerated cardiac surgery satisfactorily. Patients with more advanced cirrhosis, however, may not be suitable for elective cardiac operations with cardiopulmonary bypass. Although our results are not conclusive, coronary artery bypass grafting without cardiopulmonary bypass can be an alternative therapeutic strategy for patients with advanced cirrhosis requiring surgical revascularization.

Usefulness of a multidetector-row computed tomography scanner for detecting pannus formation.

BACKGROUND: Prosthetic valve dysfunction (PVD) as a result of pannus or thrombus formation is an infrequent but serious complication. Currently available diagnostic tools, however, are insufficient to detect a minute pannus and thrombi. The use of a more advanced diagnostic image, multidetector-row computed tomography scanner, may enable us to determine the anatomic and functional causes of PVD. METHODS: Patients who underwent aortic valve replacement with a St. Jude Medical valve were examined by transthoracic echocardiography and cineradiography to diagnose PVD. Sixteen patients with PVD (PVD group) and 12 patients with normal prosthetic valve function (control group) were studied using the multidetector-row computed tomography scanner. The multidetector-row computed tomography findings in 2 patients with PVD were validated by the observations during reoperation. RESULTS: In 13 of 16 patients (81%) in the PVD group and 3 of 12 patients (25%) in the control group, multidetector-row computed tomography demonstrated that an abnormal small tissue, regarded as pannus, was found to extend from the left ventricular septum into the pivot guard. These findings were confirmed by the observations during reoperation in 2 patients in the PVD group. CONCLUSIONS: Multidetector-row computed tomography can be a useful diagnostic technique for anatomic and functional evaluation of PVD as a result of pannus formation.

Non-occlusive condition with the Better-Header roller pump: impacts of flow dynamics and hemolysis.

PURPOSE: Impacts on hemolysis and backflow using a non-occlusive setting with the Better-Header (BH) roller pump were investigated. METHODS AND RESULTS: Pump flow of a non-occlusion setting was measured with a pump speed of 3 L/min and 5 L/min against various after-loads. With the non-occlusive setting (BH-NO350), backflow was less than 10% if the pump pressure head was <300 mmHg. When the outlet line is occluded, 80% of the set flow was shunted through the pressure relief valve and outlet pressure did not develop hazardous overpressure. During surgery with the BH-NO350, flow loss was <5% while the pump pressure was maintained at approximately 200 mmHg. An in vitro hemolysis test was conducted at 5 L/min against 350 mmHg, using the standard occlusion (BH-SO), the non-occlusion (BH-NO350), and the centrifugal pump (CP). The CP demonstrated less hemolysis than the other two groups; the BH-SO and the BH-NO350 had similar hemolytic characteristics. During cardiopulmonary bypass, no significant differences in hemolysis were seen among the BH-SO, the BH-NO350, and the CP. CONCLUSION: Possible flow loss of the non-occlusion setting with the BH should be almost negligible in most clinical situations. The BH-NO350 demonstrated hemolytic characteristics similar to those of the BH-SO, but not as good as those of the CP.

Transcatheter coil embolization of a high-flow coronary artery fistula using 0.052-inch gianturco coils: a case report.

A giant, high-flow coronary fistula is usually difficult to treat by transcatheter coil embolization, but the 0.052-inch Gianturco coil, which is larger and has a stronger shape memory than conventional coils, is now available. Using this device and additional conventional coils, a high-flow coronary artery fistula in a healthy 31-year-old man was successfully embolized. The new Gianturco coil widens the indication for the transcatheter embolization of coronary artery fistulas.

Obstruction of St Jude Medical valves in the aortic position: histology and immunohistochemistry of pannus.

OBJECTIVE: This study aims to reveal the morphological, histological, and immunohistochemical mechanism of pannus formation using resected pannus tissue from patients with prosthetic valve dysfunction. METHOD: Eleven patients with prosthetic valve (St Jude Medical valve) dysfunction in the aortic position who underwent reoperation were studied. We used specimens of resected pannus for histological staining (hematoxylin and eosin, Grocott's, azan, elastica van Gieson) and immunohistochemical staining (transforming growth factor-beta, transforming growth factor-beta receptor 1, alpha-smooth muscle actin, desmin, epithelial membrane antigen, CD34, factor VIII, CD68KP1, matrix metalloproteinase-1, matrix metalloproteinase-3, and matrix metalloproteinase-9). RESULTS: Pannus without thrombus was observed at the periannulus of the left ventricular septal side; it extended into the pivot guard, interfering with the movement of the straight edge of the leaflet. The histological staining demonstrated that the specimens were mainly constituted with collagen and elastic fibrous tissue accompanied by endothelial cells, chronic inflammatory cells infiltration, and myofibroblasts. The immunohistochemical findings showed significant expression of transforming growth factor-beta, transforming growth factor-beta receptor 1, CD34, and factor VIII in the endothelial cells of the lumen layer; strong transforming growth factor-beta receptor 1, alpha-smooth muscle actin, desmin, and epithelial membrane antigen in the myofibroblasts of the media layer; and transforming growth factor-beta, transforming growth factor-beta receptor 1, and CD68KP1 in macrophages of the stump lesion. CONCLUSIONS: Pannus appeared to originate in the neointima in the periannulus of the left ventricular septum. The structure of the pannus consisted of myofibroblasts and an extracellular matrix such as collagen fiber. The pannus formation after prosthetic valve replacement may be associated with a process of periannular tissue healing via the expression of transforming growth factor-beta.

Anomalous subaortic left brachiocephalic vein associated with tricuspid atresia: a successful bidirectional cavopulmonary connection.

Anomalous subaortic left brachiocephalic vein is an uncommon systemic venous anomaly. Here we report a case of this anomaly in a 3-month-old male infant with tricuspid atresia. The patient successfully underwent bidirectional cavopulmonary connection without cardiopulmonary bypass, although extended dissection of the bilateral brachiocephalic veins was required. The association of this venous anomaly with tricuspid atresia is extremely rare, and the presented patient is the second successful surgical case in the literature.

Anomalous origin of the left coronary artery from the pulmonary artery: successful direct reimplantation in a 50-year-old man.

Anomalous origin of the left coronary artery from the pulmonary artery is a rare congenital coronary artery anomaly that is often referred to as Bland White Garland syndrome. Most patients with this anomaly require surgical intervention early in life, and it is extremely rare that patients reach middle age without any symptoms. We present a 50-year-old man with this anomaly, who underwent direct reimplantation of the left main coronary trunk to the ascending aorta. His postoperative course was uneventful, and three and a half years after the operation, he is well and does not require medication. Several surgical procedures can be used to treat this anomaly, but we prefer to use direct reimplantation, whenever technically possible. To our knowledge, this patient is the oldest patient to have undergone a direct reimplantation without any angioplasty.

Detection of pannus by multidetector-row computed tomography.

Prosthetic valve dysfunction (PVD) due to pannus formation is an infrequent but serious complication. A 72-year-old man who underwent aortic valve replacement was diagnosed with PVD and aneurysm of the Sinus of Valsalva. Multidetector-row computed tomography (MDCT) was used to examine the cause of PVD before reoperation. MDCT demonstrated that tissue regarded as pannus extended from the left ventricular septum into the pivot guard. These findings were confirmed by observations during reoperation. MDCT can be a useful diagnostic technique for the anatomical and functional evaluation of PVD.

Surgical treatment of a descending aortic aneurysm in a patient with noncirrhotic portal hypertension and a portal systemic shunt.

A 63-year-old male with atrial fibrillation and mild mitral valve regurgitation was referred to hospital because of a descending aortic aneurysm. During the evaluation, he developed an encephalopathy because of hyperammoniaemia. Further examination revealed a portal systemic shunt, perhaps caused by the noncirrhotic portal hypertension. The patient underwent successful replacement of the aneurysm after controlling the blood ammonia level by eliminating protein from the diet and removal of nitrogen from the gastrointestinal tract. Cardiovascular surgery in a patient with noncirrhotic portal hypertension and a portal systemic shunt has not been previously reported. Meticulous management of the perioperative blood ammonia concentration is essential.

Does off-pump coronary artery bypass grafting really preserve renal function?

It is well known that the use of cardiopulmonary bypass (CPB) influences renal function and occasionally results in renal failure following cardiac surgery. Coronary artery bypass grafting (CABG) without CPB may avoid this and preserve the perioperative renal function. The present study enrolled 52 patients undergoing CABG without CPB (OPCAB group) and matched them for renal function and prognostic variables with 53 patients undergoing conventional CABG (CABG group). Perioperative renal function and early clinical results were assessed. The OPCAB group had significantly less increase in creatinine levels (0.16 +/- 0.05 vs 0.45 +/- 0.06 mg/dl; p = 0.01) and greater creatinine clearance (81.6 +/- 7.3 vs 56.3 +/- 4.8ml/min; p = 0.01) postoperatively. Postoperative recovery of free water clearance was more prompt in the OPCAB group. The duration of intubation and intensive care unit stay was significantly shorter, and the creatine kinase-MB release and blood transfusion requirements were significantly less in the OPCAB group. The OPCAB technique preserved glomerular filtration rate and prevented the increase in creatinine levels. The results suggest that the technique enables earlier patient recovery and gives superior renal protection compared with conventional CABG.

Spontaneous coronary artery dissection causing myocardial infarction and left ventricular aneurysm.

Spontaneous coronary artery dissection (SCAD) is a rare cause of myocardial infarction (MI). A 66-year-old Japanese man, who had had an anterior wall MI caused by SCAD of the left anterior descending coronary artery, developed left ventricular aneurysm 5 years later, with depressed left ventricular function and thrombus observed on echocardiography. Left endoventricular circular patch plasty according to Dor's technique was performed without coronary artery bypass grafting, because of the absense of significant coronary artery stenosis on the preoperative coronary angiogram. The clinical course of SCAD in the late phase is generally favorable, but because the prognosis of SCAD is uncertain, patients with SCAD should be carefully followed.

Treatment of acute massive/submassive pulmonary embolism.

Thirty-five consecutive patients with massive and submassive pulmonary embolism (PE) were reviewed. In 75% of these cases, PE could be suspected on the basis of electrocardiogram alone. Echocardiography was quite useful for diagnosing PE and assessing right ventricle after-load at the bedside. Spiral computer tomography was effective for obtaining a definitive diagnosis even in a relatively hemodynamically unstable patient. Thrombolysis therapy was given to 30 cases and was apparently effective in 17 cases (17/30, 56.7%). Percutaneous cardiopulmonary support (PCPS) was needed for 7 severe cases. Seven patients, including 5 of the PCPS recipients, underwent surgical embolectomy. Overall mortality was 28.6% (10/35), and surgical mortality was 28.6% (2/7). The significant predictors for mortality were systolic blood pressure <100 mmHg, dopamine >5 microg x kg(-1) min(-1), pH <7.4, PaCO2 >40 torr, base excesss <-5 mmol/L, urine output <0.8ml x kg(-1) x h(-1), intubation, cardiopulmonary resuscitation, duration from attack to emergency room >5h, shock duration >4h, aspartate aminotransferase >100U/L, alanine aminotransferase >100U/L and lactate dehydrogenase >600U/L. Predictors of surgical intervention were dopamine >5 microg x kg(-1) min(-1), shock duration >4h and PCPS. Early initiation of thombolysis therapy is recommended, except in case where it is absolutely contraindicated. Because it is difficult in the early phase of PE to make a decision to perform surgery, aggressive application of PCPS is recommended for the cardiogenic shock associated with massive PE.

Thrombolytic therapy with tissue plasminogen activator for the treatment of nonstructural malfunction of bileaflet cardiac valve prostheses.

This study was conducted to determine the effect of thrombolytic therapy with tissue plasminogen activator (t-PA) for nonstructural malfunction of bileaflet cardiac valve prostheses. Twenty-seven patients with bileaflet prosthetic valve malfunction diagnosed by a combination of cineradiography and transthoracic echocardiography were treated with the administration of intravenous t-PA. The treatment resulted in complete success in 55.6% (15 of 27), partial success in 22.2% (6 of 27), and no change in 22.2% (6 of 27). In the complete success and partial success groups, the condition of the patients in 85.7% (18 of 21) of the cases improved within 24 h after the administration of t-PA. Six cases in whom thrombolytic therapy was instituted more than 1 month (ranged from 1 to 38 months, mean 14.7 months) after the diagnosis of prosthetic valve malfunction showed significantly less effectiveness of thrombolytic therapy with t-PA. Only one patient (3.7%) had a major complication (thromboembolism) after t-PA treatment. The results suggest that thrombolytic therapy with t-PA in patients with nonstructural malfunction of bileaflet cardiac valve prostheses is effective with low incidence of complication when the treatment is instituted early after the diagnosis.

Influence of colforsin daropate hydrochloride on internal mammary artery grafts.

The effect of colforsin daropate hydrochloride (colforsin), a water-soluble forskolin derivative, on blood flow in internal mammary artery (IMA) grafts was evaluated in a prospective randomized study of 26 patients undergoing coronary artery bypass grafting. Patients were randomized to receive either colforsin treatment (colforsin; n=14) or no colforsin treatment (control; n=14). Administration of colforsin (0.5mg x kg(-1) min(-1)) was started after induction of anesthesia and was continued for 6 h. IMA blood flow and hemodynamic measurements were assessed perioperatively. During cardiopoulmonary bypass (CPB), perfusion flow was adjusted to 2.5 L/m2 and IMA free blood flow was measured. IMA blood flow was also measured 1 h after CPB by an ultrasonic flow meter. Systemic vascular resistance was significantly lower in the colforsin group during and after CPB. IMA blood flow was significantly greater in the colforsin group than in the control group during (44 +/- 2 vs 33 +/- 3 ml min-1 x m(-2), p=0.02) and after CPB (38 +/- 6 vs 20 +/- 3ml x min(-1) m(-2), p=0.01). IMA blood flow 1 h after CPB correlated inversely with concurrent systemic vascular resistance (r=-0.61, p=0.001). Intraoperative administration of colforsin daropate hydrochloride caused potent vasodilation, resulting in an increase in IMA blood flow. The results indicate that the regimen can be used perioperatively in patients undergoing coronary artery bypass grafting.

Coronary artery bypass grafting in an adult case with Kawasaki disease.

Surgical revascularization for coronary artery lesions secondary to Kawasaki disease has been rarely reported in adult patients. We reported an adult case with few coronary risk factors but with multiple coronary artery aneurysms and obstructive lesions presumably secondary to Kawasaki disease who underwent coronary artery bypass grafting (CABG) with multiple arterial grafts. The postoperative course was uneventful. Because coronary artery sequelae of Kawasaki disease can be a cause of ischemic heart disease even in adults, heightened awareness of this possibility is required for young adults with coronary lesions but without coronary risk factors.