Pravastatin restored the infarct size-limiting effect of ischemic preconditioning blunted by hypercholesterolemia in the rabbit model of myocardial infarction

AbstractOBJECTIVESWe tested to find out whether pravastatin restores the infarct size (IS)-limiting effect of ischemic preconditioning (IP) and if it has any effect on the IP-induced activation of adenosine producing enzyme ecto-5′-nucleotidase which plays a key role in the IP-induced cardioprotection.BACKGROUNDThe IS-limiting effect of IP is blunted by hypercholesterolemia. Recently, HMG-CoA reductase inhibitors are shown to have direct cytoprotective effects.METHODSRabbits were fed with a normal or cholesterol (1%) added diet with or without pravastatin (5 mg/kg/day) treatment. Infarct size was measured after 30 min occlusion and 3 h reperfusion of circumflex coronary artery with or without the IP procedure (5 min occlusion and 10 min reperfusion). Additionally, ecto-5′-nucleotidase activities of ischemic and nonischemic myocardium were measured immediately after IP procedure.RESULTSThis dose of pravastatin did not normalize the increased level of serum cholesterol. The IS-limiting effect of preceding IP (IS reduced from 36.7% to 9.6%, p < 0.001) was abolished by hypercholesterolemia (from 46.1% to 31.3%, p = NS) and restored by pravastatin treatment (from 35.2% to 9.4%, p < 0.001). Pravastatin treatment did not affect IS or the effect of IP under normocholesterolemia. The activation of ecto-5′-nucleotidase presented as the activity ratio of ischemic to nonischemic myocardium (3.1-fold in normocholesterolemia) was blunted by hypercholesterolemia (1.8-fold, p < 0.05) and restored by pravastatin treatment (2.9-fold).CONCLUSIONSPravastatin, at the dose serum cholesterol was not normalized, restored the IS-limiting effect of IP and IP-induced ecto-5′-nucleotidase activation, which were both blunted by hypercholesterolemia. The activation of ecto-5′-nucleotidase may be worth further investigation as a possible mechanism for the hypercholesterolemia-induced retardation and pravastatin-mediated restoration of the cardioprotective effect of IP

Cellular Injury of Cardiomyocytes during Hepatocyte Growth Factor Gene Transfection with Ultrasound-Triggered Bubble Liposome Destruction

We transfected naked HGF plasmid DNA into cultured cardiomyocytes using a sonoporation method consisting of ultrasound-triggered bubble liposome destruction. We examined the effects on transfection efficiency of three concentrations of bubble liposome (1 × 106, 1 × 107, 1 × 108/mL), three concentrations of HGF DNA (60, 120, 180 μg/mL), two insonification times (30, 60 sec), and three incubation times (15, 60, 120 min). We found that low concentrations of bubble liposome and low concentrations of DNA provided the largest amount of the HGF protein expression by the sonoporated cardiomyocytes. Variation of insonification and incubation times did not affect the amount of product. Following insonification, cardiomyocytes showed cellular injury, as determined by a dye exclusion test. The extent of injury was most severe with the highest concentration of bubble liposome. In conclusion, there are some trade-offs between gene transfection efficiency and cellular injury using ultrasound-triggered bubble liposome destruction as a method for gene transfection

A case of cardiac sarcoidosis masquerading as arrhythmogenic right ventricular cardiomyopathy awaiting heart transplant

SummaryWe report a case of 45-year-old man, who was diagnosed with arrhythmogenic right ventricular cardiomyopathy (ARVC) and presented with right ventricular (RV) enlargement with a global decrease in RV contractility accompanied by impairment of left ventricular function. He was placed on the heart transplant waiting list. Endomyocardial biopsy from RV septal wall did not show any evidence of sarcoidosis or inflammatory change. Four years after he was put on the heart transplant waiting list, a computed tomography chest scan for the purpose of anatomical evaluation for coronary sinus prior to biventricular pacing lead implantation incidentally showed bilateral hilar lymphadenopathy, which suggested the possibility of sarcoidosis. Biopsy of the inguinal lymph node pathologically was consistent with sarcoidosis. The 2[18F]fluoro-2-deoxy-d-glucose positron emission tomography scanning (FDG-PET) demonstrated intense uptake in the myocardium, and the patient was finally diagnosed as having cardiac sarcoidosis. After steroid treatment, the abnormal FDG-PET uptake disappeared. The patient therefore represented a case of cardiac sarcoidosis masquerading as ARVC. It should be recognized that RV involvement is one of the manifestations in cardiac sarcoidosis

Improved long-term performance of pulsatile extracorporeal left ventricular assist device

SummaryBackground and purposeThe majority of heart transplant (HTx) candidates require left ventricular assist device (LVAD) support for more than 2 years before transplantation in Japan. However, the only currently available device is the extracorporeal pulsatile LVAD. The long-term management of extracorporeal LVAD support has improved remarkably over the years. To determine which post-operative management factors are related to the long-term survival of patients on such LVAD, we retrospectively compared the incidence of complications and their management strategies between the initial and recent eras of LVAD use, classified by the year of LVAD surgery.MethodsSixty-nine consecutive patients supported by extracorporeal pulsatile LVAD as a bridge to HTx between 1994 and 2007 were reviewed retrospectively. The patients were assigned according to the time of LVAD surgery to either group A (n=30; between 1994 and 2000) or group B (n=39; between 2001 and 2007).ResultsPatients in group B survived significantly longer on LVAD support than those in group A (674.6 vs. 369.3 days; p<0.001). The 1- and 2-year survival rates were significantly higher in group B than that in group A (82% vs. 48%, p<0.0001; 68% vs. 23%, p<0.0001, respectively). The proportion of deaths due to cerebrovascular accidents was lower (17% vs. 50%, p<0.001) in group B compared with group A. The incidences of systemic infection were similar in both groups, but the proportions of patients alive and achieving transplant surgery after systemic infection were higher in group B than those in group A (55% vs. 14%, p<0.01; 14% vs. 36%, p<0.05, respectively).ConclusionsThe long-term survival of patients even on “first-generation” extracorporeal LVAD has improved significantly in the recent era. Careful management of cerebrovascular accidents and systemic infection will play important roles in the long-term LVAD management

Similarities and Differences between the Pathogenesis and Pathophysiology of Diastolic and Systolic Heart Failure

Pathophysiology of heart failure has been considered to be a damaged state of systolic function of the heart followed by a state of low cardiac output that is, systolic heart failure. Even if systolic function is preserved, left ventricular filling in diastole can be impeded and resulted in elevation of filling pressure and symptoms of heart failure. This kind of heart failure is called diastolic heart failure. Nowadays, diastolic heart failure is referred to as heart failure with preserved ejection fraction (HFpEF), whereas systolic heart failure is referred to as heart failure with reduced ejection fraction (HFrEF). In this paper, the similarities and differences between the pathogenesis and pathophysiology of diastolic and systolic heart failure were reviewed. Although diastolic heart failure is a common condition of heart failure worldwide, its pathophysiology has not been sufficiently elucidated. This is thought to be the most significant reason for a lack of established treatment methods for diastolic heart failure. We hope to proceed with future studies on this topic