Comparison between Integrated Backscatter Intravascular Ultrasound and 64-Slice Multi-Detector Row Computed Tomography for Tissue Characterization and Volumetric Assessment of Coronary Plaques

Background: The purpose of this study was to determine the cut-off values of Hounsfield units (HU) for the discrimination of plaque components and to evaluate the feasibility of measurement of the volume of plaque components using multi-detector row computed tomography (MDCT). Methods: Coronary lesions (125 lesions in 125 patients) were visualized by both integrated backscatter intravascular ultrasound (IB-IVUS) and 64-slice MDCT at the same site. The IB values were used as a gold standard to determine the cut off values of HU for the discrimination of plaque components. Results: Plaques were classified as lipid pool (n =50), fibrosis (n =65) or calcification (n =35) by IB-IVUS. The HU of lipid pool, fibrosis and calcification were 18 ± 18 HU (−19 to 58 HU), 95 ± 24 HU (46 to 154 HU) and 378 ± 99 HU (188 to 605 HU), respectively. Using receiver operating characteristic curve analysis, a threshold of 50 HU was the optimal cutoff values to discriminate lipid pool from fibrosis. Lipid volume measured by MDCT was correlated with that measured by IB-IVUS (r =0.66, p <0.001), whereas fibrous volume was not (r =0.21, p =0.059). Conclusion: Lipid volume measured by MDCT was moderately correlated with that measured by IB-IVUS. MDCT may be useful for volumetric assessment of the lipid volume of coronary plaques, whereas the assessment of fibrosis volume was unstable

Three minute, but not one minute, ischemia and nicorandil have a preconditioning effect in patients with coronary artery disease

AbstractOBJECTIVESThis study focused on 1) the determination of the optimal preconditioning (PC) duration, and 2) the protective effect of nicorandil (NC), a hybrid nitrate with a Katpchannel opening effect, during a percutaneous transluminal coronary angioplasty (PTCA) model in humans.BACKGROUNDThe ischemic PC effect is induced in 180 s ischemia, but not in 120 s ischemia in rabbit hearts. However, the duration of ischemia that induces PC effect and the role of the Katpchannel in the PC effect in humans are still unclear.METHODSForty-six patients with stable angina were randomly allocated to four groups: the duration of the first inflation as PC ischemia was 60 s in the PC60 group (n = 12), and 180 s in the PC180 group (n = 12). In the other groups, NC (80 μg/kg) was intravenously given for 1 min in the NC group (n = 12), and isosorbide dinitrate (ISDN) (40 μg/kg) was given in the ISDN group (n = 10). Five minutes after first inflation or drug administration, a second inflation was conducted for 120 s in each group. In the ECG, the lead with the largest shift in ST segment (deltaST max), and the sum of elevated ST levels in all leads (sigmaST) were determined.RESULTSIn the PC60 group, no significant difference was observed in either deltaST max or sigmaST between the first and second inflation. However, the second inflation in the PC180 group showed significantly lower levels of deltaST max and sigmaST compared with those of the first inflation. In the NC group, both deltaST max and sigmaST measured at 30 s and 60 s after balloon inflation were significantly lower than those of the first inflation in the PC60 and PC180 control groups. In the ISDN group, no significant difference was observed in deltaST max or sigmaST.CONCLUSIONIn human PTCA models, a PC effect is observed in 180 s ischemia, but not in 60 s ischemia. A pharmacological PC effect is induced by NC, a Katpchannel opener with a nitrate-like effect but not ISDN. This suggests that the opening of Katpchannels plays an important role in the protecting effect of NC

Erythropoietin Receptor Signaling Mitigates Renal Dysfunction-Associated Heart Failure by Mechanisms Unrelated to Relief of Anemia

ObjectivesWe examined the effect of asialoerythropoietin (asialoEPO), a nonerythrogenic derivative of erythropoietin (EPO), on renal dysfunction-associated heart failure.BackgroundAlthough EPO is known to exert beneficial effects on cardiac function, the clinical benefits in patients with chronic kidney disease are controversial. It remains to be addressed whether previously reported outcomes were the result of relief of the anemia, adverse effects of EPO, or direct cardiovascular effects.MethodsMice underwent 5/6 nephrectomy to cause renal dysfunction. Eight weeks later, when renal dysfunction was established, anemia and cardiac dysfunction and remodeling were apparent. Mice were then assigned to receive saline (control), recombinant human erythropoietin (rhEPO) at 5,000 IU (714 pmol)/kg, or asialoEPO at 714 pmol/kg, twice/week for 4 weeks.ResultsAlthough only rhEPO relieved the nephrectomy-induced anemia, both rhEPO and asialoEPO significantly and similarly mitigated left ventricular dilation and dysfunction. The hearts of rhEPO- or asialoEPO-treated mice showed less hypertrophy, reflecting decreases in cardiomyocyte hypertrophy and degenerative subcellular changes, as well as significant attenuation of fibrosis, leukocyte infiltration, and oxidative deoxyribonucleic acid damage. These phenotypes were accompanied by restored expression of GATA-4, sarcomeric proteins, and vascular endothelial growth factor and decreased inflammatory cytokines and lipid peroxidation. Finally, myocardial activation was observed of extracellular signal-regulated protein kinase and signal transducer and activator of transcription pathways in the treated mice.ConclusionsEPO receptor signaling exerts direct cardioprotection in an animal model of renal dysfunction-associated heart failure, probably by mitigating degenerative, pro-fibrosis, inflammatory, and oxidative processes but not through relief of anemia

NONINVASIVE ESTIMATION OF CARDIAC PROPERTIES IN PATIENTS WITH HYPERTENSION USING SPECKLE TRACKING ECHOCARDIOGRAPHY: A COMPARATIVE STUDY BETWEEN GOOD AND POOR CONTROLLED HYPERTENSION

info:eu-repo/semantics/publishe