RESUMO
BACKGROUND: Primary percutaneous coronary intervention (PCI) is the best available reperfusion strategy in patients with acute ST-segment elevation myocardial infarction (STEMI). However, PCI is associated with a serious problem known as no-reflow phenomenon, resulting in poor clinical and functional outcomes. This study aimed to compare the influences of different balloon deflation velocity on coronary flow and cardiovascular events during primary PCI in STEM as well as transient hemodynamic changes in in vitro experiments. Method and Results. 211 STEMI patients were randomly assigned to either a rapid or a slow balloon deflation group during stent deployment. The primary end point was coronary flow at the end of PCI procedure, and secondary end points included myocardial infarct size. Transient hemodynamic changes were evaluated through an in vitro experimental apparatus and a computer model. In clinical practice, the level of corrected TIMI frame count (cTFC) in slow balloon deflation after primary PCI was significantly lower than that of rapid balloon deflation, which was associated with smaller infarct size. Numerical simulations revealed that the rapid deflation led to a sharp acceleration of flow in the balloon-vessel gap and a concomitant abnormal rise in wall shear stress (WSS). CONCLUSION: This randomized study demonstrated that the slow balloon deflation during stent implantation improved coronary flow and reduced infarct size in reperfused STEMI. The change of flow in the balloon-vessel gap and WSS resulted from different balloon deflation velocity might be partly accounted for this results.
RESUMO
At present, genome-wide association study on coronary heart disease (CHD) has been carried out in several major medical research centers worldwide. Most studies of CHD susceptibility loci or regions focused on chromosome 1, 3, 9, 11 and 16, while studies on chromosome 8 are rare. To the best of our knowledge, the genome study on chromosome 8 about CHD in Chinese Han population has never been reported before. We aimed to identify CHD susceptibility loci or regions in the Chinese Han population. First, two separated DNA pooling samples were prepared from 156 CHD cases and 1000 normal controls. Then, a total of 13 microsatellite markers at an interval of 10 cM on chromosome 8 were selected for genetic scanning. Finally, the difference of allele frequency at each locus between two pooled samples was analyzed by Chi-square test. Significant differences were found between cases and controls at D8S264(8p23.3-p23.2) and D8S285(8q12.1) (both P<0.05). Therefore, 8p23.3-p23.2 and 8q12.1 are possible to be associated with CHD and further study is needed to screen susceptible genes around these regions.