Hongbing Yan

Suppression of NF-κB Reduces Myocardial No-Reflow

No-reflow phenomenon is a risk factor which severely compromises the benefits of coronary revascularization in patients with acute myocardial infarction. Inflammatory response, as an essential component of cardiac ischemia/reperfusion (I/R) injury, has been suggested to contribute to the myocardial no-reflow. Since nuclear factor kappa B (NF-κB) is a key mediator of inflammation, we reasoned that inhibition of NF-κB might reduce the extent of no-reflow. To test this hypothesis, the left circumflex coronary arteries of New Zealand white male rabbits were ligated for 1.5 h, followed by reperfusion for 1 h to induce I/R injury. Pretreatment of the rabbits with a specific NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), significantly attenuated neutrophil infiltration in the no-reflow area as well as the expansion of no-reflow. These beneficial effects were associated with a marked reduction in the serum levels of myocardial induced I/R tumor necrosis factor-α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), and CXCL16. Consistently, simulative I/R culture of human umbilical vein endothelial cells (HUVECs) resulted in an increase of TNF-α, ICAM-1 and CXCL16, and all of these changes were significantly suppressed by pretreatment of the cells with PDTC or with siRNA-mediated p65 knockdown. Our data thus suggest that inhibition of NF-κB may reduce I/R-associated myocardial no-reflow through reduction of myocardial inflammation.

Improvement of Image Quality and Diagnostic Performance by an Innovative Motion-Correction Algorithm for Prospectively ECG Triggered Coronary CT Angiography

Objective To investigate the effect of a novel motion-correction algorithm (Snap-short Freeze, SSF) on image quality and diagnostic accuracy in patients undergoing prospectively ECG-triggered CCTA without administering rate-lowering medications. Materials and Methods Forty-six consecutive patients suspected of CAD prospectively underwent CCTA using prospective ECG-triggering without rate control and invasive coronary angiography (ICA). Image quality, interpretability, and diagnostic performance of SSF were compared with conventional multisegment reconstruction without SSF, using ICA as the reference standard. Results All subjects (35 men, 57.6 ± 8.9 years) successfully underwent ICA and CCTA. Mean heart rate was 68.8±8.4 (range: 50–88 beats/min) beats/min without rate controlling medications during CT scanning. Overall median image quality score (graded 1–4) was significantly increased from 3.0 to 4.0 by the new algorithm in comparison to conventional reconstruction. Overall interpretability was significantly improved, with a significant reduction in the number of non-diagnostic segments (690 of 694, 99.4% vs 659 of 694, 94.9%; P<0.001). However, only the right coronary artery (RCA) showed a statistically significant difference (45 of 46, 97.8% vs 35 of 46, 76.1%; P = 0.004) on a per-vessel basis in this regard. Diagnostic accuracy for detecting ≥50% stenosis was improved using the motion-correction algorithm on per-vessel [96.2% (177/184) vs 87.0% (160/184); P = 0.002] and per-segment [96.1% (667/694) vs 86.6% (601/694); P <0.001] levels, but there was not a statistically significant improvement on a per-patient level [97.8 (45/46) vs 89.1 (41/46); P = 0.203]. By artery analysis, diagnostic accuracy was improved only for the RCA [97.8% (45/46) vs 78.3% (36/46); P = 0.007]. Conclusion The intracycle motion correction algorithm significantly improved image quality and diagnostic interpretability in patients undergoing CCTA with prospective ECG triggering and no rate control.