Author + information
- Alice Y. Tiong, BSc, MBBS (Hons), FRACP and
- David Brieger, MBBS, PhD, FRACP, FACC⁎ ()
- ↵⁎Department of Cardiology, Concord Repatriation General Hospital, Hospital Road, Concord, NSW 2139, Australia
We read with interest the study by Inoue et al. (1) demonstrating a time-dependent increase in neutrophil Mac-1 expression in the peripheral and coronary sinus blood, and in the trans cardiac gradient after percutaneous coronary intervention (PCI). The trans-cardiac gradient of neutrophil Mac-1 at 48 h also correlated with angiographic late lumen loss in this study.
However, the sampling site for “peripheral blood” is not clear, with the possibilities being caval, femoral, or brachial venous blood, which may result in different neutrophil Mac-1 expression (2). The sampling site also determines the sampling method. In vitro studies have shown that shear stress, even at physiological levels, can lead to down-regulation in neutrophil Mac-1 expression (3,4). Therefore, peripheral blood sampling from brachial vein with a 21-gauge needle exposes leukocytes to a higher shear stress than sampling from a 6F catheter in the coronary sinus. As a result, neutrophil Mac-1 expression in the peripheral blood may appear lower compared to coronary sinus blood. In other words, the differential shear stress with different sampling methods alone may have contributed to the trans-cardiac gradient observed.
We believe that a more reliable determination of neutrophil CD11b trans-cardiac gradient requires consistency in the sampling site for peripheral blood, and in the catheter size for sampling of both peripheral and coronary sinus blood.
- American College of Cardiology Foundation
- Inoue T.,
- Kato T.,
- Uchida T.,
- et al.
- Fukuda S.,
- Schmid-Schonbein G.W.