Myocardial cooling with ice-slush provides no cardioprotective effects in aortic valve replacement

Objectives. Topical cooling of the heart with ice-slush has been widely used for myocardial protection. No prospective, randomized study has evaluated the effect of ice-slush on acknowledged markers (CK-MB, troponin-T) of myocardial damage during aortic valve replacement (AVR). This was the first aim of the present study. A second aim was to examine whether performing a study per se reduced myocardial damage. Design. Sixty patients undergoing AVR were receiving cold crystalloid antegrade cardioplegia every 20 min. Thirty patients were randomized to achieve additional topical cooling with ice-slush. CK-MB and troponin-T were compared between groups as well as to a group of patients undergoing AVR immediately prior to the study. Results. There were no significant differences in myocardial markers between patients with or without ice-slush. However, we found significantly higher levels of troponin-T and CK-MB in patients undergoing AVR prior to start of the study. Conclusions. Topical cooling with ice-slush does not provide additional cardioprotective effects. Comparison with an historical cohort indicates that administration of crystalloid cardioplegia following a rigid protocol might reduce myocardial damage.