Does diltiazem inhibit the inflammatory response in cardiopulmonary bypass?

Background: The objective of our study was to investigate the anti-inflammatory effect and inhibiting action of diltiazem, a calcium channel blocking agent, on the systemic inflammatory response seen after cardiopulmonary bypass (CPB) in humans, in a controlled prospective study.

Material/methods: Two groups of 15 candidates for coronary artery bypass graft were enrolled in the study. In the study group, 1 g/kg/min of diltiazem was infused during cardiopulmonary bypass, while the control group received saline. Interleukin-6 and 10 (IL-6, IL-10) levels were measured from systemic arterial blood at five time points.

Results: The levels of IL-6, a marker of the severity of systemic inflammation, were significantly higher in the control group at the end of CPB and 3 hours later. At the end of CPB, the mean IL-6 level in the control group was significantly higher than in the diltiazem group (p=0.015), and at 3 hours after CPB the difference was even greater (p=0.002). The levels of IL-10, an anti-inflammatory cytokine that limits the effects of pro-inflammatory cytokines, were higher in the control group, but not statistically significant at any time point.

Conclusions: Diltiazem inhibits the release of the pro-inflammatory cytokine IL-6, which is strong evidence for its anti-inflammatory effect. It is clinically important to inhibit the inflammation that takes place during CPB and the inflammation of myocardium encountered after ischemia-reperfusion, since these effect the clinical status of the patient after CPB, as well as myocardial functions.