Left heart pump-assisted myocardial revascularization favorably affects neutrophil apoptosis

Granulocyte apoptosis is a key control process in the clearance of neutrophils from inflammatory sites, and its rate is modulated by a number of inflammatory mediators. In this study, we investigated whether the use of left ventricular-assisted technique (LVA) in beating heart myocardial revascularization would exert less impact on neutrophil apoptosis compared with conventional cardiopulmonary bypass (CPB).

Forty consecutive patients who underwent myocardial revascularization were randomly assigned to LVA (group A, 21 patients) or CPB (group B, 19 patients). Blood samples for detection of interleukin-6, interleukin-8, and tumor necrosis factor-alpha were measured at baseline and at various time points postoperatively. Neutrophil apoptosis was detected by light microscopy as well as by the annexin-V assays together with the activity of caspase 3 on postoperative samples.

Preoperative clinical and demographic data did not differ between the two groups. The two groups also were similar with respect to mortality, number of grafts performed, duration of extracorporeal circulation, and need for inotropes. However postoperatively, spontaneous apoptosis was significantly delayed in neutrophils from CPB patients compared with LVA patients. Neutrophils were activated, as indicated by increased surface expression of CD11b. Caspase 3 activity was found to be significantly reduced in neutrophils from CPB patients after 18 and 24 hours of culture.

Patients who underwent beating heart myocardial revascularization with LVA show a better preserved neutrophil apoptosis than patients treated with the CPB.