The use of granulocyte-colony stimulating factor and an intracoronary CD133+ cell infusion in patients with chronic refractory ischaemic heart disease.

Pre-clinical studies suggest that granulocyte-colony stimulating factor (GCSF) holds promise for the treatment of ischaemic heart disease (IHD). However, its safety and efficacy in this setting, and in particular in patients with chronic refractory 'no-option' IHD, is unclear. Therefore, a clinical study was initiated in 20 such 'no-option' patients, with the aim of assessing the safety and efficacy of both G-CSF administration, and also, that of an intracoronary infusion of G-CSF mobilised CD133+ cells.The study involved initial baseline cardiac ischaemia assessment (symptom based questionnaire, exercise stress test (EST), nuclear Sestamibi (MIBI) and dobutamine stress echocardiographic (DSE) imaging). Stable 'no-option' IHD patients then received open-label G-CSF commencing at 10μg/kg s/c for five days, with an EST on days four and six (to facilitate myocardial cytokine generation and stem cell trafficking). After three months, cardiac ischaemia assessment and the same regimen of G-CSF and ESTs were repeated, but in addition, leukapheresis and then a randomised double-blinded intracoronary infusion of CD133+ or unselected cells were performed. Final cardiac ischaemia assessment was three months thereafter.Eighteen male and two female subjects (mean age 62.4) were enrolled. Eight events occurred that fulfilled pre-specified 'adverse event' criteria: four ischaemic (troponin positive) episodes, two episodes of transient thrombocytopaenia (one profound), one episode of gout and one unscheduled hospitalisation for exhaustion. Troponin was positive on 17 further occasions (all CK-MB negative), however, at these instances angina severity was identical to baseline. Importantly, no adverse event(s) resulted in any detectable long-term adverse sequelae for any subject. From baseline to final follow-up, the administration of two cycles of G-CSF was associated with statistically significant improvements in a range of subjective outcomes, including anginal symptoms, quality of life and EST performance (all p 0.1). Compared to unselected cells, an intracoronary infusion of CD133+ cells did not improve either subjective or objective outcomes. In conclusion, administering G-CSF to patients with refractory 'no-option' IHD warrants careful monitoring, but may be performed with safety. A larger, randomised double-blind placebo-controlled trial of G-CSF in these patients appears warranted