Granulocyte-Colony Stimulating Factor Decreases Angina and Improves Exercise Capacity in Patients with Chronic Refractory ‘No Option’ Ischemic Heart Disease.

Granulocyte-Colony stimulating factor (G-CSF) is widely used in the treatment of hematological malignancies. The administration of G-CSF is a novel therapy for ischemic heart disease (IHD), but current data are controversial and the safety and efficacy of G-CSF in acute or chronic IHD is unclear.

Aim: to assess safety and efficacy of G-CSF administration and stem cell mobilization in patients with chronic refractory ‘no option’ IHD.

Methods: After baseline cardiac assessment (CA) [Seattle Angina Questionnaire (SAQ), Bruce exercise stress test (EST), persantin-Sestamibi and dobutamine-echocardiographic imaging], stable ‘no option’ IHD patients received open-label G-CSF 10μg/kg for 5 days, with an EST (to facilitate myocardial cytokine generation and stem cell trafficking) on the 4^th and 6^th days. After 3 months, CA and the same regimen of G-CSF and ESTs was repeated, but in addition, leucopheresis and a randomized double-blinded intracoronary infusion of either CD133+ or unselected cells was performed (randomized data remains blinded). Final CA was 3 months thereafter.

Results: Thirteen patients (12 male, 1 female, mean age 62) received 21 cycles of G-CSF. There were no deaths, Q-wave AMIs or any complications with long-term sequelae, although, transient troponin-I elevation (n = 3) and thrombocytopenia (n = 2) were observed. Mean CD133+ cell count rose from 1.28 to 56.12 x10¹²/L (p = 0.001). There was no age-related trend towards lower numbers of G-CSF mobilized CD34⁺ cells in the IHD patients, as compared to a group of younger (<60 y.o) normal male donors (n = 66). After the first cycle of G-CSF, SAQ angina frequency and physical limitation scores improved, and EST time increased (all p < 0.01). There was further but less marked improvement in each of these parameters after the second cycle of G-CSF and cell infusion. Overall, SAQ angina frequency score improved 46 points (95% CI +22 to +70, p = 0.003). This was reflected by reduced anginal frequency and nitrate use (both p < 0.005). Overall, SAQ physical limitation score improved 26 points (95% CI +17 to +35, p = 0.0003), EST time improved 97 seconds (95% CI +41 to +153, p = 0.005) and Duke Treadmill Score improved 4.3 points (95% CI −0.2 to +8.8, p = 0.058).

Conclusions: G-CSF and intracoronary cell infusion is safe in chronic ‘no option’ IHD patients. In this phase I study G-CSF improved anginal frequency, nitrate use and EST performance. A placebo controlled phase II trial investigating G-CSF with an appropriate cytokine stimulus is warranted.