Prospective Randomized Trial of Direct Endomyocardial Implantation of Bone Marrow Cells for Therapeutic Angiogenesis in Coronary Artery Diseases - PROTECT-CAD


The goal of the trial was to evaluate treatment with bone marrow mononuclear cells (BM MNC) among patients with severe coronary artery disease who have failed conventional therapies.

Study Design

Patients Enrolled: 28
Mean Follow Up: Mean 19 months
Mean Patient Age: Mean age 66 years
Female: 18

Patient Populations:

Severe coronary artery disease, not amenable to conventional revascularization and suffering from CCS class III or IV angina despite optimal medical therapy, ability to complete >3 but <10 minutes on ETT, inducible myocardial ischemia on SPECT or MRI

Primary Endpoints:

Exercise treadmill time at 6 months

Secondary Endpoints:

Acute and long-term safety, symptoms and functional class, ejection fraction on MRI, myocardial perfusion on SPECT, arrhythmias on Holter

Drug/Procedures Used:

All patients underwent harvesting of BM MNC. Patients were then randomized to low dose BM MNC(1x106 cells/0.1ml, n=9) and high dose BM MNC (2x106 cells/0.1 ml, n=10), or control (plasma) (n=9). Injections were done via catheter-based direct endomyocardial injection using guided electromechanical mapping. Patients underwent exercise treadmill testing (ETT) at baseline and 6 months.

Principal Findings:

Among the patients in the study, 68% had undergone prior coronary artery bypass surgery, and 61% had undergone percutaneous coronary intervention. All patients were hyperlipidemic, and 71% had hypertension. The mean number of injections was 14.6 per patient, with a mean procedural time of 152 minutes. One patient in the control group had failed access to the left ventricular.

At 6 month follow-up, the primary endpoint of exercise time improved from 392 seconds to 464 seconds in the BMC group (p<0.05) but there was no change in the placebo group, from 439 seconds at baseline to 404 seconds at follow-up (p=NS). There were no sustained ventricular tachycardias on Holter and no symptomatic arrhythmias. One patient in the control group and no patients in the BMC group died during follow-up.


Among patients with severe coronary artery disease who have failed conventional therapies, endomyocardial implantation of autologous bone marrow mononuclear cells was associated with longer exercise duration at 6 month follow-up compared with baseline but no difference in the control group, although a direct head-to-head comparison between the BMC and control group was not made.

The present study is one of the first randomized, blinded studies of BMC implantation in patients with severe coronary artery disease. The trial demonstrated feasibility of the procedure, as well as potential efficacy, although larger trials would be needed to validate these findings. Additionally, a direct comparison in the change in ETT duration between the two groups would provide more information. No dose response was observed between the low and high dose groups.


Tse HF, Thambar S, Kwong YL, et al. Prospective randomized trial of direct endomyocardial implantation of bone marrow cells for treatment of severe coronary artery diseases (PROTECT-CAD trial). Eur Heart J. 2007 Dec;28(24):2998-3005.

Presented by Dr. Hung-Fat Tse at the March 2006 ACC Annual Scientific Session, Atlanta, GA.

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Prevention, Atherosclerotic Disease (CAD/PAD), SCD/Ventricular Arrhythmias, Aortic Surgery, Cardiac Surgery and Arrhythmias, Interventions and Coronary Artery Disease, Interventions and Imaging, Computed Tomography, Nuclear Imaging, Hypertension

Keywords: Coronary Artery Disease, Myocardial Infarction, Tachycardia, Ventricular, Follow-Up Studies, Bone Marrow, Tomography, Emission-Computed, Single-Photon, Coronary Artery Bypass, Hypertension, Percutaneous Coronary Intervention

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