Release of biomarkers of myocardial damage after direct intramyocardial injection of genes and stem cells via the percutaneous transluminal route.

AIMS We aimed to quantify the release of biomarkers of myocardial damage in relation to direct intramyocardial injections of genes and stem cells in patients with severe coronary artery disease. METHODS AND RESULTS We studied 71 patients with 'no-option' coronary artery disease. Patients had, via the percutaneous transluminal route, a total of 11 +/- 1 (mean +/- SD) intramyocardial injections of vascular endothelial growth factor genes (n = 56) or mesenchymal stromal cells (n = 15). Injections were guided to an ischaemic area by electromechanical mapping, using the NOGA/Myostar catheter system. Plasma CKMB (upper normal laboratory limit = 5 microg/L) was 2 microg/L (2-3) at baseline; increased to 6 (5-9) after 8 h (P < 0.0001) and normalized to 4 (3-5) after 24 h. A total of eight patients (17%), receiving a volume of 0.3 mL per injection, had CKMB rises exceeding three times the upper limit, whereas no patient in the group receiving 0.2 mL had a more than two-fold CKMB increase. No patient developed new ECG changes. There were no clinically ventricular arrhythmias and no death. CONCLUSION NOGA mapping followed by direct intramyocardial injections of stem cells or genes lead to measurable release of cardiac biomarkers compared with NOGA mapping alone. The increase in biomarkers was related to the injected volume.