The aim of the sub-study of the MYSTAR randomised trial was to analyse the changes in myocardial perfusion in NOGA-defined regions of interest (ROI) with intramyocardial injections of autologous bone marrow mononuclear cells (BM-MNC) using an elaborated transformation algorithm. Patients with recent first acute myocardial infarction (AMI) and left ventricular (LV) ejection fraction (EF) between 30-45% received BM-MNC by intramyocardial followed by intracoronary injection 68 +/- 34 days post-AMI (pooled data of MYSTAR). NOGA-guided endocardial mapping and 99m-Sestamibi-SPECT (single photon emission computer tomography) were performed at baseline and at three months follow-up (FUP). ROI was delineated as a best polygon by connecting of injection points of NOGA polar maps. ROIs were projected onto baseline and FUP polar maps of SPECT calculating the perfusion severity of ROI. Infarct size was decreased (from 27.2 +/- 10.7% to 24.1 +/- 11.5%, p<0.001), and global EF increased (from 38 +/- 6.1% to 41.5 +/- 8.4%, p<0.001) three months after BM-MNC delivery. Analysis of ROI resulted in a significant increase in unipolar voltage (index of myocardial viability) (from 7.9 +/- 3.0 mV to 9.9 +/- 2.7 mV at FUP, p<0.001) and local linear shortening (index of local wall motion disturbances) (from 11.0 +/- 3.9% to 12.7 +/- 3.4%, p=0.01). NOGA-guided analysis of the intramyocardially treated area revealed a significantly increased tracer uptake both at rest (from 56.7 +/- 16.1% to 62.9 +/- 14.2%, p=0.003) and at stress (from 59.3 +/- 14.2% to 62.3 +/- 14.9%, p=0.01). Patients exhibiting >or=5% improvement in perfusion defect severity received a significantly higher number of intramyocardial BM-MNC. In conclusion, combined cardiac BM-MNC delivery induces significant improvement in myocardial viability and perfusion in the intramyocardially injected area.