Current (2019) European Society of Cardiology (ESC) Guidelines for the diagnosis and management of chronic coronary syndromes, based on the results of a pooled analysis of the three aforementioned RCTs that substantially confirms a positive effect of CD34+ intramyocardial injection on exercise time and angina frequency, classify this procedure amongst the “potential treatment options for refractory angina”, but underscore the need for larger RCTs in order to elaborate a clear recommendation [142]. Here, CD34 is linked to angina pectoris.