Our results using morpho-molecular techniques detected increased numbers of large MVs (0.8–1.34 nm) with highly negative surface charge that were positive for archaeal DNA, Mycoplasma pneumoniae antigens and MMP9 in the sera of severe myocardial infarction patients, strongly favoring our hypothesis that pathogenic archaea may play a role in worst outcomes of atherosclerosis. This evidence concerns the gene MMP9 and myocardial infarction.