The present invention relates to single polynucleotides or sets of polynucleotides for detecting single miRNAs or sets of miRNAs for diagnosing and/or prognosing of an acute coronary syndrome in a blood sample from a human. Further, the present invention relates to means for diagnosing and/or prognosing of an acute coronary syndrome comprising said polynucleotides or sets of polynucleotides. Furthermore, the present invention relates to a method for diagnosing and/or prognosing of an acute coronary syndrome based on the determination of expression profiles of single miRNAs or sets of miRNAs representative for an acute coronary syndrome compared to a reference. In addition, the present invention relates to a kit for diagnosing and/or prognosing of an acute coronary syndrome comprising means for determining expression profiles of single miRNAs or sets of miRNAs representative for an acute coronary syndrome and at least one reference.