In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: The incidence of cardiac events with VNR was 1 . 19 % [ 95 % confidence interval ( CI ) ( 0 . 75 ; 1 . 67 ) ] .
### Output Text:
The incidence of cardiac events with <span class="chemical">VNR</span> was 1 . 19 % [ 95 % confidence interval ( CI ) ( 0 . 75 ; 1 . 67 ) ] . 