This conditional shortcode will hide the whole line if there were no Additional Remarks submitted in field 13:
[gravityforms action="conditional" merge_tag="{:13}" condition="isnot" value=""]Additional Remarks: {Additional Remarks::13}[/gravityforms]
The rule there is "isnot" "empty". If it’s not empty, your "Additional Remarks: " heading and the submitted value will be shown.
You may end up with a blank line there due to the whitespace around the conditional shortcode. You can edit it so that the whitespace is inside the conditional shortcode, and there are no blank lines outside the shortcode.