D-Dimer has a 100% sensitivity but given that a significant proportion of patients will have cancer or catheter, the D-Dimer is likely to be elevated anyway and specificity is very low at ~14% and thus
this is NOT as useful a test as it is for
pulmonary embolism (PE), and it's use is best reserved for those with low to intermediate pre-test probability in which case a negative D-Dimer is an accurate means of excluding it.