How to compare the record name of the an Eloqua custom object vs Contact washing machine result

The customer have a program:

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There is a camvas step ‘Contact washing machine’:

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Where they concat a pair of contact attributes for set the Lead name that they sending to Sales through an integration action ‘Crear Lead en OSC’.

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All leads records created in Sales cloud are imported to an Eloqua custom object.

So how can we achieve to compare the record name of the leads records of Sales cloud (loaded into the Eloqua custom object) with the Lead name generated by ‘Contact washing machine’ step of the program to avoid create duplicates record leads in Sales cloud?