Confirm what parameters are passed back to our systems from Apple Pay?

Merchant can receive the same set of Transaction Detail Data via Transaction Query API as for regular credit card transaction.

Apple Pay provides a device-specific account number (it looks like a real card number but not) instead of real customer’s credit card number. The same customer’s card will have different device-specific account numbers on different customer’s devices (iPhone, iPad, iWatch).

The better explanation of Device-specific Account Number you can read here.