There's a chance the hackers may learn something that will enable them to defeat LastPass' security in the future. Unlikely but possible. If you want to void that risk I suggest exporting your passwords to a csv. Them delete them all in LastPass. Then change your LastPass Master Password to something almost impossible to crack. Then, using that csv, change the passwords in all the accounts there. Updating the csv with the new passwords as you go. Probably oughta keep the old passwords in it too. Print it out and delete the csv or keep it on a secure flash drive.
Of course you don't want the recently changed passwords back in LastPass so uninstall it. Cancel the Last Pass account once it's empty if you're paying for it. No real need to if it's a free account provided it's empty.