instruction: give me the number of patients whose admission location is transfer from hosp/extram and procedure long title is implant of pulsation balloon?
response: SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic INNER JOIN procedures ON demographic.hadm_id = procedures.hadm_id WHERE demographic.admission_location = "TRANSFER FROM HOSP/EXTRAM" AND procedures.long_title = "Implant of pulsation balloon"