instruction: how many of the patients diagnosed with ac/chr syst/dia hrt fail received drug via iv route?
response: SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic INNER JOIN diagnoses ON demographic.hadm_id = diagnoses.hadm_id INNER JOIN prescriptions ON demographic.hadm_id = prescriptions.hadm_id WHERE diagnoses.short_title = "Ac/chr syst/dia hrt fail" AND prescriptions.route = "ID"