The main goal is to learn how HeartInsight is used in clinical routine care. HeartInsight is a heart failure monitoring and notification tool within BIOTRONIK's Home Monitoring System. HeartInsight combines patient data as collected by the implanted devices to alert the attending physicians to impending worsening of heart failure events of the patients. This study will create a sound and seamless documentation of approximately 150 HeartInsight alerts, their processing, subsequent interventions and disease progressions. The data will be analyzed to characterize and quantify the use of HeartInsight in a clinical routine set-up.The patient population consists of heart failure patients with BIOTRONIK CRT-D devices that support HeartInsight.

Inclusion Criteria:

• Patient willing and able to give consent
• Participation in BIO|STREAM.HF
• HeartInsight-capable CRT-D device implanted or planned to be implanted
• Symptomatic heart failure NYHA class II or III within 45 days prior to enrollment
• HeartInsight score available or planned use of HeartInsight
• History of worsening of heart failure hospitalization or unscheduled outpatient visit with intravenous diuretic therapy for acute worsening of heart failure
• Patient is willing and able to utilize BIOTRONIK Home Monitoring via CardioMessenger and has sufficient mobile network coverage

Exclusion Criteria:

• Patient with permanent atrial fibrillation or 100% atrial pacing
• Patient is not implanted with an atrial or DX lead or atrial sensing is deactivated
• History of patient incompliance

HeartFailure patients will be recruited by their primary care clinic based on the in/exclusion criteria.