The ALLEVIATE-HF study is a prospective, randomized, controlled, blinded, multi-site, interventional, investigational device exemption (IDE) pivotal study. The purpose of the study is to demonstrate the safety and efficacy of a patient management pathway that utilizes an integrated device diagnostic-based risk stratification algorithm to guide patient care in subjects with NYHA class II and III heart failure, and to demonstrate the safety of the Reveal LINQ™ system and procedure in the study population.

The study will utilize the market released Reveal LINQ™ Insertable Cardiac Monitor with an investigational ALLEVIATE-HF RAMware download. The study will enroll up to 900 subjects at up to 75 sites in the US. Subjects will be followed until the last enrolled subject is followed for 7 months or until the end of the study, whichever occurs first, or until time of study exit or death as applicable, but no longer than 36 months.

Inclusion Criteria:

• Patient has NYHA Class II or III heart failure per most recent assessment, irrespective of left ventricular ejection fraction (LVEF)
• Patient has documented recent history of symptomatic heart failure, defined as meeting any one of the following three criteria: 1. Hospital admission with primary diagnosis of HF within the last 12 months, OR 2. Intravenous HF therapy (e.g. IV diuretics/vasodilators) or ultrafiltration within the last 6 months, OR 3. Patient had the following BNP/NT-proBNP within the last 3 months: If LVEF ≥ 50%, then BNP> 150 pg/ml or NT-proBNP > 450 pg/ml OR If LVEF is <50%, then BNP> 300 pg/ml or NT-proBNP > 900 pg/ml
• Patient is willing and able to comply with the protocol, including LINQ ICM insertion, CareLink transmissions (including adequate connectivity), study visits and remote care directions.
• Patient is 18 years of age or older.
• Patient has a life expectancy of 12 months or more.

Exclusion Criteria:

• Patient is currently implanted with a cardiovascular implantable electronic device (CIED) (e.g. ICM, pacemaker, ICD, CRT-D or CRT-P device) or hemodynamic monitor.
• Patient is receiving temporary or permanent mechanical circulatory support.
• Patient had MI or PCI/CABG within past 90 days.
• Patient has had a heart transplant, or is currently on heart transplant list.
• Patient has severe valve stenosis on echocardiogram.
• Patient has primary pulmonary hypertension (pre-capillary, WHO group 1,3,4,5).
• Patient is on chronic intravenous inotropic drug therapy (e.g. dobutamine, milrinone).
• Patient has severe renal impairment (eGFR <30 mL/min).
• Patient has systolic blood pressure of < 90 mmHg at the time of enrollment.
• Patient is on chronic renal dialysis.
• Patient is unable to undergo one round of PRN medication intervention (i.e. 4 days of increased diuretics dose).
• Patient has liver disease, defined as AST/ALT >5x normal, or bilirubin >2x normal.
• Patient has serum albumin < 3 g/dL.
• Patient has hypertrophic obstructive cardiomyopathy, constrictive pericarditis or amyloidosis.
• Patient has complex adult congenital heart disease.
• Patient has active cancer involving chemotherapy and/or radiation therapy.
• Patient weighs more than 500 pounds.
• Patient is pregnant or breastfeeding (all females of child-bearing potential must have a negative pregnancy test within 1 week of enrollment).
• Patient is enrolled in another interventional study.

Study site personnel and subjects will remain blinded to the subject's randomization assignment until the 13-month timepoint at which point the subjects will be in the intervention arm for the remainder of their participation regardless of original allocation, or until the time of investigator and/or subject contact in relation to a "high" risk status in an intervention arm subject.