How to recruit heart failure patients for clinical trials

How many Americans have heart failure?

Approximately 6.7 million Americans over 20 years of age have heart failure, and the Heart Failure Society of America projects 8.7 million by 2030 and 11.4 million by 2050. Lifetime risk has risen to 24%, meaning about 1 in 4 people will develop heart failure (HFSA HF Stats 2025).

A simple ratio puts the competition in perspective. The Heart Failure Society of America reports 6,700,000 Americans living with heart failure. Divided across 325 recruiting studies, that is roughly 20,615 people per study nationally, before eligibility criteria, geography, and patient willingness cut the pool down. Most of those patients will never hear about a trial unless a physician brings it up.

How many heart failure trials are recruiting in the United States right now?

As of October 6, 2026, ClinicalTrials.gov lists 325 heart failure studies with a status of recruiting and at least one location in the United States (ClinicalTrials.gov). Of those, 231 are interventional trials and 94 are observational studies. Industry is the lead sponsor on 95 of them, about 29%. Academic centers, cooperative groups, and government sponsors run the rest.

Interventional heart failure trials by phase:

The median interventional trial targets 115 participants in total across all of its sites. The typical industry funded trial lists 14 recruiting locations in the United States, so each site is usually expected to deliver a small slice of that total, and sponsors notice quickly which sites deliver none.

Where are heart failure trials concentrated?

Every location on every recruiting study counts here. Together the 325 studies list 3,619 recruiting US locations. These states host the most recruiting studies:

The most frequently listed institutions include Mayo Clinic, Massachusetts General Hospital, Cleveland Clinic, and Tufts Medical Center. The industry sponsors with the most recruiting heart failure trials right now include AstraZeneca, Impulse Dynamics, Novartis Pharmaceuticals, Novo Nordisk A/S, and Endotronix. If your site sits in one of the top states, you are recruiting from the same patient population as several large academic programs at once, and the patients who reach you will mostly come through the physicians who already treat them.

Which physicians manage heart failure patients?

• General cardiologists, who manage most diagnosed patients. The AAMC counts 23,011 active cardiovascular disease physicians (AAMC 2024 via Becker's).
• Heart failure specialists at hospital programs, for advanced disease and device studies.
• Primary care and internal medicine physicians, who manage many stable patients. The AAMC counts 128,953 active internal medicine physicians.
• Hospitalists, who see patients during decompensation admissions, a common entry point for post discharge studies.

What makes heart failure trials different?

Look at the phase table above. 132 of the 231 recruiting interventional heart failure trials carry no drug phase, which usually means device, procedure, or care delivery studies. Heart failure sites often run implant and monitoring device studies alongside drug trials, and device studies need a referring cardiologist comfortable with the procedure.

Eligibility usually turns on ejection fraction, NYHA class, natriuretic peptide levels, recent hospitalization, and current guideline therapy. All of that sits in the cardiologist's chart. Ask for the most recent echocardiogram with each referral.

Why physician referral matters more than volume

A large patient population does not fill trials on its own. Physicians refer a median of about five patients into clinical trials per year, which is less than 0.2% of their annual patient volume (Getz, Applied Clinical Trials). In Tufts CSDD research, physicians and nurses named lack of access to study information and lack of time as the main reasons they do not refer, and physicians in clinical practice were 2.7 times more likely to refer than physicians in hospital settings (Tufts CSDD via Applied Clinical Trials).

That is the gap a site can close. The physicians who diagnose and manage your study population already know which patients are likely to qualify. They need a short, specific summary of your open study, a named coordinator, and a reason to believe the patient will come back to them.

A practical heart failure referral plan for your site

1. Pull the live ClinicalTrials.gov list for your state and note which competing studies are enrolling the same population within driving distance of your site.
2. List the general cardiologists, heart failure clinics, and internal medicine practices within a realistic drive of your site. Community practices come first.
3. Send each physician a one page study summary: the diagnosis, the two or three criteria that decide most eligibility, what the patient will experience, and the coordinator's direct line.
4. Follow up by email and LinkedIn, and call the practices that engage.
5. Report back to the referring physician on every patient, whether or not the patient enrolls.

See how to get physicians to refer patients and the referral letter guide for templates.