How are heart failure patients assessed for device therapy? 

Heart failure is a condition where the heart is unable to pump blood around the body effectively. For many patients, medication is the first line of treatment, but some individuals may benefit from implantable medical devices. These devices, such as pacemakers or defibrillators, are designed to improve the heart’s rhythm or protect against life threatening electrical issues. 

Determining whether a patient is a suitable candidate for device therapy involves a structured clinical assessment. This process ensures that the intervention is safe, effective, and tailored to the specific needs of the individual. This article outlines the steps healthcare professionals take, following NHS and NICE guidance, to evaluate patients for cardiac devices. 

What We’ll Discuss in This Article 

• The role of the initial clinical examination and history 

• How N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels guide referral 

• The importance of echocardiograms in measuring ejection fraction 

• Understanding the significance of the QRS interval on an ECG 

• Specific NICE criteria for ICD and CRT interventions 

• The collaborative role of the specialist heart failure multidisciplinary team 

• How patient symptoms and lifestyle factors influence the final decision 

The clinical assessment process for device therapy 

The assessment for device therapy begins with a comprehensive review of the patient’s symptoms and their response to optimal medical therapy. Under NICE guidelines, patients are usually evaluated only after they have been on the best possible medication for at least three months. This ensures that the heart has had a chance to recover with non-invasive treatments before a surgical device is considered. 

Clinicians use the New York Heart Association (NYHA) classification to grade the severity of symptoms, ranging from Class I (no symptoms) to Class IV (severe symptoms even at rest). The initial diagnostic workup includes: 

• NT-proBNP Blood Test: A high level of this protein indicates the heart is under stress and helps clinicians determine the urgency of the specialist referral. 

• 12-Lead ECG: This test looks for electrical abnormalities, specifically the ‘QRS duration’, which measures how long it takes for the electrical signal to travel through the heart’s lower chambers. 

• Transthoracic Echocardiogram (Echo): This ultrasound of the heart is the ‘gold standard’ for measuring the Left Ventricular Ejection Fraction (LVEF), which indicates how much blood the heart pumps out with each beat. 

NICE criteria for ICD and CRT-P/D 

The National Institute for Health and Care Excellence (NICE) provides strict criteria for the use of Implantable Cardioverter Defibrillators (ICD) and Cardiac Resynchronisation Therapy (CRT). Generally, device therapy is considered when a patient’s LVEF is 35% or less, meaning the heart is pumping significantly less than a healthy heart. 

The choice between different devices depends on specific electrical patterns and symptom severity. For example, CRT is often recommended if the ECG shows a wide QRS interval (usually 120ms or more), which suggests the two sides of the heart are not beating in sync. Key considerations include: 

• ICD (Defibrillator): Recommended for patients at high risk of sudden cardiac arrest due to fast, dangerous heart rhythms. 

• CRT-P (Resynchronisation Pacer): Used to help the heart chambers beat together more efficiently to improve symptoms and quality of life. 

• CRT-D (Combined Device): A single device that provides both resynchronisation and defibrillation protection for those who meet both sets of criteria. 

The role of the Specialist Multidisciplinary Team 

Decisions regarding device therapy are not made by a single doctor but by a Specialist Multidisciplinary Team (MDT), often referred to as a ‘Heart Team’. This group typically includes consultant cardiologists, heart failure specialist nurses, and cardiac physiologists. They review all test results to ensure the patient is likely to benefit from the procedure and that the risks are acceptable. 

The team also considers the patient’s overall health, including other conditions like kidney disease or frailty. They must ensure that the patient is expected to survive for at least one year with a good quality of life after the device is fitted. The assessment process involves: 

• In-depth Consultation: Discussing the potential benefits and risks of the device with the patient and their family. 

• Comorbidity Review: Assessing if other health issues might complicate the surgery or reduce the effectiveness of the device. 

• Patient Choice: Ensuring the patient understands the lifestyle implications, such as driving restrictions or the need for regular device checks. 

Conclusion 

Assessing a heart failure patient for device therapy is a thorough process designed to ensure that interventions like ICDs or CRT are used appropriately. By combining blood tests, electrical readings, and heart imaging, the specialist team can identify those who will gain the most benefit in terms of symptom relief and long term survival. Most patients find that a successful device implant significantly improves their ability to perform daily activities. 

If you experience severe, sudden, or worsening symptoms, such as intense chest pain, a racing heart, or severe shortness of breath, call 999 immediately. 

Authority Snapshot 

This article was written by Dr. Rebecca Fernandez, a UK-trained physician with an MBBS and extensive experience across cardiology, internal medicine, and emergency care. Dr. Fernandez has managed critically ill patients in intensive care settings and has a deep understanding of the clinical pathways required for heart failure management. Her expertise ensures that this content is medically accurate, evidence-based, and aligned with the latest NICE and NHS clinical standards for patient safety.