What is the difference between heart failure and decreased cardiac output (cardiac output, CO)?

From the Guidelines

Heart failure and decreased cardiac output are distinct concepts, with heart failure being a clinical syndrome characterized by the heart's inability to pump sufficient blood, and decreased cardiac output being a specific hemodynamic state with reduced blood volume pumped per minute. The most recent and highest quality study on this topic is from 2024 1, which highlights the importance of understanding the differences between heart failure with reduced ejection fraction (HFrEF), heart failure with mildly reduced ejection fraction (HFmrEF), and heart failure with preserved ejection fraction (HFpEF). Key points to consider in the management of heart failure include:

• Reducing modifiable risk factors, such as hypertension and hyperlipidemia, as recommended by the American College of Cardiology Foundation (ACCF) and American Heart Association (AHA) guidelines 1
• Using ACE inhibitors and beta blockers in patients with stage B or C heart failure who have a reduced ejection fraction, as well as diuretics in patients with stage C heart failure and fluid retention 1
• Considering the use of sodium-glucose co-transporter 2 (SGLT2) inhibitors in patients with HFpEF, as demonstrated by recent randomized controlled trials 1
• Focusing on symptom improvement, reducing congestion with diuretics, and treating cardiovascular and non-cardiovascular comorbidities in patients with HFpEF In contrast, addressing decreased cardiac output may involve immediate interventions like fluid resuscitation, inotropic support, or treating the specific underlying cause, as discussed in the context of acute heart failure syndromes 1. Overall, a comprehensive approach to managing heart failure and decreased cardiac output requires consideration of the underlying pathophysiology, clinical presentation, and individual patient factors, as well as adherence to evidence-based guidelines and recommendations.

From the Research

Heart Failure vs Decreased Cardiac Output

• Heart failure is defined as the inability of the heart to deliver adequate perfusion (cardiac output) to the body at rest or exercise, or to require an elevation in cardiac filling pressures in order to do this 2.
• Decreased cardiac output can be a result of heart failure, and it is often associated with symptoms such as fatigue, shortness of breath, and swelling in the legs and feet.
• The treatment of heart failure and decreased cardiac output often involves the use of medications such as angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and beta-blockers 3, 4, 5.
• ACE inhibitors and ARBs have been shown to reduce mortality and morbidity in patients with heart failure, and they are often used in combination with beta-blockers to achieve optimal results 3, 4, 5.
• In patients with heart failure and decreased cardiac output, the goal of treatment is to improve cardiac function, reduce symptoms, and prevent hospitalization and death 2, 4, 5.

Differences between Heart Failure and Decreased Cardiac Output

• Heart failure is a clinical syndrome characterized by symptoms such as shortness of breath, fatigue, and swelling in the legs and feet, whereas decreased cardiac output is a hemodynamic abnormality that can be a result of heart failure 2.
• Heart failure can be caused by a variety of factors, including coronary artery disease, hypertension, and valvular heart disease, whereas decreased cardiac output is often a result of heart failure or other conditions such as cardiomyopathy or cardiac tamponade 3, 2, 4.
• The treatment of heart failure and decreased cardiac output often involves different approaches, with heart failure treatment focusing on improving cardiac function and reducing symptoms, and decreased cardiac output treatment focusing on improving cardiac output and preventing organ dysfunction 2, 4, 5.

Treatment Options

• ACE inhibitors and ARBs are commonly used to treat heart failure and decreased cardiac output, and they have been shown to reduce mortality and morbidity in patients with these conditions 3, 4, 5.
• Beta-blockers are also commonly used to treat heart failure, and they have been shown to reduce mortality and morbidity in patients with this condition 4.
• Inotropic agents such as dobutamine and milrinone can be used to treat decreased cardiac output, but they are often associated with adverse effects such as arrhythmias and hypotension 6.
• Newer agents such as istaroxime and omecamtiv mecarbil are being developed to treat heart failure and decreased cardiac output, and they have shown promising results in clinical trials 6.