What is Stage B heart failure?

Stage B Heart Failure: Definition and Clinical Characteristics

Stage B heart failure is structural heart disease without any current or previous symptoms of heart failure—these patients have objective cardiac abnormalities but remain completely asymptomatic. 1

Defining Structural Abnormalities

Stage B requires documented evidence of at least one of the following structural or functional cardiac abnormalities 1, 2:

• Left ventricular systolic dysfunction with LVEF ≤40% (or 41-49% for HFmrEF) 2
• Previous myocardial infarction with or without reduced ejection fraction 1
• Left ventricular hypertrophy (increased LV mass index) 1, 2
• Chamber enlargement (increased left atrial volume index and/or LV dimensions) 2
• Wall motion abnormalities 2
• Valvular heart disease 1, 2
• Evidence of increased filling pressures (E/e' ratio >9 or PA systolic pressure >35 mmHg on echo) 2

Critical Distinction from Adjacent Stages

Stage A versus Stage B: Stage A patients have only risk factors (hypertension, diabetes, coronary disease) without any structural cardiac changes, while Stage B patients have crossed a threshold into demonstrable structural abnormality. 3, 1

Stage B versus Stage C: The defining difference is symptom history—Stage B patients have never experienced heart failure symptoms, whereas Stage C patients have current or past symptoms of heart failure. Once a patient develops symptoms, they permanently move to Stage C and cannot regress back to Stage B, even if symptoms resolve with treatment. 3, 4

Clinical Significance and Natural History

Stage B represents "a point of no return, unless progression of the disease is slowed or stopped by treatment." 1, 4 These patients are at substantial risk for developing symptomatic heart failure and require aggressive evidence-based interventions to prevent progression. 5

The ACC/AHA staging system was intentionally designed to be unidirectional—patients advance from one stage to the next unless disease progression is halted by treatment, and spontaneous reversal is considered unusual. 3 This differs fundamentally from the NYHA functional classification, which fluctuates frequently based on symptoms and treatment response. 3

Evidence-Based Management Imperatives

Pharmacologic Therapy (Class I Recommendations)

• ACE inhibitors for all patients with LVEF ≤40% (Class I, Level A evidence) to prevent symptomatic HF and reduce mortality 1, 2
• Beta blockers for all patients with LVEF ≤40%, particularly post-MI patients (Class I, Level B-R evidence) 1, 2
• Statins for patients with recent or remote MI/acute coronary syndrome (Class I, Level A evidence) 1, 2
• ARBs as alternative for ACE inhibitor-intolerant patients 1, 2

Device Therapy

ICD placement is indicated for patients ≥40 days post-MI with LVEF ≤30% and NYHA Class I symptoms on optimal medical therapy, with reasonable expectation of meaningful survival >1 year. 1

Critical Medications to Avoid

• Thiazolidinediones are contraindicated in patients with LVEF <50% due to increased heart failure risk and hospitalizations 1
• Nondihydropyridine calcium channel blockers (diltiazem, verapamil) with negative inotropic effects should be avoided in patients with LVEF <50% due to potentially harmful effects 1, 2

Important Clinical Pitfall

Approximately 31% of Stage B patients may lack traditional Stage A risk factors (termed "B-not-A" group), representing a previously unrecognized population with structural cardiac dysfunction who would be missed by conventional risk factor screening. 6 These patients tend to be younger, more often women, and have left ventricular dilation as their predominant abnormality. 6 This underscores the importance of echocardiographic screening in appropriate clinical contexts beyond traditional risk factor assessment.

Enhanced Diagnostic Approach

Global longitudinal strain (GLS) provides incremental prognostic value beyond LVEF, LV mass, left atrial volume, and E/e' ratio for predicting heart failure admissions. 7 Impaired GLS (<18%) independently predicts subsequent HF with a hazard ratio of 4.09, even when standard markers of Stage B are not predictive. 7 Including GLS as a diagnostic criterion would identify additional at-risk patients who meet structural criteria for Stage B despite preserved LVEF. 7