Early Symptoms of Heart Failure That Are Often Missed

1. Introduction: The Cost of Diagnostic Delay in Heart Failure

Heart failure is frequently diagnosed later than its underlying pathology would allow, and the interval between symptom onset and confirmed diagnosis carries measurable clinical cost. Patients who present with advanced symptoms - marked breathlessness, overt fluid overload, or hospitalisation - have often experienced a preceding period of subtler symptoms that were present, but not recognised as cardiac in origin.

This gap between physiological onset and clinical recognition is not primarily a knowledge gap; the diagnostic criteria for heart failure are well established. It is, more often, a pattern-recognition problem: early heart failure symptoms overlap substantially with normal ageing, common comorbidities, and deconditioning, and can present without the classical triad of breathlessness, oedema, and fatigue that is most readily attributed to a cardiac cause.

For primary care and internal medicine clinicians - who are typically the first point of contact when these subtler symptoms emerge - maintaining a structured index of suspicion, rather than waiting for a symptom pattern that unambiguously points to the heart, is central to earlier diagnosis.

This article outlines why early heart failure symptoms are commonly missed, reviews evidence on diagnostic delay, and provides practical guidance on differentiating early heart failure from its common mimics.

2. Why Early Symptoms Are Missed: Overlap and Misattribution

Several features of early heart failure make it particularly prone to being overlooked or misattributed in routine practice.

Overlap with Normal Ageing and Deconditioning

Reduced exercise tolerance, mild fatigue, and slightly increased breathlessness on exertion are common complaints in older adults and are frequently, and reasonably, attributed to normal ageing, deconditioning, or reduced physical activity. Without a specific prompt to consider a cardiac cause, these symptoms can persist unexplained for a considerable period before further evaluation is triggered.

Comorbidity Overlap

Chronic obstructive pulmonary disease, obesity, anaemia, and depression each produce symptoms - breathlessness, fatigue, reduced activity tolerance - that closely mirror early heart failure, and frequently coexist with it. Where a plausible alternative explanation is already present in the patient's history, clinicians may reasonably attribute new or worsening symptoms to the known condition rather than investigating further for a second, less obvious cause.

Underrecognition of HFpEF Presentations

Heart failure with preserved ejection fraction, now the more common phenotype in older populations, often presents with subtler, more gradual symptoms than heart failure with reduced ejection fraction, and a normal ejection fraction on any prior echocardiography can inappropriately reassure against a heart failure diagnosis being reconsidered later.

Atypical Presentations in Older Adults and Women

Older adults, particularly those with multiple comorbidities, more often present with non-specific symptoms - confusion, reduced appetite, falls, or generalised decline - rather than classical breathlessness or oedema. Women with heart failure, and particularly HFpEF, may also present with less pronounced classical symptoms relative to men, contributing to comparatively later recognition in this group.

3. Evidence Overview: Diagnostic Delay and Its Consequences

A body of primary care and community-based research quantifies both the scale of unrecognised heart failure and the limitations of symptom-based diagnosis alone.

Prevalence of Unrecognised Heart Failure

Community screening studies among older adults presenting with exertional breathlessness have identified a substantial proportion of previously unrecognised heart failure, including unrecognised HFpEF, in patients who had not been considered for cardiac evaluation on the basis of their presenting symptoms. This work underscores that breathlessness on exertion in an older adult should prompt consideration of heart failure even where an alternative explanation seems plausible.

Diagnostic Accuracy of Symptom-Based Assessment Alone

Older studies examining the validity of clinical heart failure diagnosis in primary care found only moderate agreement between clinical diagnosis and objective confirmation, with both over- and under-diagnosis occurring when symptoms and signs were relied upon without objective testing. Subsequent evaluation of geriatric outpatients with suspected heart failure has similarly shown that individual symptoms and signs, considered in isolation, have limited discriminative value, reinforcing the case for a structured pathway incorporating natriuretic peptide testing rather than clinical impression alone.

Guideline Positions

The 2021 ESC heart failure guidelines recommend natriuretic peptide testing as an initial step in patients presenting with symptoms suggestive of heart failure in the non-acute setting, given the limitations of clinical assessment alone, reserving echocardiography for those with a positive or indeterminate result. NICE guidance similarly sets out a symptom-triggered pathway using NT-proBNP to stratify the urgency of specialist referral, explicitly designed to reduce reliance on clinical gestalt for a diagnosis that is otherwise prone to delay.

4. Clinical Assessment: Red Flags and Differentiating Features

A structured approach to symptom assessment can help distinguish early heart failure from its common mimics without requiring specialist input at the first point of contact.

Symptom Clusters Warranting Further Evaluation

• New or worsening exertional breathlessness that is disproportionate to known respiratory or musculoskeletal disease.

• Reduced exercise tolerance with a clear temporal onset, rather than a longstanding, stable baseline.

• Orthopnoea or paroxysmal nocturnal dyspnoea, which are more specific to a cardiac cause than isolated exertional breathlessness.

• Unexplained weight gain over days to weeks, ankle swelling, or increasing abdominal girth.

• New or worsening fatigue alongside any of the above, particularly where activity levels have not changed.

Atypical Presentations to Actively Consider

• In older adults: new confusion, reduced appetite, unexplained falls, or general functional decline without an alternative clear cause.

• In patients with known COPD or asthma: a change in breathlessness pattern that does not respond as expected to escalation of respiratory therapy.

• In patients with depression or anxiety diagnoses: physical symptoms (fatigue, reduced activity tolerance) that are more prominent or more rapidly progressive than the psychological symptom pattern would typically produce.

Differentiating Features from Common Mimics

Where breathlessness and fatigue are present, examination findings including elevated jugular venous pressure, a displaced apex beat, a third heart sound, or basal crackles that do not clear with coughing lend support to a cardiac cause, though their absence does not exclude early heart failure, particularly HFpEF. A pragmatic threshold is to pursue natriuretic peptide testing whenever a plausible alternative diagnosis does not fully or promptly account for the symptom pattern, rather than requiring multiple classical features to be present before testing.

5. Management Strategies: Pathways to Confirm or Exclude Heart Failure Early

Once heart failure is considered, a structured pathway supports timely confirmation or exclusion without over-referring every patient with non-specific symptoms.

Natriuretic Peptide-Led Triage

BNP or NT-proBNP testing in primary care provides an accessible first step: a normal result makes heart failure unlikely and supports investigation of alternative causes, while an elevated result should prompt echocardiography, with the degree of elevation informing the urgency of referral in line with current national guidance.

Access to Echocardiography

Timely access to echocardiography following a positive natriuretic peptide result is central to closing the diagnostic loop; local pathways that allow direct primary care request or rapid-access referral reduce the delay between initial suspicion and confirmed diagnosis.

Role of Longitudinal Home Monitoring

Structured home blood pressure monitoring, alongside simple symptom or weight tracking, can help surface the gradual changes - a slowly rising BP trend, increasing pulse pressure, or steady weight gain - that a single clinic visit is likely to miss, particularly in patients already known to be at elevated risk of heart failure.

Emerging evidence also points to a close, bidirectional relationship between hypertension, atrial fibrillation, and heart failure, with each condition capable of driving or masking the others. Early detection of either elevated blood pressure or atrial fibrillation may therefore help reduce downstream heart failure risk, making structured home monitoring particularly valuable where a single device can support both functions. Several OMRON blood pressure monitors now include automatic atrial fibrillation screening alongside standard BP measurement, allowing at-risk patients to be flagged for both conditions during routine home use, without adding a separate step to their monitoring routine.

6. Conclusion

Early heart failure symptoms are subtle by nature and overlap substantially with ageing, common comorbidities, and everyday complaints, which is precisely why they are so frequently missed at first presentation. Evidence from primary care and community screening studies consistently shows that symptom-based clinical assessment alone has limited discriminative value, reinforcing the case for a low threshold to pursue natriuretic peptide testing rather than waiting for a fully classical symptom pattern to emerge.

Key practice points for clinicians:

• Consider heart failure in older adults presenting with breathlessness, fatigue, or functional decline, even where an alternative explanation seems plausible.

• Actively look for atypical presentations - confusion, falls, reduced appetite - in frail older patients and be alert to less classical presentations in women.

• Use natriuretic peptide testing as a first-line triage step rather than relying on clinical impression alone.

• Support at-risk patients with structured home monitoring to help surface gradual change between clinic visits.

Maintaining a structured, low-threshold approach to investigation - supported by longitudinal data captured outside the clinic - gives early heart failure the best chance of being recognised while intervention can still alter its trajectory.

Omron Healthcare offers a range of clinically validated home blood pressure monitors that support longitudinal monitoring in at-risk patients, helping healthcare professionals build the trend data that can prompt earlier clinical review. OMRON Academy has also created a free short course on recognising early heart failure, available at academy.omron-healthcare.com.

Approval Code: OHEAPP-1202