By Diagram insights
Published: 2026-10-26 | 10 min read I Region: Asia-Pacific, Japan
Topics: Heart failure, cardiometabolic disease, diagnostics
By the time breathlessness and swelling appear, the heart has often been changing for years. A statement from the Japanese Heart Failure Society sets out to explain how earlier screening and prevention can protect people at risk.
Answer in brief
The changes that lead to heart failure can be detected before symptoms appear. People with high blood pressure, diabetes, chronic kidney disease, obesity, a heart rhythm disorder or previous heart damage are at higher risk.
A Japanese Heart Failure Society statement, led by Professor Hideo Izawa, gives primary care clinicians a flowchart for checking these patients with routine tests they already use. Acting early can prevent or delay progression to symptomatic heart failure.
A Japanese Heart Failure Society statement, led by Professor Hideo Izawa, gives primary care clinicians a flowchart for checking these patients with routine tests they already use. Acting early can prevent or delay progression to symptomatic heart failure.
Key takeaways
- The Japanese Heart Failure Society has recommended a clinical flowchart for the early risk assessment of asymptomatic stage A & B Heart Failure, for non-specialist clinicians (Japanese Heart Failure Society, 2026).
- A natriuretic peptide blood test moves a patient from Stage A to Stage B at NT-proBNP ≥125 pg/mL (or BNP ≥35 pg/mL). Testing to be scheduled at least once a year for Stage A patients, at least twice a year for Stage B (Japanese Heart Failure Society, 2026).
- Demographic shifts are driving an urgent need for proactive management of common risk factors such as blood pressure and diabetes with proven cardio-renal protective therapies such as SGLT2i inhibitors and GLP-1 RA for individuals with diabetes and cardiovascular risk, in Japan (Japanese Heart Failure Society, 2026).
Can heart failure develop without symptoms?
Yes. In the earliest stages of heart failure, there are no symptoms.1 Patients may not know they’re at risk, but the conditions associated with heart failure are common; type 2 diabetes, myocardial infarction (heart attack) and heart failure are closely connected2.
When 581 adults aged 60 and over, living with type 2 diabetes were screened, 27.7% were found to have heart failure that had never been diagnosed.3 And even where heart failure hasn’t developed, heart damage can go unnoticed. In a study of 1,840 adults with no clinical cardiovascular disease at the beginning, scarring was found in 7.9% – and 78% of those scars had never been previously detected by standard screening tools.4
Acting early to reduce heart failure risk can prevent or delay the condition from progressing to symptomatic heart failure. That means identifying people who are at risk and may not know it.5
At the health system level, the need for earlier diagnosis is growing. The number of Japanese outpatients with left ventricular dysfunction (a condition where the heart’s main lower pumping chamber fails to pump blood effectively to the rest of the body) is projected to rise from 979,000 in 2005 to 1.3 million by 2030 as the population ages.6
Populations across the rest of the Asia-Pacific region are also ageing: by 2050, one in four people in the region is projected to be aged 60 or over, close to 1.3 billion people.7
What are Stage A and Stage B heart failure?
Stage A and Stage B are the two stages of heart failure that come before any symptoms appear.1 They are set out in a statement from the Japanese Heart Failure Society, published in February 2026 and led by Professor Hideo Izawa of Fujita Health University, who chairs the Society’s prevention committee.1
The statement explains how clinicians can identify, test and treat people at risk of heart failure, in routine care, before the person is symptomatic.1 It includes a clinical flowchart for Stage A and Stage B heart failure, written for primary care and other non-specialist clinicians rather than for cardiologists.
The flowchart divides asymptomatic patients into two groups. Stage A is risk, but no identifiable damage. People living with hypertension, arteriosclerotic disease, diabetes, chronic kidney disease and obesity – conditions routinely managed in primary care that also increase the risk of heart failure – are classified in Stage A.1
At Stage B – pre-heart failure – there are still no symptoms, but tests show heart abnormalities or indicators of cardiac stress:
- A left ventricular ejection fraction (the percentage of blood pumped out of the heart’s main pumping chamber with each beat) below 50%
- Left ventricular hypertrophy (a thickening of the muscle wall in the heart’s main pumping chamber)
- Valve disease
- A previous myocardial infarction, atrial fibrillation, or a raised natriuretic peptide level (hormones released by heart muscle when the ventricular wall is under strain).1
Which tests can detect heart failure before symptoms appear?
These changes can be detected with tests that are already available, from a physical examination to a blood biomarker test. Tests to identify each of these changes are already available, and Professor Izawa’s flowchart structures them around a routine primary care check-up.
At every review, it asks clinicians to look for fatigue, breathlessness on exertion, waking at night short of breath, crackles at the lung bases, a third heart sound, raised jugular venous pressure, swollen ankles, and weight gain of more than 2 kg in a week.
A chest X-ray and a 12-lead electrocardiogram (ECG) complete the routine assessment. If there may be changes to the structure or function of the heart, the flowchart recommends echocardiography.1
The flowchart then adds a blood test to the clinical algorithm, to measure two biomarkers: BNP and NT-proBNP. Heart failure is unlikely below 35 pg/mL for BNP and 125 pg/mL for NT-proBNP, and the patient stays at Stage A. At or above those levels, a Stage A patient is reclassified as Stage B.1 Stage A patients should be tested at least once a year; Stage B patients at least twice.1
Does a normal blood test result rule out heart failure risk?
Not always. The result needs to be interpreted against the patient. Age, inflammation, kidney impairment, anaemia and atrial fibrillation all raise natriuretic peptide levels. Substantial obesity lowers them, so a normal result in a patient living with obesity can conceal a heart already under strain.¹
An NT-proBNP result under 125 pg/mL also doesn’t rule out heart failure risk. Among residents of Toon City in Ehime Prefecture who all started below 125 pg/mL, 17.9% of those above 55 pg/mL had crossed it five years later and moved to Stage B, compared with 4.2% of those who started at or below 55 pg/mL.¹˒8
The higher the starting level, the more likely it was; the value that best predicted progression was 52.4 pg/mL, close to the 55 pg/mL follow-up threshold the Society already recommends.8
What can people at risk do to protect their heart?
When heart failure risk is identified, a person can take steps early to protect their heart. The statement calls for aerobic exercise, weight management, strict restriction of dietary sodium, stopping smoking and moderating alcohol.¹
This isn’t new advice. Lifestyle changes are already recommended for anyone living with high blood pressure, diabetes or kidney disease. But the statement provides another reason to make changes; at Stage A, these measures can prevent changes to the heart while it’s still undamaged.
Which treatments does the statement recommend for each risk condition?
The statement also sets out next steps for the prescriber, organised by risk condition.
For hypertension, the target blood pressure is below 130/80 mmHg in clinic and below 125/75 mmHg at home.1 A trial of 12,821 adults living with type 2 diabetes found that targeting a systolic pressure under 120 mmHg cut major cardiovascular events by 21% compared with a target of 140 mmHg.9
For diabetes with cardiovascular risk, the statement favours drugs shown to protect the heart in trials: SGLT2 inhibitors, GLP-1 receptor agonists, and drugs that combine GLP-1 with a second gut hormone, GIP.¹
For obesity with a BMI of 27 or above and atherosclerotic disease, it recommends a GLP-1 receptor agonist.¹ Of 2,474 Japanese study participants followed for a median 19 years, people with a BMI of 27 to 30 had the same risk of pre-heart failure or symptomatic heart failure as those above 30.1 A trial of 17,604 people with established cardiovascular disease and overweight or obesity but no diabetes reported a 20% reduction in major adverse cardiovascular events with semaglutide.10
For chronic kidney disease, renin-angiotensin blockade combined with an SGLT2 inhibitor is the first-line treatment. Where diabetes is also present, the statement adds finerenone and semaglutide.¹ In a randomised trial of 3,533 participants followed for a median of 3.4 years, semaglutide reduced heart failure events or cardiovascular death by 27% in people with type 2 diabetes and chronic kidney disease.11
When should someone at risk of heart failure see a cardiologist?
The statement recommends that any patient whose NT-proBNP reaches 125 pg/mL, or whose BNP reaches 35 pg/mL, should see a cardiovascular specialist at least once.¹ Structural findings on echocardiography, or new abnormalities on ECG, justify a referral to establish the cause.
And any red flag – breathlessness on bending forward, waking at night short of breath, swelling of the lower legs, weight gain of more than 2 kg in a week – indicates probable Stage C and needs expedited review.¹
None of this requires new technology. Alongside physical and clinical examination, it requires a blood test most laboratories already run, ECG and imaging that already form the primary care pathway.
The statement’s aim is to keep people out of hospital and protect them from the decline in daily function once heart failure becomes symptomatic.1 For someone living with high blood pressure, diabetes or kidney disease, the heart can be checked and protected long before it fails. That’s what keeps people active, independent, and at home for a longer period of time.
What this means for you
| Policymakers and health ministries Scheduled natriuretic peptide testing for at-risk adults is a primary care intervention that uses existing laboratory capacity. The Japanese flowchart offers a model for aging Asia-Pacific economies where heart failure admissions are projected to rise. | Primary care clinicians Patients with hypertension, diabetes, chronic kidney disease, obesity or atrial fibrillation are Stage A or Stage B heart failure patients by definition. Annual natriuretic peptide testing, follow-up above 55 pg/mL NT-proBNP, and referral to a cardiovascular specialist once the 125 pg/mL threshold is crossed give a clear routine. |
| Laboratory and hospital leaders Demand for BNP and NT-proBNP testing will increase if the flowchart is adopted, with a shift toward scheduled testing in asymptomatic patients rather than testing at symptomatic presentation. Reporting a lower follow-up threshold alongside the diagnostic cut-off supports interpretation in primary care. | Patients and advocates Anyone living with high blood pressure, diabetes, kidney disease, obesity, a heart rhythm disorder or a previous heart attack can ask their doctor about natriuretic peptide testing. The steps that protect the heart – exercise, weight, salt, smoking and alcohol, plus the treatment already prescribed for the underlying condition – can start before any symptom appears. |
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FAQs
Stage A and Stage B are the two stages of heart failure before symptoms appear. Stage A is risk without damage, in people living with conditions such as hypertension, diabetes, chronic kidney disease or obesity. Stage B is pre-heart failure. Tests show a change in the heart or a raised natriuretic peptide level, but the person still has no symptoms
People living with high blood pressure, diabetes, chronic kidney disease, obesity or arteriosclerotic disease are at higher risk of heart failure. So are people with a heart rhythm disorder such as atrial fibrillation, or previous heart damage from a myocardial infarction (heart attack). Many of these conditions are routinely managed in primary care.
Yes. Routine check-ups, a 12-lead ECG, a chest X-ray, echocardiography where needed and a natriuretic peptide blood test can identify early changes in people who feel well. Damage can be present without anyone knowing. In one community study, 78% of heart scars had never been detected before.
A natriuretic peptide test is a blood test for BNP or NT-proBNP, hormones released by heart muscle under strain. Heart failure is unlikely below 35 pg/mL for BNP or 125 pg/mL for NT-proBNP. At or above those levels, a patient at risk moves to Stage B. In one Japanese cohort, 17.9% of adults starting below 125 pg/mL but above 55 pg/mL had moved to Stage B five years later.
The statement recommends a natriuretic peptide blood test at least once a year for people in Stage A, and at least twice a year for people in Stage B. Results should be read alongside factors such as age, kidney function, anaemia and weight, because these can raise or lower the level.
People at risk can take aerobic exercise, manage their weight, strictly limit salt, stop smoking and moderate alcohol. The statement also recommends treating each risk condition with drugs shown to protect the heart, such as SGLT2 inhibitors or GLP-1 receptor agonists for diabetes with cardiovascular risk, and a clinic blood pressure below 130/80 mmHg.
Any patient whose BNP reaches 35 pg/mL, or whose NT-proBNP reaches 125 pg/mL, should see a cardiovascular specialist at least once. Structural findings on echocardiography or new ECG abnormalities also justify referral. Red flags such as breathlessness on bending forward, waking at night short of breath, swollen lower legs or weight gain of more than 2 kg in a week need expedited review.
It is a scientific statement from the Japanese Heart Failure Society, published in February 2026 and led by Professor Hideo Izawa. It gives primary care and other non-specialist clinicians a flowchart for Stage A and Stage B heart failure, setting out who is at risk, how often to test, how to treat each risk condition and when to refer.
