Congestive heart failure — diagnostic evaluation

Why it is difficult in the elderly: atypical presentation, multiple comorbidities that mimic HF (COPD, obesity, anaemia, venous stasis, renal disease), and cognitive impairment limiting history-taking. Essentials stresses that HF is over-diagnosed — pedal oedema alone is not enough.

Step 1 — assess clinical probability using the ESC algorithm: symptoms, signs, prior cardiac conditions and an abnormal ECG. Presence of one or more should prompt natriuretic peptide measurement.

Step 2 — natriuretic peptides. BNP >35 pg/mL or NT-proBNP >125 pg/mL (non-acute setting) warrant echocardiography. In acute breathlessness, BNP above about 300 pg/mL favours a cardiac over a pulmonary cause. Normal values effectively rule out HF; levels also predict prognosis.

Causes of falsely raised natriuretic peptides: age, female sex, renal impairment, atrial fibrillation, pulmonary embolism, sepsis, anaemia. Falsely low: obesity, and treatment with ARNI alters BNP interpretation (use NT-proBNP).

Step 3 — echocardiography is the key confirmatory test: ejection fraction, chamber dimensions, wall thickness, diastolic parameters (E/e′, left atrial volume index, tricuspid regurgitant velocity), valvular lesions and pericardial disease. NICE: echocardiography first if previous MI; natriuretic peptide first if no previous MI.

ECG: looks for prior infarction, LV hypertrophy, atrial fibrillation, bundle branch block (relevant to CRT) and low voltage with LV hypertrophy (suggesting amyloidosis). A normal ECG makes HF very unlikely.

Chest radiograph: cardiomegaly, upper-lobe diversion, Kerley B lines, effusions; also excludes COPD, fibrosis and malignancy.

Laboratory panel: full blood count, urea, creatinine and electrolytes, eGFR, liver function, thyroid function, glucose/HbA1c, lipids, iron studies (ferritin and transferrin saturation), urinalysis.

Classify by ejection fraction: HFrEF (≤40%), HFmrEF (41–49%), HFpEF (≥50%) — HFpEF predominates in older women with hypertension.

Assess functional and geriatric domains alongside cardiac ones: NYHA class, six-minute walk, frailty, cognition, nutrition, polypharmacy and social support — these determine what treatment is feasible. Latest Updates and Current Practice Update (concise) Scoring systems for HFpEF are now standard. The 2026 ACC HFpEF consensus pathway recommends sequential use of the H2FPEF and HFA-PEFF scores, with diastolic stress echocardiography or invasive exercise haemodynamics if the diagnosis remains uncertain — an approach absent from the textbooks. Systematic search for mimics is now mandatory, in particular cardiac amyloidosis (bone scintigraphy with 99mTc-PYP/DPD plus serum free light chains and immunofixation), constrictive pericarditis, hypertrophic cardiomyopathy and high-output states. Cardiac MRI with T1 mapping and extracellular volume quantification is increasingly used. Practical change: lung ultrasound (B-lines) and point-of-care echocardiography are now widely used at the bedside to distinguish cardiac from pulmonary dyspnoea, supplementing rather than replacing the natriuretic peptide– echocardiography pathway described in the textbooks.