Investigations
1st investigations to order
transthoracic echocardiogram
Test
Allows for the accurate determination of biventricular systolic and diastolic function. Echocardiogram can also identify valvular, myocardial, or pericardial disease or may reveal evidence of underlying coronary artery disease (CAD) (regional wall motion/thickness abnormalities). A hypertrophied heart may be due to hypertension, hypertrophic obstructive cardiomyopathy, or infiltrative disease such as amyloidosis. It should be performed in every patient presenting with HF symptoms.
Result
HF with LVEF ≤40%: HF with reduced ejection fraction; LVEF 41% to 49%: HF with mildly reduced EF
ECG
Test
ECG may show evidence of underlying comorbidities. QRS duration above 120 ms should always raise the question of ventricular dyssynchrony.
Result
evidence of underlying coronary artery disease, left ventricular hypertrophy, or atrial enlargement; may be abnormal QRS duration; may identify comorbid conduction abnormalities
CXR
Test
May reveal pulmonary vascular congestion (vascular redistribution, Kerley B lines), cardiomegaly (increased cardiothoracic ratio), or pleural effusion (usually right-sided but often bilateral).
Result
abnormal
B-type natriuretic peptide (BNP)/N-terminal pro-brain natriuretic peptide (NT-pro-BNP) levels
Test
Elevated plasma BNP levels have been associated with reduced left ventricular ejection fraction, left ventricular hypertrophy, elevated left ventricular filling pressures, and acute myocardial infarction and ischaemia, although they can occur in other settings, such as pulmonary embolism and chronic obstructive pulmonary disease.[105][106][107] They are sensitive to other biological factors, such as age, sex, weight, and renal function. Elevated levels lend support to a diagnosis of abnormal ventricular function or haemodynamics causing symptomatic HF.[108][109][110] A low plasma BNP level (<100 nanograms/L or <100 picograms/mL) can rapidly rule out decompensated HF and point to a pulmonary cause. A high plasma BNP level (>400 nanograms/L or >400 picograms/mL) strongly supports the diagnosis of abnormal ventricular function (i.e., HF). Intermediate values (100-400 nanograms/L or 100-400 picograms/mL) fall into the so-called 'grey zone' and should spur a search for a potential non-cardiac cause of dyspnoea: for example, COPD. In patients presenting with dyspnoea, measurement of natriuretic peptide biomarkers is useful to support a diagnosis or exclude HF. However, elevated plasma levels of natriuretic peptides can occur with a wide variety of cardiac and non-cardiac causes; therefore, clinical judgement is necessary.
In patients with relevant symptoms and/or signs, a BNP level of ≥35 nanograms/L (≥35 picograms/mL) in ambulatory patients and ≥100 nanograms/L (≥100 picograms/mL) in hospitalised patients, or NT-pro-BNP level of ≥125 nanograms/L (≥125 picograms/mL) in ambulatory patients and ≥300 nanograms/L (≥300 picograms/mL) in hospitalised patients, is suggestive of HF.[1]
Trials with this diagnostic marker suggest that its use may reduce both the time to hospital discharge and the cost of treatment.[111][112][113] BNP levels tend to be less elevated in HF with preserved ejection fraction than in HF with low ejection fraction and are lower in obese patients.[114] Levels of BNP may be elevated in women and in people over 60 years of age who do not have HF, and thus BNP levels should be interpreted cautiously in such individuals.[74][115][116]
Result
elevated
FBC
Test
Anaemia and high lymphocyte percentage are strong risk factors and prognostic markers of poor survival.
Result
laboratory testing may reveal important HF aetiologies, the presence of disorders or conditions that can lead to or exacerbate HF; laboratory testing could also reveal important modulators of therapy
urinalysis
Test
To measure renal function and assess for underlying comorbidities.
Result
may show proteinuria/albuminuria, glucosuria, 5-hydroxyindoleacetic acid (in patients with carcinoid heart disease)
serum electrolytes (including calcium and magnesium)
Test
Baseline electrolytes should be obtained in all patients.
Result
decreased sodium (usually <135 millimols/L), altered potassium
serum creatinine, urea
Test
Reflects tissue perfusion, fluid status, rules out renal disease.
Result
normal to elevated
blood glucose
LFT
Test
Reflects abdominal congestion.
Result
normal to elevated
thyroid function tests (especially thyroid-stimulating hormone [TSH])
Test
Screening for hypo- or hyperthyroidism. Both can be a primary or contributory cause of HF.
Result
primary hypothyroidism: elevated TSH, decreased free thyroxine (FT4); hyperthyroidism: decreased TSH, elevated free triiodothyronine, elevated FT4
blood lipids
Test
Screening for dyslipoproteinaemias/metabolic syndrome.
Result
elevated in dyslipidaemia, decreased in end-stage HF, especially in the presence of cardiac cachexia
Investigations to consider
serum ferritin
Test
For evaluation of cardiomyopathy due to iron overload cardiomyopathy/haemochromatosis.
Result
elevated (normal value 22-449 picomol/L [10-200 nanograms/mL])
transferrin saturation
Test
For evaluation of cardiomyopathy due to iron overload cardiomyopathy/haemochromatosis.
Result
elevated level of transferrin saturation; complete or almost complete transferrin saturation (normal transferrin saturation 22% to 46%)
non-invasive stress imaging (cardiovascular MRI, stress echocardiogram, SPECT, PET)
Test
To detect myocardial ischaemia and viability when underlying ischaemic heart disease is suspected.
Result
ischaemia, scar, viable myocardium
standard exercise stress testing (bicycle or treadmill)
Test
Provides an objective assessment of the patient's functional exercise limitation and haemodynamic response to exercise. Test is ordered when exercise-induced arrhythmias or ischaemia are suspected. Caution should be taken if there is a high likelihood for aortic stenosis or hypertrophic obstructive cardiomyopathy.
Result
usually reduced exercise capacity in idiopathic dilated cardiomyopathy; reduced exercise capacity and signs of impaired myocardial perfusion in ischaemic cardiomyopathy; however, functional capacity may be completely normal in patients with low left ventricular systolic function
coronary angiogram
Test
Provides assessment of coronary stenosis, and is particularly indicated in patients with HF and angina, ventricular tachycardia, or cardiac arrest. It is also done in patients with HF and ischaemia on non-invasive stress test.
Result
coronary artery disease/stenosis
cardiac CT angiography
Test
Its main use is in patients with HF who have low or intermediate pre-test probability of underlying coronary artery disease, or those with equivocal non-invasive stress tests.
In clinical practice it is also useful in patients with a clinical picture of stress/Takotsubo cardiomyopathy, in whom significant proximal coronary artery disease needs to be excluded as a cause of underlying presentation and echocardiogram findings.
Result
coronary artery disease/stenosis
cardiopulmonary exercise testing with VO₂ max
Test
Provides the most objective assessment of the patient's functional status.
Result
reduced VO₂ max
6-minute walking test exercise
Test
A patient with HF who cannot walk more than 300 m in 6 minutes has a substantially greater annual risk of death than one who can walk 450 m or more.
Result
as an alternative to cardiopulmonary exercise testing it may provide an objective assessment of the patient's functional status
right heart catheterisation
Test
Considered in patients intolerant to standard medical therapy, in whom medical therapy has failed to achieve symptomatic relief, before initiation of intravenous inotrope or inodilator therapy and in candidates for heart transplantation.
Result
provides objective haemodynamic assessment of left ventricular filling pressure and direct measures of cardiac output and pulmonary and systemic resistance
endomyocardial biopsy
Test
Ordered if acute myocarditis (giant cell or eosinophilic) or primary infiltrative diseases of the heart (amyloidosis, active cardiac sarcoidosis) suspected.
Result
rarely necessary to establish the aetiology of HF; provides definitive pathological evidence of cardiac and systemic disease, e.g., amyloidosis, sarcoidosis, myocarditis, iron overload cardiomyopathy
serum HIV enzyme-linked immunosorbent assay
Test
The majority of patients who have cardiomyopathy due to HIV do not present with symptoms of HF until other clinical signs of HIV infection are apparent.
Result
positive or negative
cardiac MRI
Test
Particularly useful in evaluation of conditions such as myocarditis, constrictive pericarditis, and infiltrative cardiomyopathy.
Result
myocarditis: sub-epicardial delayed enhancement in myocardium, high signal in myocardium in T2-weighted imaging; infiltrative cardiomyopathy: amyloid (global sub-endocardial delayed enhancement); sarcoid: (delayed enhancement); no sub-endocardial delayed enhancement; constrictive pericarditis: thick pericardium as well as diastolic septal bounce with inspiration
other biomarkers
Test
Troponin is helpful in further risk stratification in chronic HF, as elevated level is associated with progressive left ventricular dysfunction and increased mortality.[102]
Soluble ST2 and galectin-3 (biomarkers for myocardial fibrosis) are predictive of death and hospitalisation in patients with HF and are additive to natriuretic peptide in their prognostic value.[103]
Result
borderline to minimally elevated
multi-slice computed tomography (MSCT)
Test
A method for left ventricular ejection fraction (LVEF) estimation. There appears to be no significant difference in LVEF estimation between MSCT and MRI, and also between MSCT and transthoracic echocardiogram.[104]
May offer additional benefit as it provides a combined evaluation of LVEF and coronary artery disease.
Result
quantifies LVEF and coronary artery disease
Use of this content is subject to our disclaimer