The diagnosis of advanced heart failure is generally based on the following symptoms, signs and haemodynamic assessments in patients with New York Heart Association (NYHA) functional class III–IV (Metra et al., 2007):
The presence of these findings despite attempts to optimise treatment for heart failure, including diuretic, renin–angiotensin–aldosterone blocker, beta-blocker (unless not tolerated) and cardiac resynchronisation therapy (where indicated), demonstrate advanced heart failure. A summary of the NYHA classification is shown below.
I – No limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation or dyspnoea
II – Slight limitation of physical activity. Comfortable at rest. Ordinary physical activity results in fatigue, palpitation, dyspnoea
III – Marked limitation of physical activity. Comfortable at rest. Less than ordinary activity causes fatigue, palpitation, or dyspnoea
IV – Unable to carry on any physical activity without discomfort. Symptoms of heart failure at rest. If any physical activity is undertaken, discomfort increases
A – No objective evidence of cardiovascular disease. No symptoms and no limitation in ordinary physical activity
B – Objective evidence of minimal cardiovascular disease. Mild symptoms and slight limitation during ordinary activity. Comfortable at rest
C – Objective evidence of moderately severe cardiovascular disease. Marked limitation in activity due to symptoms, even during less-than-ordinary activity. Comfortable only at rest
D – Objective evidence of severe cardiovascular disease. Severe limitations. Experiences symptoms even while at rest
Despite the above classifications, many patients with advanced heart failure receive a late referral for therapies such as transplantation and left ventricular assist devices (LVADs). Late referral increases the risk of right heart failure, renal and liver dysfunction, pulmonary hypertension and cardiac cachexia and resultantly, risks the patient becoming too unwell to receive advanced heart failure therapies (Baumwol, 2017). Similar findings were found in a study which reported one-third of patients initially diagnosed with non-ischemic cardiomyopathy were later found to have significant atherosclerotic coronary artery disease upon autopsy (Uretsky et al., 2000).
Producing an accurate and timely diagnosis is therefore critical to patient outcomes, but how accurate are current diagnostic tools? Echocardiography is recommended as the first-line bedside tool for the diagnosis of heart failure and prognostic assessment (Marwick, 2013; Ponikowski et al., 2016). However, geometrical assumptions can undermine the echocardiographic measurements, especially if there are poor acoustic windows (Ponikowski et al., 2016). One technique emerging as a possible alternative or addition to echocardiography is cardiovascular magnetic resonance imaging (CMR), a non-invasive imaging technique which provides precise measurements without geometrical assumption (Grothues et al., 2002). One Australian study investigated the effect of CMR in addition to transthoracic echocardiography (TTE) on diagnosis and treatment decisions. The study revealed CMR led to a change in diagnosis or confirmation of suspicion previously unconfirmed by TTE in 20% of cases. In addition, the CMR detected new findings of intracardiac thrombus in six patients, four of whom showed no thrombus visualisation on the TTE. Unsurprisingly the results of the CMR resulted in treatment management changes in almost half of all patients (n/N = 54/114). In multivariate analysis the only independent variable significantly associated with clinical impact was the presence of late gadolinium enhancement (p<0.001), whereas body mass index, echocardiography image quality and presence of sinus rhythm didn’t show statistical significance; this may be a key difference as echocardiography is limited by acoustic window which is often decreased in obese patients (Lum et al., 2018).
The ‘I Need Help’ mnemonic includes risk factors associated with all-cause mortality in heart failure patients and has been developed to support timely referral of patients as they progress from stable to advanced heart failure (Table 2). Contact with an advanced heart failure service should be initiated if a patient has any of the below risk factors.
Table 2. ‘I Need Help’ mnemonic developed by J Baumwol (2017) for the timely referral for treatment of patients with advanced heart failure.