Congestive Heart Failure

Acute precipitants:

• non-adherence with diet or medications
• acute myocardial ischaemia / infarction
• new onset arrhythmia
• intercurrent infection, especially pulmonary
• new drug therapies
  • negative inotropy
    • β blockers
    • ca blockers
    • antiarrhythmics
  • fluid retention
    • NSAIDs
    • dietary sodium and water
• acute pulmonary embolism
• anaemia
• thyrotoxicosis

Clinical Assessment:

Aim to establish the underlying cardiac diagnosis, to identify precipitating factors, to assess severity of patient’s prognosis, and to provide baseline from which to measure therapeutic response.

1. are the symptoms / signs due to heart failure?
2. what underlying process has led to heart failure?
3. what is precipitating event for this presentation?

• clinical history – symptoms of heart failure, symptoms of prior CVD
• examination – rate, rhythm, BP, JVP, apex beat, murmurs, lungs, liver, legs
• investigations
  • FBC, EUC, LFT, TFT
  • ECG & CXR
  • plasma BNP
  • echocardiography
• ± others
  • nuclear cardiac imaging
  • cardiac catheterisation
  • coronary angiography
  • investigations relevant to specific forms of cardiomyopathy

Congestive heart failure – interpreting ECG findings:

• normal ECG ⇒ question diagnosis
• pathological Q-waves ⇒ prior MI and IHD
• Bundle Branch Block ⇒ suggests extensive myocardial damage
• Left ventricular hypertrophy (suggestive of cause: i.e. outflow obstruction)
  • hypertension
  • aortic stenosis
  • hypertrophic cardiomyopathy
• Low QRS voltages (suggestive of cause: i.e. restrictive)
  • infiltrative cardiomyopathy
    • amyloidosis
    • pericardial disease
• atrial fibrillation (seen in 1/3 heart failure patients) ⇒ precipitating cause of acute deterioration
• bradyarrhythmias ⇒ heart block as precipitating cause of acute deterioration

Causes:

Systemic hypertension and ischaemic heart disease together account for almost 80-90% of heart failure and 10-20% due to valvular heart disease. (One-third of patients will also have diabetes or chronic atrial fibrillation implicated.)

• systemic hypertension – especially diastolic
• ischaemic heart disease – especially systolic
• diabetes mellitus
• chronic atrial fibrillation
• valvular heart disease
  • aortic stenosis
• cardiomyopathies
  • dilated
  • restrictive
  • hypertrophic
• other
  • metabolic / endocrine
  • drugs
    • ethanol
    • cocaine
    • anthracyclics
  • pericardial disease
  • congenital heart disease

Heart failure – when to refer?

Always.

• identify that small percentage of patients who will benefit from cardiac surgery (coronary grafting or valvular surgery)
• identify those who will benefit from implantation of biventricular pacemaker / implantable defibrillator
• advising GP on optimal drug treatment
• coordinating multidisciplinary management plan with GP and allied health personnel
  • GP, nurse, specialist, pharmacist, physiotherapist, occupational therapist, dietitian, social worker

Heart Failure – Prognosis:

New York Heart Association grades with 1-year mortality

1. Asymptomatic left ventricular dysfunction – 5%
2. Dyspnoea / fatigue on moderate exertion – 10%
3. dyspnoea / fatigue with normal daily activity – 10-20%
4. Dyspnoea / fatigue at rest – 40-50%

These are older figures and the rates have improved slightly recently. Still, the rates are a sombre statistic.

Mortality at 20 months for NYHA class II was 7.0% for HF‐ACTION, 8.1% for TOPCAT, 14.3% for DIG, and 15.0% for GUIDE‐IT. Mortality for NYHA class III was 12.1% for TOPCAT, 13.6% for HF‐ACTION, 24.3% for DIG, and 26.5% for GUIDE‐IT. (Caraballo et al, 2019)

Using NYHA class I as reference, hazard ratios (Arnold et al, 2013) are:

• class II: 1.78 (CI 1.54 – 2.06)
• class III: 3.51 (CI 3.05 – 4.04)
• class IV: 5.74 (CI 4.81 – 6.85)