Heart failure in 2018

Much has changed since 1982 (my graduation) when heart failure had a 40% 5-year survival, worse than most cancers. In the early 1980s ACE inhibitors were shown to improve heart failure survival. Likewise, beta blockers in the 1990s and spironolactone in 1999. Ideally any patient with CCF should be on this heart failure threesome. Potassium should be monitored, particularly once spironolactone is prescribed, and be very cautious if the baseline K is >4.8.

By Dr Andrew Klimaitis, Physician, Duncraig

Heart failure patients can be divided into two groups echocardiographically, with two thirds have reduced ejection fraction (systolic dysfunction) and ejection fraction (EF) is normal in the rest (diastolic dysfunction).

Nothing prolongs survival in diastolic failure. Diastolic dysfunction is often associated with LV hypertrophy, so hypertension should be aggressively treated and sleep apnoea looked for (and considered in systolic heart failure patients).

The data here concerns systolic failure.

Loop diuretics provide symptomatic relief without improving survival. In symptomatic low blood pressure stop their nitrate (especially if no angina), calcium channel blocker and thiazide, and try cutting back the frusemide (assuming they are euvolaemic) before reducing their ACE inhibitor or beta-blocker.

Natriuretic peptides (NPs) promote vasodilation and natriuresis. B(brain)NP is released by ventricular wall stress, A(atrial)NP by atrial wall stretch. The enzyme neprilysin breaks them and angiotensin II (AT-2) down; inhibition of this enzyme increases NP levels (good) but also AT-2 (bad); increased AT-2 causes vasoconstriction and fluid retention, counteracting any benefit from increased NP levels.

EntrestoTM combines an neprolysin inhibitor (sacubitril) with an angiotensin II blocker (valsartan) to counteract the increase in AT-2. The 2016 PARADIGM study compared EntrestoTM to the ACE inhibitor enalapril in NYHC stage 2-4 patients with ejection fractions under 40%. CV death and heart failure hospitalisation were reduced by 20%, and all cause mortality by 16% for those switched to EntrestoTM. When changing from an ACE inhibitor to EntrestoTM, ensure a 36 hour washout period and do not use in anyone with a history of angioedema.

Serum BNP (not covered by Medicare) can be a useful test in dyspnoeic patients. If normal (<100) they probably don’t have heart failure. If 400 they probably do. Between these values you need to rely on clinical acumen.

Implantable defibrillators are indicated in ejection fraction below 35%. Cardiac resynchronisation therapy (biventricular pacing) can be used in patients with wide QRS complexes (at least 120 ms) and significant symptoms (NYHC 3). Studies show atrial fibrillation patients with LVEF under 35% have reduced combined mortality and heart failure admission rates with AF ablation.

Digoxin does not reduce mortality but can result in less heart failure hospitalisation and improved symptoms.

Ivabradine improves a composite end-point of worsening heart failure and cardiovascular death in patients with LVEF <35% and sinus rhythm who had a heart rate of >70 despite maximal tolerated beta blocker therapy.

Author competing interests: nil relevant. Questions? Contact the editor.

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