Heart Failure with Reduced Ejection Fraction (HFrEF)
Written by Eileen Gibbons.
What is Heart Failure?
Heart failure (HF) is a clinical syndrome. Common to some of our patient group at South Island Heart, HF is caused by a structural and/or functional abnormality of the heart.
What are signs and symptoms of Heart Failure?
Although patient signs and symptoms are varied, commonly presenting symptoms include dyspnoea (shortness of breath with exertion), Orthopnoea (shortness of breath lying down), Paroxysmal nocturnal dyspnoea (waking at night due to shortness of breath), fatigue and sometimes peripheral oedema. HF is usually validated by objective evidence of pulmonary or systemic congestion and elevated natriuretic peptide levels (BNP).
What is the impact of Heart Failure?
Heart failure has significant impact on patients quality of life, with physical, social and emotional impact. It is the leading cause of hospitalisation, affecting 1-2% of the population, with Maori and Pacific island people presenting at a younger age. Heart failure has a 5 year survival rate (similar to many common cancers) if not well managed. Approximately 30% of heart failure patients die within one year of hospitalisation for heart failure, with risk for cardiovascular mortality progressively increased with recurrent heart failure readmissions. Heart failure is classified according to left ventricular ejection fraction (LVEF), confirmed on echocardiogram. Our patient cohort commonly have an LVEF <40% (Heart failure with reduced ejection fraction – referred to as HfrEF).
What are the best methods of treatment for Heart Failure?
The goals of pharmacotherapy (using pharmaceutical products as medication) are to improve clinical and functional status, quality of life, and to prevent recurrent hospitalisations due to decompensation and to reduce mortality.
Jardiance – an SGLT2 inhibitor is now considered to be standard treatment in the management of HFrEF. Guidelines now recommend SGLT2 inhibitors as one of the four foundational treatments for treatment of HFrEF. Initially considered for management of type 2 diabetes (T2DM), they have now proven to show major benefit for treatment of HfrEF independent of efficacy in treatment of T2DM.
Some of the mechanisms that underlie these benefits:
The sodium glucose co-transporter protein 2 is located in the proximal tubule of the kidneys
It is responsible for 90% of reabsorption of glucose in the glomerular ultrafiltrate
BLOCKADE of the SGLT2 protein – leads to:
Diuresis – losing water in urine
Natriuresis- losing sodium in urine
Increased glycosuria
In reducing reabsorption of sodium, this leads to increased delivery of sodium which via tubuloglomerular feedback causes afferent vasoconstriction
This increases tubuloglomerular feedback which leads to afferent constriction to the glomerular arteriole, reducing high pressure in the glomerular capsule
(Increased tubuloglomerular feedback > leads to afferent constriction)
(Decreased intraglomerular hypertension )
(Decreased hyperfiltration which reduces proteinuria))
In the absence of Diabetes, SGLT2 inhibitors have extra mechanisms beneficial to the heart, including:
Reduced Preload (Interstitial volume)
Reduced Afterload by affecting + improving vascular function
Decreased LV wall stress + decreased LV mass via these benefits
Also, benefits in reduction of major cardiovascular events.
SGLT2 inhibitors also protect the kidneys from further deterioration – reduces kidney disease progression, with a 4 x slower decline in kidney function.
They have small but useful benefits in reducing blood pressure and body weight, in patients with elevated glucose leads to reduced HbA1c, and improves quality of life, symptom frequency and burden.
Heart Failure diagnosis and treatment at South Island Heart:
If patients are being seen at South Island Heart for management of HFrEF, SGLT2 inhibitors will be one of the medications initiated, along with rapid uptitration of other guideline directed medical therapy.
Information courtesy of Boehringer Ingelheim