HISTORY, CURRENT ILLNESS AND PHYSICAL EXAMINATION

History
71-year-old patient, no known allergies. Ex-smoker for 2 years (EA 40 packs/year). Cardiovascular risk factors include high blood pressure, insulin-dependent type 2 diabetes mellitus with good control and dyslipidaemia. Cardiological history includes permanent atrial fibrillation. The last echocardiography in 2016 showed LVEF 52%, mild mitral regurgitation and estimated systolic pulmonary artery pressure (PAPS) of 35 mmHg. Patient in NYHA functional class II, with no previous admissions for heart failure. The main comorbidity was chronic renal failure being monitored by nephrology and with baseline creatinine levels around 1.5-2 mg/dl (estimated glomerular filtration rate [eGFR] of 40 ml/min/1.73 m2), peripheral vascular disease with intermittent claudication and multifactorial anaemia with endoscopic study within normal limits. Usual medication: acenocoumarol, manidipine 10 mg/day, doxazosin 8 mg/day, furosemide 40 mg/day, atorvastatin 40 mg/day, insulin glargine 18U, ferroglycine sulphate 100 mg/d; darbepoetin alfa 1 injection/week.

Present illness
The patient came to the emergency department in February 2020 due to an increase in his baseline dyspnoea of 1 week's evolution to minimal effort accompanied by orthopnoea and oedematisation of the lower limbs together with a subjective decrease in diuresis. Since then, he has had rapid palpitations. As a triggering factor, he presented with a cough with scanty whitish expectoration without fever, of 10 days' evolution, for which his primary care physician had prescribed amoxicillin/clavulanic acid 875/125 mg/8 h for 7 days.

Physical examination
Vital signs: blood pressure (BP) 175/83 mmHg, heart rate (HR) 120 bpm, baseline oxygen saturation 88%. Cardiac auscultation with irregular, tachycardic sounds. Pulmonary auscultation with hypoventilation at the bases and crackles up to midfields, together with isolated rhonchi. Tibiomalleolar oedema with grade 2 fovea.

COMPLEMENTARY TESTS
ECG: atrial fibrillation with mean ventricular response at 120 bpm, QRS 100 ms. ST-segment depression of 1 mm V4-V6, I and aVL. CBC: glucose 138 mg/dl, urea 140 mg/dl, creatinine 1.75 mg/dl, glomerular filtration rate (eGFR) 38.5 ml/min/1.73 m2, sodium (Na+) 147 mmol/l, potassium (K+) 5.2 mmol/l, NT-proBNP > 35,000 pg/ml, CA125 415 U/ml. AP chest X-ray: cardiomegaly. Aortic elongation. Bilateral pleural effusion predominantly on the right. Signs of vascular redistribution and interstitial oedema. Transthoracic echocardiography. Parasternal long-axis plane and apical 4-chamber plane: dilated left ventricle (LVED 60 mm), with moderate hypertrophy and moderate depression of global systolic function (LVEF 37%) secondary to generalised hypokinesia. High filling pressures (E/e' 19). Non-dilated right ventricle with borderline systolic function by longitudinal parameters (TAPSE 18 mm). Severe left atrial dilatation (volume 126 ml). Aortic valve sclerosis. Mitral valve with normal opening sclerosed leaflets and mild central regurgitation. Mild tricuspid insufficiency (TI) with estimated PAPS 45 mmHg. Absence of pericardial effusion. Dilated vena cava (24 mm) with plethora. B lines in both lung fields suggestive of significant pulmonary congestion. Pulsatile renal venous flow (moderate renal congestion). Cardiac magnetic resonance (CMR). Cine sequences: dilated left ventricle with eccentric hypertrophy pattern and moderately depressed systolic function (LVEF 38%). Right ventricle with normal volume and systolic function. Dilated left atrium. Provocation of ischaemia with negative regadenoson. Absence of myocardial necrosis. Intramyocardial fibrosis in the entire basal septum and in the area of intersection of the right ventricle in the medial septum.

CLINICAL EVOLUTION
The patient was admitted for decompensated heart failure in the context of respiratory infection and rapid atrial fibrillation. On admission, impaired renal function and mild hyperkalaemia were observed. Imaging tests showed dilated cardiomyopathy of non-ischaemic origin with moderately depressed LVEF and borderline right function, without significant valvular heart disease.
Intravenous diuretic treatment was administered, with clinical improvement, and the patient was discharged from hospital. Bisoprolol 2.5 mg/day, valsartan 40 mg/day and furosemide was increased to 80 mg/day. Subsequently, the patient made two visits to the emergency department for heart failure, and intravenous diuretics were administered without requiring admission, and the oral diuretic regimen was adjusted. In August the patient was admitted again for decompensation of heart failure and severe hyperkalaemia. Blood tests showed creatinine 2.24 mg/dl, GFR 28.4 ml/min/1.73 m2, Na+ 141 mmol/l, K+ 6.7 mmol/l, NT-proBNP 24.5011 pg/ml, CA125 240 U/ml. After depletive treatment and correction of hyperkalaemia on discharge, chlorthalidone 25 mg every other day and resincalcium were added to his treatment and he was referred to the heart failure unit of our centre. On the first visit, the patient was in NYHA functional class III with significant orthopnoea. Laboratory tests showed creatinine 2.97 (eGFR 20 ml/min/1.73 m2) and K+ 5.7 mmol/l.
Treatment was started with patiromer 16.8 g/day and a subcutaneous furosemide pump was prescribed. At the next visit the patient had a creatinine of 2.74 mg/dl (eGFR 23 ml/min/1.73 m2) and K+ of 4.2 mmol/l. It was then decided to add sacubitril/valsartan 24/26 mg/12h. In November, he was admitted twice more for heart failure due to recurrent bilateral pleural effusion, predominantly on the right, which required several thoracentesis and finally the placement of a permanent pleural drainage.
At the follow-up visit in December, the patient reported improvement in functional class (NYHA II) and orthopnoea, with no signs of congestion. Laboratory tests showed an improvement in renal function (creatinine 2.5 mg/dl, eGFR 25 ml/min/1.73 m2) and K+ 3.6 mmol/l. To date, the patient remains in good functional class, with no new episodes of heart failure decompensation, and pleural drainage has been removed due to the absence of debit. Images 4, 5, 6 and 7 show the evolution of creatinine, potassium and prognostic and congestion biomarkers NT-proBNP and CA125 during the patient's evolution.

DIAGNOSIS
Heart failure with reduced LVEF.
Non-ischaemic dilated cardiomyopathy.
Chronic renal disease.
Cardiorenal syndrome.
Hyperkalaemia.
