The "ABCDE" Score as a Five-step Vascular Ultrasound Examination in Heart Failure

Background: Heart failure (HF) is a clinical syndrome characterized by typical symptoms and signs caused by structural and/or functional cardiac abnormalities, resulting in a reduced cardiac output and/or elevated intra-cardiac pressures at rest or during stress. The prevalence of HF is approximately 1-2% of the adult population in developed countries, rising to ≥10% among people >70 years of age and it is the leading cause of hospitalization.

The aim of this study is the creation of a five-step ultrasound examination to evaluate and monitor HF patients during hospitalization and short follow-up.

The "ABCDE" score includes the evaluations of A, the Ankle-brachial index, ABI, B, the B-lines, C, the Carotid intima media thickness, CIMT, D, the Diameter of the abdominal aorta and of the inferior cave vein and E, the echocardiographic assessment of the ejection fraction.

This score represents an integrative ultrasound approach in the Internal Medicine/Geriatric departments:

A (ANKLE-BRACHIAL INDEX) Normal (<90): points 0 Mild obstruction (0.71-0.90): points 1 Moderate obstruction (0.41-0.70): points 2 Severe obstruction 0-0.40): points 3 B (B-LINES) Number of B-lines for each space ≤5: points 0 Number of B-lines for each space ≥ 6 to ≤ 9: points 1 Number of B-lines for each space ≥ 10 ("Full white screen"): points 3 C (IMT OR CAROTID PLAQUE) Normal: points 0 Altered IMT (>0.9 mm): points 1 Plaque presence (no significant stenosis, <70% following NASCET classification): points 2 Plaque presence (significant stenosis, >70% following NASCET classification): points 3 D (DIAMETER OF AORTA AND VCI COLLAPSIBILITY INDEX) Aorta Normal (<25 mm): points 0 Normal diameter but with calcifications: points 1 Ectasia (25-30 mm): points 2 Aneurysm (>30mm): points 3 Cave Vein Normal collapsibility index (40-75%): points 0 Altered collapsibility index (if <40% or >75%): points 1 E (EF ACCORDING TO ESC GUIDELINES 2016) HFpEF (LVEF ≥50%): points 0 HFmrEF (LVEF in the range of 40-49%):points 1 HFrEF (LVEF<40%): points 2

Methods: The study population is composed of a consecutive sample of n' HF patients admitted from the Emergency to the Internal Medicine (IM)/Geriatric Departments of n' University Hospitals from Italy or other foreign countries.

HF criteria will be established according to the recent ESC 2016 guidelines. In particular, patients will be classified in three different classes: with normal left ventricular ejection fraction (LVEF) ( ≥50%, HF with preserved EF, HFpEF), with reduced LVEF ( <40%, HF with reduced EF, HfrEF) and with an LVEF in the range of 40-49% (HfmrEF).

Moreover, patients are classified according to New York Heart Association (NYHA) classes at admission, at discharge and during follow-up.

Exclusion criteria are: concomitant acute coronary syndrome, pneumonia, chronic obstructive pulmonary disease, lung cancer or metastases, lung fibrosis, previous pneumonectomy or lobectomy, breast prothesis, obesity, also in order to to avoid the detection of B-lines other than due to HF.

Patients undergo: A (calculated for each leg at admission), B-lines counting (calculated at admission, during hospital stay and at discharge with lung ultrasound, approach 72 spaces), C (at admission), D (at admission for the aorta and at admission, during hospital stay and at discharge for the inferior cave vein) and E (at admission and discharge).

Venous blood samples are collected from each subject for routine examination on admission: hemoglobin and white blood cells count, serum creatinine, sodium, potassium, urea, total cholesterol, high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol, triglycerides, glucose, C-reactive protein (CRP) (measured with standard methods).

Moreover, NT-proBNP dosage is obtained on admission and on discharge. Urine output and diuretic dosage will be carefully reported daily. Arterial blood samples is collected on admission and on discharge to test the partial pressure of oxygen (PaO2) as indicator of HF severity (on admission) and recovery (on discharge).

An electrocardiogram recording and X-chest ray examination are obtained on admission.

MEDICAL STAFF INVOLVED IN THE ULTRASOUND EXAMINATIONS A is performed by the IM/Geriatric specialists or certification board attending students.

B,C and D examinations are performed by Medical Doctors (Radiologists or IM/Geriatric specialists certified by the Società Italiana di Ultrasonologia in Medicina e Biologia (SIUMB).

Trans-thoracic echocardiography with estimation of E is performed by Cardiologists or IM specialists certified by the Società Italiana di Ecografia Cardiovascolare, SIEC.

• ENDPOINTS:

1. RELATED TO THE BEDSIDE EVALUATION OF HF RECOVERY:

• test if B,D (for cave vein) and E assessment can precisely guide and tailoring the therapy (diuretics) during hospitalization and recovery from HF;
• test if B,D (for cave vein) and E assessment can speed up the discharge time (if compared to patients without ultrasound assessment);
• improve the use of bedside ultrasound in IM and Geriatric department. 2) RELATED TO THE GLOBAL CARDIOVASCULAR ASSESSMENT OF THE HF PATIENT:
• test if A, C and D (for aorta) assessment can better classify the global cardiovascular risk for the HF patient.

The severity of the score will be related with:

• number of hospitalization days
• number of "events" during follow up (for definition of "events", see follow up section).

FOLLOW-UP Follow-up is performed by contacting patients or their caregivers over the phone 30 and 90 days after the date of discharge. All the successive re-admissions for HF or deaths from any cause are considered as "events".

A potential correlation between the severity of each parameter considered in the "ABCDE" score with the "events" after discharge is tested.