EUROSCORE II

EUROSCORE II

• EuroSCORE II, an update of logistic EuroSCORE model, is derived from a more current data set.
• Incorporates evidence based improvements and aims to reflect better current cardiac surgical practice.
• It is a new set of risk factors including the original EuroSCORE variables modifed to improve its accuracy and renew the EuroSCORE to optimize its usefulness in contemporary cardiac surgical practice.
• Is based on data of more than 22381 patients undergoing cardiac surgery during the months May to July 2010 and were collected in 154 hospitals in 43 countries. New risk coefficients were calculated on these new data.
• Operative mortality is widely used as an indicator of the quality of cardiac surgery. To make an accurate comparison between different institutions or surgeons’ mortality data must be adjusted to the risk profiles of the patients.Euroscore II predicts hospital mortality after major cardiac surgery and is well calibrated with an excellent discriminative capacity.
• Analysis of high quality national and international database is utilized to update risk stratification.
• It has been largely demonstrated in patients undergoing on pump and off pump CABG and in valve surgeries.
• The predictive value of these models is useful in deciding indications for surgery, estimating the need for resources, obtaining proper informed consent, and monitoring the quality of surgeons and institutions.
• EuroSCORE II,according to some studies confirmed very good discriminatory capacity, good calibration ability (O/E mortality ratio), and good capability to predict prolonged ICU and postoperative stays in a contemporary patient cohort undergoing cardiac surgery.

The logistic EuroSCORE identifed the following areas for potential improvement:

 • Creatinine clearance (CC) is a better predictor than absolute serum creatinine.

 • Hepatic function is not represented.

 • Defining unstable angina by the use of intravenous nitrates is out of date.

• Some continuous variables are treated as dichotomous (number of previous heart operations, serum creatinine, pulmonary artery pressure).

• The model is not suffciently sensitive to the ‘weight’ of the intervention.

Hence, the following modifications were done -

• In the patient-related variables, insulin-dependent diabetes was added. Neurological dysfunction was changed into reduced mobility due to neurological or to musculoskeletal dysfunction.
• Renal insufficiency defined in the initial EuroSCORE as a serum creatinine of 200 μmol/l preoperatively was replaced by creatinine clearance and subdivided into two groups at increased risk, and patients preoperatively on dialysis are also identified as a separate risk group.
• In the cardiac-related variables, unstable angina, defined as rest angina requiring intravenous nitrates until arrival in the anaesthetic room, was replaced by NYHA class II, III, IV and angina CCS class 4.
• The variables left ventricular dysfunction and pulmonary hypertension were divided into new categories.
• Concerning the operation-related variables, emergency surgery, defined as carried out on referral before the beginning of the next working day, in the initial EuroSCORE has been redefined in three different risk groups namely urgent, emergency and salvage.
• Also the variable ‘other than isolated CABG’ is divided into several risk categories.
• Of note: postinfarct septal rupture as mentioned in the initial EuroSCORE is not identified in the EuroSCORE II; this is due to the low number of patients with a postinfarct septal rupture included in the database.

The risk factors are -

Patient-related factors –

Age and sex

Height and weight

Pulmonary disease

Diabetes status

Extracardiac arteriopathy

Neurological or musculoskeletal dysfunction

On dialysis Last serum creatinine

Brain-natriuretic peptide

Serum albumin

 Cardiac-related factors –

Symptomatic status

NYHA CCS

LV function

Recency and size of last myocardial infarct

Systolic PA pressure

Active endocarditis

Previous cardiac surgery

Operation-related factors -

Urgency -

Elective

Urgent

Emergency

Salvage

Type of procedure(s) performed in detail

Times of Bypass

Cross-clamp

Deep hypothermic arrest

Selective cerebral perfusion

Defnitions and explanations of the risk factors -

NYHA class - NYHA classi?cation for dyspnoea:

• I: no symptoms on moderate exertion; • II: symptoms on moderate exertion; • III: symptoms on light exertion; • IV: symptoms at rest.

CCS class 4 - CCS class 4 angina (inability to perform any activity without angina or angina at rest).

IDDM - Insulin dependent diabetes mellitus

Extracardiac arteriopathy - One or more of the following: • claudication; • carotid occlusion or >50% stenosis • amputation for arterial disease; • previous or planned intervention on the abdominal aorta, limb arteries or carotids.

Poor mobility –Severe impairment of mobility secondary to musculoskeletal or neurological dysfunction.

Previous cardiac surgery - One or more previous major cardiac operation involving opening the pericardium.

Renal dysfunction  - This is assessed by CC as estimated using the Cockcroft–Gault formula and falls into three categories:

• CC 51–85

 • on dialysis (regardless of serum creatinine)

 • CC≤50.

Active endocarditis –

Patients still on antibiotic treatment for endocarditis at the time of surgery.

Critical preoperative state - Any one or more of the following occurring preoperatively in the same hospital admission as the operation: • ventricular tachycardia or ?brillation or aborted sudden death; • cardiac massage; • ventilation before arrival in the anaesthetic room; • inotropes; • intra-aortic balloon counterpulsation or ventricular-assist device before arrival in the anaesthetic room; • acute renal failure (anuria or oliguria <10 ml/h).

LV function or LVEF –

 • good (LVEF 51% or more);

• moderate (LVEF 31–50%);

• poor (LVEF 21–30%);

• very poor (LVEF 20% or less).

Urgency of procedure -

 • Elective: routine admission for operation; • Urgent: patients not electively admitted for operation but who require surgery on the current admission for medical reasons and cannot be discharged without a definitive procedure; • Emergency: operation before the beginning of the next working day after decision to operate;

Salvage: patients requiring cardiopulmonary resuscitation (external cardiac massage) en route to the operating theatre or before induction of anaesthesia. This does not include cardiopulmonary resuscitation after induction of anaesthesia.

Recent MI - Within 90 days before operation.

Weight of procedure - This measures the extent or size of the intervention. The baseline is isolated CABG: operations ‘heavier’ than the baseline are in three categories:

• Isolated non-CABG major procedure (e.g. single valve procedure, replacement of ascending aorta, correction of septal defect, etc.);

• Two major procedures (e.g. CABG+AVR), or CABG+mitral valve repair (MVR), or AVR+replacement of ascending aorta, or CABG+maze procedure, or AVR+MVR, etc.);

• Three major procedures or more (e.g. AVR+MVR+CABG, or MVR+CABG+tricuspid annuloplasty, etc.), or aortic root replacement when it includes AVR or repair+coronary reimplantation+root and ascending replacement).

Only major cardiac procedures count towards to the total.

Examples of procedures which do not qualify are: sternotomy, closure of sternum, myocardial biopsy, insertion of intra-aortic balloon, pacing wires, closure of aortotomy, closure of atriotomy; removal of atrial appendage, coronary endarterectomy as part of CABG, etc.

Brain natriuretic peptide BNP is an independent predictor of cardiac surgical outcome but only 7.3% data was available.Hence, due to  poor availability of data it is not included in the model although it may be useful in the future.

References –

• EuroSCORE II Samer A.M.Nashef.European Journal of Cardio-Thoracic Surgery 41 (2012) 734–745
• Validation of the European System for Cardiac Operative Risk Evaluation-II model in an urban Indian population and comparison with three other risk scoring systems.Biju Sivam Pillai Annals of Cardiac Anaesthesia|Jul-Sep-2015 | Vol 18 Issue3
• Consecutive Observational Study to Validate EuroSCORE II Performances on a Single-Center, Contemporary Cardiac Surgical Cohort. Dusko Nezic JCVA April 2016,Volume 30, Issue 2, Pages 345–351
• The application of European system for cardiac operative risk evaluation II (EuroSCORE II) and Society of Thoracic Surgeons (STS) risk-score for risk stratification in Indian patients undergoing cardiac surgery.Deepak Borde, Annals of Cardiac Anaesthesia Vol. 16:3 Jul-Sep-2013

- by Dr Amarja