The EuroSCORE, initially published in 1999, was designed as a tool to predict the risk of in-hospital mortality following cardiac surgery. It served as a crucial benchmark in the field, helping clinicians assess patient risk profiles before undergoing surgical procedures. However, significant advancements in preoperative patient management, surgical techniques, and postoperative intensive care have led to a general reduction in the risks associated with cardiac surgery. This progress meant that the original EuroSCORE, over time, started to overestimate the actual risk for contemporary patients, becoming less accurate for modern risk stratification.
Recognizing the need for a more up-to-date and precise risk assessment tool, the EuroSCORE II was developed. This revised scoring system is based on a more recent and relevant patient database, reflecting current clinical practices and patient demographics. EuroSCORE II has demonstrated improved accuracy and tends to mitigate the overestimation of risk that was observed with the original EuroSCORE. Understanding the components of both EuroSCORE systems, particularly EuroSCORE II, is vital for healthcare professionals involved in cardiac surgery. The system relies on a detailed evaluation of various preoperative risk factors, which are clearly defined to ensure consistent and reliable risk calculation.
To properly utilize and interpret the EuroSCORE II, it’s essential to understand the specific definitions and explanations of the risk factors it incorporates. These factors encompass various aspects of a patient’s condition and medical history, providing a comprehensive overview of their risk profile. Below are key definitions and explanations for the risk factors used in EuroSCORE II:
NYHA Classification for Dyspnea (Shortness of Breath): This classification assesses the severity of dyspnea, a common symptom in cardiac patients.
- Class I: Patients experience no symptoms during ordinary physical activity.
- Class II: Patients experience symptoms during moderate exertion.
- Class III: Patients experience symptoms during mild exertion.
- Class IV: Patients experience symptoms even at rest.
CCS Class 4 Angina: This refers to a severe form of angina pectoris (chest pain) as defined by the Canadian Cardiovascular Society (CCS) classification.
- Class 4 Angina: Characterized by the inability to perform any physical activity without angina, or the presence of angina at rest.
Extracardiac Arteriopathy: This risk factor indicates the presence of peripheral artery disease affecting vessels outside the heart. It includes one or more of the following conditions:
- Claudication (leg pain due to poor blood flow during exercise).
- Carotid occlusion or significant stenosis (>50% as per North American Symptomatic Carotid Endarterectomy Trial criteria).
- Amputation due to arterial disease.
- Previous or planned interventions on the abdominal aorta, limb arteries, or carotid arteries.
Poor Mobility: This factor identifies patients with significant mobility impairment due to musculoskeletal or neurological dysfunction.
- Poor Mobility: Severe limitation in mobility caused by problems with muscles, bones, or the nervous system.
Previous Cardiac Surgery: This refers to patients who have undergone prior major cardiac operations requiring opening of the pericardium (the sac around the heart).
- Previous Cardiac Surgery: Having had one or more major heart surgeries in the past that involved opening the protective sac around the heart.
Renal Dysfunction: Kidney function is a critical risk factor. EuroSCORE II assesses renal function using the Cockcroft–Gault formula and categorizes it as follows:
- >85 ml/min: Normal or mildly reduced renal function.
- 51–85 ml/min: Mild to moderate renal dysfunction.
- CC ≤ 50 ml/min: Moderate to severe renal dysfunction.
- On Dialysis: Patients requiring dialysis, regardless of serum creatinine levels, are considered at high risk.
Active Endocarditis: This indicates an ongoing infection of the heart valves or the inner lining of the heart at the time of surgery.
- Active Endocarditis: Patients who are still receiving antibiotic treatment for endocarditis when they undergo surgery.
Critical Preoperative State: This encompasses severe preoperative conditions occurring during the same hospital admission as the surgery, indicating a highly unstable patient. It includes any of the following:
- Ventricular tachycardia or fibrillation, or aborted sudden cardiac death.
- Cardiac massage (chest compressions).
- Need for mechanical ventilation before arrival in the operating room.
- Use of inotropic medications (to strengthen heart contractions).
- Intra-aortic balloon counterpulsation or ventricular-assist device support before arrival in the operating room.
- Acute renal failure (anuria or oliguria – severely reduced or absent urine production).
LV Function or LVEF (Left Ventricular Ejection Fraction): This assesses the pumping function of the left ventricle, the heart’s main pumping chamber.
- Good: LVEF 51% or more (normal or near-normal function).
- Moderate: LVEF 31–50% (mildly to moderately reduced function).
- Poor: LVEF 21–30% (severely reduced function).
- Very Poor: LVEF 20% or less (very severely reduced function).
Urgency of Procedure: The timing of the surgery relative to the patient’s condition is a significant risk factor.
- Elective: Surgery scheduled as a routine admission.
- Urgent: Surgery required during the current admission for medical reasons, but not an emergency.
- Emergency: Surgery needed before the next working day following the decision to operate.
- Salvage: Surgery required in patients needing cardiopulmonary resuscitation (CPR) before anesthesia induction.
Recent MI (Myocardial Infarction): A recent heart attack, occurring within 90 days before surgery, increases surgical risk.
- Recent MI: Heart attack within the 90 days prior to the planned operation.
Weight of Procedure: This factor accounts for the complexity and extent of the surgical intervention, with isolated CABG (Coronary Artery Bypass Grafting) as the baseline. Procedures considered “heavier” are categorized as:
- Isolated non-CABG major procedure: Single valve surgery, ascending aorta replacement, septal defect correction, etc.
- Two major procedures: Combinations like CABG + valve surgery (AVR or MVR), AVR + ascending aorta replacement, CABG + Maze procedure, etc.
- Three major procedures or more: Complex combinations like AVR + MVR + CABG, MVR + CABG + tricuspid annuloplasty, or aortic root replacement including AVR or repair + coronary reimplantation + root and ascending replacement.
It’s important to note that only major cardiac procedures are considered in determining the “weight of procedure.” Minor procedures like sternotomy closure, myocardial biopsy, or insertion of pacing wires are not included in this categorization.
EuroSCORE II provides a refined and contemporary approach to risk stratification in cardiac surgery. By carefully considering these defined risk factors, clinicians can achieve a more accurate prediction of in-hospital mortality, facilitating better informed decision-making and ultimately improving patient outcomes.
