Prospective validation of the EuroSCORE II risk model in a single Dutch cardiac surgery centre

Development of an open-source tool for risk assessment in pulmonary endarterectomy

BACKGROUND

Risk prediction tools are routinely utilised in cardiothoracic surgery but have not been developed for pulmonary endarterectomy (PEA). There are no data on whether patients undergoing PEA may benefit from a tailored risk modelling approach. We develop and validate a clinically usable tool to predict PEA 90-day mortality (90DM) with the secondary aim of informing factors that may influence 5-year mortality (5YM) and improvement in patient-reported outcomes (PROs) using common clinical assessment parameters. Derived model predictions were compared to those of the currently most widely implemented cardiothoracic surgery risk tool, EuroSCORE II.

METHODS

Consecutive patients undergoing PEA for chronic thromboembolic pulmonary hypertension (CTEPH) between 2007 and 2018 (n=1334) were included in a discovery dataset. Outcome predictors included an intentionally broad array of variables, incorporating demographic, functional and physiological measures. Three statistical models (linear regression, penalised linear regression and random forest) were considered per outcome, each calibrated, fitted and assessed using cross-validation, ensuring internal consistency. The best predictive models were incorporated into an open-source PEA risk tool and validated using a separate prospective PEA cohort from 2019 to 2021 (n=443) at the same institution.

RESULTS

Random forest models had the greatest predictive accuracy for all three outcomes. Novel risk models had acceptable discriminatory ability for outcome 90DM (area under the receiver operator characteristic curve (AUROC) 0.82), outperforming that of EuroSCORE II (AUROC 0.65). CTEPH-related factors were important for outcome 90DM, but outcome 5YM was driven by non-CTEPH factors, dominated by generic cardiovascular risk. We were unable to accurately predict a positive improvement in PRO status (AUROC 0.47).

CONCLUSIONS

Operative mortality from PEA can be predicted pre-operatively to a potentially clinically useful degree. Our validated models enable individualised risk stratification at clinician point of care to better inform shared decision making.

Performance of EuroSCORE II in Octogenarians Undergoing Coronary Artery Surgery (from the KROK Registry)

Background: Octogenarians constitute the fastest-growing segment within contemporary cardiac surgery, yet precise risk assessment in this age group remains challenging. Aims: This study aimed to evaluate EuroSCORE II reliability in octogenarians undergoing isolated coronary surgery and to create an adjustment formula if necessary. Patients and Methods: All octogenarians who had isolated coronary surgery in Poland from January 2012 to December 2023, recorded in the Polish National Registry of Cardiac Surgical Procedures (KROK registry), were retrospectively assessed. EuroSCORE II's reliability was measured using the ROC curve area and observed-to-predicted mortality ratio, differentiating on-pump and off-pump cases. A nomogram was developed to enhance predictive accuracy. Results: Among 5771 octogenarians, 2729 (47.3%) underwent on-pump and 3042 (52.7%) underwent off-pump surgery. EuroSCORE II demonstrated reliability in off-pump patients (AUC:0.72, O/E ratio:0.98) but underestimated mortality for on-pump cases (AUC:0.73, O/E ratio:1.62). The lowest predicted mortality group (0.50-1.82%) showed the greatest discrepancies. Calibration was improved by adding a coefficient and creating a nomogram. Conclusions: EuroSCORE II was dependable in predicting outcomes for Polish octogenarians undergoing isolated coronary surgery. Observed mortality following on-pump surgeries was higher than expected, which was corrected by adding a coefficient to the initial EuroSCORE II calculation.

Validation of EuroSCORE II Scoring System on Isolated CABG Patient in Indonesia

BACKGROUND

Coronary Artery Bypass Graft (CABG) is one solution to overcome cardiovascular problems. EuroSCORE II is a scoring system to predict mortality risk in patients undergoing cardiac surgery including CABG. Unfortunately, there's still much debate about the benefits of EuroSCORE II in Asia, including Indonesia. This study aims to validates EuroSCORE II in predicting the outcomes in patients underwent CABG without any other procedure.

RESULTS

A total of 2628 patients were included. The mean age was 59 years, mostly male (84.97%; n = 2233). Most patients underwent elective surgery (93.07%; n = 2446) and only 1.67% (n = 44) of the patients has high EuroSCORE category. Death was found in 4.22% (n-111) patients. EuroSCORE II had fair discriminant power (AUC 0.72), but a lower mortality predicted value for each group.

CONCLUSION

The parameters in EuroSCORE II are related with mortality in isolated CABG patients, but they cannot be used as mortality predictors in Indonesia.

Dynamics in cardiac surgery: trends in population characteristics and the performance of the EuroSCORE II over time

OBJECTIVES

The aim of this study was to investigate the performance of the EuroSCORE II over time and dynamics in values of predictors included in the model.

METHODS

A cohort study was performed using data from the Netherlands Heart Registration. All cardiothoracic surgical procedures performed between 1 January 2013 and 31 December 2019 were included for analysis. Performance of the EuroSCORE II was assessed across 3-month intervals in terms of calibration and discrimination. For subgroups of major surgical procedures, performance of the EuroSCORE II was assessed across 12-month time intervals. Changes in values of individual EuroSCORE II predictors over time were assessed graphically.

RESULTS

A total of 103 404 cardiothoracic surgical procedures were included. Observed mortality risk ranged between 1.9% [95% confidence interval (CI) 1.6-2.4] and 3.6% (95% CI 2.6-4.4) across 3-month intervals, while the mean predicted mortality risk ranged between 3.4% (95% CI 3.3-3.6) and 4.2% (95% CI 3.9-4.6). The corresponding observed:expected ratios ranged from 0.50 (95% CI 0.46-0.61) to 0.95 (95% CI 0.74-1.16). Discriminative performance in terms of the c-statistic ranged between 0.82 (95% CI 0.78-0.89) and 0.89 (95% CI 0.87-0.93). The EuroSCORE II consistently overestimated mortality compared to observed mortality. This finding was consistent across all major cardiothoracic surgical procedures. Distributions of values of individual predictors varied broadly across predictors over time. Most notable trends were a decrease in elective surgery from 75% to 54% and a rise in patients with no or New York Heart Association I class heart failure from 27% to 33%.

CONCLUSIONS

The EuroSCORE II shows good discriminative performance, but consistently overestimates mortality risks of all types of major cardiothoracic surgical procedures in the Netherlands.

The performance of EuroSCORE II in CABG patients in relation to sex, age, and surgical risk: a nationwide study in 14,118 patients

BACKGROUND

To determine the discriminative accuracy and calibration of EuroSCORE II in relation to age, sex, and surgical risk in a large nationwide coronary artery bypass grafting (CABG) cohort.

METHODS

All 14,118 patients undergoing isolated CABG in Sweden during 2012-2017 were included. Individual patient data were taken from the SWEDEHEART registry. Patients were divided by age (< 60, 60-69, 70-79, ≥ 80 years), sex, and surgical risk (low: EuroSCORE < 4%, intermediate: 4-8%, high: > 8%). Discriminative accuracy was determined by the area under the receiver operating characteristic curve (AUC) and calibration by the observed/estimated (O/E) mortality ratio at 30 days.

RESULTS

AUC and O/E ratio were 0.82 (95% CI 0.79-0.85) and 0.58 (0.50-0.66) overall, 0.82 (0.79-0.86) and 0.57 (0.48-0.66) in men, and 0.79 (0.73-0.85) and 0.60 (0.47-0.75) in women. Regarding age, discriminative accuracy was highest in patients aged 60-69 years (AUC: 0.86 [0.80-0.93]) but was satisfactory in all groups (AUC: 0.74-0.80). O/E ratio varied from 0.26 for patients > 60 years to 0.90 for patients > 80 years. Regarding surgical risk, AUC and O/E ratio were 0.63 (0.44-0.83) and 0.18 (0.09-0.30) in low-risk patients, 0.60 (0.55-0.66) and 0.57 (0.46-0.68) in intermediate-risk patients, and 0.78 (0.73-0.83) and 0.78 (0.64-0.92) in high-risk patients.

CONCLUSIONS

EuroSCORE II had good discriminative accuracy independently of sex and age, but markedly overestimated mortality risk, especially in younger patients. Accuracy and calibration were better in high-risk patients than in low-risk and intermediate-risk patients.

The ability of the logistic EuroSCORE to predict long-term outcomes after coronary artery bypass graft surgery

OBJECTIVES

The European System for Cardiac Operative Risk Evaluation (EuroSCORE) predicts in-hospital mortality for patients undergoing cardiac surgery. Many variables associated with increased surgical mortality persist postoperatively. The aim of this study was to investigate the predictive value of the logistic EuroSCORE to long-term survival after coronary artery bypass surgery.

METHODS

Data were collected retrospectively for all patients undergoing coronary artery bypass graft (CABG) at a single center between January 1, 2009 and December 31, 2009. Data submitted to NICOR were used for EuroSCORE and in-hospital outcomes; longer-term, all-cause mortality from NHS digital Personal Demographic Service. Low (<3), intermediate (3-6), and high-risk (>6) logistic EuroSCORE groups were identified and analyzed using the appropriate statistical methodology, with p values less than .05 being taken as significant.

RESULTS

Six hundred and sixty-three patients underwent isolated CABG procedures during the study. The 1-, 3-, 5-, and 10-year survival rates were 97.6%, 94.3%, 89.3%, and 73.5%, respectively. Comparing survival outcomes between low-, intermediate-, and high-risk groups showed that the logistic EuroSCORE was able to predict long-term outcomes (p < .05). In addition, poor left ventricular ejection fraction, serum creatinine above 200 ml, chronic pulmonary disease, extracardiac arteriopathy, and pulmonary hypertension were identified as independent predictors of long-term mortality.

CONCLUSIONS

Our study demonstrates the logistic EuroSCORE predicted long-term outcomes following CABG surgery. This finding can inform patients of the long-term risks of CABG surgery and guide MDT decision-making.

Long-Term Outcomes after Aortic Valve and Root Replacement in a Very High-Risk Population

Background: Aortic valve and root replacement (AVRR) is a standardised procedure to treat patients with aortic valve and root disease. In centres with a well-established aortic valve and root repair program (valve repairs and Ross operations), only patients with very complex conditions receive AVRR; this procedure uses a mechanical or biological composite valve graft (modified Bentall-de Bono procedure). The aim of the study was to evaluate the short- and long-term results after AVRR in a high-risk population with complex pathologies. Methods: Between 2005 and 2018, a total of 273 consecutive patients (mean age 64 ± 12.8 years; 23% female) received AVRR. The indication for surgery was an acute type A aortic dissection in 18%, infective endocarditis in 36% and other pathologies in 46% patients; 39% were redo procedures. The median EuroSCORE II was 11.65% (range 1.48-95.63%). Concomitant surgery was required in 157 patients (58%). Results: The follow-up extended to 5.2 years (range 0.1-15 years) and it was complete in 96% of the patients. The 30-day mortality was 17%. The overall estimated survival at 5 and 10 years was 65% ± 3% and 49% ± 4%, respectively. Univariate and multivariate logistic regression analyses revealed the following risk factors for survival: perioperative neurological dysfunction (OR 5.45), peripheral artery disease (OR 4.4) and re-exploration for bleeding (OR 3.37). Conclusions: AVRR can be performed with acceptable short- and long-term results in a sick patient population. The Bentall-De Bono procedure may be determined to be suitable for only elderly or high-risk patients. Any other patients should receive an AV repair or the Ross procedure in well-established centres.

Systematic review and meta-analysis of mortality risk prediction models in adult cardiac surgery

OBJECTIVES

The most used mortality risk prediction models in cardiac surgery are the European System for Cardiac Operative Risk Evaluation (ES) and Society of Thoracic Surgeons (STS) score. There is no agreement on which score should be considered more accurate nor which score should be utilized in each population subgroup. We sought to provide a thorough quantitative assessment of these 2 models.

METHODS

We performed a systematic literature review and captured information on discrimination, as quantified by the area under the receiver operator curve (AUC), and calibration, as quantified by the ratio of observed-to-expected mortality (O:E). We performed random effects meta-analysis of the performance of the individual models as well as pairwise comparisons and subgroup analysis by procedure type, time and continent.

RESULTS

The ES2 {AUC 0.783 [95% confidence interval (CI) 0.765-0.800]; O:E 1.102 (95% CI 0.943-1.289)} and STS [AUC 0.757 (95% CI 0.727-0.785); O:E 1.111 (95% CI 0.853-1.447)] showed good overall discrimination and calibration. There was no significant difference in the discrimination of the 2 models (difference in AUC -0.016; 95% CI -0.034 to -0.002; P = 0.09). However, the calibration of ES2 showed significant geographical variations (P < 0.001) and a trend towards miscalibration with time (P=0.057). This was not seen with STS.

CONCLUSIONS

ES2 and STS are reliable predictors of short-term mortality following adult cardiac surgery in the populations from which they were derived. STS may have broader applications when comparing outcomes across continents as compared to ES2.

REGISTRATION

Prospero (https://www.crd.york.ac.uk/PROSPERO/) CRD42020220983.

Scoring Systems for Risk Stratification in Patients Undergoing Cardiac Surgery

Cardiac surgery is associated with significant mortality rates. Careful selection of surgical candidates is, therefore, vital to optimize morbidity and mortality outcomes. Risk scores can be used to inform this decision-making process. The European System for Cardiac Operative Risk Evaluation Score and the Society of Thoracic Surgeons score are among the most commonly used risk scores. There are many other scoring systems in existence; however, no perfect scoring system exists, therefore, additional research is needed as clinicians strive toward a more idealized risk stratification model. The purpose of this review is to discuss the advantages and limitations of some of the most commonly used risk stratification systems and use this to determine what an ideal scoring system might look like. This includes not only the generalizability of available scores but also their ease of use and predictive power.

Failure to achieve a satisfactory cardiac outcome after isolated coronary surgery in low-risk patients

OBJECTIVES

This study aims to investigate the incidence and determinants of major early adverse events in low-risk patients undergoing isolated coronary artery bypass grafting (CABG).

METHODS

The multicentre E-CABG registry included 7352 consecutive patients who underwent isolated CABG from January 2015 to December 2016. Patients with an European System for Cardiac Operative Risk Evaluation (EuroSCORE) II of <2% and without any major comorbidity were the subjects of the present analysis.

RESULTS

Out of 2397 low-risk patients, 11 (0.46%) died during the index hospitalization or within 30 days from surgery. Five deaths were cardiac related, 4 of which were secondary to technical failures. We estimated that 8 out of 11 deaths were potentially preventable. Logistic regression model identified porcelain aorta [odds ratio (OR) 34.3, 95% confidence interval (CI) 1.3-346.3] and E-CABG bleeding grades 2-3 (OR 30.2, 95% CI 8.3-112.9) as independent predictors of hospital death.

CONCLUSIONS

Mortality and major complications, although infrequently, do occur even in low-risk patients undergoing CABG. Identification of modifiable causes of postoperative adverse events may be useful to develop preventative strategies to improve the quality of care of patients undergoing cardiac surgery.

CLINICAL TRIAL REGISTRATION

NCT02319083 (https://clinicaltrials.gov/ct2/show/NCT02319083).

Predictive ability of EuroSCORE II integrating cardiactroponin T in patients undergoing OPCABG

Background

Preoperative risk evaluation systems are significant and important to the allocation of medical resources and the communication between doctors and patients. The European System for Cardiac Operative Risk Evaluation II (EuroSCORE II) is widely used in clinical practice. Cardiac troponin T (cTnT) can specifically and accurately reflect myocardial injury. Whether EuroSCORE II can improve the predictive power after integrating with cTnT is still unclear. This study was a retrospective single center study designed to assess the predictive ability of EuroSCORE II integrated with cTnT for patients undergoing isolated off-pump coronary artery bypass grafting (OPCABG).

Methods

This retrospective and observational cohort study included 1887 patients who underwent first isolated OPCABG. cTnT was detected within 48 h before operation in each patient. According to myocardial injury, patients were divided by cTnT into 4 stages. A new risk evaluation system was created through logistic regression with EuroSCORE II and myocardial injury classification as covariates. Then the two risk evaluation systems were comparatively assessed by regression analysis, receiver operator characteristic curves, net reclassification index, Bland–Altman plots and decision curve analysis.

Results

There were 43 in-hospital deaths, with a mortality of 2.30% (43/1887). The logistic regression analysis showed that preoperative myocardial injury classification was a significant risk factor for in-hospital mortality in both total cohort (OR 1.491, 95%CI 1.049–2.119) and subsets (OR 1.761, 95%CI 1.102–2.814). The new risk evaluation system has higher calibration and discrimination power than EuroSCORE II, both for overall cohort and subsets. Especially, the new system has obvious advantages in discrimination power in the subset of acute myocardial infarction (AUC 0.813 vs. 0.772, 0.906 vs. 0.841, and 0.715 vs. 0.646, respectively).

Conclusions

Both myocardial injury classification and EuroSCORE II are independent risk factors of in-hospital mortality in OPCABG patients. The new risk evaluation system has higher predictive ability than EuroSCORE II, especially in patients with a recent history of AMI.

Effects of Preoperative Risk Stratification on Direct In-hospital Costs for Chinese Patients with Coronary Artery Bypass Graft: A Single Center Analysis

The purpose of this study was to analyze the components of inpatient costs for coronary artery bypass graft (CABG) according to preoperative risk stratification and to provide evidence for improvement of diagnosis-related groups (DRGs) payment. All patients (n=458) receiving an isolated CABG between January 2014 and December 2016 in a tertiary referral center, in southwest China, were analyzed. Hospital mortality was predicted by the EuroSCORE II for each patient. The patients were subdivided into two groups according to the observed mortality (1.97%, 9/458): a high-risk group (group H, predicted mortality ≥1.97%) and a low-risk group (group L, predicted mortality <1.97%). Clinical outcomes, resource use, in-hospital direct costs, and reimbursement expenses were compared between the two groups. Significant differences existed between group L and group H in postoperative mortality (0.4% vs. 3.4%; P=0.02), postoperative complications (10.6% vs. 45.7%; P<0.001), postoperative length of hospital stay (17.5±4.9 days vs. 18.8±6.5 days, P=0.01), in-hospital costs ($20 256±3096 vs. $23 334±6332; P<0.001), and reimbursement expenses ($7775±2627 vs. $9639±3917; P<0.001). In general, a higher EuroSCORE II was significantly associated with a worse clinical outcome and increased costs. The CABG cost data provide evidence for improvement of DRGs payment.

Perioperative risk assessment with Euroscore and Euroscore II in patients with coronary artery or valvular disease

Nowadays, both the European System for Cardiac Operative Risk Evaluation (EuroSCORE) logistic (ESL) and EuroSCORE II (ESII) models are used worldwide in predicting in-hospital mortality after cardiac operation. However, these scales are based on different populations and represent different medical approaches. The aim of the study was to assess the effectiveness of the ESL and the ESII risk scores in predicting in-hospital death and prolonged hospitalization in intensive care unit (ICU) after coronary artery bypass grafting (CABG), aortic valve replacement (AVR), and mitral valve replacement (MVR) by comparison of an estimated risk and a real-life observation at a reference cardiac surgery unit.This retrospective study was based on medical records of patients who underwent a CABG, AVR, or MVR at a reference cardiac surgery unit in a 2-year period. Primary endpoint was defined as in-hospital death. Secondary endpoint was a prolonged hospitalization at the ICU, defined as longer than 3 days.The study encompassed 586 patients [114 (23.1%) female, mean age 65.8 ± 10.5 years], including 493 patients undergoing CABG, 66 patients undergoing AVR, and 27 patients undergoing MVR. The ESL and ESII risk scores were higher in MVR subgroup (31.7% ± 30.5% and 15.3% ± 19.4%) and AVR subgroup (9.7% ± 11.6% and 3.2% ± 4.2%) than in CABG subgroup (6.9% ± 10.4% and 2.5% ± 4.1%; P < .001). Subgroups of patients were significantly different in terms of clinical, biochemical, and echocardiography factors. Primary endpoint occurred in 36 (6.1%) patients: 21 (4.3%), 7 (10.6%), and 8 (29.7%) in CABG, AVR, and MVR subgroups, respectively. The ESII underestimated the risk of mortality. Secondary endpoint occurred in 210 (35.8%) patients: 172 (34.9%), 22 (33.4%), and 16 (59.3%) in CABG, AVR, and MVR subgroups, respectively.In the study, the perioperative risk estimated with the ESL and the ESII risk scores was compared with a real-life outcome among over 500 patients. Regardless of the type of surgery, result in the ESL was better correlated with the risk of in-hospital death.