Analysis of Risk Scores to Predict Mortality in Patients Undergoing Cardiac Surgery for Endocarditis

Prognostic models for mortality after cardiac surgery in patients with infective endocarditis: a systematic review and aggregation of prediction models

BACKGROUND

There are several prognostic models to estimate the risk of mortality after surgery for active infective endocarditis (IE). However, these models incorporate different predictors and their performance is uncertain.

OBJECTIVE

We systematically reviewed and critically appraised all available prediction models of postoperative mortality in patients undergoing surgery for IE, and aggregated them into a meta-model.

DATA SOURCES

We searched Medline and EMBASE databases from inception to June 2020.

STUDY ELIGIBILITY CRITERIA

We included studies that developed or updated a prognostic model of postoperative mortality in patient with IE.

METHODS

We assessed the risk of bias of the models using PROBAST (Prediction model Risk Of Bias ASsessment Tool) and we aggregated them into an aggregate meta-model based on stacked regressions and optimized it for a nationwide registry of IE patients. The meta-model performance was assessed using bootstrap validation methods and adjusted for optimism.

RESULTS

We identified 11 prognostic models for postoperative mortality. Eight models had a high risk of bias. The meta-model included weighted predictors from the remaining three models (EndoSCORE, specific ES-I and specific ES-II), which were not rated as high risk of bias and provided full model equations. Additionally, two variables (age and infectious agent) that had been modelled differently across studies, were estimated based on the nationwide registry. The performance of the meta-model was better than the original three models, with the corresponding performance measures: C-statistics 0.79 (95% CI 0.76-0.82), calibration slope 0.98 (95% CI 0.86-1.13) and calibration-in-the-large -0.05 (95% CI -0.20 to 0.11).

CONCLUSIONS

The meta-model outperformed published models and showed a robust predictive capacity for predicting the individualized risk of postoperative mortality in patients with IE.

PROTOCOL REGISTRATION

PROSPERO (registration number CRD42020192602).

Predictors of mortality and adverse events in patients with infective endocarditis: a retrospective real world study in a surgical centre

Purpose

Mortality in infective endocarditis (IE) is still high, and the long term prognosis remains uncertain. This study aimed to identify predictors of long-term mortality for any cause, adverse event rate, relapse rate, valvular and ventricular dysfunction at follow-up, in a real-world surgical centre.

Methods

We retrospectively analyzed 363 consecutive episodes of IE (123 women, 34%) admitted to our department with a definite diagnosis of non-device-related IE. Median follow-up duration was 2.9 years. Primary endpoints were predictors of mortality, recurrent endocarditis, and major non-fatal adverse events (hospitalization for any cardiovascular cause, pace-maker implantation, new onset of atrial fibrillation, sternal dehiscence), and ventricular and valvular dysfunction at follow-up.

Results

Multivariate analysis independent predictors of mortality showed age (HR per unit 1.031, p < 0.003), drug abuse (HR 3.5, p < 0.002), EUROSCORE II (HR per unit 1.017, p < 0.0006) and double valve infection (HR 2.3, p < 0.001) to be independent predictors of mortality, while streptococcal infection remained associated with a better prognosis (HR 0.5, p < 0.04). Major non-fatal adverse events were associated with age (HR 1.4, p < 0.022). New episodes of infection were correlated with S aureus infection (HR 4.8, p < 0.001), right-sided endocarditis (HR 7.4, p < 0.001), spondylodiscitis (HR 6.8, p < 0.004) and intravenous drug abuse (HR 10.3, p < 0.001). After multivariate analysis, only drug abuse was an independent predictor of new episodes of endocarditis (HR 8.5, p < 0.001). Echocardiographic follow-up, available in 95 cases, showed a worsening of left ventricular systolic function (p < 0.007); severe valvular dysfunction at follow-up was reported only in 4 patients, all of them had mitral IE (p < 0.03).

Conclusions

The present study highlights some clinical, readily available factors that can be useful to stratify the prognosis of patients with IE.