Development of the Post Cardiac Surgery (POCAS) prognostic score

Abstract

IntroductionThe risk of mortality in cardiac surgery is generally evaluated using preoperative risk-scale models. However, intraoperative factors may change the risk factors of patients, and the organism functionality parameters determined upon ICU admittance could therefore be more relevant in deciding operative mortality. The goals of this study were to find associations between the general parameters of organism functionality upon ICU admission and the operative mortality following cardiac operations, to develop a Post Cardiac Surgery (POCAS) Scale to define operative risk categories and to validate an operative mortality risk score.MethodsWe conducted a prospective study, including 920 patients who had undergone cardiac surgery with cardiopulmonary bypass. Several parameters recorded on their ICU admission were explored, looking for a univariate and multivariate association with in-hospital mortality (90 days). In-hospital mortality was 9%. Four independent factors were included in the POCAS mortality risk model: mean arterial pressure, bicarbonate, lactate and the International Normalized Ratio (INR). The POCAS scale was compared with four other risk scores in the validation series.ResultsIn-hospital mortality (90 days) was 9%. Four independent factors were included in the POCAS mortality risk model: mean arterial pressure, bicarbonate ratio, lactate ratio and the INR. The POCAS scale was compared with four other risk scores in the validation series. Discriminatory power (accuracy) was defined with a receiver-operating characteristics (ROC) analysis. The best accuracy in predicting in-hospital mortality (90 days) was achieved by POCAS. The areas under the ROC curves of the different systems analyzed were 0.890 (POCAS), followed by 0.847 (Simplified Acute Physiology Score (SAP II)), 0.825 (Sepsis-related Organ Failure Assessment (SOFA)), 0.768 (Acute Physiology and Chronic Health Evaluation (APACHE II)), 0.754 (logistic EuroSCORE), 0.714 (standard EuroSCORE) and 0.699 (Age, Creatinine, Ejection Fraction (ACEF) score).ConclusionsOur new system to predict the operative mortality risk of patients undergoing cardiac surgery is better than others used for this purpose (SAP II, SOFA, APACHE II, logistic EuroSCORE, standard EuroSCORE, and ACEF score). Moreover, it is an easy-to-use tool since it only requires four risk factors for its calculation.

The significance of risk adjustment for the assessment of results in intensive care. : An analysis of risk adjustment models used in Swedish intensive care.

“…Different local management routines may affect the values of these variables whereby the values of the variables may not necessarily reflect differences in risk. The problem that variables may be affected by local routines has similarities with lead-time bias [31] and may occur with other models used for risk prediction after cardiac surgery [36][37][38].…”

“…The aROC was 0.890 while validated in the full development cohort. The paper was published in 2013 [38].…”

Valoración del Euroscore y SAPS III como predictor de mortalidad hospitalaria en el postoperatorio de cirugía cardiaca

“…227,236,246,278 . El 15,10% de los pacientes que fallecieron habían sufrido un ictus previos a la cirugía cardiaca, frente al 5,7% de los pacientes que sobrevivieron (p=0,013).…”

“…Este es otro de los aspectos que se destaca en los artículos consultados, así como el tipo de cirugía al que el paciente se va a someter, siendo de mayor riesgo la cirugía combinada que la cirugía coronaria aislada o la cirugía valvular 227,246,278 .…”

“…La escala POCAS solo incluye los valores de presión arterial media, lactato, bicarbonato e INR y la escala ACEF solo valora la edad del paciente, las cifras de creatinina y la fracción de eyección. Ambas han sido utilizadas en múltiples estudios, comparando su capacidad de predicción con la del Euroscore, pero es preciso realizar una validación externa más amplia para comprobar su aplicabilidad 226,227 .…”