Herminia Torrado

Short-term independent mortality risk factors in patients with cirrhosis undergoing cardiac surgery

OBJECTIVES Cirrhosis represents a serious risk in patients undergoing cardiac surgery. Several preoperative factors identify cirrhotic patients as high risk for cardiac surgery; however, a patients preoperative status may be modified by surgical intervention and, as yet, no independent postoperative mortality risk factors have been identified in this setting. The objective of this study was to identify preoperative and postoperative mortality risk factors and the scores that are the best predictors of short-term risk. METHODS Fifty-eight consecutive cirrhotic patients requiring cardiac surgery between January 2004 and January 2009 were prospectively studied at our institution. Forty-two (72%) patients were operated on for valve replacement, 9 (16%) for a CABG and 7 (12%) for both (CABG and valve replacement). Thirty-four (58%) patients were classified as Child-Turcotte-Pugh class A, 21 (36%) as class B and 3 (5%) as class C. We evaluated the variables that are usually measured on admission and during the first 24 h of the postoperative period together with potential operative predictors of outcome, such as cardiac surgery scores (Parsonnet, EuroSCORE), liver scores (Child-Turcotte-Pugh, model for end-stage liver disease, United Kingdom end-stage liver disease score) and ICU scores (acute physiology and chronic health evaluation II and III, simplified acute physiology score II and III, sequential organ failure assessment). RESULTS Seven patients (12%) died in-hospital, of whom 5 were Child-Turcotte-Pugh class B and 2 class C. Comparing survivors vs non-survivors, univariate analysis revealed that variables associated with short-term outcome were international normalized ratio (1.5 ± 0.24 vs 2.2 ± 0.11, P < 0.0001), presurgery platelet count (171 ± 87 vs 113 ± 52 l nl(-1), P = 0.031), presurgery haemoglobin count (11.8 ± 1.8 vs 10.2 ± 1.4 g dl(-1), P = 0.021), total need for erythrocyte concentrates (2 ± 3.4 vs 8.5 ± 8 units, P < 0.0001), PaO(2)/FiO(2) at 12 h after ICU admission (327 ± 84 vs 257 ± 78, P = 0.04), initial central venous pressure (11 ± 3 vs 16 ± 4 mmHg, P = 0.02) and arterial blood lactate concentration 24 h after admission (1.8 ± 0.5 vs 2.5 ± 1.3 mmol l(-1), P = 0.019). Multivariate analysis identified initial central venous pressure as the only independent factor associated with short-term outcome (P = 0.027). The receiver operating characteristic curve showed that the model for end-stage Liver disease score had a better predictive value for short-term outcome than other scores (AUC: 90.5 ± 4.4%; sensitivity: 85.7%; specificity: 83.7%), although simplified acute physiology score III was acceptable. CONCLUSIONS We conclude that central venous pressure could be a valuable predictor of short-term outcome in patients with cirrhosis undergoing cardiac surgery. The model for end-stage liver disease score is the best predictor of cirrhotic patients who are at high risk for cardiac surgery. Sequential organ failure assessment and simplified acute physiology score III are also valuable predictors.

Influence of cirrhosis in cardiac surgery outcomes.

Liver cirrhosis has evolved an important risk factor for cardiac surgery due to the higher morbidity and mortality that these patients may suffer compared with general cardiac surgery population. The presence of contributing factors for a poor outcome, such as coagulopathy, a poor nutritional status, an adaptive immune dysfunction, a degree of cirrhotic cardiomyopathy, and a degree of renal and pulmonary dysfunction, have to be taken into account for surgical evaluation when cardiac surgery is needed, together with the degree of liver disease and its primary complications. The associated pathophysiological characteristics that liver cirrhosis represents have a great influence in the development of complications during cardiac surgery and the postoperative course. Despite the population of cirrhotic patients who are referred for cardiac surgery is small and recommendations come from small series, since liver cirrhotic patients have increased their chance of survival in the last 20 years due to the advances in their medical care, which includes liver transplantation, they have been increasingly considered for cardiac surgery. Indeed, there is an expected rise of cirrhotic patients within the cardiac surgical population due to the increasing rates of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis, especially in western countries. In consequence, a more specific approach is needed in the assessment of care of these patients if we want to improve their management. In this article, we review the pathophysiology and outcome prediction of cirrhotic patients who underwent cardiac surgery.

Evaluation of Serial Arterial Lactate Levels as a Predictor of Hospital and Long-Term Mortality in Patients After Cardiac Surgery

OBJECTIVES Although hyperlactatemia is common after cardiac surgery, its value as a prognostic marker is unclear. The aim of the present study was to determine whether postoperative serial arterial lactate (AL) measurements after cardiac surgery could predict outcome. DESIGN Prospective, observational study. SETTING Surgical intensive care unit in a tertiary-level university hospital. PARTICIPANTS Participants included 2,935 consecutive patients. INTERVENTIONS AL was measured on admission to the intensive care unit and 6, 12, and 24 hours after surgery, and evaluated together with clinical data and outcomes including in-hospital and long-term mortality. MEASUREMENTS AND MAIN RESULTS In-hospital and long-term mortality (mean follow-up 6.3±1.7 years) were 5.9% and 8.7%, respectively. Compared with survivors, nonsurvivors showed higher mean AL values in all measurements (p<0.001). Hyperlactatemia (AL>3.0 mmol/L) was a predictor for in-hospital mortality (odds ratio = 1.468; 95% confidence interval = 1.239-1.739; p<0.001) and long-term mortality (hazard ratio = 1.511; 95% confidence interval = 1.251-1.825; p<0.001). Recent myocardial infarction and longer cardiopulmonary bypass time were predictors of hyperlactatemia. The pattern of AL dynamics was similar in both groups, but nonsurvivors showed higher AL values, as confirmed by repeated measures analysis of variance (p<0.001). The area under the curve also showed higher levels of AL in nonsurvivors (80.9±68.2 v 49.71±25.8 mmol/L/h; p = 0.038). Patients with hyperlactatemia were divided according to their timing of peak AL, with higher mortality and worse survival in patients in whom AL peaked at 24 hours compared with other groups (79.1% v 86.7%-89.2%; p = 0.03). CONCLUSIONS The dynamics of the postoperative AL curve in patients undergoing cardiac surgery suggests a similar mechanism of hyperlactatemia in survivors and nonsurvivors, albeit with a higher production or lower clearance of AL in nonsurvivors. The presence of a peak of hyperlactatemia at 24 hours is associated with higher in-hospital and long-term mortality.

Is C-Reactive Protein a Biomarker for Immediate Clinical Outcome After Cardiac Surgery?

OBJECTIVE The purpose of this study was to determine the possible correlation between inflammatory activation after cardiac surgery with cardiopulmonary bypass, measured by postoperative C-reactive protein concentrations, and immediate intensive care unit outcome. DESIGN A prospective, clinical cohort study. SETTING A 10-bed surgical intensive care unit at a tertiary university hospital. PATIENTS Two hundred sixteen consecutive patients undergoing nonemergency cardiac surgery with cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS Parsonnet and Acute Physiology and Chronic Health Evaluation scores, characteristics of the surgical intervention, intensive care unit length of stay, and mortality were recorded along with the following variables: cardiac (hours requiring inotropic support and new atrial fibrillation), respiratory (oxygenation index and hours requiring intubation), renal (difference between serum creatinine at admission and maximum creatinine), and analytic (C-reactive protein at admission and 6, 24, and 48 hours later; troponin I; CK-MB; and lactate). RESULTS Postoperative C-reactive protein concentrations did not correlate with variables such as time requiring inotropic support or intubation, oxygenation index, delta serum creatinine, and intensive care unit length of stay (with the exception of cardiopulmonary bypass time and the more frequent norepinephrine requirement in patients with higher C-reactive protein concentration at 48 hours); nor did C-reactive protein correlate with the analytic variables (with the exception of the lactate peak and C-reactive protein concentrations at 24 and 48 hours). There was no correlation between C-reactive protein and postoperative variables for coronary artery bypass graft surgery and valvular groups analyzed separately. CONCLUSION Postoperative C-reactive protein does not seem to be a useful marker in predicting outcome after 48 hours in the intensive care unit.

The Influence of Body Mass Index on Outcomes in Patients Undergoing Cardiac Surgery: Does the Obesity Paradox Really Exist?

Purpose Obesity influences risk stratification in cardiac surgery in everyday practice. However, some studies have reported better outcomes in patients with a high body mass index (BMI): this is known as the obesity paradox. The aim of this study was to quantify the effect of diverse degrees of high BMI on clinical outcomes after cardiac surgery, and to assess the existence of an obesity paradox in our patients. Methods A total of 2,499 consecutive patients requiring all types of cardiac surgery with cardiopulmonary bypass between January 2004 and February 2009 were prospectively studied at our institution. Patients were divided into four groups based on BMI: normal weight (18.5–24.9 kg∙m−2; n = 523; 21.4%), overweight (25–29.9kg∙m−2; n = 1150; 47%), obese (≥30–≤34.9kg∙m−2; n = 624; 25.5%) and morbidly obese (≥35kg∙m−2; n = 152; 6.2%). Follow-up was performed in 2,379 patients during the first year. Results After adjusting for confounding factors, patients with higher BMI presented worse oxygenation and better nutritional status, reflected by lower PaO2/FiO2 at 24h and higher albumin levels 48h after admission respectively. Obese patients showed a higher risk for Perioperative Myocardial Infarction (OR: 1.768; 95% CI: 1.035–3.022; p = 0.037) and septicaemia (OR: 1.489; 95% CI: 1.282–1.997; p = 0.005). In-hospital mortality was 4.8% (n = 118) and 1-year mortality was 10.1% (n = 252). No differences were found regarding in-hospital mortality between BMI groups. The overweight group showed better 1-year survival than normal weight patients (91.2% vs. 87.6%; Log Rank: p = 0.029. HR: 1.496; 95% CI: 1.062–2.108; p = 0.021). Conclusions In our population, obesity increases Perioperative Myocardial Infarction and septicaemia after cardiac surgery, but does not influence in-hospital mortality. Although we found better 1-year survival in overweight patients, our results do not support any protective effect of obesity in patients undergoing cardiac surgery.

Age and sex differences in perioperative myocardial infarction after cardiac surgery

We investigate age and sex differences in acute myocardial infarction (AMI) after cardiac surgery in a prospective study of 2038 consecutive patients undergoing cardiac surgery with cardiopulmonary bypass. An age of ≥ 70 years implied changes in the type of AMI from the ST-segment elevation myocardial infarction (STEMI) to non-ST-segment elevation myocardial infarction (non-STEMI). Men were more likely than women to suffer from AMI after cardiac surgery (11.8% vs. 5.6%), as a result of the higher frequency of STEMI (6% of men vs. 1.8% of women; P < 0.001) in both age groups. A troponin-I (Tn-I) peak was significantly higher in patients ≥ 70 years old. In-hospital mortality was higher in patients ≥ 70 (7.3%) than in those < 70 years old (3.3%), because of the increased mortality observed in men with non-AMI (2.1% vs. 6.3%) and women with STEMI (0% vs. 28.6%) and non-STEMI (0% vs. 36.8%, P < 0.05). Old age was associated with a higher frequency of non-STEMI, Tn-I peak, mortality and length of stay in the intensive care unit (ICU). Regardless of age, men more often suffer from AMI (particularly STEMI). AMI in women had a notable impact on excess mortality and ICU stay observed in patients ≥ 70 years of age. Clinical and Tn-I peak differences are expected in relation to age and gender after AMI post-cardiac surgery.

Are there sex-based differences in serum troponin I after cardiac surgery?

Objective: To determine whether there are sex-based differences in serum troponin I (TnI) after cardiac surgery with cardiopulmonary bypass. Design: Prospective, observational, cohort study. Setting: Tertiary cardiac surgery intensive care unit (ICU) at a university hospital. Interventions: None. Measurements and Main Results: Serum TnI was measured in samples obtained at ICU admission and 6, 12, 24, and 48 hours later. A total of 761 consecutive patients were studied (444 men and 317 women). The characteristics and results of the different sex subgroups were as follows: A) Coronary bypass: 165 men and 38 women. Age, Parsonnet score, Acute Physiology and Chronic Health Evaluation III score, prevalence of renal failure, intra-aortic balloon use, and the lengths of cardiopulmonary bypass, mechanical ventilation, and ICU stay were similar in the two groups. Body mass index, red-cell transfusion needs, and use of noradrenaline were significantly higher in women, whereas dobutamine requirements were higher in men. Mortality: 3 men (1.6%) vs. 0 women (p = not significant). The TnI peak was slightly, but significantly, higher in men (6.2 ± 4.9 vs. 4.5 ± 2.6 μg/L. p < 0.05). B) Valve surgery: 279 men and 279 women. Some significant differences were found: Women were older than men and had higher Parsonnet score and transfusion needs. The other recorded variables were similar. Mitral prosthesis: 62 men and 125 women (p < 0.05). Mitral valvuloplasty: 24 men, 7 women (p < 0.05). Aortic prosthesis: 162 men, 103 women (p < 0.05). Mitral and aortic prosthesis: 31 men and 44 women (p < 0.05). TnI peaks were similar for both sexes in each valve subgroup. Mortality: 3 men (1%) vs. 11 women (3.4%) (p < 0.05). The TnI peak did not reach any significant differences between sexes (men 7.9 ± 6.0 vs. 8.5 ± 6.5 μg/L in women. p = not significant). Conclusion: No clinically relevant sex-based differences were found in the TnI peaks after cardiac surgery.

Aortoesophageal fistula, a catastrophic complication soon after successful repair of an aortic dissection type A

A 66-year-old man with a history of arterial hypertension underwent emergency cardiac surgery for aortic dissection type A, diagnosed by a computed tomographic scan ( Panel A ) after abdominal pain and syncope. The lesion was repaired with a Dacron tubular prosthesis. In the postoperative period, he improved his condition slowly under mechanical …

Does post-cardiac surgery magnesium supplementation improve outcome?

Hypomagnesemia has been linked with increased morbidity and mortality in critically ill patients. Since the condition is common after cardiopulmonary bypass surgery, the objective of this study was to determine whether magnesium supplementation in the immediate postoperative period may improve outcomes of patients undergoing cardiac surgery with cardiopulmonary bypass. This prospective, randomized, double-blind, placebo-controlled study was conducted in a third-level, cardiac surgery intensive care unit (ICU) at a university hospital. Two hundred and sixteen patients undergoing elective cardiac surgery with cardiopulmonary bypass were randomized to receive either an intravenous bolus of 1.5 g of magnesium sulphate followed by an infusion of 12 g of the same salt in 24 h (105 patients), or placebo (111 patients) administered according to the same schedule as the treatment group. No significant differences were found either in the primary end point (hours of intubation) or in the secondary end points (length of inotropic support, new atrial fibrillation, ventricular tachycardia or ventricular fibrillation, length of intensive care unit stay, or ICU or hospital mortality). Hypomagnesemia was present in 12% of patients on admission to the intensive care unit. The magnesium group had a greater need for pacemaker stimulation. In conclusion, under the conditions of the present study, magnesium supplementation after cardiac surgery with cardiopulmonary bypass does not favourably affect clinical outcomes.