Neurological outcome and modifiable events after out-of-hospital cardiac arrest in patients managed in a tertiary cardiac centre: A ten years register / Desenlaces neurológicos y acontecimientos modificables tras parada cardíaca extrahospitalaria en pacientes tratados en un centro de atención cardíaca terciaria: registro de 10 años

OBJECTIVE: A study was made of the events occurring in the early post-resuscitation phase that may help to improve the outcomes at hospital discharge. DESIGN: A retrospective cohort study (2007-2017) of a prospective Utstein type registry database was carried using multivariate logistic regression analysis. Pre- and post-hospital admission events were investigated. SETTING: A tertiary cardiac centre. PARTICIPANTS: Unconscious victims of out-of-hospital cardiac arrest (OHCA) with documented ventricular tachycardia or fibrillation. MAIN VARIABLES OF INTEREST: Events occurring before and within 72h after intensive care unit (ICU) admission were recorded. The variables were analyzed to determine their impact on hospital survival and poor neurological outcome. One-year follow-up survival was also considered. Results are presented as odds ratio (OR) and 95% confidence interval (95%CI). RESULTS: Of 245 patients admitted to our ICU after OHCA, 152 (62%) were alive and 131 (86.2%) presented good neurological outcomes (cerebral performance categories≤2) at hospital discharge. The one-year follow-up survival rate was 95.9%. Age >70 years (OR 2.0; 95%CI 1.1-4.1), previous myocardial infarction (OR 2.7; 95%CI 1.2-6.1), shock upon hospital admission (OR 2.9; 95%CI 1.3-6.2), time from call to return of spontaneous circulation (ROSC) >25min (OR 3.1; 95%CI 1.6-6.0) and anticonvulsant therapy (OR 18.2; 95%CI 5.5-60) were independent predictors of poor neurological outcome. Immediate admission to the cardiac centre (OR 0.5; 95%CI 0.3-0.9) and lactate clearance reaching plasma levels <2.5mmol/l at 12h (OR 0.4; 95%CI 0.2-0.8) were associated with better outcomes. CONCLUSIONS: Unconscious OHCA patients with documented ventricular tachycardia or fibrillation may benefit from direct admission to a reference cardiac centre. Initial haemodynamic support, urgent coronary angiography and targeted management in the cardiac ICU seem to increase the likelihood of good neurological outcomes

OBJETIVO: Llevar a cabo un estudio de los acontecimientos ocurridos en la fase inmediatamente posterior a la reanimación que puedan ayudar a mejorar los desenlaces en el momento del alta hospitalaria. DISEÑO: Se realizó un estudio retrospectivo (2007-2017) de cohorte de una base de datos de registro de tipo Utstein prospectivo mediante un análisis de regresión logística multivariable. Se investigaron los acontecimientos previos y posteriores al ingreso hospitalario. Ámbito: Un centro de atención cardíaca terciaria. PARTICIPANTES: Víctimas inconscientes de parada cardíaca extrahospitalaria (OHCA) con fibrilación o taquicardia ventricular documentada. VARIABLES PRINCIPALES DE INTERÉS: Se registraron los acontecimientos ocurridos antes y durante las 72h posteriores al ingreso en la unidad de cuidados intensivos (UCI). Se analizaron las variables para determinar su impacto en la supervivencia hospitalaria y los malos desenlaces neurológicos. También se tuvo en consideración la supervivencia en el seguimiento a lo largo de un año. Los resultados se presentan con valores de oportunidad relativa (OR) e intervalo de confianza del 95% (IC del 95%). RESULTADOS: De los 245 pacientes ingresados en nuestra UCI tras una OHCA, 152 (62%) seguían vivos y 131 (86,2%) presentaban unos buenos desenlaces neurológicos (categorías de rendimiento cerebral≤2) en el momento del alta hospitalaria. La tasa de supervivencia en el seguimiento a lo largo de un año fue del 95,9%. La edad>70 años (OR: 2,0; IC del 95%: 1,1-4,1), los antecedentes de infarto de miocardio (OR: 2,7; IC del 95%: 1,2-6,1), el choque en el momento del ingreso hospitalario (OR: 2,9; IC del 95%: 1,3-6,2), el tiempo transcurrido entre la llamada y el regreso a la circulación espontánea (ROSC)>25min (OR: 3,1; IC del 95%: 1,6-6,0) y la administración de tratamiento anticonvulsivo (OR: 18,2; IC del 95%: 5,5-60) fueron factores predictivos independientes de un mal desenlace neurológico. El ingreso inmediato en un centro de cuidados cardíacos (OR: 0,5; IC del 95%: 0,3-0,9) y el hecho de que el aclaramiento de lactato alcanzase unos niveles plasmáticos<2,5mmol/l al cabo de 12h (OR: 0,4; IC del 95%: 0,2-0,8) se asociaron con unos mejores desenlaces. CONCLUSIONES: Los pacientes inconscientes tras OHCA y con fibrilación o taquicardia ventricular documentada podrían beneficiarse del ingreso directo en un centro cardíaco de referencia. El apoyo hemodinámico inicial, la angiografía coronaria urgente y el tratamiento dirigido en la UCI cardíaca parecen aumentar la probabilidad de obtener unos buenos desenlaces neurológicos

Blood transfusion and ischaemic outcomes according to anemia and bleeding in patients with non-ST-segment elevation acute coronary syndromes: Insights from the TAO randomized clinical trial.

BACKGROUND: The benefits and risks of blood transfusion in patients with acute myocardial infarction who are anemic or who experience bleeding are debated. We sought to study the association between blood transfusion and ischemic outcomes according to haemoglobin nadir and bleeding status in patients with NST-elevation myocardial infarction (NSTEMI). METHODS: The TAO trial randomized patients with NSTEMI and coronary angiogram scheduled within 72h to heparin plus eptifibatide versus otamixaban. After exclusion of patients who underwent coronary artery bypass surgery, patients were categorized according to transfusion status considering transfusion as a time-varying covariate. The primary ischemic outcome was the composite of all-cause death or MI within 180 days of randomization. Subgroup analyses were performed according to pre-transfusion hemoglobin nadir and bleeding status. RESULTS: 12,547 patients were enrolled. Among these, blood transfusion was used in 489 (3.9%) patients. Patients who received transfusion had a higher rate of death or MI (29.9% vs. 8.1%, p<0.01). This excess risk persisted after adjustment on GRACE score and nadir of hemoglobin (HR 3.36 95%CI 2.63-4.29 p<0.01). Subgroup analyses showed that blood transfusion was associated with a higher risk in patients without overt bleeding (adjusted HR 6.25 vs. 2.85; p-interaction 0.001) as well as in those with hemoglobin nadir > 9.0 g/dl (HR 4.01; p-interaction<0.0001). CONCLUSION: In patients with NSTEMI, blood transfusion was associated with an overall increased risk of ischaemic events. However, this was mainly driven by patients without overt bleeding and those hemoglobin nadir > 9.0g/dl. This suggests possible harm of transfusion in those groups.

Neurological outcome and modifiable events after out-of-hospital cardiac arrest in patients managed in a tertiary cardiac centre: A ten years register.

OBJECTIVE: A study was made of the events occurring in the early post-resuscitation phase that may help to improve the outcomes at hospital discharge. DESIGN: A retrospective cohort study (2007-2017) of a prospective Utstein type registry database was carried using multivariate logistic regression analysis. Pre- and post-hospital admission events were investigated. SETTING: A tertiary cardiac centre. PARTICIPANTS: Unconscious victims of out-of-hospital cardiac arrest (OHCA) with documented ventricular tachycardia or fibrillation. MAIN VARIABLES OF INTEREST: Events occurring before and within 72h after intensive care unit (ICU) admission were recorded. The variables were analyzed to determine their impact on hospital survival and poor neurological outcome. One-year follow-up survival was also considered. Results are presented as odds ratio (OR) and 95% confidence interval (95%CI). RESULTS: Of 245 patients admitted to our ICU after OHCA, 152 (62%) were alive and 131 (86.2%) presented good neurological outcomes (cerebral performance categories≤2) at hospital discharge. The one-year follow-up survival rate was 95.9%. Age >70 years (OR 2.0; 95%CI 1.1-4.1), previous myocardial infarction (OR 2.7; 95%CI 1.2-6.1), shock upon hospital admission (OR 2.9; 95%CI 1.3-6.2), time from call to return of spontaneous circulation (ROSC) >25min (OR 3.1; 95%CI 1.6-6.0) and anticonvulsant therapy (OR 18.2; 95%CI 5.5-60) were independent predictors of poor neurological outcome. Immediate admission to the cardiac centre (OR 0.5; 95%CI 0.3-0.9) and lactate clearance reaching plasma levels <2.5mmol/l at 12h (OR 0.4; 95%CI 0.2-0.8) were associated with better outcomes. CONCLUSIONS: Unconscious OHCA patients with documented ventricular tachycardia or fibrillation may benefit from direct admission to a reference cardiac centre. Initial haemodynamic support, urgent coronary angiography and targeted management in the cardiac ICU seem to increase the likelihood of good neurological outcomes.

Quantification of aortic flow by phase-contrast magnetic resonance in patients with bicuspid aortic valve.

AIMS: Bicuspid aortic valve (BAV) causes complex flow patterns in the ascending aorta (AAo), which may compromise the accuracy of flow measurement by phase-contrast magnetic resonance (PC-MR). Therefore, we aimed to assess and compare the accuracy of forward flow measurement in the AAo, where complex flow is more dominant in BAV patients, with flow quantification in the left ventricular outflow tract (LVOT) and the aortic valve orifice (AV), where complex flow is less important, in BAV patients and controls. METHODS AND RESULTS: Flow was measured by PC-MR in 22 BAV patients and 20 controls at the following positions: (i) LVOT, (ii) AV, and (iii) AAo, and compared with the left ventricular stroke volume (LVSV). The correlation between the LVSV and the forward flow in the LVOT, the AV, and the AAo was good in BAV patients (r = 0.97/0.96/0.93; P < 0.01) and controls (r = 0.96/0.93/0.93; P < 0.01). However, in relation with the LVSV, the forward flow in the AAo was mildly underestimated in controls and much more in BAV patients [median (inter-quartile range): 9% (4%/15%) vs. 22% (8%/30%); P < 0.01]. This was not the case in the LVOT and the AV. The severity of flow underestimation in the AAo was associated with flow eccentricity. CONCLUSION: Flow measurement in the AAo leads to an underestimation of the forward flow in BAV patients. Measurement in the LVOT or the AV, where complex flow is less prominent, is an alternative means for quantifying the systolic forward flow in BAV patients.

Electronic cardiac medicine: present and future opportunities.

The second half of the 20th century witnessed a revolution in electronic medicine similar to that in pharmacology in the decades before. The advent of the implantable pacemaker, implantable cardioverter-defibrillators, cardiac resynchronisation therapies, insertable loop recorders and more, have improved diagnoses and reduced mortality and morbidity in millions of patients suffering from cardiac disease. The possibility to monitor patients continually without need for frequent office visits has the potential to reduce follow-up burden on physicians, facilitate increased use of home-based care and further improve the safety for patients. This review summarises the role of cardiac device therapies today and some of the developments which we can hope for in the nearest future.

Estimates of lifetime attributable risk of cancer after a single radiation exposure from 64-slice computed tomographic coronary angiography.

AIMS: To estimate the life attributable risk (LAR) of cancer incidence over a wide range of dose radiation exposure and a large spectrum of possible diagnostic computed tomographic coronary angiography (CTCA) scenarios. METHODS: This study included 561 consecutive patients who underwent a successful prospective ECG-gating CTCA protocol (low-dose group) 64-slice CTCA and 188 patients who underwent retrospective ECG-gating CTCA with ECG-triggered dose modulation CTCA (high-dose group). LAR was computed, given the organ equivalent dose, for all cancers in both sexes. LAR was tabulated for each decile of dose-length product by 10-year age classes, separately for each sex. RESULTS: Estimates of LAR of any cancer for an exposure at age < or =40 year were lower in males than in females for any given quantile. At age >/ or =50 years, LAR was similar between sexes only at the lowest exposure doses, whereas at higher dosage, it was, in general, higher for women. At the median age of this case series (62 years) and for a radiation exposure ranging from 1.33 to 3.81 mSv, LAR was 1 in 4329 (or 23.1 per 10(5) persons exposed) and 1 in 4629 (or 21.6 per 10(5) persons) in men and women, respectively. For an exposure ranging from 10.34 to 18.97 mSv at the same median age, the LAR of cancer incidence was 1 in 1336 (or 74.8 per 10(5) persons) in men and doubled (1 in 614 or 162.8 per 10(5) persons) in women. CONCLUSIONS: This study provided an estimate of the LAR of cancer in middle-aged patients of both sexes after a single diagnostic CTCA, providing an easy-to-read table.

Relation between coronary atherosclerotic plaques and traditional risk factors in people with no history of cardiovascular disease undergoing multi-detector computed coronary angiography.

AIMS: To prospectively investigate the prevalence of coronary artery plaques (CAP) as detected by computed tomography-based angiography in a large number of consecutive individuals with no history of coronary artery disease (CAD) or acute coronary syndrome; to evaluate whether traditional risk factors are related to prevalence of CAP and to the expected 10-year risk of first major or fatal cardiovascular event (CVE). DESIGN: Prospective, single-centre, cross-sectional study. SETTING: The division of Cardiology at Fondazione Cardiocentro Ticino Lugano, Switzerland. METHODS: We prospectively included 920 consecutive individuals with no history of CAD who underwent computed tomography coronary angiography (CTCA). Risk estimation of fatal and non-fatal CVE was assessed using Global Assessment Risk (GAR) and Systematic Coronary Risk Evaluation (SCORE), respectively. Logistic regression was used to assess the association of risk factors with the prevalence of CAP. RESULTS: CAP was found in 459 (49.9%) individuals. Older age, higher body mass index, male gender, diabetes, hypertension and dyslipidaemia all increased the likelihood of the CAP burden at univariable analysis (p<0.001). At the multivariable analysis older age, male gender, hypertension and diabetes independently increased the likelihood of CAP burden (p<0.001). An increase in likelihood of CAP was observed in the presence of one, two and three or more risk factors and with an increasing value of GAR and SCORE. Notably, about 18% of subjects with CAP did not report any traditional risk factors and among individuals without CAPs, 12% had three or more risk factors. CONCLUSIONS: A direct relation between the prevalence of CAP, number of risk factors and the related 10-year risk of CVE was found. 18% of subjects without risk factors had CAP. In these individuals CTCA may help in further optimising the risk reduction strategies on an individual basis.

[Cell therapies in cardiology: results from the first randomized clinical trials]. / Thérapie cellulaire en cardiologie: bilan des premiers essais cliniques randomisés.

Following acute myocardial infarction, necrotic cardiac tissue is replaced by scar leading to ventricular remodeling and pump failure. Transplantation of autologous bone marrow-derived cells into the heart, early post-infarct, aims to prevent ventricular remodeling. This strategy has been evaluated in four controlled, randomized clinical trials, which provided mixed results. A transient improvement in ventricular function was observed in one trial, and a modest improvement (the duration of which remains to be determined) in an additional trial, whereas two trials showed negative results. A modest benefit of bone marrow cell transplantation was also observed in patients with chronic ischemic heart disease. Despite mixed results reported so far, cell therapy of heart disease still is in its infancy and has considerable room for improvement.

Starc II, a multicenter randomized placebo-controlled double-blind clinical trial of trapidil for 1-year clinical events and angiographic restenosis reduction after coronary angioplasty and stenting.

The objective of this study was to investigate the effect of trapidil 200 mg t.i.d. in preventing the occurrence of death, of myocardial infarction and the need for repeat revascularization at 12 months after balloon PTCA with or without stenting. Coronary restenosis after stenting is still a major drawback of percutaneous coronary interventions (PCI) for 30-40% of patients. Trapidil has been shown to prevent restenosis after PTCA. Eligible patients were randomized to placebo or oral trapidil 200 mg t.i.d. at least 48 hr before PCI and continuing 6 months after a successful balloon angioplasty or stent implantation. Aspirin was given to all patients, and ticlopidine 250 mg b.i.d. to those who received a stent for 4 weeks. In a randomized subgroup of 216 patients, quantitative coronary angiography was performed also at 6-month follow-up. Out of the 933 patients enrolled, primary endpoint incidence was 20.3% in trapidil and 18.0% in placebo (P = 0.37). When recurrence or deterioration of angina was added to the combined endpoint, incidence was 27.4% in trapidil and 23.0% in placebo (P = 0.12). Restenosis rate in patients with 6-month angiography was 25.0% in trapidil arm vs. 30.1% in placebo (P = 0.43). Stent restenosis rate was similar in patients randomized to trapidil or placebo (30.2% vs. 23.8%, respectively; P = 0.44), while in patients treated with balloon angioplasty, it was lower in trapidil (17.1%) than in placebo (40.0%; P = 0.03). Oral trapidil 200 mg t.i.d. for 6 months in addition to aspirin did not influence the occurrence of major cardiac events after coronary angioplasty with or without stenting. In a prespecified subgroup of 191 patients treated with balloon angioplasty only, trapidil reduced angiographic restenosis.

Italian BiodivYsio open registry (BiodivYsio PC-coated stent): study of clinical outcomes of the implant of a PC-coated coronary stent.

UNLABELLED: Rapid technological developments have made new materials available for percutaneous coronary intervention procedures. The coronary stent in particular has undergone progressive structural improvements leading to the recent availability of a third generation of stents, namely, coated stents. The rapid evolution of the stent has often made its evaluation problematical, since trials are frequently confined to small groups of patients in single centers. The purpose of this registry was to verify the safety and efficacy of the BiodivYsio stent (a stent coated with phosphorylcholine polymer) in a broad population of patients who reflect the daily reality of coronary intervention in a cardiac catheterization laboratory. METHODS AND RESULTS: The registry was designed to collect the principal angiographic and clinical data of a consecutive series of Oreal worldO patients. Patients were treated with a BiodivYsio stent (Biocompatibles, Galway, United Kingdom) in 12 centers (11 Italian and 1 Swiss) between January 1998 and January 1999. Procedural, in-hospital, 30-day and six-month follow-up data were collected. The monitoring, data entry and statistical analyses were carried out by an independent center. During the study, 218 patients were enrolled; 165 (76%) male and 53 (24%) female, with an average age of 61.6 +/- 9.4 years (range, 36Eth 84 years). A total of 258 stents were implanted in 233 lesions (1.1 stents per lesion), of which 233 (90%) were the BiodivYsio PC coated stent, the remaining 25 implants were of other stent types. The percutaneous transluminal coronary angioplasty and stenting procedure were carried out in 109 (50%) patients with unstable angina, 65 (30%) with stable angina, 29 (13%) with acute myocardial infarction, and 15 (7%) patients with silent ischemia. Procedural success was achieved in 217/218 (99.5%) patients. Optimal results were achieved in 212 (97.7%) patients. In 34 (15.6%) cases, patients were treated with periprocedural abciximab. During the hospitalization period, one (0.4%) death occurred on day 7 due to subacute occlusion of the stent, and 3 (1.4%) myocardial infarctions were reported. At 30-day follow-up, 211 (97.2%) patients were asymptomatic, as were 189 (87%) patients at clinical follow-up at 6 months. CONCLUSIONS: This study evaluated the safety and efficacy of a third-generation stent. The results demonstrate a high procedural success rate and a low incidence of major adverse cardiac events at short- and medium-term follow-up. It appears that the BiodivYsio stent should be considered safe in clinical and/or anatomical situations with a high risk of complications, confirming the hypothesis that PC may have non-thrombogenic properties. To corroborate these results, an appropriately designed study would be required to measure the stentOs efficacy in the most suitable clinical context, i.e., clinical situations that are at the highest risk of ischemic relapse.

PTX3, A prototypical long pentraxin, is an early indicator of acute myocardial infarction in humans.

BACKGROUND: Inflammation is an important component of ischemic heart disease. PTX3 is a long pentraxin whose expression is induced by cytokines in endothelial cells, mononuclear phagocytes, and myocardium. The possibility that PTX3 is altered in patients with acute myocardial infarction (AMI) has not yet been tested. METHODS AND RESULTS: Blood samples were collected from 37 patients admitted to the coronary care unit (CCU) with symptoms of AMI. PTX3 plasma concentrations, as measured by ELISA, higher than the mean+2 SD of age-matched controls (2.01 ng/mL) were found in 27 patients within the first 24 hours of CCU admission. PTX3 peaked at 7.5 hours after CCU admission, and mean peak concentration was 6.94+/-11.26 ng/mL. Plasma concentrations of PTX3 returned to normal in all but 3 patients at hospital discharge and were unrelated to AMI site or extent, Killip class at entry, hours from symptom onset, and thrombolysis. C-reactive protein peaked in plasma at 24 hours after CCU admission, much later than PTX3 (P<0.001). Patients >64 years old and women had significantly higher PTX3 concentrations at 24 hours (P<0.05). PTX3 was detected by immunohistochemistry in normal but not in necrotic myocytes. CONCLUSIONS: PTX3 is present in the intact myocardium, increases in the blood of patients with AMI, and disappears from damaged myocytes. We suggest that PTX3 is an early indicator of myocyte irreversible injury in ischemic cardiomyopathy.

Influence of promoter and WHV post-transcriptional regulatory element on AAV-mediated transgene expression in the rat brain.

Recombinant adeno-associated viruses (rAAVs) can transduce several tissues, including the brain. However, in brain the duration of gene expression in different areas is variable, which has been ascribed to viral (CMV) promoter silencing in some regions over time. We have compared expression of enhanced green fluorescent protein (EGFP) in the nigrostriatal pathway of rats mediated by rAAVs containing the CMV or platelet-derived growth factor-beta chain (PDGF-beta) promoter. In addition, we studied the effects of the woodchuck hepatitis virus post-transcriptional regulatory element (WPRE) on transgene expression in vivo. The rAAV vectors containing the neuron-specific PDGF-beta chain promoter transduced significantly more dopaminergic neurons than titer-matched vectors carrying the CMV promoter. Moreover, the WPRE further increased EGFP expression, and a rAAV vector incorporating both the PDGF-beta chain promoter and the WPRE resulted in efficient EGFP expression in dopaminergic neurons and their projections in the striatum for at least 41 weeks after virus injection. Our results emphasize the importance of a strong tissue-specific promoter in achieving optimal transgene expression, not only in long-term but also in short-term studies where viral titers may be limiting. Furthermore, they suggest that incorporation of the WPRE into rAAVs, and possibly other types of vectors, is useful to enhance transgene expression in vivo.

Long-term safety of an early ACE-inhibitor treatment of patients with acute myocardial infarction: results of the 3 year follow-up period on 696 Swiss patients randomized to the ISIS-4 trial. ISIS-Switzerland Study Group.

Several large scale clinical trials showed that early ACE inhibitor treatment in patients with acute myocardial infarction reduced 30-day mortality. While the short-term evidence of benefit and risks appears to be consistent among trials, scarce data are available with respect to the long-term effects of short-term treatments. This study shows that the early reduction in mortality rate observed among patients treated with captopril persists for up to 3 years. This suggests that the benefit achieved in the acute phase in not lost even after a long period of time.

[Therapy of acute myocardial infarct (1994-1996) at non-university hospitals in Switzerland (CHAMI Study)]. / Die Therapie des akuten Herzinfarkts (1994-1996) an nicht-universitären Spitälern in der Schweiz (CHAMI-Studie).

The CHAMI study (Confederatio Helvetica Acute Myocardial Infarction) recorded the therapies administered for acute myocardial infarction in 520 consecutive patients between October 1994 and February 1996 at 10 non-academic hospitals in Switzerland. The patients in this group consisted of 363 men and 157 women with an average age of 63.2 years. The prescribed medications administered from the day of hospital admission until the day of discharge were recorded. In the acute phase, the patients were given the following therapy: thrombolytic agents 40%, i.v. nitrates 65%, i.v. beta-blockers 22%, aspirin 95%, oral beta-blockers 36%, ACE inhibitors 14%. Impressive was the lower distribution of thrombolytic agents and beta-blockers among the older patients (age > 70) (thrombolytic agents 52.1% vs 28.4%; oral beta-blockers 44.0% vs 29.1%) and in particular among women (thrombolytic agents 26.8% vs 46%; oral beta-blockers 29.3% vs 39.7%) in men. Therapy at hospital discharge consisted, inter alia, of aspirin (73%), beta-blockers (54%), ACE inhibitors (3%), and lipid lowering agents (10%). The hospital mortality was 12.6%. The CHAMI study provided the participating hospitals with a quality control comparison with other participating centers and impressively demonstrated with the example of the lipid lowering agents, that the significance of secondary prophylaxis is assigned too little importance in contrast to acute therapy.

Determination of cardiac output during mechanical ventilation by electrical bioimpedance or thermodilution in patients with acute lung injury: effects of positive end-expiratory pressure.

OBJECTIVE: To evaluate the usefulness of transthoracic electrical bioimpedance in sedated and paralyzed patients with acute lung injury during mechanical ventilation with and without early application of positive end-expiratory pressure (PEEP). DESIGN: Prospective, repeated-measures study. SETTING: University-affiliated intensive care center. PATIENTS: Ten patients with acute lung injury. INTERVENTIONS: Simultaneous, three-paired cardiac output (CO) measurements by transthoracic electrical bioimpedance (TEB) and thermodilution (TD) were made at 0 and 15 cm H2O of PEEP. MEASUREMENTS AND MAIN RESULTS: The average of the TD-CO measurements was 7.22 +/- 2.12 (SD) L/min during 0 cm H2O of positive end-expiratory pressure (ZEEP), and 6.91 +/- 1.72 L/min during PEEP (NS). The average of the TEB-CO measurements was 4.48 +/- 1.37 L/min during ZEEP, and 6.03 +/- 2.03 L/min during PEEP (p < .05). For each level of PEEP, bias and precision between methods were calculated. Bias calculations between TD-CO and TEB-CO ranged from -1.54 +/- 7.02 L/min at ZEEP to -2.52 +/- 4.28 L/ min at PEEP, and -2.47 +/- 6.09 L/min for mixed data at ZEEP and PEEP. There was no significant correlation between the percent change with PEEP in TEB-CO and TD-CO (r2 =.05, NS). CONCLUSIONS: In patients with acute lung injury: a) the agreement between TEB-CO and TD-CO measurements is poor; b) agreement is not clinically improved by application of PEEP; and c) TEB cannot monitor trends in CO.