The effectiveness of right heart catheterization in the initial care of critically ill patients. SUPPORT Investigators

Agreement of central venous saturation and mixed venous saturation in cardiac surgery patients

OBJECTIVE

Comparison of the bias and the limits of agreement (LOA; 2 SD) of the central venous saturation (S(cv)O(2)) before, during and after coronary artery bypass graft surgery with a simultaneous measurement of the mixed venous saturation (S(v)O(2)).

DESIGN AND SETTING

Prospective controlled study in a university hospital department of anaesthesiology.

PATIENTS

60 patients with coronary artery bypass surgery, 300 paired measurements of S(v)O(2) and S(cv)O(2).

MEASUREMENTS AND RESULTS

S(cv)O(2) and S(v)O(2) were analysed after induction of anaesthesia 15 min after cardiopulmonary bypass and 1, 6 and 18 h after admission to the intensive care unit. Regression analysis for the pooled measurements of S(cv)O(2) and S(v)O(2) showed a correlation R (2) = 0.52. After induction of anaesthesia 15 min after weaning from cardiopulmonary bypass and 6 h after admission to the intensive care unit the correlation coefficient was R (2) = 0.46, on admission to the intensive care unit it was R (2) = 0.42, and at 18 h it was R (2) = 0.38. Bland-Altman analysis for the measurements of S(cv)O(2) and S(v)O(2) showed a mean bias and LOA of 0.3% and -11.9 to +12.4%. In patients with a low S(cv)O(2) there was a trend to overestimate the S(v)O(2) by using the S(cv)O(2). The only factor that influenced the DeltaS(v)O(2) - S(cv)O(2) was the oxygen extraction rate (R (2) = 0.16). In patients with S(cv)O(2) below 70% this association was more pronounced (R (2) = 0.60).

CONCLUSIONS

Our findings demonstrate that oxygen extraction rate is the major factor in the difference between S(v)O(2) and S(cv)O(2). Under certain circumstances S(cv)O(2) differed substantially from S(v)O(2). Therefore in selected patients both parameters should be monitored to exclude general or focal hypoperfusion.

Mortality in peripheral arterial disease: a comparison of patients managed by vascular specialists and general practitioners

BACKGROUND

Peripheral arterial disease (PAD) is undertreated by general practitioners (GPs). However, the impact of the suboptimal clinical management is unknown.

OBJECTIVE

To assess the mortality rate of PAD patients in relation to the type of physician who provides their care (GP or vascular specialist).

DESIGN

Prospective study.

SETTING

Primary care practice and academic vascular laboratory.

PARTICIPANTS

GP patients (n = 60) were those of the Peripheral Arteriopathy and Cardiovascular Events study (PACE). Patients managed by specialists (n = 82) were consecutive subjects with established PAD who were referred to our vascular laboratory during the enrollment period of the PACE study.

MEASUREMENTS

All-cause and cardiovascular mortality.

RESULTS

After 32 months of follow-up, specialist management was associated with a lower rate of all-cause mortality (RR = 0.04; 95% CI 0.01-0.34; p = .003) and cardiovascular mortality (RR = 0.07; 95% CI 0.01-0.65; p = .020), after adjustment for patients' characteristics. Specialists were more likely to use antiplatelet agents (93% vs 73%, p < .001), statins (62% vs 25%, p < .001) and beta blockers (28% vs 3%, p < .001). Survival differences between specialists and GPs disappeared once the use of pharmacotherapies was added to the proportional hazard model. The fully adjusted model showed that the use of statins was significantly associated with a reduced risk of all-cause mortality (RR = 0.02; 95% CI 0.01-0.73, p = .034) and cardiovascular mortality (RR = 0.02; 95% CI 0.01-0.71, p = .033).

CONCLUSIONS

Specialist management of patients with symptomatic PAD resulted in better survival than generalist management. This effect appears to be mainly caused by the more frequent use of effective medicines by specialists.

Utility of impedance cardiography for dyspneic patients in the ED

BACKGROUND

Dyspnea is one of the most common emergency department (ED) symptoms, but early diagnosis and treatment are challenging because of multiple potential causes. Hemodynamic parameters may aid in the evaluation of dyspnea, but are difficult to assess. Impedance cardiography is a noninvasive hemodynamic measurement method that may assist in early ED decision making.

METHODS

This study is intended to determine the accuracy in differentiating cardiac from noncardiac causes of dyspnea using impedance cardiography-derived hemodynamic parameters compared to ED physician opinion in light of initial history, and physical and laboratory tests. The final diagnosis, made after patient hospital record review, was compared with ED physician and impedance cardiography diagnoses.

RESULTS

A total of 52 patients were included: 14 women and 38 men, aged 68.5 +/- 14.2 years. There were significant differences in values of stroke index (25.7 vs 32.9, P < .05), cardiac index (2.3 vs 3.1, P < .0001), velocity index (35.1 vs 53.2, P < .01), and systolic time ratio (0.55 vs 0.44, P < .05) between the cardiac and noncardiac groups, respectively. Impedance cardiography measurements demonstrated better sensitivity (75% vs 60%), specificity (88% vs 66%), and positive and negative predictive values (79% vs 52% and 85% vs 72%, respectively) compared with those of the ED physician in distinguishing cardiac from noncardiac causes of dyspnea.

CONCLUSION

Impedance cardiography data result in improvement in ED physician differentiation of cardiac from noncardiac causes of dyspnea.

Role of intracranial pressure values and patterns in predicting outcome in traumatic brain injury: a systematic review

INTRODUCTION

Raised intracranial pressure (ICP) has been consistently associated with poor neurological outcome. Our purpose was to systematically review the literature to estimate the association between ICP values and patterns and short- and long-term vital and neurological outcome.

METHODS

Systematic review of studies identified from MEDLINE, EMBASE, and COCHRANE Registry search from 1966 to 2005, and reference lists of identified articles, with independent assessment of methodological quality, population, ICP values and patterns, management of raised ICP and neurological outcomes. Summary odds ratios (OR) were calculated for the main outcomes using proportional odds models and logistic regression.

RESULTS

Four prospective studies (409 patients) reported the effect of ICP values, and five studies (677 patients) reported the effect of ICP patterns on neurological outcome. No study reported neurological outcomes beyond 1 year. Relative to normal ICP (<20 mmHg), raised ICP was associated with elevated OR of death: 3.5 [95%CI: 1.7, 7.3] for ICP 20-40, and 6.9 [95%CI: 3.9, 12.4] for ICP>40. Raised but reducible ICP was associated with a 3-4-fold increase in the OR of death or poor neurological outcome. Refractory ICP pattern was associated with a dramatic increase in the relative risk of death (OR 114.3 [95%CI: 40.5, 322.3]).

CONCLUSIONS

Refractory ICP and response to treatment of raised ICP could be better predictors of neurological outcome than absolute ICP values. Limitations in the design of the studies analyzed precluded identification of the role of ICP monitoring in predicting short- and long-term outcomes.

Digital output volumetric pulmonary artery catheters eliminate interoperator interpretation variability and improve consistency of treatment decisions

BACKGROUND

The pulmonary artery catheter (PAC) has been fraught with controversy over issues of safety and impact on outcomes variables for many years. Multiple attempts to quantify the utility of this diagnostic instrument have failed to resolve the matter. Previous investigations have focused on either quantifying inter-rater variability of waveform output interpretation from PACs or on clinical outcomes when PACs are used in care. We tested the hypothesis that the true link between a diagnostic tool and outcomes is treatment selection, and an instrument that minimizes or eliminates the need for data interpretation would also minimize the variability of treatment selections.

STUDY DESIGN

We performed a prospective, single institutional, single blinded survey study.

RESULTS

The inter-rater variability of waveform interpretation among all raters was notable (p < 0.01); for continuous end diastolic volume index interpretation, there was no notable inter-rater variability (p=1.0). Inter-rater variability of treatment selections based on waveform interpretation was notable for all raters (p < 0.01). Continuous end diastolic volume index data presentation of hemodynamic status did not result in notable inter-rater variability in treatment selections (p=0.10). Treatment choices based on continuous end diastolic volume index among raters with 5 or more years of experience are not different from clinical practice guideline-directed choices (p > 0.05), independent of patient ventilator status.

CONCLUSIONS

Digital output volumetric PACs eliminate inter-rater variability of data interpretation, decrease inter-rater variability of data-driven treatment selections, and improve rater agreement with clinical practice guidelines when compared with traditional waveform output PACs.

Diagnostic and prognostic utility of brain natriuretic Peptide in subjects admitted to the ICU with hypoxic respiratory failure due to noncardiogenic and cardiogenic pulmonary edema

BACKGROUND

Brain natriuretic peptide (BNP) is useful in diagnosing congestive heart failure (CHF) in patients presenting in the emergency department with acute dyspnea. We prospectively tested the utility of BNP for discriminating ARDS vs cardiogenic pulmonary edema (CPE).

METHODS

We enrolled ICU patients with acute hypoxemic respiratory failure and bilateral pulmonary infiltrates who were undergoing right-heart catheterization (RHC) to aid in diagnosis. Patients with acute coronary syndrome, end-stage renal disease, recent coronary artery bypass graft surgery, or preexisting left ventricular ejection fraction

RESULTS

Eighty patients were enrolled. Median BNP was 325 pg/mL (interquartile range [IQR], 82 to 767 pg/mL) in acute lung injury/ARDS patients, vs 1,260 pg/mL (IQR, 541 to 2,020 pg/mL) in CPE patients (p = 0.0001). The correlation between BNP and pulmonary capillary wedge pressure was modest (r = 0.27, p = 0.02). BNP offered good discriminatory performance for the final diagnosis (C-statistic, 0.80). At a cut point /= 1,200 pg/mL, BNP had a specificity of 92% for CPE. Higher levels of BNP were associated with a decreased odds for ARDS (odds ratio, 0.4 per log increase; p = 0.007) after adjustment for age, history of CHF, and right atrial pressure. BNP was associated with in-hospital mortality (p = 0.03) irrespective of the final diagnosis and independent of APACHE (acute physiology and chronic health evaluation) II score.

CONCLUSION

In ICU patients with hypoxemic respiratory failure, BNP appears useful in excluding CPE and identifying patients with a high probability of ARDS, and was associated with mortality in patients with both ARDS and CPE. Larger studies are necessary to validate these findings.

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Key Words

• ards
• brain natriuretic peptide
• cardiogenic pulmonary edema
• respiratory failure
• swan-ganz catheter

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MESH Headings

• Aged
• Aged, 80 and over
• Biomarkers/blood
• Cardiac Catheterization
• Diagnosis, Differential
• Disease Progression
• Female
• Follow-Up Studies
• Heart Failure/blood
• Heart Failure/complications
• Heart Failure/diagnosis
• Hospitalization
• Humans
• Hypoxia/blood
• Hypoxia/diagnosis
• Hypoxia/etiology
• Immunoassay
• Intensive Care Units
• Male
• Middle Aged
• Natriuretic Peptide, Brain/blood
• Prognosis
• Pulmonary Edema/blood
• Pulmonary Edema/complications
• Pulmonary Edema/diagnosis
• Pulmonary Wedge Pressure
• Respiratory Insufficiency/blood
• Respiratory Insufficiency/diagnosis
• Respiratory Insufficiency/etiology
• Retrospective Studies
• Stroke Volume
• Ventricular Function, Right
• Ventricular Pressure

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Grants

• K23 AG024837 NIA NIH HHS
• R01 HL073146 NHLBI NIH HHS

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Affiliation(s)

Dimitri Karmpaliotis Cardiology of Georgia, Piedmont Hospital, Fuqua Heart Center, 95 Collier Rd NW, Suite 2075, Atlanta, GA 30309, USA.
Ajay J Kirtane
Christopher P Ruisi
Tamar Polonsky
Atul Malhotra
Daniel Talmor
Ioanna Kosmidou
Petr Jarolim
James A de Lemos
Marc S Sabatine
C Michael Gibson
David Morrow

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Collaborators Collapse

Hemodynamic monitoring in shock and implications for management. International Consensus Conference, Paris, France, 27-28 April 2006

OBJECTIVE

Shock is a severe syndrome resulting in multiple organ dysfunction and a high mortality rate. The goal of this consensus statement is to provide recommendations regarding the monitoring and management of the critically ill patient with shock.

METHODS

An international consensus conference was held in April 2006 to develop recommendations for hemodynamic monitoring and implications for management of patients with shock. Evidence-based recommendations were developed, after conferring with experts and reviewing the pertinent literature, by a jury of 11 persons representing five critical care societies.

DATA SYNTHESIS

A total of 17 recommendations were developed to provide guidance to intensive care physicians monitoring and caring for the patient with shock. Topics addressed were as follows: (1) What are the epidemiologic and pathophysiologic features of shock in the ICU? (2) Should we monitor preload and fluid responsiveness in shock? (3) How and when should we monitor stroke volume or cardiac output in shock? (4) What markers of the regional and micro-circulation can be monitored, and how can cellular function be assessed in shock? (5) What is the evidence for using hemodynamic monitoring to direct therapy in shock? One of the most important recommendations was that hypotension is not required to define shock, and as a result, importance is assigned to the presence of inadequate tissue perfusion on physical examination. Given the current evidence, the only bio-marker recommended for diagnosis or staging of shock is blood lactate. The jury also recommended against the routine use of (1) the pulmonary artery catheter in shock and (2) static preload measurements used alone to predict fluid responsiveness.

CONCLUSIONS

This consensus statement provides 17 different recommendations pertaining to the monitoring and caring of patients with shock. There were some important questions that could not be fully addressed using an evidence-based approach, and areas needing further research were identified.

Comparison of uncalibrated arterial waveform analysis in cardiac surgery patients with thermodilution cardiac output measurements

Introduction

Cardiac output (CO) monitoring is indicated only in selected patients. In cardiac surgical patients, perioperative haemodynamic management is often guided by CO measurement by pulmonary artery catheterisation (CO_PAC). Alternative strategies of CO determination have become increasingly accepted in clinical practice because the benefit of guiding therapy by data derived from the PAC remains to be proven and less invasive alternatives are available. Recently, a device offering uncalibrated CO measurement by arterial waveform analysis (CO_Wave) was introduced. As far as this approach is concerned, however, the validity of the CO measurements obtained is utterly unclear. Therefore, the aim of this study was to compare the bias and the limits of agreement (LOAs) (two standard deviations) of CO_Wave at four specified time points prior, during, and after coronary artery bypass graft (CABG) surgery with a simultaneous measurement of the gold standard CO_PAC and aortic transpulmonary thermodilution CO (CO_Transpulm).

Methods

Data from 30 patients were analysed during this prospective study. CO_PAC, CO_Transpulm, and CO_Wave were determined in all patients at four different time points prior, during, and after CABG surgery. The CO_PAC and the CO_Transpulm were measured by triple injection of 10 ml of iced isotone sodium chloride solution into the central venous line of the PAC. Measurements of CO_Wave were simultaneously taken at these time points.

Results

The overall correlation showed a Spearman correlation coefficient between CO_PAC and CO_Wave of 0.53 (p < 0.01) and 0.84 (p < 0.01) for CO_PAC and CO_Transpulm. Bland-Altman analysis showed a mean bias and LOAs of 0.6 litres per minute and -2.2 to +3.4 litres per minute for CO_PAC versus CO_Wave and -0.1 litres per minute and -1.8 to +1.6 litres per minute for CO_PAC versus CO_Transpulm.

Conclusion

Arterial waveform analysis with an uncalibrated algorithm CO_Wave underestimated CO_PAC to a clinically relevant extent. The wide range of LOAs requires further evaluation. Better results might be achieved with an improved new algorithm. In contrast to this, we observed a better correlation of thermodilution CO_Transpulm and thermodilution CO_PAC measurements prior, during, and after CABG surgery.

Use of 3-Dimensional Color Doppler Echocardiography to Measure Stroke Volume in Human Beings: Comparison with Thermodilution

BACKGROUND

The availability of accurate noninvasive measurements of cardiac output (CO) would be useful in assessing disease severity and the effects of therapeutic interventions in many different clinical settings. Current noninvasive methods are limited by their dependence on geometric assumptions. We tested the feasibility of a new technique for CO measurements based on 3-dimensional color Doppler echocardiographic (3D-CD) imaging.

OBJECTIVE

We sought to compare the accuracy of CO determination in human beings as measured by 3D-CD and conventional 2-dimensional echocardiography (2DE) using thermodilution as the gold standard for comparison.

METHODS

Simultaneous 3D-CD, 2DE, and thermodilution data were acquired in 47 patients postcardiac transplantation with good acoustic windows who required routine hemodynamic evaluation with a pulmonary artery catheter. Data were stored on compact disc and analyzed offline using custom software. Echocardiographic data were compared against thermodilution using linear regression and Bland-Altman analysis.

RESULTS

Correlation coefficients for 3D-CD and 2DE of the left ventricular outflow tract were r = 0.94 and r = 0.78, respectively. Correlation coefficients for 3D-CD and 2DE of the mitral valve were r = 0.93 and r = 0.75, respectively. Compared with 2DE, 3D-CD demonstrated a smaller bias and narrower limits of agreement in the left ventricular outflow tract (-1.84 +/- 16.8 vs -8.6 +/- 36.2 mL) and mitral valve inflow (-0.2 +/- 15.6 vs 10.0 +/- 26 mL).

CONCLUSION

The 3D-CD determination of CO is feasible and accurate. Compared with previous noninvasive modalities, 3D-CD has the advantages of independence of geometric assumptions and ease of image acquisition and analysis.

Anti-inflammatory Strategies and Hemostatic Agents: Old Drugs, New Ideas

Hemostatic abnormalities occur following injury associated with both cardiac and noncardiac surgery. These changes are part of inflammatory pathways with signaling mechanisms that link these diverse pathways. The inflammatory response to surgery is exacerbated by allogeneic blood transfusion by enhancing intrinsic inflammatory activity and directly increasing plasma levels of inflammatory mediators. Surgical patients can be preventively treated with pharmacologic agents to modulate inflammatory responses. Multiple studies have reported preventive pharmacologic therapies to reduce bleeding and the need for allogeneic transfusions in surgery. Strategies for cardiac surgical patients during cardiopulmonary bypass include administration of either lysine analogs, such as epsilon aminocaproic acid and tranexamic acid, or the serine protease inhibitor aprotinin.

Injury in the Elderly and End-of-Life Decisions

The elderly constitute the fastest growing sector of the population of the United Stated and geriatric trauma patients are presenting for care with increasing frequency. These patients are challenging particularly because of their vulnerability to severe injury, limited physiologic response to stress, and frequent presence of comorbid medical conditions complicating care. Many elderly trauma victims require prolonged intensive care and some fail to improve or succumb despite the best efforts because of the extent of their injuries and their underlying disease. These patients may present profound ethical challenges for trauma surgeons as the goals of care shift from salvage to end-of-life care.

Pulmonary artery catheter and fluid management in acute lung injury and the acute respiratory distress syndrome

The PAC provides a wealth of information about circulatory and respiratory systems and intravascular fluid volume over time. Specifically, the PAC allows measurement of central venous and pulmonary arterial pressure, pulmonary artery occlusion pressure, mixed venous blood gases, and indicator-dilution cardiac output. Based on these quantitative date, systemic and pulmonary vascular resistance can be derived. The PAC is frequently used in patients with ALI and ARDS, both to confirm the diagnosis and to optimize hemodynamic management. In this article, we review the evidence on the use of the PAC in patients with ALI/ARDS, paying particular attention to the recently published fluid and catheter treatment trial by the ARDS Clinical Trials Network.

New horizons: NT-proBNP for risk stratification of patients with shock in the intensive care unit

B-type natriuretic peptide (BNP) and amino-terminal pro-BNP (NT-proBNP) are promising cardiac biomarkers that have recently been shown to be of diagnostic value in decompensated heart failure, acute coronary syndromes and other conditions resulting in myocardial stretch and volume overload. In view of the high prevalence of cardiac disorders in the intensive care unit, the experience of elevated natriuretic peptide levels in the critically ill might be of enormous diagnostic and therapeutic value. BNP and NT-proBNP levels rise to different degrees in critical illness and may also serve as markers of severity and prognosis in diseases beyond acute or chronic heart failure. The diagnostic and prognostic use of natriuretic peptides in the intensive care setting for patients with various forms of shock could be an attractive alternative as noninvasive markers of cardiac dysfunction that could obviate the need for pulmonary artery catheterization in some patients.

[Pulmonary artery catheter in anaesthesiology and intensive care medicine]

The indication for the use of the pulmonary artery catheter (PAC) in high-risk patients is still a matter of discussion. Observational studies suggested that the use of the PAC did not result in decreased mortality but may even lead to increased mortality and morbidity. Therefore, a number of randomized controlled trials have been performed throughout recent years in patients suffering from sepsis/ARDS, congestive heart failure, multi-organ failure and those undergoing high-risk non-cardiac surgery. The majority of recent randomized studies failed to demonstrate any benefit of the PAC with respect to mortality and morbidity. However, the use of the PAC was also regularly not associated with an increase in morbidity and/or mortality. This review gives an overview of measurement parameters obtained by the current generation of PACs, alternatives to the PAC and recent studies on the use of the PAC in clinical practice.

Real-time Three-dimensional Color Doppler Echocardiography Overcomes the Inaccuracies of Spectral Doppler for Stroke Volume Calculation

Real-time 3-dimensional echocardiography is increasingly used in clinical cardiology. Studies have been shown that this technique can be accurately used to assess both cardiac mass and chamber volumes. We review the work showing that real-time 3-dimensional Doppler echocardiography can be used to accurately calculate intracardiac flow volumes that can potentially be used to assess cardiac function, intracardiac shunt, and valve regurgitation.

Pulmonary-artery versus central venous catheter to guide treatment of acute lung injury

BACKGROUND

The balance between the benefits and the risks of pulmonary-artery catheters (PACs) has not been established.

METHODS

We evaluated the relationship of benefits and risks of PACs in 1000 patients with established acute lung injury in a randomized trial comparing hemodynamic management guided by a PAC with hemodynamic management guided by a central venous catheter (CVC) using an explicit management protocol. Mortality during the first 60 days before discharge home was the primary outcome.

RESULTS

The groups had similar baseline characteristics. The rates of death during the first 60 days before discharge home were similar in the PAC and CVC groups (27.4 percent and 26.3 percent, respectively; P=0.69; absolute difference, 1.1 percent; 95 percent confidence interval, -4.4 to 6.6 percent), as were the mean (+/-SE) numbers of both ventilator-free days (13.2+/-0.5 and 13.5+/-0.5; P=0.58) and days not spent in the intensive care unit (12.0+/-0.4 and 12.5+/-0.5; P=0.40) to day 28. PAC-guided therapy did not improve these measures for patients in shock at the time of enrollment. There were no significant differences between groups in lung or kidney function, rates of hypotension, ventilator settings, or use of dialysis or vasopressors. Approximately 90 percent of protocol instructions were followed in both groups, with a 1 percent rate of crossover from CVC- to PAC-guided therapy. Fluid balance was similar in the two groups, as was the proportion of instructions given for fluid and diuretics. Dobutamine use was uncommon. The PAC group had approximately twice as many catheter-related complications (predominantly arrhythmias).

CONCLUSIONS

PAC-guided therapy did not improve survival or organ function but was associated with more complications than CVC-guided therapy. These results, when considered with those of previous studies, suggest that the PAC should not be routinely used for the management of acute lung injury. (ClinicalTrials.gov number, NCT00281268.).

A review of the application of propensity score methods yielded increasing use, advantages in specific settings, but not substantially different estimates compared with conventional multivariable methods

OBJECTIVE

Propensity score (PS) analyses attempt to control for confounding in nonexperimental studies by adjusting for the likelihood that a given patient is exposed. Such analyses have been proposed to address confounding by indication, but there is little empirical evidence that they achieve better control than conventional multivariate outcome modeling.

STUDY DESIGN AND METHODS

Using PubMed and Science Citation Index, we assessed the use of propensity scores over time and critically evaluated studies published through 2003.

RESULTS

Use of propensity scores increased from a total of 8 reports before 1998 to 71 in 2003. Most of the 177 published studies abstracted assessed medications (N=60) or surgical interventions (N=51), mainly in cardiology and cardiac surgery (N=90). Whether PS methods or conventional outcome models were used to control for confounding had little effect on results in those studies in which such comparison was possible. Only 9 of 69 studies (13%) had an effect estimate that differed by more than 20% from that obtained with a conventional outcome model in all PS analyses presented.

CONCLUSIONS

Publication of results based on propensity score methods has increased dramatically, but there is little evidence that these methods yield substantially different estimates compared with conventional multivariable methods.

Practical sources of error in measuring pulmonary artery occlusion pressure: a study in participants of a special intensivist training program of The Scandinavian Society of Anaesthesiology and Intensive Care Medicine (SSAI)

BACKGROUND

Physiological data obtained with the pulmonary artery catheter (PAC) are susceptible to errors in measurement and interpretation. Little attention has been paid to the relevance of errors in hemodynamic measurements performed in the intensive care unit (ICU). The aim of this study was to assess the errors related to the technical aspects (zeroing and reference level) and actual measurement (curve interpretation) of the pulmonary artery occlusion pressure (PAOP).

METHODS

Forty-seven participants in a special ICU training program and 22 ICU nurses were tested without pre-announcement. All participants had previously been exposed to the clinical use of the method. The first task was to set up a pressure measurement system for PAC (zeroing and reference level) and the second to measure the PAOP.

RESULTS

The median difference from the reference mid-axillary zero level was - 3 cm (-8 to + 9 cm) for physicians and -1 cm (-5 to + 1 cm) for nurses. The median difference from the reference PAOP was 0 mmHg (-3 to 5 mmHg) for physicians and 1 mmHg (-1 to 15 mmHg) for nurses. When PAOP values were adjusted for the differences from the reference transducer level, the median differences from the reference PAOP values were 2 mmHg (-6 to 9 mmHg) for physicians and 2 mmHg (-6 to 16 mmHg) for nurses.

CONCLUSIONS

Measurement of the PAOP is susceptible to substantial error as a result of practical mistakes. Comparison of results between ICUs or practitioners is therefore not possible.

Methods to adjust for bias and confounding in critical care health services research involving observational data

Observational data are often used for research in critical care. Unlike randomized controlled trials, where randomization theoretically balances confounding factors, studies involving observational data pose the challenge of how to adjust appropriately for the bias and confounding that are inherent when comparing two or more groups of patients. This paper first highlights the potential sources of bias and confounding in critical care research and then reviews the statistical techniques available (matching, stratification, multivariable adjustment, propensity scores, and instrumental variables) to adjust for confounders. Finally, issues that need to be addressed when interpreting the results of observational studies, such as residual confounding, causality, and missing data, are discussed.

Survival, Hemodynamics, and Tissue Oxygenation after Head Trauma

BACKGROUND

The aims of this study were to describe the early time course of hemodynamic and tissue perfusion and oxygenation patterns in survivors and nonsurvivors after head injury; to suggest physiologic mechanisms responsible for the observed patterns; and to evaluate postinjury parameters that might be useful for treatment. The hypothesis was that reduced hemodynamics and tissue oxygenation and reduced arterial oxygen saturation affect outcomes.

STUDY DESIGN

Sixty patients with head trauma were noninvasively monitored on arrival in the emergency department to assess the temporal hemodynamic patterns associated with head injury; patients who were brain dead were excluded because they have very different hemodynamic patterns. Cardiac index, mean arterial pressure, and heart rate were monitored to assess cardiac function, pulse oximetry to reflect changes in pulmonary function, and transcutaneous oxygen and carbon dioxide to reflect tissue perfusion function. Patients were stratified by inhospital survival outcomes, the Glasgow Coma Scale, and the presence or absence of associated somatic injuries.

RESULTS

When all head injured patients were considered together, the predominant findings were high cardiac index, hypertension, mild tachycardia, normal pulmonary function, and reduced tissue oxygenation. The subset of survivors and those with high Glasgow Coma Scale had greater than normal cardiac index responses (4.02 +/- 0.01 (SEM) L/min/m2, p < 0.01 versus normal) and better tissue oxygenation (217 +/- 2 mmHg PtcO2/FiO2) than nonsurvivors (70 +/- 3 mmHg, p < 0.01) and those with low Glasgow Coma Scale (160 +/- 2, p < 0.05). Patterns of patients with associated somatic injuries were similar to those with isolated head injury.

CONCLUSIONS

The study suggested that survivors' cardiac index, tissue oxygenation, and arterial oxygen saturation may be considered as markers of resuscitation. Nonsurvivors of head injury had normal blood flow with reduced tissue oxygenation that might have contributed to unfavorable outcomes.

Ambulatory Hemodynamic Monitoring From an Implanted Device: Components of Continuous 24-Hour Pressures That Correlate to Supine Resting Conditions and Acute Right Heart Catheterization

Information from an implantable hemodynamic monitoring system (IHM) aids in management of patients with heart failure. This study identified which components of 24-hour IHM data best estimate resting conditions. Thirty-two patients with heart failure received an IHM in the right ventricular (RV) outflow tract. RV hemodynamics were divided into seven components of a 24-hour recording and were compared with resting supine values. Ambulatory pressures approximating rest were then compared with acute invasive catheterization values. Resting RV pressures from the IHM averaged 41+/-16/10+/-6 mm Hg and estimated pulmonary artery diastolic pressure was 21+/-8 mm Hg. Nighttime (midnight to 4 a.m.) minimum pressures from the IHM best approximated supine resting conditions. RV and pulmonary artery pressures during catheterization were higher than the nighttime minimum, although RV diastolic pressure was not statistically different. Minimum RV and pulmonary artery pressures during nighttime approximate observed resting conditions; invasive catheterization pressures are higher than IHM resting values.

The Utility of Microvascular Perfusion Assessment in Heart Failure: A Pilot Study

BACKGROUND

The evaluation of heart failure is routinely based on subjective patient symptoms and physician examination. We propose the noninvasive evaluation of microvascular and global perfusion can objectify heart failure severity and provide additional prognostic information.

METHODS

A prospective, observational pilot study of patients previously stratified into New York Heart Association (NYHA) heart failure classes and who after a routine cardiology clinic evaluation were felt to be at their stable baseline state. Measurements included: thoracic impedance (Zo), hypothenar tissue hemoglobin oxygen saturation (StO2), and Zo-derived cardiac index (CI). To determine if adverse outcomes (hospitalization or death) occurred, patients or their families were contacted 6 months after enrollment and their charts reviewed. Monitor values between the NYHA classes were compared using analysis of variance. Values of those who later developed adverse outcomes were compared to patients who remained stable using a Student t-test (P < .05 considered significant). A Kaplan-Meier survival curve was used to describe the adverse outcome rate over time, and a Cox's proportional hazards model was used to relate perfusion values to adverse outcomes.

RESULTS

There were no differences in CI (P = .08), Zo (P = .38), or StO2 (P = .14) found between NYHA classes (n = 46). After 6 months, 6 patients required hospitalization for heart failure and 1 died. This group had lower StO2 values compared with the stable group (P = .015). The time course of the adverse events was found not to be due to chance alone when evaluated using a Kaplan-Meier curve and the StO2 was significantly associated with time to adverse outcome (P < .05).

CONCLUSIONS

Outpatient heart failure patients who later develop adverse outcomes have significantly lower StO2 values than those who remain stable. This suggests cardiac performance in stable heart failure patients may be better reflected at the microvascular level using measures such as StO2 as opposed to a global level using the physical exam or impedance cardiography. StO2 may serve as a predictor for future adverse events and as an adjunct to current evaluation techniques.

Goal directed therapy: how long can we wait?

Intensive monitoring and aggressive management of perioperative haemodynamics (goal directed therapy) have repeatedly been reported to reduce the significant morbidity and mortality associated with high risk surgery. It may not matter what particular monitor is used to assess cardiac output but it is essential to ensure adequate oxygen delivery. If this management cannot begin preoperatively, it is still worth beginning goal directed therapy in the immediate postoperative period.

Pulse contour analysis after normothermic cardiopulmonary bypass in cardiac surgery patients

Introduction

Monitoring of the cardiac output by continuous arterial pulse contour (CO_PiCCOpulse) analysis is a clinically validated procedure proved to be an alternative to the pulmonary artery catheter thermodilution cardiac output (CO_PACtherm) in cardiac surgical patients. There is ongoing debate, however, of whether the CO_PiCCOpulse is accurate after profound hemodynamic changes. The aim of this study was therefore to compare the CO_PiCCOpulse after cardiopulmonary bypass (CPB) with a simultaneous measurement of the CO_PACtherm.

Methods

After ethical approval and written informed consent, data of 45 patients were analyzed during this prospective study. During coronary artery bypass graft surgery, the aortic transpulmonary thermodilution cardiac output (CO_PiCCOtherm) and the CO_PACtherm were determined in all patients. Prior to surgery, the CO_PiCCOpulse was calibrated by triple transpulmonary thermodilution measurement of the CO_PiCCOtherm. After termination of CPB, the CO_PiCCOpulse was documented. Both CO_PACtherm and CO_PiCCOtherm were also simultaneously determined and documented.

Results

Regression analysis between CO_PACtherm and CO_PiCCOtherm prior to CPB showed a correlation coefficient of 0.95 (P < 0.001), and after CPB showed a correlation coefficient of 0.82 (P < 0.001). Bland-Altman analysis showed a mean bias and limits of agreement of 0.0 l/minute and -1.4 to +1.4 l/minute prior to CPB and of 0.3 l/minute and -1.9 to +2.5 l/minute after CPB, respectively. Regression analysis of CO_PiCCOpulse versus CO_PiCCOtherm and of CO_PiCCOpulse versus CO_PACtherm after CPB showed a correlation coefficient of 0.67 (P < 0.001) and 0.63 (P < 0.001), respectively. Bland-Altman analysis showed a mean bias and limits of agreement of -1.1 l/minute and -1.9 to +4.1 l/minute versus -1.4 l/minute and -4.8 to +2.0 l/minute, respectively.

Conclusion

We observed an excellent correlation of CO_PiCCOtherm and CO_PACtherm measurement prior to CPB. Pulse contour analysis did not yield reliable results with acceptable accuracy and limits of agreement under difficult conditions after weaning from CPB in cardiac surgical patients. The pulse contour analysis thus should be re-calibrated as soon as possible, to prevent false therapeutic consequences.

Evaluation of hemodynamic measurements, including lithium dilution cardiac output, in anesthetized dogs undergoing ovariohysterectomy

OBJECTIVE

To measure cardiac output in healthy female anesthetized dogs by use of lithium dilution cardiac output and determine whether changes in mean arterial pressure were caused by changes in cardiac output or systemic vascular resistance.

DESIGN

Prospective clinical study.

ANIMALS

20 healthy female dogs.

PROCEDURE

Dogs were anesthetized for ovariohysterectomy. Ten dogs breathed spontaneously throughout anesthesia, and 10 dogs received intermittent positive-pressure ventilation. Cardiovascular and respiratory measurements, including lithium dilution cardiac output, were performed during anesthesia and surgery.

RESULTS

Mean arterial pressure and systemic vascular resistance index were low after induction of anesthesia and just prior to surgery and increased significantly after surgery began. Cardiac index (cardiac output indexed to body surface area) did not change significantly throughout anesthesia and surgery.

CONCLUSIONS AND CLINICAL RELEVANCE

Results provide baseline data for cardiac output and cardiac index measurements during clinical anesthesia and surgery in dogs. Changes in mean arterial pressure do not necessarily reflect corresponding changes in cardiac index.

Acute respiratory distress syndrome: a historical perspective

Though well described even in ancient writings, the acute respiratory distress syndrome (ARDS) gained major medical attention with the availability of mechanical ventilation and establishment of intensive care units. In the 50 years since this beginning there have been remarkable advances in the understanding of the etiology, physiology, histology, and epidemiology of this often lethal complication of common human maladies. Until recently, improvements in outcome have mainly followed improvements in intensive care unit operation and their associated life support systems, and have not come through discoveries made in the course of prospective randomized trials. In spite of the remarkable increase in research focused on ARDS, there remain a large number of unanswered clinical questions that are potentially extremely important with regard to short-term morbidity as well as long-term outcome. The ARDS Clinical Trials Network study of tidal volume has proven that randomized trials in ARDS with positive results are possible even when using difficult primary outcome measures such as mortality or ventilator-free days. Therefore, the rich combination of new trial strategies, potential treatments, experienced investigators, and increasingly standardized routine care set the stage for rapid advances to be made in the short- and long-term outcomes of this devastating syndrome.

A matched-cohort study of selected clinical and utilization outcomes for an asthma care support program

Estimating the economic and clinical impact of asthma disease management programs traditionally has relied on non-experimental designs and employed matching or stratification methods with limited success. Selecting similar comparison subjects is problematic since subjects must be compared across numerous pretreatment factors. In cases where treatment and comparison subjects differ greatly on observed characteristics, conclusions may be particularly sensitive to an incorrectly specified model used for matching. A propensity score method constructs matched samples of treated-control pairs, addresses program selection bias, and reduces bias in estimates of treatment effects. To investigate the program effects of an asthma care support program delivered to high-risk asthmatics (persons with a previous inpatient admission, emergency department [ED] visit, or observation visit), we conducted a matched-cohort study on 196 participants. Using administrative claims data and selected clinical indicators, we analyzed hospitalization, ED, and physician office visit rates to estimate effects of program enrollment. Total hospitalizations, asthma-related hospitalizations, bed days, and ED visits for participants were lower and statistically different from that of the matched-cohort group during the program period, suggesting the beneficial effects of monitoring, education, and counseling activities for participants. Where controlled randomized clinical trials cannot be performed because of ethical, cost, or feasibility issues, the use of propensity scores provides an alternative for estimating treatment effects using observational data. This study employs a propensity score-matching methodology to select a subset of comparison units most comparable to treatment units, and documents the beneficial outcomes of participation in an asthma care support program.

Recommended guidelines for reviewing, reporting, and conducting research on post-resuscitation care: The Utstein style

The aim of this report is to establish recommendations for reviewing, reporting, and conducting research during the post-resuscitation period in hospital. It defines data that are needed for research and more specialised registries and therefore supplements the recently updated Utstein template for resuscitation registries. The updated Utstein template and the out-of-hospital "Chain of Survival" describe factors of importance for successful resuscitation up until return of spontaneous circulation (ROSC). Several factors in the in-hospital phase after ROSC are also likely to affect the ultimate outcome of the patient. Large differences in survival to hospital discharge for patients admitted alive are reported between hospitals. Therapeutic hypothermia has been demonstrated to improve the outcome, and other factors such as blood glucose, haemodynamics, ventilatory support, etc., might also influence the result. No generally accepted, scientifically based protocol exists for the post-resuscitation period in hospital, other than general brain-oriented intensive care. There is little published information on this in-hospital phase. This statement is the result of a scientific consensus development process started as a symposium by a task force at the Utstein Abbey, Norway, in September 2003. Suggested data are defined as core and supplementary and include the following categories: pre-arrest co-morbidity and functional status, cause of death, patients' quality of life, in-hospital system factors, investigations and treatment, and physiological data at various time points during the first three days after admission. It is hoped that the publication of these recommendations will encourage research into the in-hospital post-resuscitation phase, which we propose should be included in the chain-of-survival as a fifth ring. Following these recommendations should enable better understanding of the impact of different in-hospital treatment strategies on outcome.

Management of septic shock with a norepinephrine-based haemodynamic algorithm

Management of septic shock (SS) with a norepinephrine (noradrenaline)-based haemodynamic algorithm.

INTRODUCTION

The choice of the best vasopressor for haemodynamic management of septic shock is controversial. Nevertheless, very few studies have been focused on evaluating different management algorithms. The aim of this study was to evaluate the performance of a norepinephrine (NE)-based management protocol. Experience with NE as the initial vasopressor, even if not comparative, could bring relevant data for planning future trails. We also wanted to evaluate the compliance of critical care physicians and nurses with haemodynamic management protocol.

PATIENTS AND METHOD

A norepinephrine-based algorithm for the management of septic shock that commands different sequential interventions according to its requirements, was applied prospectively to 100 consecutive septic shock patients.

RESULTS

Norepinephrine was used as the first vasoactive drug in all patients with a maximum dose of 0.31+/-0.3 microg kg(-1)min(-1) and an ICU mortality of 33%. Physicians applied correctly all the steps of the algorithm in 92% of the patients. Applying the algorithm, avoided the use of pulmonary artery catheter in 31 patients and led to use of lower doses of vasoactive agents than in many other clinical experiences.

CONCLUSION

In conclusion, our data support extended use of an algorithm based on norepinephrine for treating septic shock patients. This is the first clinical study that uses NE as the initial vasopressor drug systematically, and although not comparative, the mortality rates adjusted to APACHE II, are comparable to other studies. It also gives support for future clinical trials comparing norepinephrine with dopamine in this setting.

Comparison of thermal dilution and electrical impedance dilution methods for measurement of cardiac output in standing and exercising horses

OBJECTIVE

To compare cardiac output measured in the pulmonary artery and a carotid artery by use of thermal and electrical impedance dilution. Animals-7 fit, clinically normal Standardbreds between 2 and 5 years of age.

PROCEDURE

Transient changes in electrical impedance and temperature of blood were induced by bolus injections of ice-cold saline hypertonic (6% and 9% NaCl) solutions. Cardiac output was calculated by applying Stewart-Hamilton principles to the indicator dilution transients. Measurements were made during sequential exercise episodes on a level treadmill over approximately an 8-fold range of cardiac output values.

RESULTS

We detected agreement between cardiac output determined by use of electrical impedance dilution at the pulmonary artery and carotid artery. Cardiac output from thermal dilution measured at the carotid artery exceeded that measured at the pulmonary artery. Cardiac output from the thermal dilution technique exceeded cardiac output from the electrical impedance dilution technique at both locations.

CONCLUSIONS AND CLINICAL RELEVANCE

The electrical impedance indicator is conserved on first transit; therefore cardiac output measured by electrical impedance dilution at the carotid artery is reliable over a large range of values. Thermal dilution provides a larger estimate of cardiac output, compared with the electrical impedance dilution technique, probably because of a loss of indicator. The transpulmonary electrical impedance dilution technique may have potential for clinical application, particularly in animals in which catheterization of the pulmonary artery is not appropriate or blood loss must be minimized.

A matched-cohort study of health services utilization outcomes for a heart failure disease management program

Chronic disease is the leading cause of illness, disability, and death in the United States, affecting nearly 100 million Americans. Heart failure alone affects nearly 4.9 million Americans, with another 550,000 newly diagnosed cases each year. The aim of this study was to investigate the program effects of a heart failure care support program. A two-group cohort study matching on propensity scores was used to investigate 277 heart failure care support program participants and corresponding matched non-participants. Measures used were rates of hospitalizations, emergency department visits, physician office visits, and heart failure-related prescription drug use and procedures. Relative to the matched control group, program participants experienced 26.3% (p = 0.023) fewer inpatient admissions, 37.9% (p = 0.018) inpatient bed days, 33.3% (p = 0.059) more beta blocker use, 76.7% (p = 0.048) more alpha blocker use, 22.2% (p = 0.006) more lipid panels, 13.4% (p = 0.019) more electrocardiographies, 50.0% (p = 0.008) fewer cardiac catheterizations, and 94.6% (p = 0.014) more pneumonia vaccinations. The current study employs a propensity score matching methodology to select a subset of comparison patients most comparable to treatment patients, and documents the beneficial health services outcomes of participation in a heart failure care support program.

NT-ProBNP in Acute Heart Failure: Correlation With Invasively Measured Hemodynamic Parameters During Recompensation

BACKGROUND

N-terminal brain natriuretic peptide (NT-proBNP) level is elevated in patients with acute and chronic heart failure. This study addresses whether NT-proBNP correlates with invasively measured hemodynamic parameters and whether a decrease of NT-proBNP over time correlates with invasively monitored hemodynamic improvement.

METHODS AND RESULTS

Twenty consecutive patients with acute exacerbation of chronic heart failure (New York Heart Association class III-IV) were included in this prospective study. NT-proBNP and hemodynamic measurements by balloon-tipped pulmonary artery catheter were performed simultaneously. Recompensation strategies included vasodilators, diuretics, and inotropes. The patients were divided in 2 subgroups. Group A, by definition, had a hemodynamic improvement over 24 hours with an increase of cardiac index of >30% and a decrease of pulmonary capillary wedge pressure of >30%. Group B did not show a hemodynamic improvement. Group A had a decline of NT-proBNP levels to 42% of the baseline value over 32 hours. In group B, the NT-pro BNP levels did not change significantly over 32 hours.

CONCLUSION

The decrease of NT-proBNP correlates with hemodynamic improvement in patients with decompensated heart failure. The relative changes of NT-proBNP seem to be a reliable diagnostic tool in monitoring these patients. There results have been confirmed in a larger patient group.

Clinical review: New technologies -- venturing out of the intensive care unit

The delivery of critical care is no longer limited to the intensive care unit. The information gained by utilization of new technologies has proven beneficial in some populations. Research into earlier and more widespread use of these modalities may prove to be of even greater benefit to critically ill patients.

Equipment review: the success of early goal-directed therapy for septic shock prompts evaluation of current approaches for monitoring the adequacy of resuscitation

A recent trial utilizing central venous oxygen saturation (SCVO₂) as a resuscitation marker in patients with sepsis has resulted in its inclusion in the Surviving Sepsis Campaign guidelines. We review the evidence behind SCVO₂ and its relationship to previous trials of goal-directed therapy. We compare SCVO₂ to other tools for assessing the adequacy of resuscitation including physical examination, biochemical markers, pulmonary artery catheterization, esophageal Doppler, pulse contour analysis, echocardiography, pulse pressure variation, and tissue capnometry. It is unlikely that any single technology can improve outcome if isolated from an organized pattern of early recognition, algorithmic resuscitation, and frequent reassessment. This article includes a response to the journal's Health Technology Assessment questionnaire by the manufacturer of the SCVO₂ catheter.

Using computerized medical databases to measure and to improve the quality of intensive care

This article reviews the potential for using computerized databases to measure the quality of care in the intensive care unit. There are 2 types of computerized databases used to assess quality of care: administrative databases used primarily for purposes other than medical care and electronic medical record databases collected specifically for clinical purposes. Quality of care is a difficult property to measure but is generally assessed along 3 domains: structure, process, and outcome. There are several problems with using computerized medical databases to measure and improve quality of care. Many factors known to be important to measuring the severity of illness and process of care in critically ill patients are not captured in routine administrative databases. The criteria for the ethical use of electronic medical record data for research, clinical care, and quality improvement are identical to those that should be applied to using paper medical records. Standardizing a minimal intensive care unit dataset, identifying and measuring optimal processes of care, and understanding the limits of risk adjusted outcomes are all important steps in the process of the optimal use of computerized databases to study and improve the quality of care in the intensive care unit.

Application of a propensity score approach for risk adjustment in profiling multiple physician groups on asthma care

OBJECTIVES

To develop a propensity score-based risk adjustment method to estimate the performance of 20 physician groups and to compare performance rankings using our method to a standard hierarchical regression-based risk adjustment method.

DATA SOURCES/STUDY SETTING

Mailed survey of patients from 20 California physician groups between July 1998 and February 1999.

STUDY DESIGN

A cross-sectional analysis of physician group performance using patient satisfaction with asthma care. We compared the performance of the 20 physician groups using a novel propensity score-based risk adjustment method. More specifically, by using a multinomial logistic regression model we estimated for each patient the propensity scores, or probabilities, of having been treated by each of the 20 physician groups. To adjust for different distributions of characteristics across groups, patients cared for by a given group were first stratified into five strata based on their propensity of being in that group. Then, strata-specific performance was combined across the five strata. We compared our propensity score method to hierarchical model-based risk adjustment without using propensity scores. The impact of different risk-adjustment methods on performance was measured in terms of percentage changes in absolute and quintile ranking (AR, QR), and weighted kappa of agreement on QR.

RESULTS

The propensity score-based risk adjustment method balanced the distributions of all covariates among the 20 physician groups, providing evidence for validity. The propensity score-based method and the hierarchical model-based method without propensity scores provided substantially different rankings (75 percent of groups differed in AR, 50 percent differed in QR, weighted kappa=0.69).

CONCLUSIONS

We developed and tested a propensity score method for profiling multiple physician groups. We found that our method could balance the distributions of covariates across groups and yielded substantially different profiles compared with conventional methods. Propensity score-based risk adjustment should be considered in studies examining quality comparisons.

[Cardiopulmonary monitoring in gastroenterological and renal emergencies]

Predominantly elderly and multimorbide patients require frequently intensive care observation and treatment due to acute gastrointestinal and renal disease. Manifest circulatory and rhythm instability, acute heart failure and severe metabolic or electrolyte derangements present indications for submission to a critical care unit. Stabilization of vital functions, control of specific therapeutic procedures (e. g. renal replacement therapy), and early recognition of secondary complications belong to the tasks of intensive care. Beyond a baseline monitoring available procedures comprises a broad spectrum from pulseoxymetrie to pulmonary artery catheter monitoring depending of the need of the individual patient.

The prognostic use of right heart catheterization data in patients with advanced heart failure: How relevant are invasive procedures in the risk stratification of advanced heart failure in the era of neurohormones?

BACKGROUND

Right heart catheterization long has been a routine investigation in advanced heart failure, and its measurements have been linked variably to prognosis. However, in the modern era, newer potential markers of prognosis are coming to light. This study reconsiders the use of right heart catheterization data and compares their use to that of N-terminal pro-brain natriuretic peptide (NT-proBNP), a neurohormone linked with prognosis in chronic heart failure.

METHODS

We assessed prospectively the prognostic potential of baseline right heart catheterization data in 97 consecutive patients with advanced heart failure referred to the Scottish Cardiopulmonary Transplant Unit for consideration of cardiac transplantation. Patients underwent baseline routine investigation, including right heart catheterization and blood draws for NT-proBNP analysis. Patients were observed for a median of 370 days.

RESULTS

The primary end-point of all-cause mortality was reached in 17 patients (17.5%), and the secondary end-point of all-cause mortality or urgent cardiac transplantation was reached in 21 (21.6%) patients. Univariate predictors of all-cause mortality included pulmonary artery systolic pressure (PASP), pulmonary artery wedge pressure (PAWP), and NT-proBNP concentration greater than their median values. Univariate predictors of the secondary end-point included right atrial pressure, PASP, PAWP, and NT-proBNP concentration greater than their median values, and left ventricular ejection fraction, cardiac output, and cardiac index less than their median values. In multivariate analyses, however, only NT-proBNP concentration remained an independent predictor of all-cause mortality. Both NT-proBNP concentration and PAWP were independent predictors of all-cause mortality and of the need for urgent cardiac transplantation.

CONCLUSION

Baseline data from routine right heart catheterization are of limited prognostic use in advanced heart failure. A baseline NT-proBNP concentration is a superior, non-invasive method of risk stratification in this era of measuring neurohormones.