Comparison of calibrated and uncalibrated arterial pressure-based cardiac output monitors during orthotopic liver transplantation

Arterial pressure-based cardiac output monitors (APCOs) are increasingly used as alternatives to thermodilution. Validation of these evolving technologies in high-risk surgery is still ongoing. In liver transplantation, FloTrac-Vigileo (Edwards Lifesciences) has limited correlation with thermodilution, whereas LiDCO Plus (LiDCO Ltd.) has not been tested intraoperatively. Our goal was to directly compare the 2 proprietary APCO algorithms as alternatives to pulmonary artery catheter thermodilution in orthotopic liver transplantation (OLT). The cardiac index (CI) was measured simultaneously in 20 OLT patients at prospectively defined surgical landmarks with the LiDCO Plus monitor (CI(L)) and the FloTrac-Vigileo monitor (CI(V)). LiDCO Plus was calibrated according to the manufacturer's instructions. FloTrac-Vigileo did not require calibration. The reference CI was derived from pulmonary artery catheter intermittent thermodilution (CI(TD)). CI(V)-CI(TD) bias ranged from -1.38 (95% confidence interval = -2.02 to -0.75 L/minute/m(2), P = 0.02) to -2.51 L/minute/m(2) (95% confidence interval = -3.36 to -1.65 L/minute/m(2), P < 0.001), and CI(L)-CI(TD) bias ranged from -0.65 (95% confidence interval = -1.29 to -0.01 L/minute/m(2), P = 0.047) to -1.48 L/minute/m(2) (95% confidence interval = -2.37 to -0.60 L/minute/m(2), P < 0.01). For both APCOs, bias to CI(TD) was correlated with the systemic vascular resistance index, with a stronger dependence for FloTrac-Vigileo. The capability of the APCOs for tracking changes in CI(TD) was assessed with a 4-quadrant plot for directional changes and with receiver operating characteristic curves for specificity and sensitivity. The performance of both APCOs was poor in detecting increases and fair in detecting decreases in CI(TD). In conclusion, the calibrated and uncalibrated APCOs perform differently during OLT. Although the calibrated APCO is less influenced by changes in the systemic vascular resistance, neither device can be used interchangeably with thermodilution to monitor cardiac output during liver transplantation.

Students' knowledge of symptoms and risk factors of potential life-threatening medical conditions

In order to assess medical students' knowledge of Basic Life Support (BLS) principles, we defined a minimal knowledge (MK) of three life-threatening medical conditions that should be universally known: cardiac arrest, heart attack and stroke, and compared the results with those of laypersons.

Secondary prevention through cardiac rehabilitation: physical activity counselling and exercise training: key components of the position paper from the Cardiac Rehabilitation Section of the European Association of Cardiovascular Prevention and Rehabilitation

Cardiac patients after an acute event and/or with chronic heart disease deserve special attention to restore their quality of life and to maintain or improve functional capacity. They require counselling to avoid recurrence through a combination of adherence to a medication plan and adoption of a healthy lifestyle. These secondary prevention targets are included in the overall goal of cardiac rehabilitation (CR). Cardiac rehabilitation can be viewed as the clinical application of preventive care by means of a professional multi-disciplinary integrated approach for comprehensive risk reduction and global long-term care of cardiac patients. The CR approach is delivered in tandem with a flexible follow-up strategy and easy access to a specialized team. To promote implementation of cardiac prevention and rehabilitation, the CR Section of the EACPR (European Association of Cardiovascular Prevention and Rehabilitation) has recently completed a Position Paper, entitled 'Secondary prevention through cardiac rehabilitation: A condition-oriented approach'. Components of multidisciplinary CR for seven clinical presentations have been addressed. Components include patient assessment, physical activity counselling, exercise training, diet/nutritional counselling, weight control management, lipid management, blood pressure monitoring, smoking cessation, and psychosocial management. Cardiac rehabilitation services are by definition multi-factorial and comprehensive, with physical activity counselling and exercise training as central components in all rehabilitation and preventive interventions. Many of the risk factor improvements occurring in CR can be mediated through exercise training programmes. This call-for-action paper presents the key components of a CR programme: physical activity counselling and exercise training. It summarizes current evidence-based best practice for the wide range of patient presentations of interest to the general cardiology community.

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: complex congenital cardiac lesions

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. They have distinctive forms of heart failure and their cardiac disease can be associated with pulmonary hypertension, thromboemboli, complex arrhythmias and sudden death. Medical aspects that need to be considered relate to the long-term and multisystemic effects of single ventricle physiology, cyanosis, systemic right ventricles, complex intracardiac baffles and failing subpulmonary right ventricles. Since the 2001 Canadian Cardiovascular Society Consensus Conference report on the management of adults with CHD, there have been significant advances in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. Part III of the guidelines includes recommendations for the care of patients with complete transposition of the great arteries, congenitally corrected transposition of the great arteries, Fontan operations and single ventricles, Eisenmenger's syndrome, and cyanotic heart disease. Topics addressed include genetics, clinical outcomes, recommended diagnostic workup, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy risk and follow-up requirements. The complete document consists of four manuscripts, which are published online in the present issue of The Canadian Journal of Cardiology. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.

Value of the SYNTAX score for risk assessment in the all-comers population of the randomized multicenter LEADERS (Limus Eluted from A Durable versus ERodable Stent coating) trial

OBJECTIVES: We aimed to assess the predictive value of the SYNTAX score (SXscore) for major adverse cardiac events in the all-comers population of the LEADERS (Limus Eluted from A Durable versus ERodable Stent coating) trial. BACKGROUND: The SXscore has been shown to be an effective predictor of clinical outcomes in patients with multivessel disease undergoing percutaneous coronary intervention. METHODS: The SXscore was prospectively collected in 1,397 of the 1,707 patients enrolled in the LEADERS trial (patients after surgical revascularization were excluded). Post hoc analysis was performed by stratifying clinical outcomes at 1-year follow-up, according to 1 of 3 SXscore tertiles. RESULTS: The 1,397 patients were divided into tertiles based on the SXscore in the following fashion: SXscore8 and 16 (SXhigh) (n=461). At 1-year follow-up, there was a significantly lower number of patients with major cardiac event-free survival in the highest tertile of SXscore (SXlow=92.2%, SXmid=91.1%, and SXhigh=84.6%; p<0.001). Death occurred in 1.5% of SXlow patients, 2.1% of SXmid patients, and 5.6% of SXhigh patients (hazard ratio [HR]: 1.97, 95% confidence interval [CI]: 1.29 to 3.01; p=0.002). The myocardial infarction rate tended to be higher in the SXhigh group. Target vessel revascularization was 11.3% in the SXhigh group compared with 6.3% and 7.8% in the SXlow and SXmid groups, respectively (HR: 1.38, 95% CI: 1.1 to 1.75; p=0.006). Composite of cardiac death, myocardial infarction, and clinically indicated target vessel revascularization was 7.8%, 8.9%, and 15.4% in the SXlow, SXmid, and SXhigh groups, respectively (HR: 1.47, 95% CI: 1.19 to 1.81; p<0.001). CONCLUSIONS: The SXscore, when applied to an all-comers patient population treated with drug-eluting stents, may allow prospective risk stratification of patients undergoing percutaneous coronary intervention. (LEADERS Trial Limus Eluted From A Durable Versus ERodable Stent Coating; NCT00389220).

Cardiac imaging after myocardial infarction

After myocardial infarction, optimal clinical management depends critically on cardiac imaging. Remodelling and heart failure, presence of inducible ischaemia, presence of dysfunctional viable myocardium, future risk of adverse events including risk of ventricular arrhythmias, need for anticoagulation, and other questions should be addressed by cardiac imaging. Strengths and weaknesses, recent developments, choice, and timing of the different non-invasive techniques are reviewed for this frequent clinical scenario.

Risk stratification of normotensive patients with acute symptomatic pulmonary embolism

Treatment guidelines recommend strong consideration of thrombolysis in patients with acute symptomatic pulmonary embolism (PE) that present with arterial hypotension or shock because of the high risk of death in this setting. For haemodynamically stable patients with PE, the categorization of risk for subgroups may assist with decision-making regarding PE therapy. Clinical models [e.g. Pulmonary Embolism Severity Index (PESI)] may accurately identify those at low risk of overall death in the first 3 months after the diagnosis of PE, and such patients might benefit from an abbreviated hospital stay or outpatient therapy. Though some evidence suggests that a subset of high-risk normotensive patients with PE may have a reasonable risk to benefit ratio for thrombolytic therapy, single markers of right ventricular dysfunction (e.g. echocardiography, spiral computed tomography, or brain natriuretic peptide testing) and myocardial injury (e.g. cardiac troponin T or I testing) have an insufficient positive predictive value for PE-specific mortality to drive decision-making toward such therapy. Recommendations for outpatient treatment or thrombolytic therapy for patients with PE necessitate further development of prognostic models and conduct of clinical trials that assess various treatment strategies.

Combinations of prognostic tools for identification of high-risk normotensive patients with acute symptomatic pulmonary embolism

In haemodynamically stable patients with acute symptomatic pulmonary embolism (PE), studies have not evaluated the usefulness of combining the measurement of cardiac troponin, transthoracic echocardiogram (TTE), and lower extremity complete compression ultrasound (CCUS) testing for predicting the risk of PE-related death.

Implantable cardioverter-defibrillator and cardiac resynchronization therapy in patients with left ventricular noncompaction

Patients with left ventricular noncompaction (LVNC) have an increased risk for life-threatening ventricular arrhythmias. The benefit from implantable cardioverter-defibrillators (ICD) in these patients has been investigated only in small series. Therefore, the aim of the present study was to analyze the clinical outcome of a larger population of patients with LVNC who were treated with an ICD.

Left atrial appendage closure with amplatzer cardiac plug in atrial fibrillation: initial European experience

In most patients with atrial fibrillation (AF) and stroke, there is thrombotic embolization from the left atrial appendage (LAA). Percutaneous closure of the LAA is a novel alternative for the treatment of patients with AF at a high risk of stroke, in whom long-term anticoagulation therapy is not possible or not desired. This study details the initial experience with the Amplatzer Cardiac Plug (ACP) in humans.

Cardiac troponin testing and the simplified Pulmonary Embolism Severity Index. The SWIss Venous ThromboEmbolism Registry (SWIVTER)

A low simplified Pulmonary Embolism Severity Index (sPESI), defined as age ≤80 years and absence of systemic hypotension, tachycardia, hypoxia, cancer, heart failure, and lung disease, identifies low-risk patients with acute pulmonary embolism (PE). It is unknown whether cardiac troponin testing improves the prediction of clinical outcomes if the sPESI is not low. In the prospective Swiss Venous Thromboembolism Registry, 369 patients with acute PE and a troponin test (conventional troponin T or I, highly sensitive troponin T) were enrolled from 18 hospitals. A positive test result was defined as a troponin level above the manufacturers assay threshold. Among the 106 (29%) patients with low sPESI, the rate of mortality or PE recurrence at 30 days was 1.0%. Among the 263 (71%) patients with high sPESI, 177 (67%) were troponin-negative and 86 (33%) troponin-positive; the rate of mortality or PE recurrence at 30 days was 4.6% vs. 12.8% (p=0.015), respectively. Overall, risk assessment with a troponin test (hazard ratio [HR] 3.39, 95% confidence interval [CI] 1.38-8.37; p=0.008) maintained its prognostic value for mortality or PE recurrence when adjusted for sPESI (HR 5.80, 95%CI 0.76-44.10; p=0.09). The combination of sPESI with a troponin test resulted in a greater area under the receiver-operating characteristic curve (HR 0.72, 95% CI 0.63-0.81) than sPESI alone (HR 0.63, 95% CI 0.57-0.68) (p=0.023). In conclusion, although cardiac troponin testing may not be required in patients with a low sPESI, it adds prognostic value for early death and recurrence for patients with a high sPESI.

Clinical outcomes of patients with severe aortic stenosis at increased surgical risk according to treatment modality

Objectives The aim of this study was to assess the role of transcatheter aortic valve implantation (TAVI) compared with medical treatment (MT) and surgical aortic valve replacement (SAVR) in patients with severe aortic stenosis (AS) at increased surgical risk. Background Elderly patients with comorbidities are at considerable risk for SAVR. Methods Since July 2007, 442 patients with severe AS (age: 81.7 ± 6.0 years, mean logistic European System for Cardiac Operative Risk Evaluation: 22.3 ± 14.6%) underwent treatment allocation to MT (n = 78), SAVR (n = 107), or TAVI (n = 257) on the basis of a comprehensive evaluation protocol as part of a prospective registry. Results Baseline clinical characteristics were similar among patients allocated to MT and TAVI, whereas patients allocated to SAVR were younger (p < 0.001) and had a lower predicted peri-operative risk (p < 0.001). Unadjusted rates of all-cause mortality at 30 months were lower for SAVR (22.4%) and TAVI (22.6%) compared with MT (61.5%, p < 0.001). Adjusted hazard ratios for death were 0.51 (95% confidence interval: 0.30 to 0.87) for SAVR compared with MT and 0.38 (95% confidence interval: 0.25 to 0.58) for TAVI compared with MT. Medical treatment (<0.001), older age (>80 years, p = 0.01), peripheral vascular disease (<0.001), and atrial fibrillation (p = 0.04) were significantly associated with all-cause mortality at 30 months in the multivariate analysis. At 1 year, more patients undergoing SAVR (92.3%) or TAVI (93.2%) had New York Heart Association functional class I/II as compared with patients with MT (70.8%, p = 0.003). Conclusions Among patients with severe AS with increased surgical risk, SAVR and TAVI improve survival and symptoms compared with MT. Clinical outcomes of TAVI and SAVR seem similar among carefully selected patients with severe symptomatic AS at increased risk.

Adverse cardiac events during catecholamine vasopressor therapy: a prospective observational study

PURPOSE: To determine the incidence of and risk factors for adverse cardiac events during catecholamine vasopressor therapy in surgical intensive care unit patients with cardiovascular failure. METHODS: The occurrence of any of seven predefined adverse cardiac events (prolonged elevated heart rate, tachyarrhythmia, myocardial cell damage, acute cardiac arrest or death, pulmonary hypertension-induced right heart dysfunction, reduction of systemic blood flow) was prospectively recorded during catecholamine vasopressor therapy lasting at least 12 h. RESULTS: Fifty-four of 112 study patients developed a total of 114 adverse cardiac events, an incidence of 48.2 % (95 % CI, 38.8-57.6 %). New-onset tachyarrhythmia (49.1 %), prolonged elevated heart rate (23.7 %), and myocardial cell damage (17.5 %) occurred most frequently. Aside from chronic liver diseases, factors independently associated with the occurrence of adverse cardiac events included need for renal replacement therapy, disease severity (assessed by the Simplified Acute Physiology Score II), number of catecholamine vasopressors (OR, 1.73; 95 % CI, 1.08-2.77; p = 0.02) and duration of catecholamine vasopressor therapy (OR, 1.01; 95 % CI, 1-1.01; p = 0.002). Patients developing adverse cardiac events were on catecholamine vasopressors (p < 0.001) and mechanical ventilation (p < 0.001) for longer and had longer intensive care unit stays (p < 0.001) and greater mortality (25.9 vs. 1.7 %; p < 0.001) than patients who did not. CONCLUSIONS: Adverse cardiac events occurred in 48.2 % of surgical intensive care unit patients with cardiovascular failure and were related to morbidity and mortality. The extent and duration of catecholamine vasopressor therapy were independently associated with and may contribute to the pathogenesis of adverse cardiac events.

Sonographic Assessment of Fetal Cardiac Function: Indirect Measurements of Fetal Cardiac Function, Newer Techniques and Clinical Applications

Noninvasive blood flow measurements based on Doppler ultrasound studies are the main clinical tool for studying the cardiovascular status of fetuses at risk for circulatory compromise. Usually, qualitative analysis of peripheral arteries and in particular clinical situations such as severe growth restriction or volume overload also of venous vessels close to the heart or of flow patterns in the heart is being used to gauge the level of compensation in a fetus. However, quantitative assessment of the driving force of the fetal circulation, the cardiac output remains an elusive goal in fetal medicine. This article reviews the methods for direct and indirect assessment of cardiac function and explains new clinical applications. Part 1 of this review describes the concept of cardiac function and cardiac output and the techniques that have been used to quantify output. Part 2 summarizes the use of arterial and venous Doppler studies in the fetus and gives a detailed description of indirect measurements of cardiac function (like indices derived from the duration of segments of the cardiac cycle) with current examples of their application.

Sonographic Assessment of Fetal Cardiac Function: Introduction and Direct Measurement of Cardiac Function

Noninvasive blood flow measurements based on Doppler ultrasound studies are the main clinical tool for studying the cardiovascular status in fetuses at risk for circulatory compromise. Usually, qualitative analysis of peripheral arteries and, in particular clinical situations such as severe growth restriction or volume overload, also of venous vessels close to the heart or of flow patterns in the heart are being used to gauge the level of compensation in a fetus. Quantitative assessment of the driving force of the fetal circulation, the cardiac output, however, remains an elusive goal in fetal medicine. This article reviews the methods for direct and indirect assessment of cardiac function and explains new clinical applications. Part 1 of this review describes the concept of cardiac function and cardiac output and the techniques that have been used to quantify output. Part 2 summarizes the use of arterial and venous Doppler studies in the fetus and gives a detailed description of indirect measures of cardiac function (like indices derived from the duration of segments of the cardiac cycle) with current examples of their application.