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Giora Landesberg

Publications and source records attributed to Giora Landesberg.

16 recordsLinked to original sources
PubMed2006

A clinical survival score predicts the likelihood to benefit from preoperative thallium scanning and coronary revascularization before major vascular surgery.

AIMS: Guidelines advocate selective non-invasive testing before major non-cardiac surgery, yet data defining who may benefit from such tests is lacking. We aimed to find the predictors that define patients who are most likely to benefit from preoperative cardiac testing and coronary revascularization (CR). METHODS AND RESULTS: In 624 consecutive major vascular surgery patients, the preoperative thallium scanning (PTS) results and subsequent CRs were correlated with long-term (3-15 years) survival. Of all patients, 510 (80.6%) had PTS, 154 (24.7%) had moderate-severe ischaemia on PTS, and 96 (15.4%) underwent CR. Seven predictors: age >or=65, diabetes, cerebrovascular disease, ischaemic heart disease, congestive heart failure, ST-depression on preoperative ECG, and renal insufficiency, independently determined long-term survival. A long-term survival score (LTSS) comprised of these predictors, divided all patients into low, intermediate, and high-risk groups (0-1, 2-3, >or=4 predictors, respectively) with a 5-year survival of 83 +/- 2%, 60 +/- 3%, and 34 +/- 6%, respectively. Compared with low-risk patients, intermediate and high-risk patients had worse survival [HR (CI) = 2.6 (2.0-3.4) and 5.9 (4.1-8.9), respectively, P < 0.001]. Yet, only the intermediate-risk group had better long-term survival following preoperative CR [HR = 0.48 (0.31-0.75), P = 0.001]. The low-risk groups' favourable survival and high-risk groups' poor survival were not significantly affected by CR. CONCLUSION: Intermediate-risk patients (LTSS 2-3) are most likely to have a long-term survival benefit from PTS and CR.

Aged↗
PubMed2006

Performance of department staff in the window between discovery of collapse to cardiac arrest team arrival.

INTRODUCTION: Guideline-directed therapy during the first minutes of resuscitation may be life saving. This study assessed the performance of American Heart Association (AHA) guidelines by trained departmental staff in the period between discovery of collapse and emergency team arrival. METHODS: Over a period of 24 months, departmental performance prior to the arrival of the emergency team (median 180 s) was assessed by debriefings conducted within 24h of each event in a 740-bed tertiary hospital with a dedicated certified resuscitation team. Outcome measures were failure to meet AHA treatment recommendations (primary) and return of spontaneous circulation (ROSC)/survival to hospital discharge (secondary). RESULTS: Two hundred and forty four events were included (216 patients). Mean age was 69+/-17 years; 45% were women. The underlying causes of collapse were mainly cardiac (39%) or respiratory (32%). Residents conducted most of the resuscitations (69%) prior to the arrival of the emergency team. Basic diagnostic measures such as assessments of pulse and rhythm were not performed in 19 and 33% of events. Therapeutic measures such as positive pressure ventilation, chest compressions and defibrillation were not provided according to the guidelines in 17, 12 and 44% of the events. ROSC occurred in 62% of events; 54% of VF/VT, 30% of asystole, 22% of PEA and 76% of bradyarrhythmias/severe bradycardias. Survival to hospital discharge was 37% overall and 41% for patients found in VF/VT (n=33). CONCLUSIONS: Trained departmental staff performed poorly in the moments between patient discovery and arrival of the emergency team. Since patient outcomes were comparable to those described in the literature, poor resuscitation performance may be commonplace in hospitals where ward personnel are expected to deliver advanced life support prior to arrival of the emergency team.

Adult↗
PubMed2006

Anesthesia for the elderly: selected topics.

PURPOSE OF REVIEW: With the graying of the Western population, there is a continuous increase in the proportion of elderly patients undergoing surgical procedures. Geriatric anesthesia is emerging from a 'subspecialty' to the mainstream of today's anesthesia and perioperative care. Much has been written on anesthesia for the elderly, but this review will concentrate on selected topics related to elderly care that represent current unresolved and pertinent issues for the care of the elderly surgical patient. RECENT FINDINGS: Postoperative cognitive dysfunction, cardiac diastolic dysfunction and prophylactic perioperative beta-blockade in the process of major noncardiac surgery are three main topics that have recently attracted great interest in clinical practice and research, and have therefore been chosen as the selected topics for this current review. SUMMARY: Although age is a clear risk factor for postoperative cognitive dysfunction, the association of general anesthesia with cognitive dysfunction is less clear, as is the effect of anesthesia per se or surgery on long-term cognitive dysfunction. Cardiac diastolic dysfunction is a relatively new and evolving concept in anesthesia and perioperative medicine, yet clearly diastolic dysfunction even with a normal ejection fraction may have a significant effect on the perioperative outcome and management of elderly patients. Small, but powerful studies have shown significant outcome benefit with prophylactic perioperative beta-blockade in high-risk patients undergoing major noncardiac surgery. Data from other studies, however, are still conflicting and the final verdict awaits larger scale outcome studies.

Adrenergic beta-Antagonists↗
PubMed2006

Effects of synchronized cardiac assist device on cardiac energetics.

A novel physiological cardiac assist device (PCAD), the LEV RAM assist device, which is synchronized with the failing heart ejection, was developed to improve the failing heart systolic and diastolic functions and cardiac energetics. The PCAD uses a single short cannula, which is inserted into the beating left ventricle (LV) by means of a specially designed device. Blood is ejected from the PCAD into the LV after the opening of the aortic valve and augments the cardiac stroke work. The same amount of blood is withdrawn from the LV into the PCAD, through the same cannula, during the diastole. The study aims to test the effects of the PCAD on cardiac energetics and coronary blood flow. Adult normal sheep were anesthetized and the heart was exposed by left thoracotomy. Pressures transducers (Millar Instruments, Inc., Houston, TX) were inserted into the LV and aorta. LV volume was measured by sonocrystals (Sonometrics Corp., London, Ontario, Canada) and impedance catheter (CD Lycom, Argonstrat 116 Zoetermeer, 2718 SP The Netherlands). Flowmeters (transonic) measured the cardiac output (CO) and the coronary arteries (left anterior descending (LAD) and circumflex) flows. A thin cannula was inserted into the coronary sinus and the oxygen content of the LV and the coronary sinus were determined (AVOXimeter-1000). Pressure-volume loops, myocardial energetics, and coronary flow were measured. The displaced PCAD volume was 11 mL. Four different levels of assist were studied by changing the frequency of the assist: (1) assist beat after three successive regular beats [1:4], (2) assist every third beat [1:3], (3) alternate assist and normal beat [1:2], and (4) continuous assist [1:1]. Cardiac output (CO) and stroke volume (SV) increased proportionally with increasing frequency of assist. Systolic mechanical efficiency of the PCAD was above 90%. Simultaneously, the PCAD decreased the end-diastolic volume (EDV; diastolic unloading). The PCAD increased coronary flow and decreased cardiac arterial-venous O(2) difference. We conclude that the PCAD efficiently augments CO and stroke work, decreases preload, and decreases the coronary arterial-venous O(2) difference; all these may expedite cardiac reverse remodeling, and promote recovery of function and eventual easy explanation of the device.

Animals↗
PubMed2005

Myocardial ischemia, cardiac troponin, and long-term survival of high-cardiac risk critically ill intensive care unit patients.

OBJECTIVES: To determine the incidence and association of myocardial ischemia with troponin elevation and survival in high-cardiac-risk intensive care patients. DESIGN: Prospective observational study. SETTING: Intensive care unit of a tertiary hospital. SUBJECTS: One-hundred one general intensive care unit patients having a history of coronary artery disease or at least two risk factors for coronary artery disease. INTERVENTIONS: Continuous 12-lead electrocardiographic monitoring with on-line ST-trend analysis, daily cardiac troponin measurements, clinical and physiologic assessment, and up to 2-yr follow-up for survival. MEASUREMENTS AND MAIN RESULTS: During 8,988 hrs or a mean +/- sd of 95 +/- 85 hrs/patient of continuous 12-lead electrocardiographic monitoring, 21 patients (21%) had ischemic ST-segment changes, characterized in most (19) by ST depression and lasting >60 mins in 15 (71.4%). Of the 38 patients (38%) with troponin elevation, myocardial infarction was clinically suspected in four and myocardial ischemia on continuous 12-lead electrocardiographic monitoring was observed in 14 (36.8%). Fourteen (66.7%) of the patients with ischemic ST changes and 12 (75%) of those with prolonged (>60 mins) ischemia had troponin elevation. The sensitivity, specificity, and positive and negative predictive values of prolonged (>60 mins) ischemia predicting troponin elevation were 31.6%, 95.2%, 80.0%, and 69.8%, respectively. Prolonged (>60 mins) ischemia was significantly associated with troponin elevation by both univariate and multivariate analyses (odds ratio = 9.0; p = .008). Acute Physiology and Chronic Health Evaluation II score, renal failure, and the use of norepinephrine also independently predicted troponin elevation. Troponin but not ischemia predicted increased 1-month, 6-month, and 2-yr mortality (odds ratio = 6.0, 3.2, and 2.99, respectively; p < .001). CONCLUSIONS: Silent ischemia is strongly associated with troponin elevation in high-cardiac-risk intensive care unit patients, and troponin elevation predicts both early and late mortality.

Adolescent↗
PubMed2005

Monitoring for myocardial ischemia.

During the last 20 years, studies using continuous perioperative electrocardiogram (ECG) monitoring in patients at high risk for postoperative cardiac complications have revolutionized our understanding of the pathophysiology, circumstances, timing and possible prevention of perioperative ischemia and postoperative cardiac morbidity and mortality. The present review attempts to provide a comprehensive and practical summary of the current knowledge on perioperative myocardial ischemia. It starts with a description of the conventional definition of myocardial ischemia on exercise stress-testing and continues with a summary of the findings and insights collected from ambulatory Holter monitoring in non-surgical patients with coronary artery disease. It then recaps the variety of studies using perioperative ischemia monitoring to detail the concepts and controversies brought about by this type of monitoring, and tries to portray a general picture of the association of perioperative ischemia and postoperative cardiac complications-including myocardial infarction-and emphasize the importance of postoperative, not just intraoperative, ischemia monitoring.

Electrocardiography↗
PubMed2004

Cardiac troponin after major vascular surgery: the role of perioperative ischemia, preoperative thallium scanning, and coronary revascularization.

OBJECTIVES: We sought to determine the role of preoperative predictors, particularly ischemia, on preoperative thallium scanning (PTS) and coronary revascularization on low-level and conventional troponin elevations after major vascular surgery. BACKGROUND: Postoperative cardiac troponin (cTn) elevations have recently been shown to predict both short- and long-term mortality after vascular surgery. METHODS: The perioperative data, including PTS and subsequent coronary revascularization, continuous perioperative 12-lead ST-segment trend monitoring, cTn-I and/or cTn-T, and creatine kinase-MB fraction in the first three postoperative days, were prospectively collected in 501 consecutive elective major vascular procedures. RESULTS: Moderate to severe inducible ischemia on PTS was associated with a 49.0% incidence of low-level (cTn-I >0.6 and/or cTn-T >0.03 ng/ml) and 22.4% conventional (cTn-I >1.5 and/or cTn-T >0.1 ng/ml) troponin elevation. In contrast, patients with preoperative coronary revascularization had 23.4% and 6.4% low-level and conventional troponin elevations, respectively, similar to patients without ischemia on PTS. By multivariate logistic regression, ischemia on PTS was the most important predictor of both low-level and conventional troponin elevations (adjusted odds ratios [ORs] 2.5 and 2.7, p = 0.02 and 0.04, respectively), whereas preoperative coronary revascularization predicted less troponin elevations (adjusted ORs 0.35 and 0.16, p = 0.045 and 0.022, respectively). Postoperative ischemia (>10 min), the more so prolonged (>30 min) ischemia was the only independent predictor of troponin elevation if added with the preoperative predictors to the multivariate analysis (ORs 15.8 and 22.8, respectively, p < 0.001). CONCLUSIONS: Troponin elevations occur frequently after vascular surgery. They are strongly associated with postoperative ischemia, predicted by inducible ischemia on PTS, and reduced by preoperative coronary revascularization.

Aged↗
PubMed2004

Augmentation of dilated failing left ventricular stroke work by a physiological cardiac assist device.

A novel physiological cardiac assist device (PCAD), otherwise known as the LEVRAM assist device, which is synchronized with the heartbeat, was developed to assist the left ventricle (LV) in chronic heart failure (CHF). The PCAD utilizes a single cannula, which is inserted in less than 15 s through the apex of the beating LV by means of a specially designed device. Blood is withdrawn from the LV into the PCAD in diastole and is injected back to the LV, through the same cannula, during the systolic ejection phase, thereby augmenting stroke volume (SV) and stroke work (SW). CHF with dilated LV was induced in sheep by successive intracoronary injections of 100-microm beads. The sheep (92.2 +/- 25.9 kg, n = 5) developed stable CHF with increased LV end-diastolic diameter (69.4 +/- 3.3 mm) and end-diastolic volume (LVEDV = 239 +/- 32 mL), with severely reduced ejection fraction (23.8 +/- 7.6%), as well as mild-to-moderate mitral regurgitation. The sheep were anesthetized, and the heart was exposed by left thoracotomy. Pressure was measured in the LV and aorta (Millar). The SV was measured by flow meters and the LV volume by sonocrystals. Assist was provided every 10 regular beats, and the assisted beats were compared with the preceding unassisted beats, at the same LVEDV. The PCAD displaced 13.6 +/- 3.4 mL, less than 8% of LVEDV. Added SW was calculated from the assisted and control pressure-volume loops. The efficiency, defined as an increase in SW divided by the mechanical work of the PCAD, was 85.4 +/- 16.9%. We conclude that the PCAD, working with a small displaced blood volume in synchrony with the heartbeat, efficiently augments the SW of the dilated failing LV. The PCAD is suggested for use as a permanent implantable device in CHF.

Animals↗
PubMed2003

Association of cardiac troponin, CK-MB, and postoperative myocardial ischemia with long-term survival after major vascular surgery.

OBJECTIVES: The aim of this study was to determine the long-term prognosis with postoperative markers of myocardial ischemia and infarction. BACKGROUND: Cardiac troponins (cTn) are superior to creatine kinase-MB fraction (CK-MB) in detecting perioperative myocardial infarction (PMI). However, their threshold levels signifying PMI and their long-term prognostic value are not yet determined. METHODS: A cohort of 447 consecutive patients who underwent 501 major vascular procedures was prospectively studied. Perioperative continuous 12-lead electrocardiogram monitoring, cardiac troponin-I (cTn-I) and/or cardiac troponin-T (cTn-T), and CK-MB levels on the first three postoperative days, and long-term survival were determined. The association of different cutoff levels of CK-MB, troponin, and ischemia duration with long-term survival was investigated. RESULTS: Between 14 (2.9%) and 107 (23.9%) of the patients sustained PMI, depending on the biochemical criteria used. Elevated postoperative CK-MB, cTn, and prolonged (>30 min) ischemia, at all cutoff levels examined, predicted long-term mortality independent of the preoperative predictors: patient's age, type of vascular surgery, previous myocardial infarction, and renal failure (Cox multivariate analysis). Both CK-MB >10% and cTn-I >1.5 ng/ml and/or cTn-T >0.1 ng/ml independently predicted a 3.75-fold and 2.06-fold increase in long-term mortality (p = 0.006 and 0.012, respectively). Similarly, both CK-MB >5% and cTn-I >0.6 ng/ml and/or cTn-T >0.03 ng/ml independently predicted a 2.15-fold and 1.89-fold increase in mortality (p = 0.018 and 0.01, respectively). Patients with both these markers elevated had a 4.19-fold increase in mortality (p < 0.001). CONCLUSIONS: Postoperative CK-MB and troponin, even at low cutoff levels, are independent and complementary predictors of long-term mortality after major vascular surgery.

Adult↗
PubMed2003

Preoperative thallium scanning, selective coronary revascularization, and long-term survival after major vascular surgery.

BACKGROUND: Ischemia on thallium scanning is a strong predictor of long-term mortality in CAD patients. Whether coronary revascularization (CR) in patients with significant ischemia on preoperative thallium scanning (PTS) improves long-term survival after major vascular surgery has not been determined. METHODS AND RESULTS: The perioperative data, including PTS and subsequent CR in patients with moderate to severe reversible ischemia on PTS, and long-term survival of 502 consecutive patients who underwent 578 major vascular procedures were analyzed retrospectively. Patients with PTS who ultimately did not undergo the planned vascular operation were also studied. Cox regression and propensity score analyses were used to analyze survival. A total of 407 patients (81.1%) had PTS: 221 (54.3%) had no or mild defects (group I); 50 (12.3%) had moderate-severe fixed defects (group II); 62 (15.2%) had moderate-severe reversible ischemia yet did not undergo CR (group III); and 74 (18.2%) had moderate-severe reversible ischemia and subsequent CR by CABG (36) or PTCA (38; group IV). Patients who sustained major complications as a result of the preoperative cardiac workup were included in group IV. By multivariate analysis, age, type of vascular surgery, presence of diabetes, previous myocardial infarction, and moderate-severe ischemia on PTS independently predicted mortality (P=0.001, 0.009, 0.039, 0.006, and 0.029, respectively), and preoperative CR predicted improved survival (OR 0.52, P=0.018). Group IV had better survival than group III even when subdivided according to normal and reduced left ventricular function (OR 0.40 and 0.41, P=0.035 and 0.021, respectively). CONCLUSIONS: Long-term survival after major vascular surgery is significantly improved if patients with moderate-severe ischemia on PTS undergo selective CR.

Aged↗
PubMed2003

GESDOR - a generic execution model for sharing of computer-interpretable clinical practice guidelines.

We developed the Guideline Execution by Semantic Decomposition of Representation (GESDOR) model to share guidelines encoded in different formats at the execution level. For this purpose, we extracted a set of generalized guideline execution tasks from the existing guideline representation models. We then created the mappings between specific guideline representation models and the set of the common guideline execution tasks. Finally, we developed a generic task-scheduling model to harmonize the existing approaches to guideline task scheduling. The evaluation has shown that the GESDOR model can be used for the effective execution of guidelines encoded in different formats, and thus realizes guideline sharing at the execution level.

Decision Making, Computer-Assisted↗
PubMed2002

Perioperative myocardial ischemia and infarction: identification by continuous 12-lead electrocardiogram with online ST-segment monitoring.

BACKGROUND: Perioperative myocardial ischemia is conventionally monitored using five electrocardiographic leads, with only one precordial lead placed at V5. This is based on studies from more than a decade ago. The authors reassessed this convention by analyzing data obtained from continuous on-line 12-lead electrocardiographic monitoring. METHODS: One hundred eighty-five consecutive patients undergoing vascular surgery were monitored by continuous 12-lead ST-trend analysis during and for 48-72 h after surgery. Cardiac troponin I was measured in the first 3 postoperative days, and cardiac outcome was prospectively recorded. Ischemia was defined as ST deviation, relative to the reference preanesthesia electrocardiogram, of 0.2 mV or more in one lead or 0.1 mV or more in two contiguous leads, lasting more than 10 min. RESULTS: During 11,132 patient-hours of monitoring, 38 patients (20.5%) had 66 transient ischemic events, with all but one denoted by ST-segment depression. Twelve patients (6.5%) sustained postoperative infarction (cardiac troponin I > 3.1 ng/ml). Among the 38 patients with ischemia, lead V3 most frequently (86.8%) demonstrated ischemia, followed by V4 (78.9%) and V5 (65.8%). Among the 12 patients with infarction, V4 was most sensitive to ischemia (83.3%), followed by V3 and V5 (75% each). Combining two precordial leads increased the sensitivity for detecting ischemia (97.4% for V3 + V5 and 92.1% for either V4 + V5 or V3 + V4) and infarction (100% for V4 + V5 or V3 + V5 and 83.3% for V3 + V4). On average, baseline preanesthesia ST was above isoelectric in V1 through V3 and below isoelectric in V5 through V6. Lead V4 was closest to the isoelectric level on the baseline electrocardiogram, rendering it most suitable for ischemia monitoring. CONCLUSIONS: As a single lead, V4 is more sensitive and appropriate than V5 for detecting prolonged postoperative ischemia and infarction. Two precordial leads or more are necessary so as to approach a sensitivity of greater than 95% for detection of perioperative ischemia and infarction.

Anesthesia↗