Rate of colonization of health care workers by carbapenem-resistant Enterobacteriaceae in an endemic hospital: A prospective study.

The role of health care workers in transmission of carbapenem-resistant Enterobacteriaceae (CRE) has not been evaluated thoroughly. We sought to determine the rate of fecal carriage of CRE among health care workers in our hospital, which is endemic for CRE (prevalence of 19 out of 800 beds and incidence of 128 out of 49,325 hospital admissions). We found no carriers among the 177 health care workers that participated in the study, suggesting that transmission does not occur through personnel gastrointestinal carriage of the bacteria.

Symptoms in severe aortic stenosis are associated with decreased compensatory circumferential myocardial mechanics.

BACKGROUND: Symptomatic patients with severe aortic stenosis (AS) demonstrate abnormal left ventricular (LV) mechanics. The aim of this study was to compare mechanics in asymptomatic and symptomatic patients with severe AS using two-dimensional myocardial strain imaging. METHODS: One hundred fifty-four patients with severe AS (aortic valve area ≤ 1.0 cm(2)) referred to a heart valve clinic from 2004 to 2011 were studied. Thirty patients were asymptomatic, with normal LV ejection fractions (≥ 55%), without other significant valvular disease or wall motion abnormalities. Thirty-two symptomatic patients who underwent early aortic valve replacement, with similar age, gender, LV ejection fraction, and aortic valve area, were selected for comparison. Both groups were also compared with 32 healthy subjects with similar age and gender distributions and normal echocardiographic results who served as controls. LV longitudinal and circumferential strain and rotation were measured using speckle-tracking software applied to archived echocardiographic studies. Conventional echocardiographic and myocardial mechanical parameters were compared among the study subgroups. RESULTS: Patients with asymptomatic severe AS demonstrated smaller reductions in longitudinal strain, higher (supernormal) apical circumferential strain (-38 ± 6% vs -35 ± 4%, P < .05), and extreme (supernormal) apical rotation (12.2 ± 4.9° vs 2.9 ± 1.7°, P < .0005) compared with symptomatic patients. Apical rotation < 6° was the single significant predictor of symptoms in logistic regression analysis of clinical, echocardiographic, and mechanical parameters. Twelve asymptomatic patients underwent eventual aortic valve replacement and showed decreases in strain and apical rotation compared with baseline values. CONCLUSIONS: Longitudinal strain was uniformly low in patients with severe AS and lower in those with symptoms. Compensatory circumferential myocardial mechanics (increased apical circumferential strain and rotation) were absent in symptomatic patients. Thus, myocardial mechanics may help in the follow-up of patients with severe AS and timing of valve surgery.

Excessive respiratory variation in tricuspid regurgitation systolic velocities in patients with severe tricuspid regurgitation.

AIMS: Respiratory changes in tricuspid regurgitation (TR) systolic velocities are occasionally demonstrated by Doppler echocardiography in patients with TR. We tested the hypothesis that excessive respiratory changes in TR velocities are diagnostic of severe TR. METHODS AND RESULTS: The difference between the maximal (expiratory) and minimal (inspiratory) TR systolic velocities during spontaneous respiration was measured by Doppler echocardiography in 68 patients with severe TR and 68 patients with moderate TR. The diagnostic value of the respiratory changes in TR velocity for detecting severe TR was assessed. The respiratory differences in TR velocities were greater in patients with severe TR (0.72 ± 0.30 m/s), compared with patients with moderate TR (0.28 ± 0.18; P < 0.001). Using receiver-operating characteristics analysis, the area under the curve for the respiratory difference in TR velocities for diagnosing severe TR was 0.92 (95% confidence interval: 0.87-0.96; P < 0.001). A difference in TR velocity ≥0.6 m/s had a sensitivity of 66%, specificity of 94%, positive predictive value of 92%, and a negative predictive value of 74% for diagnosing severe TR. Among patients with severe TR, excessive values of TR velocity difference were associated with signs of more severe TR (greater right ventricular size and malcoaptation of the tricuspid valve leaflets). CONCLUSION: Excessive respiratory changes in Doppler measurements of TR systolic velocities are a specific sign of severe TR.

Frequency, determinants and outcome of pulmonary hypertension in patients with aortic valve stenosis.

INTRODUCTION: The frequency, causes and prognostic implications of pulmonary hypertension (PHT) in patients with severe aortic stenosis (AS) are not well defined. The objectives of this study were to determine the frequency of PHT [pulmonary artery systolic pressure (PASP) >50 mm Hg] in patients with severe AS, identify the factors associated with PHT and assess the relationship between PHT and clinical outcome. METHODS: Patients with severe AS (aortic valve area ≤1.0 cm) and an echocardiographic estimate of PASP were identified by using the institutional echocardiography laboratory database. Patients with atrial fibrillation, mitral valve stenosis or a mitral prosthesis were excluded from analysis. The associations between clinical and echocardiographic parameters and PHT and the relationship between PHT and outcome were examined. RESULTS: During the study period, 216 patients fulfilled the inclusion criteria (age: 75 ± 11 years; 43% men), and PHT was present in 64 patients (29.6%). By multivariate analysis, reduced left ventricular (LV) systolic function (LV ejection fraction ≤45% and lower stroke volume) and impaired LV diastolic function (mitral inflow E/A ratio ≥1.5 and greater left atrium size) were independent predictors of PHT. Mortality was higher among patients with PHT managed medically (adjusted hazard ratio, 1.87; 95% confidence interval, 1.06-3.30; P = 0.011), whereas patients with PHT who underwent aortic valve replacement had an excellent outcome. CONCLUSIONS: PHT is common in patients with AS and is related to the severity of LV systolic and diastolic dysfunction. PHT is associated with poorer outcome in medically treated patients.

Relation of myocardial mechanics in severe aortic stenosis to left ventricular ejection fraction and response to aortic valve replacement.

Decreased left ventricular (LV) longitudinal strain and increased circumferential LV strain have been demonstrated in patients with severe aortic stenosis (AS) and normal LV ejection fraction (LVEF). Biplane myocardial mechanics normalize after aortic valve replacement (AVR). This study objective was to examine LV mechanics before and soon after AVR in patients with AS and LV systolic dysfunction. Paired echocardiographic studies before and soon (7 ± 3 days) after AVR were analyzed in 64 patients with severe AS: 32 with normal LVEF (≥ 50%), 16 with mild to moderate LV dysfunction (LVEF <36% to 50%), and 16 with severe LV dysfunction (LVEF ≤ 35%). Longitudinal myocardial function was assessed from 3 apical views (average of 18 segments) and circumferential function was assessed at mid-LV and apical levels (average of 6 segments per view). Strain, strain rate, and mid-LV and apical rotations were measured using 2-dimensional velocity vector imaging. Before AVR (1) longitudinal strain was low in all patients and correlated with LVEF (ρ = 0.74, p <0.001), (2) mid-LV circumferential strain was supranormal in patients with normal LVEF and low in patients with low LVEF (ρ = 0.88, p <0.001), and (3) apical rotation was highest in patients with mild to moderate LV dysfunction. After AVR, LVEF increased in patients with LV dysfunction and myocardial mechanics partly normalized. In conclusion, compensatory mechanisms (high circumferential strain in patients with preserved LVEF and increased apical rotation in patients with mild to moderate LV dysfunction) were observed in patients with severe AS. Compensatory mechanics were lost in patients with severe LV dysfunction. AVR partly reversed these changes in patients with LV dysfunction.

Large pseudoaneurysms of the mitral-aortic intervalvular fibrosa: long-term natural history without surgery in two patients.

A pseudoaneurysm of the mitral-aortic intervalvular fibrosa is a well-described complication of aortic valve endocarditis and aortic valve replacement. It may occasionally cause complications, but it may also remain uncomplicated and asymptomatic for unknown periods. Although corrective surgery is commonly recommended, the appropriate therapeutic approach to this pathology is unclear. The current report describes two patients with large pseudoaneurysms of the mitral-aortic intervalvular fibrosa, who were treated conservatively without surgery without any adverse clinical events during long-term follow-up. Therefore, conservative follow-up of this pathology with echocardiographic monitoring appears to be a valid and safe alternative for surgery, especially in patients at high risk for surgical intervention.

Frequency, characteristics, and outcome of patients with aortic stenosis, left ventricular dysfunction, and high (versus low) trans-aortic pressure gradient.

BACKGROUND: Trans-aortic pressure gradient in patients with aortic stenosis and left ventricular systolic dysfunction is typically low but occasionally high. OBJECTIVES: To examine the distribution of trans-aortic PG in patients with severe AS and severe LV dysfunction and compare the clinical and echocardiographic characteristics and outcome of patients with high versus low PG. METHODS: Using the echocardiographic laboratory database at our institution, 72 patients with severe AS (aortic valve area < or = 1.0 cm2) and severe LV dysfunction (LV ejection fraction < or = 30%) were identified. The characteristics and outcome of these patients were compared. RESULTS: PG was high (mean PG > or = 35 mmHg) in 32 patients (44.4%) and low (< 35 mmHg) in 40 (55.6%). Aortic valve area was slightly smaller in patients with high PG (0.63 + 0.15 vs. 0.75 +/- 0.16 cm2 in patients with low PG, P = 0.003), and LV ejection fraction was slightly higher in patients with high PG (26 +/- 5 vs. 22 +/- 5% in patients with low PG, P = 0.005). During a median follow-up period of 9 months 14 patients (19%) underwent aortic valve replacement and 46 patients (64%) died. Aortic valve replacement was associated with lower mortality (age and gender-adjusted hazard ratio 0.19, 95% confidence interval 0.05-0.82), whereas trans-aortic PG was not (P = 0.41). CONCLUSIONS: A large proportion of patients with severe AS have relatively high trans-aortic PG despite severe LV dysfunction, a finding partially related to more severe AS and better LV function. Trans-aortic PG is not related to outcome in these patients.

Differential effects of afterload on left ventricular long- and short-axis function: insights from a clinical model of patients with aortic valve stenosis undergoing aortic valve replacement.

BACKGROUND: The effects of left ventricular (LV) afterload on longitudinal versus circumferential ventricular mechanics are largely unknown. Our objective was to examine changes in LV deformation before and early after aortic valve replacement (AVR) in patients with severe aortic valve stenosis (AS). METHODS: Paired echocardiographic studies before and early (7 +/- 3 days) after AVR were analyzed in 45 patients (age 67 +/- 12 years, 49% men) with severe AS and normal LV ejection fraction without segmental wall motion abnormalities. Longitudinal myocardial function was assessed from 3 apical views (average of 18 segments). Circumferential function was assessed at mid and apical levels (averaging 6 segments per view). Strain, strain rate (SR), and LV twist (relative rotation of the mid and apex) were measured using 2-dimensional strain software. RESULTS: Early post-AVR, (1) LV size and LV ejection fraction did not change; (2) longitudinal systolic strain, which was lower than normal before AVR, increased (-12.8 +/- 1.7 to -15.9 +/- 2.2, P < .05), whereas mid-LV circumferential strain, which was higher than normal, decreased (-27.0 +/- 5.1 to -22.3 +/- 4.9, P < .05); (3) longitudinal early diastolic SR increased (0.6 +/- 0.1 to 0.7 +/- 0.2, P < .05), whereas mid-LV circumferential diastolic SR decreased (1.2 +/- 0.5 to 1.0 +/- 0.3, P < .05); and (4) LV twist increased (3.7 degrees +/- 2.1 degrees to 6.1 degrees +/- 2.9 degrees , P < .05). CONCLUSIONS: Aortic valve stenosis causes differential changes in longitudinal and circumferential mechanics that partially normalize after AVR. These findings provide new insights into the mechanical adaptation of the LV to chronic afterload elevation and its response to unloading.

An academic medical center under prolonged rocket attack--organizational, medical, and financial considerations.

The Rambam Medical Center, the major academic health center in northern Israel, serving a population of two million and providing specialized tertiary care, was exposed to an unprecedented experience during the Second Lebanon War in the summer of 2006. For more than one month, it was subjected to continuous rocket attacks, but it continued to provide emergency and routine medical services to the civilian population and also served the military personnel who were evacuated from the battlefront. To accomplish the goals of serving the population while itself being under fire, the Rambam Medical Center had to undertake major organizational decisions, which included maximizing safety within the hospital by shifting patients and departments, ensuring that the hospital was properly fortified, managing the health professional teams' work schedules, and providing needed services for the families of employees. The Rambam Medical Center's Level I trauma center expertise included multidisciplinary teams and extensive collaborations; modern imaging modalities usually reserved for peacetime medical practice were frequently used. The function of the hospital teams during the war was efficient and smooth, based on the long-term actions taken to prepare for disasters and wartime conditions. Routine hospital services continued, although at 60% of normal occupancy. Financial losses incurred were primarily due to the decrease in revenue-generating activity. The two most important components of managing the hospital under these conditions are (1) the ability to arrive at prompt and meaningful decisions with respect to the organizational and medical hospital operations and (2) the leadership and management of the professional staff and teams.

Pulmonary hypertension is an independent predictor of mortality in hemodialysis patients.

Pulmonary hypertension in patients with end-stage renal disease on hemodialysis is a newly described entity. To determine its impact, we measured selected clinical variables in the survival of 127 hemodialysis patients. Overall, pulmonary hypertension was found in 37 of these patients; it was already prevalent in 17 of them before initiation of dialysis and was associated with severe cardiac dysfunction. In the other 20 it developed after dialysis began, without obvious cause. These two subgroups of patients had similar survival curves, which were significantly worse in comparison to those without pulmonary hypertension. Following the initiation of hemodialysis, 20 patients with otherwise matched clinical variables survived significantly longer than the 20 who developed pulmonary hypertension after dialysis began. With univariate analysis, significant hazard ratios were found for age at onset of hemodialysis therapy (1.7), valvular diseases (1.8), pulmonary hypertension prevalence before hemodialysis (3.6) and incident after hemodialysis (2.4) for predicting mortality. In a multivariable Cox proportional hazard model, the development of pulmonary hypertension both before and after initiation of hemodialysis had significantly increased odds ratios and remained an independent predictor of mortality. Our study shows the incidence of pulmonary hypertension, after initiation of hemodialysis therapy, is a strong independent predictor of mortality nearly equal to that associated with long-standing severe cardiac abnormalities.

Functional tricuspid regurgitation in patients with pulmonary hypertension: is pulmonary artery pressure the only determinant of regurgitation severity?

BACKGROUND: Pulmonary hypertension is a common cause of functional tricuspid regurgitation (TR), but other factors play a role in determining TR severity. The objectives of our study were to determine the distribution of TR severity in relation to pulmonary artery systolic pressure (PASP) and to define the determinants of TR severity. METHODS: The echocardiographic reports and selected echocardiographic studies of patients with echocardiographic estimation of PASP were reviewed. Patients with organic tricuspid valve (TV) disease were excluded from the analysis. RESULTS: Among 2,139 patients, the frequency of moderate or severe TR was progressively greater in patients with higher PASP. Nevertheless, TR was only mild in a substantial proportion of patients with high PASP (mild TR in 65.4% of patients with PASP 50-69 mm Hg and in 45.6% of patients with PASP >or= 70 mm Hg). By multivariate analysis, age, female gender, PASP (odds ratio, 2.26 per 10-mm Hg increase; 95% confidence interval, 1.95 to 2.61), pacemaker lead, right atrial (RA) and right ventricular enlargement, left atrial enlargement, and organic mitral valve disease were independently associated with greater degrees of TR. In patients with PASP >or= 70 mm Hg, RA size, tricuspid annular diameter, and TV tethering area were greater in patients with greater degrees of TR. CONCLUSIONS: PASP is a strong determinant of TR severity, but many patients with pulmonary hypertension do not exhibit significant TR. In addition to PASP, demographic characteristics, mechanical factors, remodeling of the right heart cavities, and other factors (possibly reflecting the presence of atrial fibrillation or occult organic TV disease) are predictive of TR severity.

Arterio-venous access in end-stage renal disease patients and pulmonary hypertension.

BACKGROUND: The syndrome of pulmonary hypertension (PHT) in end-stage renal disease (ESRD) has been described in patients on chronic hemodialysis (HD) therapy via arterial-venous (A-V) access. However, the exact timing for the development of the PHT is unknown. This study was designed to evaluate changes in pulmonary artery pressure (PAP) following creation of the vascular access. PATIENTS AND METHODS: PAP and cardiac-output (CO) values were recorded in 12 pre-dialysis patients without PHT a few months after the access formation, before treatment with HD was started, and the prevalence of PHT was calculated. Clinical data was compared between patients with and without PHT. RESULTS: The systolic PAP values were increased in "ve of the 12 pre-dialysis patients (42%) by 21+/-9 mm Hg to more than 35 mm Hg. Patients with and without PHT differed only in that CO was signi"cantly higher among the former. CONCLUSIONS: The development of PHT following access formation represents a failure of the pulmonary circulation to accommodate the access-mediated elevated CO. Pre-dialysis patients scheduled for access formation should be screened for the presence of sub-clinical PHT. "Positive" patients should proceed to peritoneal dialysis or advance to kidney transplantation; rather than getting access and HD therapy.

Echocardiography-based spectrum of severe tricuspid regurgitation: the frequency of apparently idiopathic tricuspid regurgitation.

BACKGROUND: The cause of tricuspid valve (TV) regurgitation (TR) occasionally remains unclear. The objectives of our study were to define the causal spectrum of severe TR diagnosed by echocardiography at a tertiary medical center and to assess the relative frequency and determine the clinical and echocardiographic characteristics of TR without an apparent cause (idiopathic TR). METHODS: Consecutive patients with severe TR were identified by the echocardiography laboratory computerized database. The echocardiographic reports of all patients were reviewed and the causes of TR were determined. The echocardiographic studies and medical charts were reviewed in patients without an obvious cause of TR. RESULTS: Of 242 consecutive patients diagnosed with severe TR, organic TV disease was evident in 23 patients (9.5%) and significant pulmonary hypertension (estimated pulmonary artery systolic pressure > 50 mm Hg) in an additional 157 patients (64.9%). After further excluding patients with various confounding factors, possibly associated with occult organic TV disease or significant pulmonary hypertension, 23 patients (9.5%) had severe TR without an apparent cause. Of these, TV coaptation appeared relatively intact, allowing adequate estimation of pulmonary artery pressure, in 15 patients (6.2% of all patients with severe TR; idiopathic TR group). Patients with idiopathic TR were older (76 +/- 10 years), with a high frequency of atrial fibrillation (93%), and prominent TV annular dilatation. CONCLUSIONS: After excluding multiple potential causes of TR, severe TR is occasionally idiopathic. Annular dilatation (secondary to aging, atrial fibrillation, or other causes) is the likely mechanism of TR in these patients.

Pulmonary hypertension in hemodialysis patients: an unrecognized threat.

Pulmonary hypertension (PH) is a progressive, fatal pulmonary circulatory disease that accompanies many conditions (including left to right side shunt) with compensatory elevated cardiac output. PH also complicates chronic hemodialysis (HD) therapy immediately after the creation of an arteriovenous (AV) access, even before starting HD therapy. It tends to regress after temporary AV access closure and after successful kidney transplantation. Affected patients have significantly higher cardiac output. This syndrome is associated with a statistically significant survival disadvantage. The laboratory hallmark of this syndrome is reduced basal and stimulatory nitric oxide (NO) levels. It appears that patients with end-stage renal disease (ESRD) acquire endothelial dysfunction that reduces the ability of their pulmonary vessels to accommodate the AV access-mediated elevated cardiac output, exacerbating the PH. Doppler echocardiographic screening of ESRD patients scheduled for HD therapy for the occurrence of PH is indicated. Early diagnosis enables timely intervention, currently limited to changing dialysis modality or referring for kidney transplantation.

Left ventricular filling hemodynamics in patients with pulmonary edema and preserved versus reduced left ventricular ejection fraction: a prospective Doppler echocardiographic study.

BACKGROUND: Objective evidence of elevated left ventricular (LV) filling pressures is infrequently demonstrated in clinical practice in patients with heart failure (HF) and preserved LV ejection fraction (LVEF) and the clinical diagnosis of HF is commonly questionable in these patients. The objective of this study was to examine whether elevated LV filling pressures can be demonstrated noninvasively in consecutive patients with HF and preserved (vs reduced) LVEF. METHODS: Echocardiography was performed in 141 patients hospitalized with acute pulmonary edema (within 3 days of admission in 83.6%). LV filling was assessed in 116 patients without significant valve disease (median age 76 years; 51.7% men) and LV filling pressures were estimated based on mitral and pulmonary venous flow patterns and mitral annular diastolic velocities. RESULTS: LVEF was preserved (> or =45%) in 49 patients (42.2%) and reduced (<45%) in 67 patients (57.8%). In patients with in sinus rhythm, normal LV filling pattern and abnormal relaxation, pseudonormal, and restrictive LV filling patterns (the latter two patterns associated with elevated LV filling pressures) were evident in 8, 1, 11, and 9 patients with preserved LVEF, versus 5, 11, 15, and 23 patients with reduced LVEF, respectively (P = .01) (LV filling pattern was nonconclusive in 12 patients). In patients with atrial arrhythmias, elevated LV filling pressures were evident in 4 of 14 patients with preserved LVEF and 3 of 4 patients with reduced LVEF. Overall, elevated LV filling pressures were demonstrable in 24 patients with preserved LVEF (49.0%) and in 41 patients with reduced LVEF (68.3%) (P = .26). CONCLUSIONS: Elevated LV filling pressures are frequently evident by Doppler echocardiography in patients with HF and preserved or reduced LVEF. Thus, Doppler echocardiography can provide objective noninvasive evidence of abnormal LV filling in a large proportion of patients with HF and preserved LVEF.

Pulmonary hypertension in chronic dialysis patients with arteriovenous fistula: pathogenesis and therapeutic prospective.

PURPOSE OF REVIEW: End-stage renal disease patients receiving chronic haemodialysis via arteriovenous access often develop various cardiovascular complications, including vascular calcification, cardiac-vascular calcification and atherosclerotic coronary disease. This review describes recently published studies that demonstrate a high incidence of pulmonary hypertension among patients with end-stage renal disease receiving long-term haemodialysis via a surgical arteriovenous fistula. Both end-stage renal disease and long-term haemodialysis via arteriovenous fistula may be involved in the pathogenesis of pulmonary hypertension by affecting pulmonary vascular resistance and cardiac output. RECENT FINDINGS: Morbidity and mortality from cardiovascular disease are greatly increased in patients on maintenance haemodialysis therapy. Using Doppler echocardiography, we found a significant increase in cardiac output in 40% of chronic haemodialysis patients, probably related to the large arteriovenous access or altered vascular resistance as a result of the local vascular tone and function expressed by the imbalance between vasodilators such as nitric oxide, and vasoconstrictors such as endothelin-1. SUMMARY: We propose different potential mechanisms as explanations for the development of pulmonary hypertension. Hormonal and metabolic derangement associated with end-stage renal disease might lead to pulmonary arterial vasoconstriction and an increase in pulmonary vascular resistance. Pulmonary arterial pressure may be further increased by high cardiac output resulting from the arteriole-venous access itself, worsened by commonly occurring anaemia and fluid overload.

Comparison of multidetector computed tomography versus echocardiography for assessing regional left ventricular function.

Multidetector computed tomography (MDCT) of the heart is a rapidly developing technique mainly used to evaluate the coronary arteries. However, it is also capable of evaluating ventricular function. It compares well with magnetic resonance imaging in calculating volumes and ejection fractions, but little has been reported on its ability to assess left ventricular (LV) segmental wall motion (LVSWM). This study compared semiquantitative LVSWM scoring by MDCT with echocardiography as the gold standard. Thirty-nine patients underwent MDCT angiography on a 16-slice scanner. Short- and long-axis LV slices were created at different phases of the cardiac cycle and visually evaluated using cine mode. Echocardiography was performed <48 hours after MDCT for 21 patients after acute myocardial infarctions and <1 month after MDCT for 18 patients without acute myocardial infarctions. Two blinded observers scored the MDCT and echocardiographic examinations according to the 16-segment model, scoring each segment from 1 (normal) to 3 (akinetic). Segmental dysfunction was found in 27 patients by echocardiography and in 24 by MDCT. An identical score was given by the 2 methods in 502 of 616 assessable segments (82%). Using a binary analysis (normal or abnormal), there was 89% agreement (546 of 616 segments). MDCT had a sensitivity of 66% (103 of 155 segments) and a specificity of 96% (443 of 461 segments) compared with echocardiography as the gold standard. Most disagreements occurred in the right coronary artery segments. In conclusion, MDCT can be used to evaluate LVSWM, showing good agreement with echocardiography, except for the right coronary artery segments.

Intermittent coronary sinus occlusion complicating coronary sinus cannulation during coronary artery bypass operation.

Coronary sinus (CS) thrombosis is a rare event, usually complicating invasive procedures that cause trauma to the CS. Based on anecdotal case reports, this pathology is frequently associated with serious complications and is commonly fatal. We describe a case of intermittent CS thrombosis resulting from CS cannulation during coronary artery bypass grafting operation. This complication was further complicated by myocardial infarction, left ventricular free wall rupture, and pseudoaneurysm formation. The characteristic echocardiographic findings and a review of the literature on this rare complication are presented.

Haptoglobin polymorphism predicts 30-day mortality and heart failure in patients with diabetes and acute myocardial infarction.

Patients with diabetes presenting with acute myocardial infarction (AMI) have an increased rate of death and heart failure. Patients with diabetes homozygous for the haptoglobin (Hp) 1 allele (Hp 1-1) develop fewer vascular complications. We tested the hypothesis that Hp type is related to the outcome of patients with diabetes presenting with AMI. We prospectively assessed the relationship between Hp type and 30-day mortality and heart failure in 1,437 patients with AMI (506 with diabetes). Multivariate logistic regression identified a significant interaction between Hp type and diabetes status on these outcome measures. Hp type was not related to outcome among patients without diabetes. In contrast, Hp 1-1 was associated with a strong protective effect with regard to the primary end point of death (OR 0.14, P = 0.015) and for death and heart failure (OR 0.35; 95% CI 0.15-0.86, P = 0.018) among patients with diabetes. Finally, among patients with diabetes, Hp 1-1 was associated with smaller infarct size. This study demonstrates that in patients with diabetes and AMI, the Hp type is an important determinant of clinical outcome and infarct size.

The pathogenesis of pulmonary hypertension in haemodialysis patients via arterio-venous access.

BACKGROUND: We recently have shown a high incidence of unexplained pulmonary hypertension (PHT) in end-stage renal disease (ESRD) patients on chronic haemodialysis (HD) therapy via arterio-venous (A-V) access. This study evaluated the possibility that PHT in these patients is triggered or aggravated by chronic HD via surgical A-V access, and the role of endothelin-1 (ET-1) and nitric oxide (NO) in this syndrome. METHODS: Forty-two HD patients underwent clinical evaluation. Pulmonary artery pressure (PAP) was evaluated using Doppler echocardiography. Levels of ET-1 and NO metabolites in plasma were determined before and after the HD procedure and were compared between subgroups of patients with and without PHT. RESULTS: Out of 42 HD patients studied, 20 patients (48%) had PHT (PAP = 46+/-2; range 36-82 mmHg) while the rest had a normal PAP (29+/-1 mmHg) (P<0.0001). HD patients with PHT had higher cardiac output compared with those with normal PAP (6.0+/-1.2 vs 5.2+/-0.9 l/min, P<0.034). HD patients, with or without PHT, had elevated plasma ET-1 levels compared with controls (1.6+/-0.7 and 2.4+/-0.8 fmol/ml vs 1.0+/-0.2, P<0.05) that remained unchanged after the HD procedure. HD patients without PHT and control subjects showed similar basal plasma levels of NO2 + NO3 (24.2+/-5.2 vs 19.7+/-3.1 microM, P>0.05) that was significantly higher compared with HD patients with PHT (14.3+/-2.3 microM, P<0.05). HD therapy caused a significant increase in plasma NO metabolites that was greater in patients without PHT (from 24.2+/-5.2 to 77.1+/-9.6 microM, P<0.0001, and from 14.3+/-2.3 to 39.9+/-11.4 microM, P<0.0074, respectively). Significant declines in PAP (from 49.8+/-2.8 to 38.6+/-2.2 mmHg, P<0.004) and cardiac output (CO) (from 7.6+/-0.6 to 6.1+/-0.3 l/min, P<0.03) were found in 11 HD patients with PHT that underwent successful transplantation. Similarly, temporary closure of the A-V access by a sphygmomanometer in eight patients with PHT resulted in a transient decrease in CO (from 6.4+/-0.6 to 5.3+/- 0.5 l/min, P = 0.18) and systolic PAP (from 47.2+/-3.8 to 34.6+/-2.8 mmHg, P<0.028). CONCLUSIONS: This study demonstrates a high prevalence of PHT among patients with ESRD on chronic HD via a surgical A-V fistula. In view of the vasodilatory and antimitogenic properties of NO, it is possible that the attenuated basal and HD-induced NO production in patients with PHT contributes to the increased pulmonary vascular tone. Furthermore, the partial restoration of normal PAP and CO in HD patients that underwent either temporal A-V shunt closure or successful transplantation indicates that excessive pulmonary blood flow is involved in the pathogenesis of the disease.