Venous thrombosis in patients with short- and long-term central venous catheter-associated Staphylococcus aureus bacteremia.

OBJECTIVE: Infection and thrombosis are important complications of intravascular catheters. The purpose of this study was to determine the incidence of thrombosis in patients with central venous catheter-associated Staphylococcus aureus bacteremia and the utility of physical examination for diagnosing upper extremity or neck venous thrombosis. DESIGN: Prospective observational cohort. SETTING: Tertiary care facility. PATIENTS: In all, 65 consecutive patients with catheter-associated S. aureus bacteremia with central venous catheters of the internal jugular, brachial, or subclavian veins were eligible for participation. INTERVENTION: From July 1999 through August 2004, enrolled patients underwent physical examination and ultrasonography independently to identify the presence of catheter-associated thrombosis. Study ultrasonograms were interpreted blindly using defined criteria. Outcomes were defined at 12-wk follow-up. MEASUREMENTS AND MAIN RESULTS: A total of 48 patients were enrolled. By ultrasonography, definite or possible thrombosis was present in 34 of 48 patients (71%) in this cohort. Death or recurrent bacteremia occurred in 11/34 (32%) infected patients with thrombosis and two of 14 (14%) infected patients without thrombosis (p = .29). Sensitivity of all physical examination findings, either alone or in combination, was low (< or = 24%). Only engorged veins upon hand elevation and the presence of multiple physical examination abnormalities were specific (100% each). CONCLUSIONS: Thrombosis is a common complication of central venous catheter-associated S. aureus bacteremia. Patients with central venous catheter-associated S. aureus bacteremia should undergo ultrasonography to detect thromboses even if the physical examination is normal.

Relation of troponin elevation to outcome in patients with infective endocarditis.

Elevated troponin is increasingly recognized as a marker of cardiac injury and poor outcomes in diverse disease states. It was hypothesized that patients with infective endocarditis (IE) and elevated cardiac troponin would have more extensive IE and worse clinical outcomes. Patients were enrolled as part of the International Collaboration on Endocarditis (ICE) prospective cohort study; analysis of these patients was done retrospectively. Data from 83 consecutively enrolled patients from a single center were evaluated. Cardiac troponin I (cTnI) was drawn for clinical indications and before any cardiac surgery in 51 of the 83 patients. Outcomes evaluated were hospital mortality, annular or myocardial abscess on the basis of echocardiography or surgery, and central nervous system events. Of 51 patients with cTnI drawn, 33 (65%) had elevated cTnI > or =0.1 mg/dl. There were no differences in age, gender, prosthetic valve IE, Staphylococcus aureus IE, or history of coronary artery disease, congestive heart failure, or diabetes mellitus between patients with and without cTnI elevations. Patients with elevated cTnI were less likely to have isolated right-sided IE and more likely to have left ventricular systolic dysfunction or renal dysfunction (p <0.05 for each). In conclusion, elevated cTnI was associated with the composite of death, abscess, and central nervous system events (p <0.001).

The relationship between the initiation of antimicrobial therapy and the incidence of stroke in infective endocarditis: an analysis from the ICE Prospective Cohort Study (ICE-PCS).

BACKGROUND: Embolic events to the central nervous system are a major cause of morbidity and mortality in patients with infective endocarditis (IE). The appropriate role of valvular surgery in reducing such embolic events is unclear. The purpose of this study was to determine the relationship between the initiation of antimicrobial therapy and the temporal incidence of stroke in patients with IE and to determine if this time course differs from that shown for embolic events in previous studies. METHODS: Prospective incidence cohort study involving 61 tertiary referral centers in 28 countries. Case report forms were analyzed from 1437 consecutive patients with left-sided endocarditis admitted directly to participating centers. RESULTS: The crude incidence of stroke in patients receiving appropriate antimicrobial therapy was 4.82/1000 patient days in the first week of therapy and fell to 1.71/1000 patient days in the second week. This rate continued to decline with further therapy. Stroke rates fell similarly regardless of the valve or organism involved. After 1 week of antimicrobial therapy, only 3.1% of the cohort experienced a stroke. CONCLUSIONS: The risk of stroke in IE falls dramatically after the initiation of effective antimicrobial therapy. The falling risk of stroke in patients with IE as a whole precludes stroke prevention as the sole indication for valvular surgery after 1 week of therapy.

Urinary tract infection in patients with acute coronary syndrome: a potential systemic inflammatory connection.

BACKGROUND: Inflammation has been linked with atherosclerotic disease development and instability. Contributors to systemic inflammation, such as subclinical infection, may trigger acute coronary syndromes (ACSs). METHODS: Using a case-control study design, we evaluated the prevalence of urinary tract infection (UTI) among 100 consecutive ACS patients, compared with a contemporary control group undergoing elective coronary artery bypass graft (CABG) surgery. Cases were excluded if ACS was not confirmed by chart review or if a urinalysis was not obtained

Changing patient characteristics and the effect on mortality in endocarditis.

BACKGROUND: Limited data exist on recent demographic and microbiological changes in infective endocarditis (IE) and the impact of these changes on patient survival. METHODS: Data were collected from all patients with definite or possible IE at Duke University Medical Center, Durham, NC, from 1993 to 1999. Logistic regression analysis was used to identify demographic and microbiological changes that occurred in patients with IE over the study period. The impact of these changes on survival was evaluated using Cox proportional hazards modeling. RESULTS: Among the 329 study patients, rates of hemodialysis dependence, immunosuppression, and Staphylococcus aureus infection increased during the study period (P=.04, P=.008, and P<.001, respectively), while rates of infection due to viridans group streptococci decreased (P=.007). Hemodialysis was independently associated with S aureus infection (odds ratio, 3.1; 95% confidence interval, 1.6-5.9). Patients with S aureus IE had a higher 1-year mortality rate (43.9% vs 32.5%; P=.04) that persisted after adjustment for other illness severity characteristics (hazard ratio, 1.5; 95% confidence interval, 1.03-2.3). CONCLUSIONS: The demographic and microbiological characteristics of IE at our institution have changed over the past decade in ways that suggest a link between medical practice and IE characteristics. Staphylococcus aureus has emerged as a dominant cause of IE, and is an independent predictor of mortality. These findings identify clinical settings that may warrant closer surveillance and more aggressive measures in the identification and prevention of endocarditis.

Imaging techniques for diagnosis of infective endocarditis.

With the ability to structurally characterize cardiac manifestations, echocardiography is used for the diagnosis and management of infective endocarditis. In establishing the diagnosis according to the Duke criteria, the findings of endocardial involvement (vegetation, abscess, prosthetic valve dehiscence) or new valvular regurgitation represent "major" diagnostic criteria. As echocardiography cannot reliably differentiate noninfective from infective lesions, however, proper diagnosis lies in correlating echocardiography with clinical findings. The more invasive transesophageal approach provides substantially greater image resolution; this approach should be considered first in the evaluation of patients with higher prior probabilities of endocarditis and those with potential endocardial complications.

Imaging techniques for diagnosis of infective endocarditis.

Cardiac imaging, specifically echocardiography, has greatly enhanced the ability of clinicians to effectively diagnose and manage IE. Echocardiograms should generally be obtained in all patients suspected of having IE, both to establish the diagnosis and to identify complicated cardiac involvement that may warrant surgical intervention. Transesophageal imaging is more sensitive and specific than the transthoracic approach and currently represents the optimal approach to echocardiographic imaging. Manifestations of endocardial involvement include vegetations, abscesses, aneurysms, fistulae, leaflet perforations, and valvular dehiscence. The roles of other imaging modalities including CT, MRI, and nuclear imaging have yet to be fully established.

Left hemiparesis from atrial myxoma emboli.

Atrial Myxomas are benign primary tumors of the heart, arising mainly from the left atrium. Clinical signs and symptoms produced by atrial myxomas may be non-specific or result in mechanical obstruction of cardiac function, arrhythmias, and embolization. The authors present a case of a 60-year-old woman who developed total left hemiparesis resulting from left atrial myxoma embolization causing complete occlusion of the right middle cerebral artery.

Relationship of left ventricular hypertrophy and diastolic function with cardiovascular and renal outcomes in African Americans with hypertensive chronic kidney disease.

African Americans with hypertension are at high risk for adverse outcomes from cardiovascular and renal disease. Patients with stage 3 or greater chronic kidney disease have a high prevalence of left ventricular (LV) hypertrophy and diastolic dysfunction. Our goal was to study prospectively the relationships of LV mass and diastolic function with subsequent cardiovascular and renal outcomes in the African American Study of Kidney Disease and Hypertension cohort study. Of 691 patients enrolled in the cohort, 578 had interpretable echocardiograms and complete relevant clinical data. Exposures were LV hypertrophy and diastolic parameters. Outcomes were cardiovascular events requiring hospitalization or causing death; a renal composite outcome of doubling of serum creatinine or end-stage renal disease (censoring death); and heart failure. We found strong independent relationships between LV hypertrophy and subsequent cardiovascular (hazard ratio, 1.16; 95% confidence interval, 1.05-1.27) events, but not renal outcomes. After adjustment for LV mass and clinical variables, lower systolic tissue Doppler velocities and diastolic parameters reflecting a less compliant LV (shorter deceleration time and abnormal E/A ratio) were significantly (P<0.05) associated with future heart failure events. This is the first study to show a strong relationship among LV hypertrophy, diastolic parameters, and adverse cardiac outcomes in African Americans with hypertension and chronic kidney disease. These echocardiographic risk factors may help identify high-risk patients with chronic kidney disease for aggressive therapeutic intervention.

Left ventricular hypertrophy by electrocardiography and echocardiography in the African American Study of Kidney Disease Cohort Study.

Although electrocardiographic criteria for diagnosing left ventricular hypertrophy have a low sensitivity in the general population, their test characteristics have not been evaluated in the high-prevalence group of American Americans with chronic kidney disease. The purpose of the current study was to evaluate these test characteristics among African Americans (n = 645) with hypertensive kidney disease as part of the African-American Study of Kidney Disease and Hypertension cohort. Electrocardiograms were read by 2 cardiologists at an independent core laboratory using the 2 Sokolow-Lyon criteria and the Cornell criteria. Left ventricular hypertrophy on echocardiography was defined as left ventricular mass index greater than 49.2 and greater than 46.7 g/m(2.7) in men and women, respectively. Sixty-nine percent of the population had left ventricular hypertrophy on echo, whereas 34% had left ventricular hypertrophy by any of the electrocardiographic criteria. Sensitivity by individual electrocardiographic criteria was 16.5% by Sokolow-Lyon-1, 19.3% by Sokolow-Lyon-2, and 24.7% by Cornell criteria, with specificity ranging from 89% to 92%. When using any of the 3 criteria, sensitivity increased to 40.4% with a decrease in specificity to 78.0%. Consistent with findings in a general population, left ventricular hypertrophy by electrocardiography had low sensitivity and high specificity in this cohort of African Americans with hypertensive kidney disease.

Association of troponin T, detected with highly sensitive assay, and outcomes in infective endocarditis.

Troponin levels have been correlated with adverse outcomes in multiple disease processes, including congestive heart failure, acute coronary syndromes, sepsis, and, in a few small series, infective endocarditis. We hypothesized that a novel measurement of troponin using a highly sensitive assay would correlate with adverse outcomes when prospectively studied in patients with infective endocarditis. At a single center in the International Collaboration on Endocarditis, 42 patients met the inclusion criteria and underwent testing for cardiac troponin T (cTnT) using both a standard and a highly sensitive precommercial assay. The cTnT levels were associated with the prespecified primary composite outcome of death, central nervous system event, and cardiac abscess. Secondary outcomes included the individual components of the composite outcome and the need for cardiac surgery. A receiver operating characteristic curve was derived and used to identify the optimal cutpoint for cTnT using the highly sensitive assay. cTnT was detectable with the highly sensitive assay in 39 (93%) of 42 patients with infective endocarditis and with the standard assay in 25 (56%) of 42 (p <0.05). Of the 42 patients, 15 experienced the composite outcome, 4 died, 9 had a central nervous system event, and 5 had a cardiac abscess. With the hs-cTnT assay, the median cTnT was greater in the patients who experienced the primary outcome (0.12 vs 0.02 ng/ml, p <0.05). According to the receiver operating characteristic curve analysis (area under the curve of 0.74), cTnT levels of ≥0.08 ng/ml produced optimal specificity (78%) for the primary outcome. The patients with a cTnT level of ≥0.08 ng/ml were more likely to experience the primary outcome (odds ratio 7.0, 95% confidence interval 1.7 to 28.6, p <0.01) and a central nervous system event (odds ratio 9.3, 95% confidence interval 1.3 to 24.1, p = 0.02). In conclusion, cTnT is detectable in 93% of patients with infective endocarditis using a novel highly sensitive assay, with higher levels correlating with poor clinical outcomes.

Relation of level of B-type natriuretic peptide with outcomes in patients with infective endocarditis.

Elevated B-type natriuretic peptide (BNP) is a marker of poor outcomes in heart failure, acute coronary syndromes, and sepsis. Elevated cardiac troponin I (cTnI) is associated with adverse outcomes in infective endocarditis. It was hypothesized that elevated BNP would be associated with increased rates of morbidity and mortality in patients with infective endocarditis, particularly when combined with elevated cTnI. Consecutively enrolled patients in the International Collaboration on Endocarditis Prospective Cohort Study (ICE-PCS) were evaluated at a single center. The association between elevated BNP and a composite outcome of death, intracardiac abscess, and central nervous system event and the individual components of the composite was determined. Similar analyses were performed in patients who had BNP and cTnI measured. Of 103 patients, 45 had BNP measured for clinical indications. The median BNP level was higher in patients with the composite outcome (1,498 vs 433 pg/ml, p = 0.03) and in those who died (2,150 vs 628 pg/ml, p = 0.04). Elevated BNP was significantly associated with the composite outcome (p <0.01) and intracardiac abscess (p = 0.02). Patients with elevation of BNP and cTnI had a significantly higher probability of the composite outcome (69%) than patients with either BNP or cTnI elevated (29%) or neither BNP nor troponin elevated (0%) (p for trend <0.01). In conclusion, these data demonstrate a significant association between elevated BNP alone and in combination with cTnI for serious outcomes in infective endocarditis and warrant prospective evaluation.

Prevalence and correlates of left ventricular hypertrophy in the African American Study of Kidney Disease Cohort Study.

African Americans with hypertensive renal disease represent a high-risk population for cardiovascular events. Although left ventricular hypertrophy is a strong predictor of adverse cardiac outcome, the prevalence and associated factors of left ventricular hypertrophy in this patient population are not well described. The African American Study of Kidney Disease Cohort Study is a prospective, observational study that is an extension of the African American Study of Kidney Disease randomized clinical trial that was conducted from 1994 to 2001 in African Americans with hypertension and mild-to-moderate renal dysfunction. Echocardiograms and 24-hour ambulatory blood pressure monitoring were performed at the baseline visit of the cohort. Of 691 patients enrolled in the cohort study, 599 patients had interpretable baseline echocardiograms and ambulatory blood pressure data. Left ventricular hypertrophy was defined using a cut point for left ventricular mass index >49.2 g/m(2.7) in men and >46.7 m/m(2.7) in women. The majority of patients had left ventricular hypertrophy (66.7% of men and 73.9% of women). In a multiple regression analysis, higher average day and nighttime systolic blood pressure, younger age, and lower predicted glomerular filtration rate were associated with left ventricular hypertrophy, but albuminuria was not. These data demonstrate a striking prevalence of left ventricular hypertrophy in the African American Study of Kidney Disease Cohort and identify potential targets for prevention and therapeutic intervention in this high-risk patient population.