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Christopher H Cabell

Publications and source records attributed to Christopher H Cabell.

36 records · Page 2Linked to original sources
PubMed2004

Native valve endocarditis due to coagulase-negative staphylococci: report of 99 episodes from the International Collaboration on Endocarditis Merged Database.

Using a large cohort of patients from the International Collaboration on Endocarditis Merged Database, we compared coagulase-negative staphylococcal (CoNS) native-valve endocarditis (NVE) to NVE caused by more common pathogens. Rates of heart failure and mortality were similar between patients with CoNS NVE and patients with Staphylococcus aureus NVE, but rates for both groups were significantly higher than rates for patients with NVE due to viridans streptococci. These results emphasize the importance of CoNS as a cause of NVE and the potential for serious complications with this infection.

Aged↗
PubMed2004

Persistent bacteremia due to methicillin-resistant Staphylococcus aureus infection is associated with agr dysfunction and low-level in vitro resistance to thrombin-induced platelet microbicidal protein.

BACKGROUND: The causes of persistent bacteremia (PB) due to methicillin-resistant Staphylococcus aureus (MRSA) are poorly understood. This investigation examined potential associations between PB with key clinical features and several in vitro bacterial genotypic and phenotypic characteristics, in isolates from 1 institution. METHODS: Pulsed-field gel electrophoresis (PFGE) relatedness, thrombin-induced platelet microbicidal protein (tPMP)-susceptibility phenotype, accessory gene regulator (agr) genotype and functionality (via delta-lysin production), and autolysis phenotypes were assessed in MRSA isolates from the bloodstream of 21 prospectively identified patients with PB (blood cultures positive after > or =7 days of therapy) and of 18 patients with resolving bacteremia (RB) (sterile blood cultures within the first 2-4 days of therapy) due to MRSA. RESULTS: The 2 groups had comparable baseline characteristics but differed in their clinical courses (e.g., endocarditis was more frequent in patients with PB than in those with RB [43% vs. 0%, respectively; P=.0016]); isolates from patients with PB exhibited higher rates of (1) survival in vitro after exposure to tPMP (22.4+/-14.8% vs. 11.6+/-6.5%, respectively; P=.005); (2) defective delta-lysin production (71.4% vs. 38.9%, respectively; P=.057); (3) non-agr genotype II profile (100% vs. 77.8%, respectively; P=.037); and (4) overrepresentation of a specific PFGE genotype (85.7% vs. 44.4%, respectively; P=.015). CONCLUSIONS: Isolates from patients with PB differed from those in patients with RB, in several in vitro characteristics. Further studies will be necessary to define how these factors might affect clinical outcome.

Anti-Bacterial Agents↗
PubMed2004

Usefulness of myocardial viability or ischemia in predicting long-term survival for patients with severe left ventricular dysfunction undergoing revascularization.

In 107 patients with coronary disease and severe left ventricular dysfunction, we examined the prognostic power of viability identified by dobutamine stress echocardiography. At a mean follow-up of 27 months, patients with viable myocardium who underwent revascularization had a significant survival advantage over all other patients (2-year survival 83.5% vs 57.2%, p = 0.0037).

Angioplasty, Balloon, Coronary↗
PubMed2004

Early predictors of in-hospital death in infective endocarditis.

BACKGROUND: Data on early determinants of outcome in infective endocarditis (IE) are limited. We evaluated the prognostic significance of early clinical characteristics in a large, prospective cohort of patients with IE. METHODS AND RESULTS: Two hundred sixty-seven consecutive patients with definite or possible IE by modified Duke criteria and echocardiography performed within 7 days of presentation were evaluated. Acute physiology was assessed by the Acute Physiology, Age, Chronic Health Evaluation II (APACHE II) score at the time of presentation, and early heart failure was diagnosed by Framingham criteria. In-hospital mortality rate in the cohort was 19% and similar for patients with definite or possible IE (20% versus 16%, respectively; P=0.464). Independent predictors of death determined by logistic regression modeling were diabetes mellitus (OR 2.48; 95% CI, 1.24 to 4.96), Staphylococcus aureus as causative organism (OR, 2.06; 95% CI, 1.01 to 4.20), APACHE II score (OR, 1.07; 95% CI, 1.01 to 1.12), and embolic event (OR, 2.79; 95% CI, 1.15 to 6.80). Early echocardiographic findings of the Duke criteria were not predictive of death. CONCLUSIONS: Early in the course of IE, readily available clinical characteristics that reflect the host-pathogen interaction are predictive of in-hospital death. These factors may identify those patients with IE for more aggressive treatment.

APACHE↗
PubMed2004

Current Treatment Options for Patients with Endocarditis: The Evolving Indications for Cardiac Surgery.

Infective endocarditis (IE) is a serious and deadly disease. Despite medical advances over the past half century, more than one half of patients with IE suffer a serious complication, and the mortality rate remains approximately 20% during the initial hospitalization and approaches 40% at 1 year. In patients with documented IE, the treatment centers on two main aspects: effective antibiotic therapy and consideration of surgical therapy. Effective antibiotic therapy is the mainstay of treatment and focuses on sustained bactericidal concentrations tailored specifically to the causative microorganism. Surgical therapy is also an important option for many patients with IE. The goals of surgical therapy are to eradicate the focus of infection, to repair endocardial destruction, and to prevent the development of complications and relapse of infection. Ideally, surgical therapy should offer a survival advantage over medical therapy alone. Recent evidence supports the survival benefit of surgery in patients with IE, specifically in those with heart failure and complicated, left-sided IE. Future therapeutic strategies may include broader indications for surgery, as well as new treatments such as immune-modulating agents.

Journal Article↗
PubMed2004

Increasing rates of cardiac device infections among Medicare beneficiaries: 1990-1999.

BACKGROUND: Although cardiac devices have been found to reduce symptoms and mortality rates in appropriate patient populations, the implications of certain important risks, such as infection, are incompletely understood. The purpose of this study was to use a large population-based database to define the population that is at risk for cardiac device infections, determine the prevalence of device infections, and study changes in the rates of cardiac device implantation and infection in the past decade. METHODS: Patients with cardiac device implantations and infections were identified with claims files from the Health Care Finance Administration for Medicare beneficiaries from January 1, 1990, through December 31, 1999. Rates of implantation of cardiac devices were determined. Time trend analyses were performed to determine the significance of the observed change in rates. RESULTS: Cardiac device implantation rates increased from 3.26 implantations per 1000 beneficiaries in 1990 to 4.64 implantations per 1000 beneficiaries in 1999, which represents an increase of 42% in 10 years (P for trend <.001). Cardiac device infections showed a larger increase, from 0.94 device infections per 1000 beneficiaries in 1990 to 2.11 device infections per 1000 beneficiaries in 1999, which represents an increase of 124% during the study period (P for trend <.001). CONCLUSIONS: During the previous decade, there was a significant increase in both cardiac device implantations and infections in elderly patients, although the increase in the rates of device infections was substantially higher. Additional studies are needed to better understand the relationship and timing between cardiac device implantation and infection.

Aged↗
PubMed2004

Importance of echocardiography in patients with severe nonischemic heart failure: the second Prospective Randomized Amlodipine Survival Evaluation (PRAISE-2) echocardiographic study.

BACKGROUND: Echocardiography is used commonly in clinical practice when caring for patients with heart failure. It is unknown whether the presence of certain findings provides an incremental ability to predict survival beyond the use of baseline clinical findings alone. The second PRAISE-2 echocardiographic study was prospectively designed to identify echocardiographic predictors of survival among patients with nonischemic cardiomyopathy and heart failure and to determine if components of the echocardiographic examination add prognostic information to baseline demographic and clinical information. METHODS: One hundred patients participated in the second Prospective Randomized Amlodipine Survival Evaluation Study (PRAISE-2) echocardiographic study; of these, 93 had full and interpretable echocardiographic examinations. Cox proportional hazards modeling was used to assess the relation between various characteristics and survival as well as to assess the incremental prognostic information gained by echocardiography beyond the clinical examination. RESULTS: Seven of 10 routine echocardiographic measures were significantly associated with death. These included mitral regurgitation (hazard ratio [HR], 2.31; 95% CI, 1.02, 5.27), left ventricular ejection fraction <20% (HR, 2.59; 95% CI, 1.14, 5.88), restrictive left ventricular filling pattern (HR, 2.37; 95% CI, 1.05, 5.32), and peak D velocity (HR, 1.62; 95% CI, 0.38, 0.87). The only statistically significant clinical predictor of survival was dyspnea at rest. The addition any of several echocardiographic parameters to baseline clinical information significantly improved the ability to predict survival. CONCLUSIONS: Several readily available echocardiographic parameters are predictive of death and when added to clinical examination findings significantly improve the ability to determine prognosis among patients with nonischemic cardiomyopathy and heart failure.

Amlodipine↗
PubMed2004

Novel approaches to clinical trials: device-related infections.

The explosive growth in the use of cardiac devices and the continued large number of thoracic operations produce a significant number of costly infectious complications. These infections represent a leading cause of death and disability after device implantation or surgery. Unfortunately, few objective data are available to validate the clinical epidemiology of surgical and device-related infections, and although the number of randomized trials is increasing, too few have tested strategies for prophylaxis or treatment, particularly in the cardiac arena. Because of the expected increase in invasive vascular procedures and device implantations, it is timely to consider innovative approaches to clinical research that will hasten the translation of effective therapeutic strategies and technologies into clinical practice. Because of the multidisciplinary nature of the care of patients undergoing thoracic surgery or device implantation, bringing together existing networks and several arms of the Federal government could rapidly advance this field to provide a definitive base of evidence to guide clinical practice and improve clinical outcomes. The remainder of the articles in this supplement discuss specific issues on the diagnosis and treatment of device-related or surgical infection. The purpose of this manuscript is to discuss issues about the design of studies and their organization.

Antibiotic Prophylaxis↗
PubMed2003

Clinical identifiers of complicated Staphylococcus aureus bacteremia.

BACKGROUND: Complications of Staphylococcus aureus bacteremia (SAB) are often difficult to identify. The ability to accurately predict the likelihood of these complications would impact patient management. This investigation sought to define readily available clinical characteristics that could help identify patients at risk for complicated SAB. METHODS: A prospective, observational cohort study was conducted from September 1994 through December 1999. Patients were followed up for 12 weeks after the initial positive blood culture result. The primary end point was complicated SAB (attributable mortality, complicated infection, embolic stroke, or recurrent S aureus infection during the 12-week follow-up period). The predictive model was validated using bootstrap resampling. RESULTS: Complicated SAB was present in 43% of 724 consecutive adult hospitalized patients identified during the study period. The full predictive model had a high discriminative ability (bootstrap-corrected c index, 0.78). The strongest predictor of complicated SAB was a positive follow-up blood culture result at 48 to 96 hours. A scoring system based on the presence or absence of 4 risk factors (community acquisition, skin examination findings suggesting acute systemic infection, persistent fever at 72 hours, and positive follow-up blood culture results at 48-96 hours) accurately identified complicated SAB (bootstrap-corrected c index, 0.76). CONCLUSION: Readily available clinical variables can help identify patients at risk for complicated SAB.

Adult↗
PubMed2003

Survival after coronary revascularization, with and without mitral valve surgery, in patients with ischemic mitral regurgitation.

BACKGROUND: The most appropriate treatment for patients with ischemic mitral regurgitation (IMR) is often debated. We compared the survival rates of patients with IMR undergoing different treatment strategies, namely: medical therapy, percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG), and CABG + mitral valve (MV) surgery. METHODS AND RESULTS: Patients undergoing catheterization between 1986 and 2001 were included. IMR was defined as: >or=grade 2+ mitral regurgitation (MR) and significant coronary artery disease (CAD) without primary mitral valve disease. Patients undergoing catheterization for the evaluation of congenital or other valvular heart disease were excluded. Multivariable Cox proportional hazards modeling was utilized to assess the independent relation between treatment and survival. Propensity score methods were used to correct for the nonrandom assignment of treatment. Of the 2,757 patients who met study criteria: 1,305 were treated medically, 537 underwent PCI, 687 underwent CABG, and 228 underwent CABG + MV surgery. The median duration of follow-up was 3.2 (0.9, 7.1) years. Patients undergoing CABG + MV surgery had more severe MR and more severe heart failure than those treated by other modalities. After adjusting for differences in baseline characteristics, patients undergoing PCI, CABG, and CABG + MV surgery had a 31% (hazards ratio [HR]=0.69; P=0.0001), 42% (HR=0.58; P=0.0001), and 42% (HR=0.58; P=0.0001) reduction in the risk of death, respectively, compared with those undergoing medical therapy. The performance of mitral valve surgery with CABG was not associated with improved survival versus CABG alone (P=0.258). CONCLUSIONS: Among patients with IMR, treatment with PCI, CABG, or CABG + MV surgery is associated with improved survival compared with medical therapy.

Aged↗
PubMed2003

Staphylococcus aureus bacteremia after median sternotomy: clinical utility of blood culture results in the identification of postoperative mediastinitis.

BACKGROUND: Mediastinitis is a complication of coronary artery bypass graft surgery (CABG) that can be difficult to diagnose. This study evaluated the utility of blood culture results in identifying patients with mediastinitis. METHODS AND RESULTS: All unique patients undergoing CABG at our institution over a 60-month study period (n=5500) and all blood cultures performed on these patients or=1 blood culture drawn within 90 days of CABG. Mediastinitis occurred in 46 of 60 (76.7%) patients with blood cultures positive for Staphylococcus aureus, 15 of 126 (11.9%) patients with blood cultures positive for other pathogens, 37 of 669 (5.5%) patients with blood cultures with no growth, and 44 of 4645 (0.9%) patients with no blood cultures obtained. The isolation of S aureus from even 1 blood culture drawn after or=1 blood culture obtained after CABG. CONCLUSIONS: Among patients with blood cultures drawn after CABG, S aureus bacteremia strongly suggests the presence of mediastinitis.

Academic Medical Centers↗
PubMed2003

Relation of frequency and severity of mitral regurgitation to survival among patients with left ventricular systolic dysfunction and heart failure.

The goal of this study was to examine the frequency of mitral regurgitation (MR) in patients with left ventricular (LV) systolic dysfunction and to relate its presence and severity to long-term survival. Remodeling of the left ventricle after myocyte injury leads to a progressive change in LV size and shape, and it may lead to the development of MR. The frequency of MR and its relation to survival in patients with LV systolic dysfunction has not been completely characterized. We analyzed the histories, coronary anatomy, and degree of MR in patients with symptomatic heart failure and LV ejection fraction <40% who underwent cardiac catheterization between 1986 and 2000. Cox's proportional hazards modeling was used to assess the independent effect of MR on survival. Two thousand fifty-seven patients met study criteria; MR was common in this cohort (56.2%). Of patients with MR, 811 (70.1%) had mild (grades 1+ or 2+) and 345 (29.8%) had moderate or severe (grades 3+ or 4+) regurgitation. Survival rates at 1, 3, and 5 years were significantly lower in patients with moderate to severe MR versus those with mild or no MR (p <0.001). MR was found to be an independent predictor of mortality after multivariable analysis (hazards ratio 1.23, 95% confidence interval 1.13 to 1.34, p = 0.0001). This relation of MR and survival was present in those with ischemic and nonischemic cardiomyopathies. MR is common in patients with LV systolic dysfunction and heart failure. After adjusting for other clinical variables, the presence of MR independently predicted worsened survival.

Age Distribution↗
PubMed2003

Progress toward a global understanding of infective endocarditis. Lessons from the International Collaboration on Endocarditis.

In the century and a quarter since William Osler delivered his famed Gulstonian lectures on endocarditis, continual advancements have been made in understanding and treating this disease. Here we have reviewed some key aspects of current knowledge in the areas of population epidemiology, host factors, microorganisms, and diagnosis. The advent of the ICE investigation provides the opportunity to further expand our understanding of IE by developing a very large, global database of IE patients whose clinical, echocardiographic, and microbiologic findings have been characterized with standard methodology. Further, ICE may serve as a rich source of material for investigators seeking to perform specific studies. Finally, the ICE infrastructure creates the opportunity for performing randomized trials to test therapeutic strategies. Although many obstacles remain to be overcome, ICE has created the opportunity for a quantum leap in our knowledge of IE over the next 25 years.

Comprehension↗
PubMed2002

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.

Adult↗
PubMed2002

Progress toward a global understanding of infective endocarditis. Early lessons from the International Collaboration on Endocarditis investigation.

In the century and a quarter since William Osler delivered his framed lectures on endocarditis substantial advancements have occurred in the understanding and treatment of this disease. This article summarizes current understanding of endocarditis in the areas of population epidemiology, host factors, microorganisms, diagnosis, and therapy. In addition, the authors discuss possible directions for investigation in the future, including a new multinational consortium, the International Collaboration on Endocarditis (ICE). This collaboration aims to provide a mechanism to advance the understanding of endocarditis in areas difficult to study without an established network. The multinational nature of the collaboration may also permit a more global view of IE and provide opportunities for studies such as randomized trials of therapeutic treatment strategies.

Bacteria↗