Vineet Chopra

Relation between red blood cell distribution width (RDW) and all-cause mortality at two years in an unselected population referred for coronary angiography

BACKGROUND Red blood cell distribution width (RDW), a numerical measure of the variability in size of circulating erythrocytes, has recently been shown to be a strong predictor of adverse outcomes in patients with heart failure and in patients with prior myocardial infarction but no symptomatic heart failure at baseline, even after adjustment for hematocrit. However, there are no data in other cardiac populations, including patients with acute coronary syndromes (ACS). METHODS The present study investigated the long-term prognostic significance of baseline RDW in a well-characterized cohort of 389 male patients who were referred to coronary angiography for a variety of indications. All patients were followed prospectively for all-cause mortality, and data regarding this endpoint was available for 97% of the population at 24 months. RESULTS After controlling for a variety of baseline variables (including hemoglobin and the presence of heart failure), RDW (analyzed as a categorical variable comparing the upper tertile of baseline values to the lower two levels combined) was a strong and independent predictor of all-cause mortality using a Cox proportional hazards model [hazard ratio (HR) 2.69, 95% confidence interval (CI) 1.50-4.84, p=0.0008]. In addition, baseline RDW was also an independent predictor of all-cause mortality in the non-anemic (HR 4.73, 95% CI 2.06-10.86, p=0.0003) and ACS (HR 2.90, 95% CI 1.32-6.38, p=0.0082) subpopulations of patients. CONCLUSIONS These data demonstrate that elevated RDW is a strong and independent predictor of all-cause mortality in an unselected population of male patients across a broad spectrum of risk (including ACS) referred for coronary angiography.

The Risk of Bloodstream Infection Associated with Peripherally Inserted Central Catheters Compared with Central Venous Catheters in Adults: A Systematic Review and Meta-Analysis

BACKGROUND Peripherally inserted central catheters (PICCs) are associated with central line-associated bloodstream infection (CLABSI). The magnitude of this risk relative to central venous catheters (CVCs) is unknown. OBJECTIVE To compare risk of CLABSI between PICCs and CVCs. METHODS MEDLINE, CinAHL, Scopus, EmBASE, and Cochrane CENTRAL were searched. Full-text studies comparing the risk of CLABSI between PICCs and CVCs were included. Studies involving adults 18 years of age or older who underwent insertion of a PICC or a CVC and reported CLABSI were included in our analysis. Studies were evaluated using the Downs and Black scale for risk of bias. Random effects meta-analyses were used to generate summary estimates of CLABSI risk in patients with PICCs versus CVCs. RESULTS Of 1,185 studies identified, 23 studies involving 57,250 patients met eligibility criteria. Twenty of 23 eligible studies reported the total number of CLABSI episodes in patients with PICCs and CVCs. Pooled meta-analyses of these studies revealed that PICCs were associated with a lower risk of CLABSI than were CVCs (relative risk [RR], 0.62; 95% confidence interval [CI], 0.40-0.94). Statistical heterogeneity prompted subgroup analysis, which demonstrated that CLABSI reduction was greatest in outpatients (RR [95% CI], 0.22 [0.18-0.27]) compared with hospitalized patients who received PICCs (RR [95% CI], 0.73 [0.54-0.98]). Thirteen of the included 23 studies reported CLABSI per catheter-day. Within these studies, PICC-related CLABSI occurred as frequently as CLABSI from CVCs (incidence rate ratio [95% CI], 0.91 [0.46-1.79]). LIMITATIONS Only 1 randomized trial met inclusion criteria. CLABSI definition and infection prevention strategies were variably reported. Few studies reported infections by catheter-days. CONCLUSIONS Although PICCs are associated with a lower risk of CLABSI than CVCs in outpatients, hospitalized patients may be just as likely to experience CLABSI with PICCs as with CVCs. Consideration of risks and benefits before PICC use in inpatient settings is warranted.

Bloodstream Infection, Venous Thrombosis, and Peripherally Inserted Central Catheters: Reappraising the Evidence

The widespread use of peripherally inserted central catheters (PICCs) has transformed the care of medical and surgical patients. Whereas intravenous antibiotics, parenteral nutrition, and administration of chemotherapy once necessitated prolonged hospitalization, PICCs have eliminated the need for such practice. However, PICCs may not be as innocuous as once thought; a growing body of evidence suggests that these devices also have important risks. This review discusses the origin of PICCs and highlights reasons behind their rapid adoption in medical practice. We evaluate the evidence behind 2 important PICC-related complications--venous thrombosis and bloodstream infections--and describe how initial studies may have led to a false sense of security with respect to these outcomes. In this context, we introduce a conceptual model to understand the risk of PICC-related complications and guide the use of these devices. Through this model, we outline recommendations that clinicians may use to prevent PICC-related adverse events. We conclude by highlighting important knowledge gaps and identifying avenues for future research in this area.

Effect of Perioperative Statins on Death, Myocardial Infarction, Atrial Fibrillation, and Length of Stay A Systematic Review and Meta-analysis

OBJECTIVE To assess the influence of perioperative statin treatment on the risk of death, myocardial infarction, atrial fibrillation, and hospital and intensive care unit length of stay in statin-naive patients undergoing cardiac or noncardiac surgery. DATA SOURCES MEDLINE via PubMed, EMBASE, Biosis, and the Cochrane Central Register of Controlled Trials via Ovid. Additional studies were identified through hand searches of bibliographies, trial Web sites, and clinical experts. Randomized controlled trials reporting the effect of perioperative statins in statin-naive patients undergoing cardiac and noncardiac surgery were included. STUDY SELECTION Two investigators independently selected eligible studies from original research published in any language studying the effects of statin use on perioperative outcomes of interest. DATA EXTRACTION Two investigators performed independent article abstraction and quality assessment. DATA SYNTHESIS Fifteen randomized controlled studies involving 2292 patients met the eligibility criteria. Random-effects meta-analyses of unadjusted and adjusted data were performed according to the method described by DerSimonian and Laird. Perioperative statin treatment decreased the risk of atrial fibrillation in patients undergoing cardiac surgery (relative risk [RR], 0.56; 95% CI, 0.45 to 0.69; number needed to treat [NNT], 6). In cardiac and noncardiac surgery, perioperative statin treatment reduced the risk of myocardial infarction (RR, 0.53; 95% CI, 0.38 to 0.74; NNT, 23) but not the risk of death (RR, 0.62; 95% CI, 0.34 to 1.14). Statin treatment reduced mean length of hospital stay (standardized mean difference, -0.32; 95% CI, -0.53 to -0.11) but had no effect on length of intensive care unit stay (standardized mean difference, -0.08; 95% CI, -0.25 to 0.10). CONCLUSIONS Perioperative statin treatment in statin-naive patients reduces atrial fibrillation, myocardial infarction, and duration of hospital stay. Wider use of statins to improve cardiac outcomes in patients undergoing high-risk procedures seems warranted.

Triggers of Hospitalization for Venous Thromboembolism

Background— The rate of hospitalization for venous thromboembolism (VTE) is increasing in the United States. Although predictors of hospital-acquired VTE are well-known, triggers of VTE before hospitalization are not as clearly defined. The objective of this study was to evaluate triggers of hospitalization for VTE. Methods and Results— A case-crossover study was conducted. Subjects were participants in the Health and Retirement Study, a nationally representative sample of older Americans. Data were linked to Medicare files for hospital and nursing home stays, emergency department visits, outpatient visits including physician visits, and home health visits from years 1991 to 2007 (n=16 781). The outcome was hospitalization for venous thromboembolism (n=399). Exposures during the 90-day period before hospitalization for VTE were compared with exposures occurring in 4 comparison periods. Infection was the most common trigger of hospitalization for VTE, occurring in 52.4% of the risk periods before hospitalization. The adjusted incidence rate ratios (IRRs; 95% confidence interval) were 2.90 (2.13, 3.94) for all infection, 2.63 (1.90, 3.63) for infection without a previous hospital or skilled nursing facility stay, and 6.92 (4.46, 10.72) for infection with a previous hospital or skilled nursing facility stay. Erythropoiesis-stimulating agents and blood transfusion were also associated with VTE hospitalization (IRR=9.33, 95% confidence interval: 1.19, 73.42; IRR=2.57, 95% confidence interval: 1.17, 5.64; respectively). Other predictors included major surgeries, fractures (IRR=2.81), immobility (IRR=4.23), and chemotherapy (IRR=5.70). These predictors, combined, accounted for a large proportion (69.7%) of exposures before VTE hospitalization as opposed to 35.3% in the comparison periods. Conclusions— Risk prediction algorithms for VTE should be reevaluated to include infection, erythropoiesis-stimulating agents, and blood transfusion.

The Role of Social Media in Online Weight Management: Systematic Review

Background Social media applications are promising adjuncts to online weight management interventions through facilitating education, engagement, and peer support. However, the precise impact of social media on weight management is unclear. Objective The objective of this study was to systematically describe the use and impact of social media in online weight management interventions. Methods PubMed, PsycINFO, EMBASE, Web of Science, and Scopus were searched for English-language studies published through March 25, 2013. Additional studies were identified by searching bibliographies of electronically retrieved articles. Randomized controlled trials of online weight management interventions that included a social media component for individuals of all ages were selected. Studies were evaluated using 2 systematic scales to assess risk of bias and study quality. Results Of 517 citations identified, 20 studies met eligibility criteria. All study participants were adults. Because the included studies varied greatly in study design and reported outcomes, meta-analysis of interventions was not attempted. Although message boards and chat rooms were the most common social media component included, their effect on weight outcomes was not reported in most studies. Only one study measured the isolated effect of social media. It found greater engagement of participants, but no difference in weight-related outcomes. In all, 65% of studies were of high quality; 15% of studies were at low risk of bias. Conclusions Despite the widespread use of social media, few studies have quantified the effect of social media in online weight management interventions; thus, its impact is still unknown. Although social media may play a role in retaining and engaging participants, studies that are designed to measure its effect are needed to understand whether and how social media may meaningfully improve weight management.

The Problem With Peripherally Inserted Central Catheters

CENTRAL VENOUS CATHETERS (CVCS) PROVIDE REliable venous access for tasks as diverse as delivery of medication, laboratory testing, and hemodynamic monitoring and occupy a fundamental role in the management of seriously ill patients. However, despite their many benefits, CVCs are not innocuous and are associated with important complications. Among these, central line–associated bloodstream infection (CLABSI) and venous thromboembolism are significant because they are difficult to detect, increase the cost of care, and are potentially life-threatening adverse events. Consequently, studies to predict and prevent these complications have become a research priority. Because of the frequent use of CVCs in the intensive care unit (ICU), efforts to reduce these unfavorable outcomes have traditionally focused on critically ill patients, a population for which substantial progress has been made. For example, improvements in measurement of infectious episodes by standardized definitions and diffusion of evidence-based practices have led to a 58% decrease in CLABSI in ICUs across the United States. Similarly, evidence-based guidelines emphasizing risk estimation and pharmacological prophylaxis have decreased the risk of CVC-related venous thromboembolism in ICU patients. Important shifts in the epidemiology of CVCs from ICU to non-ICU settings, however, may threaten this progress. For instance, in a survey involving 2459 patients in 6 medical centers, the majority of CVCs (70%) were being used in non-ICU patients. Furthermore, CVCs remain in place for longer durations when inserted in non-ICU settings, theoretically increasing the risk of CLABSI and venous thromboembolism. Recent data confirm this concern: of the 9826 CLABSIs reported by participating National Healthcare Safety Network hospitals in 2010, 31% occurred in non-ICU patients. In a study seeking to simplify the estimation of venous thrombosis risk in hospitalized patients, the presence of a CVC was among 4 of the strongest risk factors associated with venous thromboembolism. These findings are all the more concerning because lack of comprehensive surveillance for CLABSI in some non-ICU settings, absence of a homogenous patient and clinician population in contrast to those within ICUs, and controversies regarding venous thromboembolism prophylaxis represent major barriers to prevention in non-ICU settings. Peripherally inserted central catheters (PICCs) are venous catheters that are inserted peripherally, and terminate in central veins such that they may be categorized as CVCs. For multiple reasons, PICCs have become among the most frequently encountered CVC in non-ICU patients. For instance, these devices are safer to insert than CVCs, eliminate the discomfort associated with phlebotomy and scheduled peripheral intravenous line changes, and provide extended and reliable venous access. Because specially trained nurses commonly place PICCs at the patient’s bedside, ready access to these devices has increased. Furthermore, because PICCs reduce cost by enabling earlier hospital discharge through home intravenous therapy, payers have welcomed and supported the widespread use of these venous catheters. These logistical factors notwithstanding, a key factor contributing to increasing PICC use is the perception that they are safer than CVCs with respect to important complications. Initial studies found PICC-related bloodstream infection rates were significantly lower than rates associated with CVCs. However, accumulating evidence suggests that the risk of PICC-related complications is not uniform. For example, Ajenjo et al reported that PICC-related CLABSI was almost twice as likely for PICCs that were inserted in ICU settings compared with non-ICU settings (4.79 vs 2.79 episodes per 1000 catheter-days, respectively; relative risk, 1.70 [95% CI, 1.10–2.61]). With respect to venous thromboembolism, factors such as site of PICC insertion (right or left arm), number of PICC lumens, the position of the PICC tip, and patient characteristics such as malignancy, prior venous thromboembolism, or both, interact to influence risk of thrombosis. Taken together, these data suggest that the risk of CLABSI and venous thromboembolism associated with PICCs is dynamic and varies according to

PICC-associated bloodstream infections: prevalence, patterns, and predictors.

BACKGROUND Growing use of peripherally inserted central catheters (PICCs) has led to recognition of the risk of PICC-associated bloodstream infection. We sought to identify rates, patterns, and patient, provider, and device characteristics associated with this adverse outcome. METHODS A retrospective cohort of consecutive adults who underwent PICC placement from June 2009 to July 2012 was assembled. Using multivariable logistic and Cox-proportional hazards regression models, covariates specified a priori were analyzed for their association with PICC-associated bloodstream infection. Odds ratios (OR) and hazard ratios (HR) with corresponding 95% confidence intervals (CI) were used to express the association between each predictor and the outcome of interest. RESULTS During the study period, 966 PICCs were inserted in 747 unique patients for a total of 26,887 catheter days. Indications for PICC insertion included: long-term antibiotic administration (52%, n = 503), venous access (21%, n = 201), total parenteral nutrition (16%, n = 155), and chemotherapy (11%, n = 107). On bivariate analysis, intensive care unit (ICU) status (OR 3.23; 95% CI, 1.84-5.65), mechanical ventilation (OR 4.39; 95% CI, 2.46-7.82), length of stay (hospital, OR 1.04; 95% CI, 1.02-1.06 and ICU, OR 1.03; 95% CI, 1.02-1.04), PowerPICCs (C. R. Bard, Inc., Murray Hill, NJ; OR 2.58; 95% CI, 1.41-4.73), and devices placed by interventional radiology (OR 2.57; 95% CI, 1.41-4.68) were associated with PICC-bloodstream infection. Catheter lumens were strongly associated with this event (double lumen, OR 5.21; 95% CI, 2.46-11.04, and triple lumen, OR 10.84; 95% CI, 4.38-26.82). On multivariable analysis, only hospital length of stay, ICU status, and number of PICC lumens remained significantly associated with PICC bloodstream infection. Notably, the HR for PICC lumens increased substantially, suggesting earlier time to infection among patients with multi-lumen PICCs (HR 4.08; 95% CI, 1.51-11.02 and HR 8.52; 95% CI, 2.55-28.49 for double- and triple-lumen devices, respectively). CONCLUSIONS PICC-associated bloodstream infection is most associated with hospital length of stay, ICU status, and number of device lumens. Policy and procedural oversights targeting these factors may be necessary to reduce the risk of this adverse outcome.

Is Statin Use Associated with Reduced Mortality After Pneumonia? A Systematic Review and Meta-analysis

OBJECTIVE The objective of this study was to perform a systematic review and meta-analysis of the effects of statins on mortality following pneumonia. METHODS We searched MEDLINE, EMBASE, BIOSIS, Cochrane CENTRAL Register of Controlled Trials, Cambridge Scientific Abstracts, BIOSIS, and Scopus. Studies were included if they involved: participants ≥18 years of age; patients with community-acquired pneumonia; current statin users; and reported overall or adjusted mortality after pneumonia. RESULTS Of 491 citations identified, 13 studies involving 254,950 patients met eligibility criteria. Pooled unadjusted data showed that statin use was associated with lower mortality after pneumonia (odds ratio [OR] 0.62, 95% confidence interval [CI], 0.54-0.71). Pooling of adjusted data also showed reduced mortality after pneumonia (OR 0.66, 95% CI, 0.55-0.79). However, this effect was attenuated in subgroup analysis by confounders and in prospective studies. CONCLUSIONS Although statin use is associated with decreased mortality after pneumonia, this effect weakens in important subgroups. Only a randomized controlled study can fully explore the link between statins and pneumonia mortality.

Low Plasma RANTES Levels Are an Independent Predictor of Cardiac Mortality in Patients Referred for Coronary Angiography

Objective—Our objective was to evaluate the prognostic value of baseline plasma RANTES levels in patients with known or suspected coronary artery disease. RANTES is a chemokine produced by a variety of cell types including platelets that has been implicated in atherosclerosis. Methods and Results—Baseline plasma RANTES levels were measured in 389 male patients undergoing coronary angiography at a Veterans Affairs Medical Center. The patients were followed-up prospectively for the occurrence of cardiac mortality and myocardial infarction. Follow-up data at 24 months were available for 97% of patients. In the entire cohort of patients, low baseline RANTES levels were an independent predictor of cardiac mortality. For cardiac death at 24 months, the survival rate was 87.3% in the lowest tertile of RANTES values, compared with 94% in the upper 2 tertiles combined (P=0.0298 by log rank test). Furthermore, when patients were risk-stratified into those with and without an acute coronary syndrome, RANTES was an independent predictor of both cardiac mortality and myocardial infarction in those without an acute coronary syndrome. Finally, RANTES was also an independent predictor of cardiac mortality in the diabetic subset. Conclusions—In a cohort of male patients undergoing coronary angiography, low baseline plasma RANTES levels are an independent predictor of cardiac mortality.