Jeremiah R. Brown

Long-Term Survival After Cardiac Surgery is Predicted by Estimated Glomerular Filtration Rate

BACKGROUND Estimated glomerular filtration rate (eGFR) before coronary artery bypass graft (CABG) surgery is a key risk factor of in-hospital mortality. However, in patients with normal renal function before CABG, acute kidney injury develops after the procedure, making postoperative renal function assessment necessary for evaluation. Postoperative eGFR and its association with long-term survival have not been well studied. METHODS We studied 13,593 consecutive CABG patients in northern New England from 2001 to 2006. Patients with preoperative dialysis were excluded. Data were linked to the Social Security Association Death Master File to assess long-term survival. Kaplan-Meier and log-rank techniques were used. Patients were stratified by established categories of postoperative eGFR (90 or greater, 60 to 89, 30 to 59, 15 to 29, and less than 15 mL x min(-1) x 1.73 m(-2)). RESULTS Median follow-up was 2.8 years (mean, 2.7; range, 0 to 5.5). Patients with moderate to severe acute kidney injury (less than 60) after CABG had significantly worse survival than patients with little or no acute kidney injury (90 or greater). CONCLUSIONS Patients having moderate to severe acute kidney injury after CABG surgery had worse 5-year survival compared with patients who had normal or near-normal renal function.

Palliative Care Consultations for Heart Failure Patients: How Many, When, and Why?

OBJECTIVE In preparation for development of a palliative care intervention for patients with heart failure (HF) and their caregivers, we aimed to characterize the HF population receiving palliative care consultations (PCCs). METHODS AND RESULTS Reviewing charts from January 2006 to April 2011, we analyzed HF patient data including demographic and clinical characteristics, Seattle Heart Failure scores, and PCCs. Using Atlas qualitative software, we conducted a content analysis of PCC notes to characterize palliative care assessment and treatment recommendations. There were 132 HF patients with PCCs, of which 37% were New York Heart Association functional class III and 50% functional class IV. Retrospectively computed Seattle Heart Failure scores predicted 1-year mortality of 29% [interquartile range (IQR) 19-45] and median life expectancy of 2.8 years [IQR 1.6-4.2] years. Of the 132 HF patients, 115 (87%) had died by the time of the audit. In that cohort the actual median time from PCC to death was 21 [IQR 3-125] days. Reasons documented for PCCs included goals of care (80%), decision making (24%), hospice referral/discussion (24%), and symptom management (8%). CONCLUSIONS Despite recommendations, PCCs are not being initiated until the last month of life. Earlier referral for PCC may allow for integration of a broader array of palliative care services.

Effects of Intra-Arterial and Intravenous Iso-Osmolar Contrast Medium (Iodixanol) on the Risk of Contrast-Induced Acute Kidney Injury: A Meta-Analysis

Background: The iso-osmolar contrast agent iodixanol may be associated with a lower incidence of contrast-induced acute kidney injury (CI-AKI) than low-osmolar contrast media (LOCM), but previous meta-analyses have yielded mixed results. Objectives: To compare the incidence of CI-AKI between iodixanol and LOCM. Methods: Studies were identified from literature searches to December 2009, clinicaltrials.gov, and conference abstracts from the past 2 years including 2010. Only prospective, randomized comparisons between iodixanol and LOCM with CI-AKI [increase in serum creatinine (sCr) ≧0.5 mg/dl or ≧25% from baseline, as defined in the trial] as a primary and/or secondary endpoint and a Jadad score ≧2 were included. A random-effects model was used to obtain pooled relative risks (RRs) for CI-AKI in analyses based on route of administration [intra-arterial (IA) or intravenous (IV)], definition of CI-AKI, and timing of sCr measurements. Results: 145 potential articles were identified, of which 25 were included in the meta-analysis. Following IA administration (n = 19), the RR for CI-AKI (≧0.5 mg/dl definition) with iodixanol, compared with LOCM, was 0.462 [95% confidence interval (CI): 0.272–0.786, p = 0.004, 15 studies]. Using the ≧25% definition, there was a lower incidence of CI-AKI with iodixanol versus LOCM, but the difference was not statistically significant (RR: 0.577, 95% CI: 0.297–1.12, p = 0.104, 11 studies). In the IV trials, there was no significant difference in the incidence of CI-AKI using either definition (≧0.5 mg/dl definition: RR: 0.967, 95% CI: 0.188–4.972, p = 0.968, 3 trials; ≧25% definition: RR: 0.656, 95% CI: 0.316–1.360, p = 0.257, 4 trials). Conclusions: IA but not IV administration of iodixanol is associated with a significantly lower risk of CI-AKI than LOCM.

Primary percutaneous coronary intervention for patients presenting with ST-elevation myocardial infarction: process improvements in rural prehospital care delivered by emergency medical services.

BACKGROUND Safe and effective patient care for ST-elevation myocardial infarction (STEMI) relies on prompt emergency medical service (EMS) and established care coordination with receiving hospitals to conduct primary percutaneous coronary intervention (PCI). Likewise, a new emphasis has been placed on first medical contact-to-balloon (E2B) times as opposed to door-to-balloon times, identifying prehospital care as an important contributing factor for high-quality STEMI care. Therefore, we evaluated EMS processes of care before and after a period of continuous quality improvement to improve E2B times in our rural tertiary care medical center. METHODS A retrospective, consecutive cohort study was conducted on 177 patients who received primary PCI at Dartmouth-Hitchcock Medical Center, a rural hospital, from January 1, 2006 to October 31, 2009. This cohort was stratified from January 1, 2008 to May 1, 2008 (n = 88) and May 1, 2008 to October 31, 2009 (n = 89), to acknowledge periods of no improvement (pre) and continuous quality improvement (post) in STEMI care. Primary outcome measures included frequency of non-PCI-capable hospital bypass, E2B, and frequency of prehospital electrocardiogram (ECG) and cardiac catheterization laboratory (CCL) activation. Descriptive statistics and log-rank tests were used to determine whether measures differed significantly by time period. A time-to-event analysis was conducted using a Cox proportional hazards model to assess the impact of outcomes measures on E2B pre/post-May 1, 2008. RESULTS Patients who presented before May 1, 2008 had longer E2B times compared with patients in the post-May 1, 2008 cohort (145.1 minutes vs 115.2 minutes, t test P = .01). A log-rank test confirmed this (pre: 130 minutes vs post: 106 minutes, χ(2) = 5.3, log-rank P = .02). Similarly, patients who presented before May 1, 2008 had lower percentages of prehospital ECGs (49% vs 80%, P = .001) and CCL activations (4% vs 32%, P < .001). When prehospital ECGs (140 minutes vs 106 minutes, χ(2) = 5.9, log-rank P = .01) or CCL activations (125 minutes vs 98 minutes, χ(2) = 4.2, log-rank P = .04) were conducted, E2B times were significantly reduced. Patients who received both prehospital ECGs and prehospital CCL activations had significantly reduced E2B times compared with those who did not (125 minutes vs 91 minutes, χ(2) = 4.8, P = .02). CONCLUSIONS The time saving benefits of prehospital ECGs may not be fully realized unless prehospital CCL activations also occur. EMS providers achieved further reductions in median E2B of approximately 24 minutes when prehospital ECGs were combined with prehospital CCL activation. Every effort should be made by PCI-capable medical centers to assess prehospital STEMI care and to integrate EMS providers into regional STEMI care quality improvement initiatives and education.

Contrast-Induced Acute Kidney Injury: The At-Risk Patient and Protective Measures

Contrast-induced acute kidney injury (CI-AKI) is a major complication following radiocontrast procedures. In this review, we characterize the recent literature on CI-AKI, risk factors, prevention, biomarkers, and new technologies. The premise of CI-AKI prophylaxis should focus on implementing mandatory standing orders before and after cardiac catheterization for hydration with normal saline or sodium bicarbonate and use of high-dose (1200-mg) N-acetylcysteine. Contrast agents may play a role in preventing CI-AKI. Implement catheter-laboratory technology and awareness to limit the amount of contrast dye used for any patient.

Review of Case-Mix Corrected Survival Curves

Survival is an end point of immense interest in cardiothoracic research. In observational studies, the comparison of survival between groups of patients is usually accomplished using a toolbox that includes Kaplan-Meier survival curves and the Cox model. The Cox model yields comparisons between groups adjusted for case-mix differences, whereas the Kaplan-Meier is a plot of survival over time without adjustment. During the past decade, new methods have emerged for case-mix adjustment of survival curves and are increasingly being used in cardiothoracic research. The purpose of this report is to describe, illustrate, and review several approaches to case-mix adjusted survival (or event-free) curves.

Physician specialty and variation in carotid revascularization technique selected for Medicare patients

OBJECTIVE Carotid artery stenting (CAS) has become an alternative to carotid endarterectomy (CEA) for select patients with carotid atherosclerosis. We hypothesized that the choice of CAS vs CEA varies as a function of treating physician specialty, which would result in regional variation in the relative use of these treatment types. METHODS We used Medicare claims (2002-2010) to calculate annual rates of CAS and CEA and examined changes by procedure type over time. To assess regional preferences surrounding CAS, we calculated the proportion of revascularizations by CAS, across hospital referral regions, defined according to the Dartmouth Atlas of Healthcare. We then examined relationships between patient factors, physician specialty, and regional use of CAS. RESULTS The annual number of all carotid revascularization procedures decreased by 30% from 2002 to 2010 (3.2 to 2.3 per 1000; P = .005). Whereas rates of CEA declined by 35% during these 8 years (3.0 to 1.9 per 1000; P < .001), CAS utilization increased by 5% during the same interval (0.30 to 0.32 per 1000; P = .014). Variation in utilization of carotid revascularization varied across the Unites States, with some regions performing as few as 0.7 carotid procedure per 1000 beneficiaries (Honolulu, Hawaii) and others performing nearly 8 times as many (5.3 per 1000 in Houma, La). Variation in procedure type (CEA vs CAS) was evident as well, as the proportion of carotid revascularization procedures that were constituted by CAS varied from 0% (Casper, Wyo, and Meridian, Miss) to 53% (Bend, Ore). The majority of CAS procedures were performed by cardiologists (49% of all CAS cases), who doubled their rates of CAS during the study period from 0.07 per 1000 in 2002 to 0.15 per 1000 in 2010. CONCLUSIONS Variation in rates of carotid revascularization exists. Whereas rates of carotid revascularization have declined by more than 30% in recent years, utilization of CAS has increased. The proportion of all carotid revascularization procedures performed as CAS varies markedly by geographic region, and regions with the highest proportion of cardiologists perform the most CAS procedures. Evidence-based guidelines for carotid revascularization will require a multidisciplinary approach to ensure uniform adoption across specialties that care for patients with carotid artery disease.

Hospital Mortality in the United States following Acute Kidney Injury.

Acute kidney injury (AKI) is a common reason for hospital admission and complication of many inpatient procedures. The temporal incidence of AKI and the association of AKI admissions with in-hospital mortality are a growing problem in the world today. In this review, we discuss the epidemiology of AKI and its association with in-hospital mortality in the United States. AKI has been growing at a rate of 14% per year since 2001. However, the in-hospital mortality associated with AKI has been on the decline starting with 21.9% in 2001 to 9.1 in 2011, even though the number of AKI-related in-hospital deaths increased almost twofold from 147,943 to 285,768 deaths. We discuss the importance of the 71% reduction in AKI-related mortality among hospitalized patients in the United States and draw on the discussion of whether or not this is a phenomenon of hospital billing (coding) or improvements to the management of AKI.

Globular Tail Fragment of Myosin-V Displaces Vesicle-Associated Motor and Blocks Vesicle Transport in Squid Nerve Cell Extracts

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Incidence and In‐Hospital Mortality of Acute Kidney Injury (AKI) and Dialysis‐Requiring AKI (AKI‐D) After Cardiac Catheterization in the National Inpatient Sample

Background Acute kidney injury (AKI) and dialysis‐requiring AKI (AKI‐D) are common, serious complications of cardiac procedures. Methods and Results We evaluated 3 633 762 (17 765 214 weighted population) cardiac catheterization or percutaneous coronary intervention (PCI) hospital discharges from the nationally representative National Inpatient Sample to determine annual population incidence rates for AKI and AKI‐D in the United States from 2001 to 2011. Odds ratios for both conditions and associated in‐hospital mortality were calculated for each year in the study period using multiple logistic regression. The number of cardiac catheterization or PCI cases resulting in AKI rose almost 3‐fold from 2001 to 2011. The adjusted odds of AKI and AKI‐D per year among cardiac catheterization and PCI patients were 1.11 (95% CI: 1.10–1.12) and 1.01 (95% CI: 0.99–1.02), respectively. Most importantly, in‐hospital mortality significantly decreased from 2001 to 2011 for AKI (19.6–9.2%) and AKI‐D (28.3–19.9%), whereas odds of associated in‐hospital mortality were 0.50 (95% CI: 0.45–0.56) and 0.70 (95% CI: 0.55–0.93) in 2011 versus 2001, respectively. The population‐attributable risk of mortality for AKI and AKI‐D was 25.8% and 3.8% in 2001 and 41.1% and 6.5% in 2011, respectively. Males and females had similar patterns of AKI increase, although males outpaced females. Conclusions The Incidence of AKI among cardiac catheterization and PCI patients has increased sharply in the United States, and this should be addressed by implementing prevention strategies. However, mortality has significantly declined, suggesting that efforts to manage AKI and AKI‐D after cardiac catheterization and PCI have reduced mortality.