30-day Mortality Hazard Ratio Research Articles

Abstract 109: In-Hospital Worsening Heart Failure is Associated With Poor Patient Outcomes and Increased Health Care Utilization

Background: A subset of patients hospitalized with acute heart failure (AHF) experiences worsening clinical status while hospitalized and require escalation of therapy. This phenomenon, termed in-hospital worsening heart failure (WHF), is an endpoint for many clinical trials but limited data exist on the prevalence of WHF in clinical practice and associated outcomes. Methods: We analyzed inpatient data from Acute Decompensated Heart Failure National Registry (ADHERE) linked to Medicare claims data to describe outcomes and health care utilization of patients that developed WHF. In-hospital WHF was defined by any of the following: use of inotropes or intravenous vasodilators >12 hours after admission; initiation of mechanical circulatory support, hemodialysis, or ventilation after the first inpatient day; or transfer to the ICU after initial admission to a regular hospital ward. Patients with WHF were compared to those with an uncomplicated hospital course and those that had a complicated hospital presentation, defined as requiring the above advanced therapies on arrival. Results: The study population consisted of 63,727 patients hospitalized between 01/2001 and 12/2004. Of these, WHF developed in 7032 (11%), 15,361 (24%) presented with a complicated presentation and 41,334 (65%) with an uncomplicated hospital course. Observed mean length of stay was longest in the WHF cohort (10.0 days) followed by complicated presentation (6.3 days) and uncomplicated course (4.8 days). Patients with WHF also had higher observed rates of mortality and all-cause readmission at 30 days and 1 year after discharge (P<0.001; Figure). The adjusted hazard ratio for 30-day mortality was 2.56 (99% CI 2.34-2.80) for WHF compared to an uncomplicated hospital course and 1.29 (1.17-1.42) compared to a complicated presentation. Medicare payments were also higher for patients with WHF with an adjusted cost ratio at 30 days of 1.35 (99% CI 1.24-1.46) for WHF compared to an uncomplicated hospital course and 1.11 (1.02-1.22) compared to a complicated presentation. Conclusion: In a large, multicenter registry, in-hospital WHF was common and associated with higher rates of mortality, all-cause readmission, and Medicare payments. Preventing and treating WHF represents an important therapeutic target among patients hospitalized with AHF.

Acute kidney injury based on KDIGO (Kidney Disease Improving Global Outcomes) criteria in patients with elevated baseline serum creatinine undergoing cardiac surgery.

IntroductionPreoperatively elevated serum creatinine (SCr) is considered an independent risk factor for morbidity and mortality after cardiac surgery. The aim of this study was to apply the Kidney Disease Improving Global Outcomes classification for acute kidney injury in a population of patients with preoperatively elevated serum creatinine who underwent cardiac surgery (coronary artery bypass grafting or cardiac valve surgery) and to evaluate the acute worsening of renal function as a predictor of 30-day mortality.MethodsThis was a single-center retrospective study that included patients from the Postoperative Cardiac Surgery Intensive Care Unit of the Hospital de Base, São José do Rio Preto Medical School. Demographics, type of surgery, laboratory data and pre, peri and postoperative data were obtained from a prospectively collected database. From January 2003 to June 2013, 2,878 patients underwent cardiac surgery, either coronary artery bypass grafting or cardiac valve surgery, at the Hospital de Base of São José do Rio Preto Medical School. Out of those, 918 showed elevated preoperative serum creatinine, with SCr > 1.30 mg/dL for men and > 1.00 mg/dL for women. Five hundred and forty nine patients (60%) undergoing coronary artery bypass grafting and 369 patients (40%) undergoing cardiac valve surgery. A Multivariate Cox Proportional Hazard Model (stepwise) was used to assess the relationship between AKI and mortality at 30 days.ResultsOut of the 918 patients studied, 391 (43%) had postoperative AKI: 318 (35%) had Kidney Disease Improving Global Outcomes stage 1, 27 (2.9%) had Kidney Disease Improving Global Outcomes stage 2, and 46 (5.0%) had Kidney Disease Improving Global Outcomes stage 3. Patients in every stage of acute kidney injury showed progressive increase in EuroSCORE values, 30-day mortality ratescardiopulmonary bypass duration, and intensive care length of stay. Among patients classified as Kidney Disease Improving Global Outcomes stage 3, 76% required dialysis with a 30-day mortality of 66%. The Cox proportional hazards model showed that the hazard ratio for 30-day mortality was 4.8 for Kidney Disease Improving Global Outcomes stage 1 patients, 13.5 for Kidney Disease Improving Global Outcomes stage 2 patients, and 20.8 for Kidney Disease Improving Global Outcomes stage 3 patients (P<0.001 for all). Subgroup analyses (coronary artery bypass grafting and cardiac valve surgery) had similar results.ConclusionIn this population, acute kidney injury based on the Kidney Disease Improving Global Outcomes criteria was a powerful predictor of 30-day mortality in patients with elevated preoperative serum creatinine who underwent cardiac surgery (coronary artery bypass grafting or cardiac valve surgery).

Cross-sectional and Case-Control Analyses of the Association of Kidney Function Staging With Adverse Postoperative Outcomes in General and Vascular Surgery

This study aimed to assess kidney dysfunction in general surgical patients and examine the effect on postoperative mortality and morbidity. An estimated 13% of the US population has chronic kidney disease (CKD), but awareness among patients and caregivers is lacking. The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) data sets for 2005-2007 were analyzed. Preoperative kidney function was assessed by the Modification of Diet in Renal Disease formula for estimated glomerular filtration rate (eGFR) and staged according to National Kidney Foundation. Cross-sectional analyses were performed for 30-day mortality (Cox proportional hazard) and incidence of major complications (nominal logistic regression). A case-control cohort of colectomy cases was analyzed comparing patients in the stage 4 CKD group and the no CKD group (no-CKD). Sixty-four percent of evaluable patients had reduced eGFR, but eGFR was not evaluable in 28% of the surgical cases. In the 260,352 evaluable cases, adjusted hazard ratio for 30-day mortality was 2.30 [95% confidence interval (CI), 2.11-2.51] for stage 3 CKD; 3.37 (95% CI, 3.01-3.76) for stage 4 CKD; and 3.05 (95% CI, 2.68-3.47) for stage 5 CKD compared with no-CKD (P < 0.0001). CKD was an independent risk factor for having major complications postsurgery [stage 3, odds ratio (OR) = 1.24 (95% CI, 1.19-1.29); stage 4, OR = 1.65 (95% CI, 1.52-1.78); and stage 5 CKD, OR = 1.40 (95% CI, 1.30-1.51); P < 0.0001]. The case-control for colectomy was confirmatory: increased 30-day mortality in stage 4 CKD versus no-CKD (hazard ratio = 2.58, 95% CI, 1.13-5.92; P = 0.025). Renal insufficiency may be underrecognized in the general and vascular (noncardiac) surgery population, is a leading independent predictor of poor early postoperative outcomes, and should be routinely assessed in the preoperative setting.

Effect of Renal Impairment on Mortality of Patients With Cirrhosis and Spontaneous Bacterial Peritonitis

The effects of end-stage renal disease (ESRD) on the mortality of patients with cirrhosis and spontaneous bacterial peritonitis (SBP) have not been determined. We collected data from Taiwan's National Health Insurance Database on 2592 patients with cirrhosis who were hospitalized with SBP from January 1 to December 31, 2004. Patients were matched with individuals from a national mortality database; 30-day and 1-year mortalities were calculated for each group and compared to calculate hazard ratios (HRs). Of the patients with cirrhosis and SBP, 300 (11.5%) had renal function impairment. Of these, 145 had acute renal failure, 70 had ESRD, and 75 had chronic kidney disease. Overall, 30-day and 1-year mortality were 21.3% and 51.7%, respectively. After adjusting for age, sex, and underlying comorbidities, HRs for 30-day mortality from renal function impairment, acute renal failure, ESRD, and chronic kidney disease were 3.00, 4.68, 1.93, and 1.37, respectively. The HRs for 1-year mortality from renal function impairment, acute renal failure, ESRD, and chronic kidney disease were 2.03, 2.78, 1.70, and 1.37, respectively. The adjusted HRs for 30-day and 1-year mortality of patients with acute renal failure were 2.6 and 1.6, respectively, compared with patients with ESRD. Acute renal failure is a better determinant of 30-day and 1-year mortality than renal function impairment in cirrhotic patients with SBP.

Impact of Estimated Glomerular Filtration Rate After Valve and Combined Valve and Coronary Surgery

Preoperative renal impairment predicts postoperative mortality in patients undergoing cardiac surgery. We examined the impact of three equations for glomerular filtration rate (GFR) estimation on mortality. This is a retrospective, observational study on patients undergoing valve (n = 594) and combined valve and coronary procedures (n = 412). Glomerular filtration rate was estimated with modification in diet and renal disease (MDRD), Cockcroft-Gault (CG) equation, and Mayo-Clinic (MC) equation. Mean age was 65 ± 11 years and mean logistic EuroSCORE was 9.0 [95% confidence interval (CI): 8.4-9.7]. Preoperative kidney dysfunction (eGFR <60 ml/min/1.73 m²) is associated with increased risk for mortality. Hazard ratios for 30-day mortality differed between eGFR equations [MC 2.6 (95% CI: 1.6-4.1); MDRD 2.9 (95% CI: 1.9-4.4); CG 3.9 (95% CI: 2.2-5.2)]. Discriminatory performance of GFR equations was comparable with logistic EuroSCORE, but CG and MC discriminated significantly better than MDRD. Median intensive care unit stay did not differ, but Bland-Altman plots showed considerable variation between eGFR equations, indicating that they cannot be used interchangeably. Substantial amount of agreement was achieved with CG and MDRD. Only one equation should be used in one institution. The bias between equations varied considerably. Impaired preoperative kidney dysfunction is associated with increased risk for mortality irrespective of the formula used.

Elevated Admission Glucose and Mortality in Elderly Patients Hospitalized With Heart Failure

Although some professional societies recommend target-driven glucose control for all hospitalized patients, the association between elevated glucose and adverse outcomes has not been well established in patients hospitalized with heart failure. We evaluated a nationally representative cohort of 50,532 elderly patients hospitalized with heart failure in the United States between April 1998 and June 2001. The association between admission glucose and all-cause mortality at 30 days and 1 year was analyzed with multivariable Cox regression models, both in the entire cohort and in patients with and without diabetes mellitus. After multivariable adjustment, no significant relationship was found between glucose and 30-day mortality (for glucose groups of >110 to 140, >140 to 170, >170 to 200, and >200 mg/dL; hazard ratios for 30-day mortality were 1.09 (95% confidence interval, 0.98 to 1.22), 1.27 (95% confidence interval, 1.11 to 1.45), 1.16 (95% confidence interval, 0.98 to 1.37), and 1.00 (95% confidence interval, 0.87 to 1.15), respectively, versus glucose < or =110 mg/dL; P for linear trend=0.53). Results were similar for 1-year mortality and did not differ between patients with and without known diabetes mellitus (for diabetesxglucose interaction, P=0.11 and 0.55 for 30-day and 1-year mortality, respectively). We found no significant association between admission glucose levels and mortality in a large cohort of patients hospitalized with heart failure. Our findings suggest that the relationship between hyperglycemia and adverse outcomes seen in acute myocardial infarction cannot be automatically extended to patients hospitalized with other cardiovascular conditions.

Glucose metabolism and acute myocardial infarction

For over 50 years, efforts have been made to develop beneficial glycometabolic support strategies for patients with myocardial ischaemia and infarction. The concept of providing maximal metabolic support to injured myocardial cells is elegant, and has led to relatively simple and low-cost interventions. Glucose–insulin–potassium (GIK) therapy focuses on infusion of high doses of glucose to halt free fatty acid production, and various schemes have been studied over the past decades. Clinical results of GIK infusion have been mixed, with results varying from impressive survival benefits to excess mortality. The CREATE-ECLA study, in which 20 201 patients were randomized to GIK infusion or standard treatment after ST-segment elevation myocardial infarction, showed no benefit of GIK infusion (hazard ratio for 30-day mortality, 1.03; 95% CI, 0.95–1.13). GIK also showed a neutral effect on secondary endpoints. This result, together with a number of other recent studies, supports the current opinion that GIK does not give a clinically significant benefit in acute myocardial infarction (AMI). The traditional GIK scheme often induces hyperglycaemia, as the insulin component is not titrated to maintain normoglycaemia. In the article, Goyal et al. report on elevated glucose levels in patients with AMI and the prognostic value of these levels for adverse outcome (30and 180-day mortality). Goyal et al. have analysed the glucose values collected in the CARDINAL (Complement and ReDuction of INfarct size after Angioplasty or Lytics) studies. In a cohort of 1469 patients, glucose levels were determined at baseline and 24 h thereafter. More than half of the patients had a baseline glucose level higher than 7.8 mmol/L. Of these patients, one-third showed no or only moderate decrease in glucose during the first 24 h. Moreover, a considerable number of patients who presented with a baseline glucose lower than 7.8 mmol/L had a rising glucose level during the first 24 h. Although a large number of reports have described the association between hyperglycaemia at admission and adverse outcome, data on glucose levels at later moments after infarction are scarce. The association between hyperglycaemia at admission and adverse outcome was confirmed by Goyal et al., but more importantly, the change in glucose in the first 24 h was shown to be an independent predictor of adverse outcome. There are three straightforward explanations for this association. First, the change in glucose may be a marker of clinical condition. As the multivariate prognostic model only included baseline characteristics, the change in glucose was the only parameter that contained information about the clinical course of a patient during the first 24 h. Adverse developments during this important initial period, for example unsuccessful reperfusion therapy, may prevent a drop in glucose level. Second, the failure of glucose to drop may be a result of pre-existing glycometabolic dysregulation, either subclinical or frank previously undiagnosed diabetes, which is known to negatively affect prognosis. The third possibility is most interesting from an intervention-oriented point of view: hyperglycaemia might be causally related to adverse outcome, and treatment may therefore improve outcome. Unfortunately, this retrospective study cannot discern the respective contributions of these explanations. Indeed, retrospective studies cannot answer the question whether insulin therapy to treat persistent hyperglycaemia will be beneficial in AMI patients. In critically ill patients admitted to a predominantly cardiosurgical intensive care unit, a large randomized clinical trial has evaluated intensive insulin therapy aiming for normoglycaemia. In a cohort of 1548 patients, insulin therapy markedly reduced mortality during the stay on the intensive care unit (8.0 vs. 5.8%, P, 0.04). A number of complications related to critical illness occurred significantly less frequently with intensive insulin therapy. Although the exact mechanisms that have led to these impressive results of intensive insulin therapy still need more study, a number of mechanisms that may play a role have been identified. Some of these mechanisms may also apply to patients with AMI. For instance, hyperglycaemia is associated with a pro-inflammatory and pro-thrombotic state, and interferes with normal endothelial function. Insulin not only antagonizes these negative aspects of hyperglycaemia, but may also boast intrinsic beneficial effects, such as improved glucose utilization and increased myocardial perfusion. In contrast, evident differences between patients

A comparison of generalist and pulmonologist care for patients hospitalized with severe chronic obstructive pulmonary disease: resource intensity, hospital costs, and survival

PURPOSE: Both generalist and pulmonologist physicians care for patients with severe chronic obstructive pulmonary disease (COPD). We studied patients hospitalized with severe COPD to explore whether supervision of care by pulmonologists is associated with greater costs or better survival. SUBJECTS AND METHODS: We studied 866 adults with severe COPD enrolled in the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT), a prospective study at five academic medical centers. Patients were admitted to the hospital or transferred to an intensive care setting for treatment of severe COPD, defined by hypoxia (PaO2 <60 mm Hg) and hypercapnia (PaCO2 >50 mm Hg) or hypercapnia alone if on supplemental oxygen. Resource intensity was measured using a modified version of the Therapeutic Intervention Scoring System and estimated hospital costs. To account for differences in the patient case mix, propensity scores were developed to represent each patient’s probability of having a pulmonologist as attending physician and each patient’s probability of being in an intensive care unit (ICU) at study admission. RESULTS: Of the 866 patients studied, 512 had generalists and 354 pulmonologists as their attending physicians. The median patient age was 70 years; 52% were male; 14% died within 30 days. After adjusting for baseline differences in patient characteristics, there were no differences in resource intensity and hospital costs in those treated by pulmonologists or generalists. Adjusted average resource intensity scores for the entire hospitalization were 16.5 for pulmonologists and 17.0 for generalists ( P = 0.34). Estimated hospital costs were the same ($6,400) for patients treated by pulmonologists and generalists ( P = 0.99). Patients with pulmonologists as attending physicians did not experience better survival. Comparing patients of pulmonologists to patients of generalists, the adjusted hazard ratio for 30-day mortality was 1.6 (95% confidence interval: 0.98, 2.5); the hazard ratio for 180-day mortality was 1.2 (0.9, 1.7). CONCLUSIONS: Our findings suggest that for patients hospitalized with exacerbation of severe COPD, those with pulmonologist attending physicians do not have higher hospital resource use or better survival than those with generalist attending physicians.