Characterization of growth patterns and carcass characteristics of male and female broilers from four commercial strains fed high or low density diets.

Over the last few decades, the poultry industry has seen the emergence of various market segments that are beneficial for rearing various flock sizes. Two concurrent experiments consisting of 1,200 broilers each were conducted to evaluate the effects of broiler size and diet on the performance of four commercially available broiler strains, including 2 standard yielding (SY) and 2 high yielding (HY) strains. Within each experiment (Experiment 1: males, Experiment 2: females), a small bird (38 and 40 d processing) and big bird (47 and 54 d processing) debone market were targeted to give variable carcass size. Two polyphasic diets were fed based on varying of amino acid densities. The low-density diet (L) consisted of 1.20, 1.10, 1.00, and 0.96% digestible Lys and the high-density diet (H) consisted of 1.32, 1.21, 1.10, and 1.06% across the 4-phases, respectively, with similar essential amino acid to digestible Lys ratios between the L and H diets in each phase. Weekly BW, BW gain, feed intake, and feed conversion ratio were assessed, as well as processing yields during both experiments. Broilers fed the H diets responded better than those fed the L diets, regardless of sex, with increased BW and decreased FCR (P < 0.05). Male HY strains provided the highest carcass yields (P < 0.05) compared to SY strains, with no differences observed in females (P > 0.05). High density diets (Diet H) also produced increases in carcass, breast, and tender yield (P < 0.05) for males, but that trend was not present in carcass yield for females (P < 0.05). Overall, strain impacted performance traits and carcass yields. Therefore, the use of specific strains and amino acid density for various market segments is beneficial for integrators to maximize return.

Predicting reamputation risk in patients undergoing lower extremity amputation due to the complications of peripheral artery disease and/or diabetes.

BACKGROUND: Patients undergoing amputation of the lower extremity for the complications of peripheral artery disease and/or diabetes are at risk of treatment failure and the need for reamputation at a higher level. The aim of this study was to develop a patient-specific reamputation risk prediction model. METHODS: Patients with incident unilateral transmetatarsal, transtibial or transfemoral amputation between 2004 and 2014 secondary to diabetes and/or peripheral artery disease, and who survived 12 months after amputation, were identified using Veterans Health Administration databases. Procedure codes and natural language processing were used to define subsequent ipsilateral reamputation at the same or higher level. Stepdown logistic regression was used to develop the prediction model. It was then evaluated for calibration and discrimination by evaluating the goodness of fit, area under the receiver operating characteristic curve (AUC) and discrimination slope. RESULTS: Some 5260 patients were identified, of whom 1283 (24·4 per cent) underwent ipsilateral reamputation in the 12 months after initial amputation. Crude reamputation risks were 40·3, 25·9 and 9·7 per cent in the transmetatarsal, transtibial and transfemoral groups respectively. The final prediction model included 11 predictors (amputation level, sex, smoking, alcohol, rest pain, use of outpatient anticoagulants, diabetes, chronic obstructive pulmonary disease, white blood cell count, kidney failure and previous revascularization), along with four interaction terms. Evaluation of the prediction characteristics indicated good model calibration with goodness-of-fit testing, good discrimination (AUC 0·72) and a discrimination slope of 11·2 per cent. CONCLUSION: A prediction model was developed to calculate individual risk of primary healing failure and the need for reamputation surgery at each amputation level. This model may assist clinical decision-making regarding amputation-level selection.

Mortality prediction following non-traumatic amputation of the lower extremity.

BACKGROUND: Patients who undergo lower extremity amputation secondary to the complications of diabetes or peripheral artery disease have poor long-term survival. Providing patients and surgeons with individual-patient, rather than population, survival estimates provides them with important information to make individualized treatment decisions. METHODS: Patients with peripheral artery disease and/or diabetes undergoing their first unilateral transmetatarsal, transtibial or transfemoral amputation were identified in the Veterans Affairs Surgical Quality Improvement Program (VASQIP) database. Stepdown logistic regression was used to develop a 1-year mortality risk prediction model from a list of 33 candidate predictors using data from three of five Department of Veterans Affairs national geographical regions. External geographical validation was performed using data from the remaining two regions. Calibration and discrimination were assessed in the development and validation samples. RESULTS: The development sample included 5028 patients and the validation sample 2140. The final mortality prediction model (AMPREDICT-Mortality) included amputation level, age, BMI, race, functional status, congestive heart failure, dialysis, blood urea nitrogen level, and white blood cell and platelet counts. The model fit in the validation sample was good. The area under the receiver operating characteristic (ROC) curve for the validation sample was 0·76 and Cox calibration regression indicated excellent calibration (slope 0·96, 95 per cent c.i. 0·85 to 1·06; intercept 0·02, 95 per cent c.i. -0·12 to 0·17). Given the external validation characteristics, the development and validation samples were combined, giving a total sample of 7168. CONCLUSION: The AMPREDICT-Mortality prediction model is a validated parsimonious model that can be used to inform the 1-year mortality risk following non-traumatic lower extremity amputation of patients with peripheral artery disease or diabetes.

Age-related changes in the composition and mechanical properties of human nasal cartilage.

Nasal cartilage is widely used in reconstructive surgery for the replacement of soft tissue defects and nasal reconstruction procedures. The ability to shape harvested tissue and the performance in the transplant site are related to the mechanical properties of nasal cartilage. Several studies have documented changes in composition and mechanical properties of other cartilages with age, but little is known about these processes in nasal cartilage. In this study, 45 human nasal septum specimens were gathered from patients 15-60 years of age after reconstructive surgery. Samples were cut to 6 mm in diameter and tested in confined compression to determine equilibrium modulus and hydraulic permeability and analyzed for glycosaminoglycan and hydroxyproline content. Equilibrium modulus decreased significantly with increasing donor age (P<0.01) while hydraulic permeability increased significantly (P<0.02). Glycosaminoglycan (GAG) content decreased significantly with age (P<0.05), while hydroxyproline content showed a slight, but not significant, increase with age (P>0.2). These trends are qualitatively similar to those observed in articular cartilage, suggesting the existence of a systemic process of cartilage degradation that is independent of mechanical loading. Further, the relationships between biochemical composition and mechanical properties were age-dependent, with cartilage from patients less than 30 years of age showing greater dependence of equilibrium modulus and hydraulic permeability on GAG and hydroxyproline content. This suggests that changes in matrix organization may accompany changes in tissue composition.

Comparison of short-term outcomes following coronary artery stenting in men versus women.

This study sought to determine whether women have more adverse in-hospital outcomes after percutaneous transluminal coronary angioplasty (PTCA) and stenting compared with men. There is still controversy regarding whether female gender is an independent predictor of mortality after PTCA. No study has examined gender differences in outcomes following the dissemination of stenting. Data were obtained from the Nationwide Inpatient Sample. In 1997, there were 118,548 angioplasties (36% occurred in women and 59% involved placement of stents). Outcomes included same-admission mortality and coronary artery bypass grafting (CABG). Analyses were performed separately for patients with and without acute myocardial infarction (AMI). In 1997, women had a roughly twofold higher mortality than men in every comparison group, including conventional PTCA alone and stents. Mortality rates after stenting were 4.0% for women and 2.0% for men with AMI (p <0.0001), and 1.1% and 0.5%, respectively, for patients without AMI (p <0.0001). The adjusted odds ratios were 1.47 (95% confidence interval 1.23 to 1.75), and 1.65 (95% confidence interval 1.33 to 2.04), respectively. Similarly, following stenting, women had significantly higher CABG rates than men in both the AMI (1.6% vs 1.2%, p = 0.025) and no AMI groups (1.5% vs 1.0%, p <0.0001). After multivariate adjustment, the results retained significance in the no AMI setting, whereas there was a trend toward significance in the AMI group. This study demonstrates that, despite improved overall outcomes in patients who received stents, women who underwent stenting had higher rates of same-admission mortality and CABG compared with men. Furthermore, it confirms that female gender is an independent predictor of mortality after conventional PTCA.

The use of trimodality therapy for the treatment of operable esophageal carcinoma in the veteran population: patient survival and outcome analysis.

BACKGROUND: In an effort to improve the cure rates associated with surgical therapy, neoadjuvant chemoradiotherapy is being used with increasing frequency before resection (trimodality therapy). A variety of clinical trials have reviewed this approach, but only one study to the authors' knowledge has shown a survival benefit for trimodality therapy. The extent to which trimodality therapy has gained acceptance in general practice is not clear. The objective of the current study was to determine the extent to which both surgery and trimodality therapy are used for the management of esophageal carcinoma within a large, national health care system and to determine the outcome of patients treated with these treatment approaches. METHODS: The current study was a retrospective cohort study. The study population was comprised of all veterans who underwent either surgery alone or trimodality therapy for operable esophageal carcinoma between the fiscal years of 1993 and 1997. Data were obtained from the Veterans Administration Patient Treatment File, Outpatient Clinic File, and the Beneficiary Identification Record Locator System. The main outcome measures were perioperative mortality and patient survival. RESULTS: During the study period, 695 patients underwent either surgery alone or trimodality therapy for esophageal carcinoma. Five hundred thirty-four (77%) patients were treated with surgery only. One hundred sixty-one (23%) patients underwent surgery after induction chemoradiotherapy (trimodality therapy). Patients selected for trimodality therapy were younger (mean age, 60.8 years vs. 65.6 years), had fewer comorbidities, and were more likely to have a midesophageal tumor. The median survival for all patients was 15.2 months. The type of treatment had no apparent effect on survival. Favorable prognostic factors included younger age, a distal esophageal tumor, and the absence of metastases. The overall perioperative mortality was 13.7 %. The use of trimodality therapy did not increase perioperative mortality. CONCLUSIONS: Trimodality therapy is commonly used within the VA system. The nonrandomized nature of this study does not allow comparison of trimodality therapy to surgery alone, but the overall survival was limited for all patients. The predictors of survival are related to the biology of the disease, and they include patient age, tumor location, and stage at diagnosis.

Racial differences in outcomes of veterans undergoing percutaneous coronary interventions.

BACKGROUND: In the era of stenting relatively little is known about racial differences in the outcomes of percutaneous interventions (PCI). The purpose of this study was to determine whether there were racial differences with respect to short- and long-term outcomes in veterans undergoing PCI. METHODS: We used the national Department of Veterans Affairs (VA) patient treatment file to identify 24,625 African American and white veterans who had PCI in VA medical centers between October 1, 1994, and September 30, 1999. Baseline demographic characteristics were obtained, as was a measure of comorbidity. Short-term outcomes included hospital mortality and same-admission coronary artery bypass surgery, and long-term outcomes were vital status and rehospitalization. Multivariate statistical methods were used to adjust for patient differences when comparing both short- and long-term outcomes for African American and white veterans. RESULTS: African Americans were 11% of veterans, and in comparison with their white counterparts had more hypertension, diabetes, and acute myocardial infarction. African Americans less often underwent stenting (44% vs 49%), although hospital mortality (2.0% vs 1.9%) and same-admission bypass surgery (1.9% vs 2.2%) rates were similar. Two-year survival was 89% in African Americans and 91% in white veterans (P =.0014), and after adjustment for covariates African Americans had slightly higher mortality rates (hazard ratio 1.11, 95% confidence interval 1.05-1.17). At 2 years almost 61% of both African American and white veterans were rehospitalized for any reason. CONCLUSION: Short- and long-term outcomes for African American and white veterans undergoing PCI in VA medical centers were similar, although African Americans underwent stenting less often.

Trends in peripheral vascular procedures in the Veterans Health Administration, 1989-1998.

OBJECTIVE: To assess trends in peripheral vascular procedures performed in Veterans Health Administration (VHA) facilities. METHODS: All discharges with peripheral vascular procedures recorded for 1989-1998 were analyzed. The VHA user population was used to calculate age-specific rates. Trends were evaluated using frequency tables and Poisson regression. RESULTS: The VHA had 55,916 discharges with peripheral vascular procedures performed almost exclusively in men. Indications included peripheral vascular disease (53.7%), gangrene (19.3%), surgical complications (13.3%), and ulcers and infection (9.6%). The VHA age-specific rates were higher than US population rates for persons 45 to 64 years, similar for those 65 to 74 years, and lower for those 75 years and older. The age-specific rates declined slightly over the 10 years of observation, with the greatest decline noted in men age 45 to 65. CONCLUSION: The VHA provides almost 8% of all US peripheral vascular procedures in males. The VHA age-specific rates differ from the US rates with a shift to younger patients. The rates decreased for all age groups between 1989-1998.

Mechanical stimulation induces pp125(FAK) and pp60(src) activity in an in vivo model of trabecular bone formation.

Utilizing an in vivo model of trabecular bone formation, we demonstrated the temporal and spatial activation of pp125(FAK) in response to specific mechanical load stimuli. Bone chambers equipped with hydraulic actuators were aseptically inserted into each proximal tibial metaphysis of adult, male dogs under general anesthesia. The load stimulus consisted of a trapezoidal waveform, with a maximum compressive load of 17.8 N, loading rate of 89 N/s, at 1 Hz frequency. One chamber was loaded for 2 (120 cycles), 15 (900 cycles), or 30 min (1,800 cycles), whereas the contralateral chamber served as unloaded control. Bone chambers were biopsied at postload time points of 0, 15, and 45 min. Load-induced activation of FAK was rapid, and the duration of activation was dependent on the number of applied load cycles. Mechanical stimulation increased the association of FAK with Src and the time course of complex formation paralleled the temporal activation of FAK. Evaluation of cryosections revealed prominent FAK immunoreactivity among marrow fibroblasts and stromal cells.

Comparison of outcomes of coronary stenting versus conventional coronary angioplasty in the department of veterans affairs medical centers.

Although the short-term benefits of stent deployment have been established, less is known about long-term outcomes. This study compares short- and long-term outcomes in veterans undergoing stenting and conventional coronary angioplasty. We used Department of Veterans Affairs databases to identify 27,224 veterans who had undergone percutaneous coronary intervention (PCI) in Veterans Affairs medical centers between October 1994 and September 1999. Patients were classified according to whether they had acute myocardial infarction (AMI) as the principal diagnosis. Baseline characteristics were similar in the stent and conventional groups. In AMI, hospital mortality was 2.9% for those with stents and 4.8% for those who underwent conventional coronary angioplasty (p <0.0001), whereas for patients without AMI, hospital mortality was similar (1.2% vs 1.4%, p = 0.12). For AMI, same-admission bypass surgery rates were lower in the stent group (0.7% vs 3.2%, p <0.0001) and in the group without AMI (1.2% vs 3.3%, p <0.0001). Two-year survival was better for stenting in veterans with (90% vs 88%, p = 0.006) and without (92% vs 91%, p = 0.008) AMI. For AMI, 2-year rehospitalization rates for PCI (10% vs 13%, p <0.0001), coronary artery bypass surgery (4% vs 6%, p <0.0001), and unstable angina (17% vs 23%) were lower for those who had stenting. In the no-AMI group, 2-year rehospitalization rates for PCI (14% vs 17%, p <0.0001), coronary artery bypass surgery (5% vs 8%, p <0.0001), and unstable angina (22% vs 29%, p <0.0001) were lower in the stent group. Veterans who underwent stenting had lower hospital mortality, reduced rates of same-admission bypass surgery, marginally better survival, and lower rates of rehospitalization than their counterparts who had conventional coronary angioplasty.

Unstable angina in the myocardial infarction triage and intervention registry (MITI): short- and long-term outcomes in men and women.

BACKGROUND: Studies of unstable angina have focused on hospital mortality; long-term mortality studies have been limited by small numbers of patients or health care providers. The objectives of this study were to determine whether men and women with unstable angina had different presentations, mortality rates, and procedure utilization. METHODS: We analyzed a prospective observational registry of 4305 men (60%) and 2847 women (40%) with unstable angina who were admitted to coronary care units in King County, Washington, between 1988 and 1994. We compared the rates of symptoms, survival, and procedure utilization between sexes after adjustment for age, race, insurance status, and medical history. RESULTS: Women were older and had higher rates of hypertension and congestive heart failure than men but had lower rates of cigarette smoking, previous myocardial infarction, and previous procedure use (P <.0001). Women had significantly higher rates of dyspnea, nausea, and epigastric pain and less diaphoresis than men did (P <.0001). Women underwent fewer procedures, but after adjustment for age and medical history this difference was no longer significant except for coronary bypass grafting (odds ratio 0.50, 95% confidence interval [CI] 0.37-0.69); after index hospitalization, men and women underwent procedures at similar rates. Although women had higher rehospitalization rates than men, early mortality (odds ratio 0.89, 95% CI 0.55-1.4) and late mortality (hazard ratio 0.98, 95% CI 0.95-1.0) were similar between men and women after adjustment for age. CONCLUSIONS: Women and men with unstable angina have different risk factors and symptoms upon presentation but have similar procedure use and mortality rates.

Improved outcomes associated with stenting in the healthcare cost and utilization project.

Recent results from Medicare indicated that both hospital mortality and the use of same admission coronary artery bypass graft (CABG) surgery were lower in patients receiving stents, and that stenting did not alter the finding of improved outcomes at high volume centers. The purpose of this report is to compare outcomes in a national sample of patients of all ages receiving stents with those undergoing conventional balloon angioplasty. A second purpose is to evaluate the volume outcome hypothesis. This study included 100,318 angioplasties from 191 hospitals in 19 states; 43,966 (44%) involved stent placement. The major outcomes of interest were same admission hospital death and same admission CABG surgery. In comparison to patients with conventional angioplasty, patients receiving stents were younger, less often female and nonwhite, and had less diabetes and hypertension. In the group without infarction, hospital mortality was lower in the stent group (0.7% vs 0.9%, P = 0.01), as was the use of same admission bypass surgery (1.4% vs 2.7%, P < 0.0001). The same pattern was true for myocardial infarction; hospital mortality (2.7% vs 4.2%, P < 0.0001) and bypass surgery rates (1.6% vs 5.3%, P < 0.0001) were lower in the stent group. These results persisted after adjustment for important predictors of outcome. In general, outcomes were better in high volume centers, although in the stent group, there was no clear relationship between volume and outcome. These results support earlier findings that hospital mortality and particularly same admission surgery rates are lower with stenting. Although the volume outcome association for stenting was less clear in this study than in Medicare, these results do not mean that the fundamental volume outcome relationship has been changed by stenting.

The relationship between alcohol screening questionnaires and mortality among male veteran outpatients.

OBJECTIVE: This study evaluated whether responses to alcohol screening questionnaires predicted mortality in a Department of Veterans Affairs (VA) primary care population. METHOD: This study involved 5,703 male outpatients (mean age = 64) who were enrolled in General Internal Medicine clinics at three Veterans Affairs (VA) medical centers and returned mailed questionnaires in 1993-94. The two questionnaires included the CAGE and Alcohol Use Disorders Identification Test (AUDIT) alcohol screening tests. Mortality was ascertained using the VA Beneficiary Identification and Record Locator System. Five-year crude and adjusted mortality rates were calculated for patients who screened positive and patients who screened negative on each alcohol screening test. RESULTS: The risk of mortality was increased among drinkers who scored > or = 8 on the full AUDIT (hazard ratio: 1.47; 95% confidence interval [CI]: 1.08-2.00) or the three AUDIT consumption questions (1.58; 1.11-2.27), after adjusting for age, smoking, sociodemographic characteristics and chronic illnesses. The risk of mortality was also increased among drinkers who reported drinking > or = 3 drinks daily (1.69; 1.28-2.22) or prior alcohol treatment (1.66; 1.27-2.17), in "fully adjusted" models. A positive CAGE score (> or = 2) was associated with significantly increased risk of mortality among drinkers in a model adjusted only for age and smoking (1.27; 1.02-1.58). Among nondrinkers, neither a positive CAGE score (> or = 2) nor report of prior alcohol treatment was associated with increased risk of mortality. CONCLUSIONS: VA outpatients who reported drinking during the previous year and who had a positive result on an alcohol screening test experienced higher mortality over the subsequent 5 years than did patients who screened negative.

Design of self-processing antimicrobial peptides for plant protection.

Small antimicrobial peptides are excellent candidates for inclusion in self-processing proteins that could be used to confer pathogen resistance in transgenic plants. Antimicrobial peptides as small as 22 amino acids in length have been designed to incorporate the residual amino acids left from protein processing by the tobacco etch virus'(TEVs') NIa protease. Also, by minimizing the length of these peptides and the number of highly hydrophobic residues, haemolytic activity was reduced without affecting the peptide's antimicrobial activity.

Outcomes of coronary angioplasty procedures performed in rural hospitals.

PURPOSE: To determine how many rural hospitals in the United States performed coronary angioplasty; to compare patient outcomes in rural and urban hospitals; and to assess whether outcomes were better in rural hospitals in which more procedures were performed. SUBJECTS AND METHODS: In 1996, among patients 65 years of age and older, 201,869 coronary angioplasties were performed in 996 hospitals that were included in the Medicare Provider Analysis and Review files. Geographic location was defined as rural or urban, according to U.S. Census Bureau criteria. Outcome variables were in-hospital death and coronary artery bypass surgery performed during the same admission. Hospital volumes were categorized as low (< or = 100 cases or fewer per year), medium (101 to 200 cases per year), or high (> 200 cases per year). RESULTS: Fifty-one rural hospitals accounted for 4% of all angioplasties performed. After angioplasty, in-hospital mortality was greater in rural hospitals (8.1% versus 6.4%, P = 0.001) among patients with acute myocardial infarction, but was not different for patients without infarction (1.4% versus 1.3%, P = 0.41). Coronary artery bypass surgery rates during the same admission were similar in rural and urban hospitals. In general, in-hospital mortality and same-admission surgery rates were lower in high-volume centers in both rural and urban areas. CONCLUSION: Although in-hospital mortality after angioplasty for acute myocardial infarction was worse in low- and medium-volume rural centers, overall outcomes in rural and urban hospitals were similar.

The association between institutional primary angioplasty procedure volume and outcome in elderly Americans.

BACKGROUND: The association between greater procedure volume and improved patient outcome in cardiac procedures has been established in percutaneous transluminal coronary angioplasty (PTCA), coronary stent placement and coronary bypass surgery. The association between primary angioplasty volume and outcome has not been evaluated. METHODS: We evaluated the association between the volume of primary angioplasty procedures with short- and long-term outcome in 6,124 patients with documented acute myocardial infarction. Patients without shock on presentation treated with primary coronary angioplasty within 12 hours of hospital admission were selected from consecutive infarct patients included in the Cooperative Cardiovascular Project database. Patients were divided into quartiles based on the volume of primary PTCA procedures performed at their admitting hospital. RESULTS: The majority of United States (US) hospitals performed less than three primary PTCA procedures per month. Patients admitted to hospitals in the lowest volume quartile of primary PTCA had 31% higher 30-day mortality than those admitted to the highest volume quartile. After adjustment for baseline differences in patient characteristics, there was an association between admission to higher volume primary PTCA hospitals and lower 30-day mortality (odds ratio per volume quartile = 0.91; 95% confidence interval = 0.83-0.99). CONCLUSION: Eighty-two percent of US hospitals perform less than three primary PTCA procedures per month. In elderly Americans treated with primary PTCA, we observed an association between admission to higher volume hospitals and lower short- and long-term mortality. This association was independent of total PTCA volumes.

Institutional volumes and coronary angioplasty outcomes before and after the introduction of stenting.

CONTEXT: An increasing number of patients undergoing percutaneous transluminal coronary angioplasty (PTCA) are receiving coronary stents. OBJECTIVES: To assess whether the introduction of coronary stenting has changed hospital mortality or same-admission coronary artery bypass grafting (CABG) and whether the hospital's procedure volume affects these outcomes. DESIGN: Observational study using hospital claims. SETTING: Nonfederal hospitals that performed PTCA in California in 1993 and 1996. PATIENTS: 35,350 patients who underwent PTCA in 1993 (before the introduction of stenting) and 43,040 patients who had PTCA in 1996 (43% of whom received stents). MEASUREMENTS: Hospital stenting volumes for 1996 were divided into terciles; total PTCA procedures per year were categorized as low (< or = 200), medium (201 to 400), or high (> 400). Outcome variables included hospital death and coronary artery bypass grafting (CABG) performed during the same admission. Patients with a principal diagnosis of acute myocardial infarction (AMI) were analyzed separately from those without such a diagnosis. RESULTS: From 1993 to 1996, the characteristics of patients undergoing PTCA did not change substantially. The use of same-admission CABG decreased by 13% (from 6.0% to 5.2%; P = 0.008) in the AMI group and by 30% (from 3.7% to 2.6%; P < 0.001) in the no-AMI group. Hospital mortality did not change significantly in either group. Procedure volume was not related to hospital mortality. However, rates of same-admission CABG were significantly lower at hospitals with high annual stenting volumes than at low-volume centers (1.3% vs. 2.3% among patients in the no-AMI group; P < 0.001). CONCLUSIONS: Hospital mortality rates after PTCA have not changed considerably since the introduction and diffusion of coronary stenting. However, rates of same-admission CABG have decreased in recent years and are lowest at hospitals with high procedure volumes.

Coronary artery stent outcomes in a Medicare population: less emergency bypass surgery and lower mortality rates in patients with stents.

BACKGROUND: Randomized trials of coronary stents versus conventional balloon angioplasty have demonstrated improved short- and long-term outcomes for selected patients receiving stents. The purpose of this study was to compare outcomes in patients receiving stents with those undergoing conventional balloon angioplasty in everyday clinical practice. METHODS AND RESULTS: This study uses information from the Medicare Provider Analysis and Review files for fiscal years 1994 and 1996, the first year the coronary stent code was used. For patients 65 years of age and older, 165,657 cases in 1994 and 201,869 in 1996, including 74,836 cases with stent placement, were identified. Outcomes included hospital deaths, use of same- admission coronary artery bypass surgery, and either or both. Analyses were performed separately for those with and those without a principal diagnosis of acute myocardial infarction. Hospital mortality rates were similar in both years, but the use of same-admission coronary artery bypass surgery was lower in 1996. In that year, for both patients with and those without acute myocardial infarction, hospital death and the use of same-admission coronary artery bypass surgery were lower in the stent group. Additionally, results in the stent group were generally better at high-volume (>200 cases per year) institutions, as was the case for the prestent, 1994 results. CONCLUSIONS: This study documents improved short-term outcomes in older patients who undergo coronary stent placement. Stenting did not eliminate the finding of improved outcomes at high-volume centers.

Association between percutaneous transluminal coronary angioplasty volumes and outcomes in the Healthcare Cost and Utilization Project 1993-1994.

Studies from a variety of settings have indicated that outcomes for coronary angioplasty are improved when performed in institutions with high caseloads (> 400/year). The purpose of this investigation was to examine the volume outcome hypothesis for coronary angioplasty in a 20% stratified sample of acute care, non-federal hospitals in 17 states. Data were derived from the Nationwide Inpatient Sample from the Health Care Cost and Utilization Project releases 2 and 3. From these records, 163,527 angioplasties from 214 hospitals were selected. Outcomes included hospital mortality, same-admission coronary artery bypass surgery, and a combined end point of either death or same-admission surgery, or both. Hospital volumes were defined as low (< or = 200 cases/year), medium (201 to 400), and high (> 400). Analyses were conducted separately for patients with and without a principal discharge diagnosis of acute myocardial infarction (AMI). For both AMI and no-AMI groups, the rates of adverse outcomes were generally lower in high-volume institutions, and this finding was true in both univariate and multivariate analyses. Although 27% of hospitals were in the low-volume category, only 5% of all procedures were performed in these institutions. Projecting to all United States hospitals for the 2 years, if all procedures performed in low-volume centers had been done in high-volume institutions, 137 deaths could have been averted (90 AMIs, 47 no-AMIs) as well as 404 (46 AMIs, 358 no-AMIs) same-admission surgeries. The results of this study support the hypothesis that better results are obtained in higher volume institutions, but also show that in 1993 and 1994, relatively few patients had their procedures performed in low-volume institutions.