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Pregnancy associated plasma protein-A and risk stratification of patients presenting with chest pain in the emergency department.

BACKGROUND: The aim of this study was to evaluate the clinical utility of serum pregnancy associated plasma protein-A (PAPP-A) levels in assisting triage of an intermediate to high-risk patient presenting with chest pain in the Emergency Department and no definite evidence of an acute coronary syndrome. METHODS: Serum levels of PAPP-A were measured in 59 patients presenting with chest pain to the Emergency Department. The patients were independently grouped according to the presence of acute coronary syndromes or the absence thereof. RESULTS: In a multivariate model that corrected for age, sex, type of chest pain, number of risk factors, history of coronary artery disease, troponin levels, and non-specific ECG changes, PAPP-A levels were still predictive of a final diagnosis of acute coronary syndrome in patients presenting with chest pain to the Emergency Department (Odds Ratio, 2.093; 95th confidence intervals, 1.037-4.224; p=0.039). CONCLUSIONS: Elevated serum PAPP-A levels were predictive of a diagnosis of acute coronary syndrome in intermediate- to high-risk patients presenting to the Emergency Department with chest pain and no definite evidence of an acute coronary syndrome. Thus, serum PAPP-A may be valuable as an adjunct, minimally invasive marker to improve risk stratification in chest pain patients.

Acute Disease↗

Radiosurgery for treatment of brain metastases: estimation of patient eligibility using three stratification systems.

PURPOSE: To compare three patient stratification systems predicting survival: recursive partitioning analysis (RPA), score index for radiosurgery in brain metastases (SIR), and a proposed basic score for brain metastases (BS-BM). METHODS AND MATERIALS: We analyzed the outcome of 110 patients treated with Leksell Gamma Knife radiosurgery between December 1999 and January 2003. The BS-BM was calculated by evaluating three main prognostic factors: Karnofsky performance status, primary tumor control, and presence of extracranial metastases. RESULTS: The median survival was 27.6 months for RPA Class I, 10.7 months for RPA Class II, and 2.8 months for RPA Class III (p <0.0001). Using the SIR, the median survival was 27.7, 10.8, 4.6, and 2.4 months for a score of 8-10, 5-7, 4, and 0-3, respectively (p <0.0001). The median survival was undefined in patients with a BS-BM of 3 (55% at 32 months) and was 13.1 months for a BS-BM of 2, 3.3 months for a BS-BM of 1, and 1.9 months for a BS-BM of 0 (p <0.0001). The backward elimination model in multivariate Cox analysis identified SIR and BS-BM as the only two variables significantly associated with survival (p = 0.031 and p = 0.043, respectively). CONCLUSION: SIR and BS-BM were the most accurate for estimating survival. They were specific enough to identify patients with short survival (SIR 0-3 and BS-BM 0). Because of it simplicity, BS-BM is easier to use.

Adult↗

Stress myocardial perfusion single-photon emission computed tomography is clinically effective and cost effective in risk stratification of patients with a high likelihood of coronary artery disease (CAD) but no known CAD.

OBJECTIVES: We sought to evaluate the prognostic and cost implications of stress myocardial perfusion single-photon emission computed tomography (SPECT), or MPS, in patients with a high pretest likelihood (>0.85) of coronary artery disease (CAD) with no previous CAD. BACKGROUND: Sparse data are available regarding the prognostic performance characteristics of MPS in this patient group. METHOD: We followed up 1,270 consecutive patients with no previous revascularization or myocardial infarction (MI), with a pre-exercise tolerance test (ETT) likelihood of CAD > or =0.85, who underwent exercise or adenosine stress MPS (follow-up 94.4% complete; 2.2 +/- 1.2 years; 60 hard events [5.9%, 2.6%/year]). Risk adjustment of survival data was done using Cox proportional hazards analysis. Costs per reclassification of risk were calculated using assumed costs and threshold analyses. RESULTS: In patients treated medically after MPS, normal MPS had a low risk of cardiac death and hard events (0.6% and 1.3% per year, respectively). With increasing extent and severity of MPS defects, the risk of both cardiac death and hard events increased significantly (p < 0.05). Cox models indicated that the addition of MPS data resulted in incremental prognostic value over pre-MPS data (chi-square increase 48 to 87, p < 0.0001). Compared with strategies of initial referral to ETT in patients able to exercise, initial referral to MPS appeared to be a more cost-effective strategy. Similarly, compared with a strategy of direct referral to catheterization in patients with a high likelihood of CAD, initial referral to MPS is a cost-saving approach. CONCLUSIONS: In patients with a high likelihood of CAD but without known CAD, stress MPS yields incremental value and achieves risk stratification in a cost-effective manner. The current results support a strategy of initial stress imaging in this patient cohort, as a reasonable alternative to direct referral to catheterization or initial ETT.

Aged↗

Gender disparities in the diagnosis and treatment of non-ST-segment elevation acute coronary syndromes: large-scale observations from the CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the American College of Cardiology/American Heart Association Guidelines) National Quality Improvement Initiative.

OBJECTIVES: We hypothesized that significant disparities in gender exist in the management of patients with non-ST-segment elevation (NSTE) acute coronary syndromes (ACS). BACKGROUND: Gender-related differences in the diagnosis and treatment of ACS have important healthcare implications. No large-scale examination of these disparities has been completed since the publication of the revised American College of Cardiology/American Heart Association guidelines for management of patients with NSTE ACS. METHODS: Using data from the CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the American College of Cardiology/American Heart Association Guidelines) National Quality Improvement Initiative, we examined differences of gender in treatment and outcomes among patients with NSTE ACS. RESULTS: Women (41% of 35,875 patients) were older (median age 73 vs. 65 years) and more often had diabetes and hypertension. Women were less likely to receive acute heparin, angiotensin-converting enzyme inhibitors, and glycoprotein IIb/IIIa inhibitors and less commonly received aspirin, angiotensin-converting enzyme inhibitors, and statins at discharge. The use of cardiac catheterization and revascularization was higher in men, but among patients with significant coronary disease, percutaneous revascularization was performed in a similar proportion of women and men. Women were at higher risk for unadjusted in-hospital death (5.6% vs. 4.3%), reinfarction (4.0% vs. 3.5%), heart failure (12.1% vs. 8.8%), stroke (1.1% vs. 0.8%), and red blood cell transfusion (17.2% vs. 13.2%), but after adjustment, only transfusion was higher in women. CONCLUSIONS: Despite presenting with higher risk characteristics and having higher in-hospital risk, women with NSTE ACS are treated less aggressively than men.

Acute Disease↗

Electrocardiography and Doppler echocardiography for risk stratification in patients with chronic heart failure: incremental prognostic value of QRS duration and a restrictive mitral filling pattern.

OBJECTIVES: This prospective study tested whether Doppler echocardiographic variables add incremental value to QRS duration in determining the prognosis of patients with chronic heart failure (CHF) and systolic dysfunction. BACKGROUND: Diastolic dysfunction frequently is observed in patients with CHF, but its prognostic impact relative to that of QRS duration is unknown. METHODS: A total of 193 patients with CHF and an ejection fraction <45% were enrolled prospectively. Echo measurements included left ventricular dimensions/volumes, ejection fraction, mitral early/late diastolic velocity ratio, deceleration time, and tissue Doppler mitral annular velocities. The mitral filling pattern was classified as either restrictive (RFP) or nonrestrictive. A cardiac event (cardiac death or urgent cardiac transplantation) was defined as combined study end point. RESULTS: During a follow-up of 385 +/- 270 days, 24 patients suffered an event (cardiac death, n = 21; urgent transplantation, n = 3). The RFP, QRS duration, left ventricular systolic diameter, and mitral annular early diastolic velocity were independent predictors of an event. In patients with QRS duration >144 ms, the outcome was markedly poorer in the presence of RFPs as compared with their absence. Similarly, despite a QRS duration <or =144 ms, the outcome was worse in the presence of a RFP. A risk-stratification model based on the three strongest independent predictors separated groups into those with good prognosis and those with high, intermediate, and low event-free survival rates. CONCLUSIONS: In subjects with CHF and systolic dysfunction, transmitral flow patterns add incremental value to QRS duration in determining the prognosis.

Chronic Disease↗

Microvolt T-wave alternans for the risk stratification of ventricular tachyarrhythmic events: a meta-analysis.

OBJECTIVES: The objective of this study was to perform a meta-analysis of the predictive value of microvolt T-wave alternans (MTWA) testing for arrhythmic events in a wide variety of populations. BACKGROUND: Previous studies describing the use of MTWA as a predictor of ventricular tachyarrhythmic events have been limited by small sample sizes and disparate populations. METHODS: Prospective studies of the predictive value of exercise-induced MTWA published between January 1990 and December 2004 were retrieved. Data from each article were abstracted independently by two authors using a standardized protocol. Summary estimates of the predictive value of MTWA were made using a random-effects model. RESULTS: Data were accumulated from 19 studies (2,608 subjects) across a wide range of populations. Overall, the positive predictive value of MTWA for arrhythmic events was 19.3% at an average of 21 months' follow-up (95% confidence interval [CI] 17.7% to 21.0%), the negative predictive value was 97.2% (95% CI 96.5% to 97.9%), and the univariate relative risk of an arrhythmic event was 3.77 (95% CI 2.39 to 5.95). There was no difference in predictive value between ischemic and nonischemic heart failure subgroups. The positive predictive value varied depending on the population of patients studied (p < 0.0001). CONCLUSIONS: Microvolt T-wave alternans testing has significant value for the prediction of ventricular tachyarrhythmic events; however, there are significant limitations to its use. The predictive value of MTWA varies significantly depending on the population studied. Careful standardization is needed for what constitutes abnormal MTWA. The incremental prognostic value of MTWA when used with other methods of risk stratification is unclear.

Adult↗

The potential of myocardial perfusion scintigraphy for risk stratification of asymptomatic patients with type 2 diabetes.

Patients with diabetes, in particular patients with type 2 diabetes, are at a 2- to 4-fold higher risk of cardiovascular mortality compared with their nondiabetic peers. Patients with diabetes are also more likely to have silent ischemia and less likely to survive a myocardial infarction than nondiabetic patients. Recent studies with electron beam computed tomography (EBCT) have shown that subclinical atherosclerosis is common in patients with diabetes, and studies with myocardial perfusion scintigraphy (with single-photon emission computed tomography) or stress echocardiography have demonstrated that between 25% and 50% of asymptomatic diabetic patients have ischemia during exercise or pharmacological stress and that a substantial proportion of these patients go on to develop major cardiovascular events within several years. Clearly, asymptomatic diabetic patients include a subset of individuals at high risk of cardiovascular disease who would benefit from improved risk stratification beyond that possible with risk factor scoring systems alone. Single-photon emission computed tomography, stress echocardiography, and possibly EBCT or multi-slice computed tomography, are emerging as valuable diagnostic tools for identifying asymptomatic diabetic patients who might require early and aggressive intervention to manage their cardiovascular risk.

Algorithms↗

Corrected QT variability in serial electrocardiograms in long QT syndrome: the importance of the maximum corrected QT for risk stratification.

OBJECTIVES: We evaluated the incremental prognostic information provided by multiple corrected QT (QTc) measurements on serial electrocardiograms (ECGs) in patients with the inherited long QT syndrome (LQTS). BACKGROUND: A baseline QTc of > or =500 ms has been shown to be associated with increased risk of cardiac events among LQTS patients. However, the value of QTc measurements on follow-up ECGs in risk assessment has not been determined. METHODS: The risk of a first LQTS-related cardiac event during adolescence was assessed in 375 patients enrolled in the International LQTS Registry for whom serial follow-up ECGs were recorded before age 10. RESULTS: The mean +/- SD difference between the minimum and maximum QTc values on serial ECGs recorded in study patients was 47 +/- 40 ms. The maximum QTc interval recorded before age 10 was the strongest predictor of cardiac events during adolescence (adjusted hazard ratio [HR] = 2.74; p < 0.001). Other follow-up QTc measures, including the baseline, the mean, and the most recent QTc interval recorded before age 10, were less significant risk factors. After adjusting for the maximum QTc value during follow-up, no significant association remained between the baseline QTc value and the risk of subsequent cardiac events (HR = 1.04; p = 0.91). CONCLUSIONS: In LQTS patients, there is a considerable variability in QTc measures in serial follow-up ECGs. The maximum QTc interval provides incremental prognostic information beyond the baseline measurement. We suggest that risk stratification in LQTS patients should include follow-up ECG data.

Adolescent↗

Gender-specific risk stratification with B-type natriuretic peptide levels in patients with acute dyspnea: insights from the B-type natriuretic peptide for acute shortness of breath evaluation study.

OBJECTIVES: We examined whether B-type natriuretic peptide (BNP) levels allow gender-specific risk stratification in patients with acute dyspnea. BACKGROUND: B-type natriuretic peptide levels determined in patients with heart failure correlate with the severity of disease and prognosis. Gender differences in risk prediction are poorly examined. METHODS: The BASEL (B-type natriuretic peptide for Acute Shortness of Breath Evaluation) Study enrolled 190 female and 262 male patients presenting with acute dyspnea. RESULTS: At 24 months, cumulative mortality was comparable in women and men (38% vs. 35%, p = 0.66). Cox regression analyses revealed that BNP levels >500 pg/ml indicated a 5.1-fold increase in mortality for women (95% confidence interval [CI] 3.0 to 8.5, p < 0.001) versus a 1.8-fold increase in men (95% CI 1.2 to 2.6; p = 0.007). The area under the receiver-operating characteristic curve (AUC) for BNP to predict death was significantly higher in female (AUC: 0.80, 95% CI 0.73 to 0.86) than in male patients (AUC: 0.64, 95% CI 0.57 to 0.71; p = 0.001 for the comparison of AUC(women) versus AUC(men)). Women with BNP >500 pg/ml displayed a higher mortality as compared with men with BNP >500 pg/ml (68% vs. 46%, p = 0.015). Interaction analysis showed that BNP is a stronger predictor of death in women than in men (p = 0.008). CONCLUSIONS: B-type natriuretic peptide plasma levels seem to be stronger predictors of death in women than in men.

Acute Disease↗

Bedside risk stratification after acute myocardial infarction: prospective evaluation of the use of heart rate and left ventricular function.

OBJECTIVE: This study evaluated the predictive power of heart rate (HR) assessed from the standard 12-lead electrocardiogram (ECG) or from Holter recordings for future mortality and arrhythmic events in survivors of acute myocardial infarction (AMI). METHODS: Data from 432 consecutive survivors of AMI (343 men, 89 women; mean [SD] age, 58 [11] years) were analyzed. Heart rate was assessed from a standard 12-lead ECG and from 24-hour Holter recordings obtained at hospital discharge. In addition, left ventricular ejection fraction (LVEF) was noninvasively determined. The study end point was prospectively defined as a composite end point comprising mortality and arrhythmic events (ie, sudden death, resuscitated ventricular fibrillation, sustained ventricular tachycardia). Patients were followed for an average (SD) of 41 (25) months. RESULTS: Patient age, LVEF, and HR were univariate risk predictors of event-free survival. Multivariate analysis by means of a stepwise regression analysis revealed LVEF ( chi2 11.4, P = .0007), age ( chi 2 9.2, P = .02), and HR assessed from the standard 12-lead ECG ( chi2 7.1, P = .008) as independent risk parameters. CONCLUSIONS: Bedside risk stratification of survivors of AMI is feasible using simple parameters such as age, LVEF, and HR.

Adult↗

Right- and left-sided colorectal cancers display distinct expression profiles and the anatomical stratification allows a high accuracy prediction of lymph node metastasis.

Accurate preoperative prediction of lymph node metastasis and degree of tumor invasion would facilitate an appropriate decision of the extent of surgical resection of cancers to reduce unnecessary complication or to minimize the risk of recurrence in patients. We analyzed gene expression profiles characteristic of the invasiveness of colorectal carcinoma in a total of 89 cases, using a cDNA array and pattern classification algorithms. We set binary classes for a panel of clinicopathologic parameters, each of which was divided at different levels for categories (discrete) or values (continuous). We searched an optimal combination of genes to discriminate the classes by using of a feature subset selection algorithm, which was applied to a set of genes preselected on the basis of statistical difference in expression (two-sided t test, P < or = 0.05). We used a sequential forward feature selection which additively searched a combination of genes, giving a minimal leave-one-out classification error rate of a k-nearest neighbor classifier. In the process of gene preselection, we found a remarkable difference in the expression pattern of genes according to the anatomical location of cancers. The difference was most prominent when the classes were set for cecum, ascending colon, transverse colon, and descending colon (CATD) versus sigmoid colon and rectum (SR). By stratifying these two locations, we were able to extract gene expression profiles characteristic of the classes of the presence versus absence of lymph node metastasis, lymphatic invasion, vascular invasion and degree of mural invasion, and pathological stages, with an accuracy of more than 90%. These results suggest that colorectal cancers harbor distinct molecular pathophysiological statuses according to their right-to-left locations, of which stratification is important for pattern classification of cDNA array data.

Adult↗

Combined stratification of refractory anemia according to both WHO and IPSS criteria has a prognostic impact and improves identification of patients who may benefit from stem cell transplantation.

A retrospective analysis of the relationship between the initial classification according to either FAB or WHO criteria, the presence of risk factors and the type of therapy including stem cell transplantation (SCT) on the survival was performed in a group of 106 patients with primary myelodysplastic syndrome (MDS) of FAB RA subtype. Allogeneic SCT early in the course of the disease did not significantly affect median survival in RA patients evaluated either according to FAB criteria (63.2 months in 17 SCT patients versus 64.4 months in 89 non-transplanted (non-SCT) patients) or in subgroups classified separately according to WHO (64.0 months in SCT versus 91.0 months in non-SCT RA patients and 66.2 months in SCT versus 43.0 months in non-SCT refractory cytopenia with multilineage dysplasia (RCMD) patients) or International Prognostic Scoring System (IPSS) criteria despite decreased incidence of leukemic transformation (5% in SCT versus 32% in non-SCT patients). Neither univariate or multivariate analysis of different clinical and laboratory parameters revealed a significant effect of SCT on 3 or 5 years survival in RA patients. The most probable explanation was a relatively high rate of transplantation related mortality (41%) on one hand together with a slow disease progression towards leukemia (24% at 5 years in non-SCT) on the other hand. A more refined stratification of patients based on the combined WHO morphology classification and IPSS cytogenetic criteria revealed subgroup of 11 non-SCT patients with RCMD and poor karyotype with median survival significantly different from that in five SCT patients (9.2 months in non-SCT versus 89.3 months in SCT, P=0.05). Thus, combined WHO morphology/IPSS cytogenetics criteria may be helpful for identification of the high risk patients with the RA group who may benefit from early SCT despite the relatively high incidence of SCT-related complications.

Anemia, Refractory↗

Stratification of the biologic aggressiveness of non-small cell lung cancer using DNA flow cytometry and immunohistochemistry for the retinoblastoma protein.

DNA ploidy pattern and S-phase fraction (SPF) measured by flow cytometry and expression of the retinoblastoma gene product (pRB) estimated by immunohistochemistry were correlated with outcome in 114 patients who received a curative operation for primary non-small cell lung cancer (NSCLC). One hundred ten tumors yielded an adequate DNA histogram, and all tumors exhibited an assessable immunohistochemical stain. DNA diploidy was detected in 31 tumors and DNA aneuploidy in 79 tumors. The mean SPF was 14.1 +/- 6.4%. Eighty tumors were positively stained, and 34 tumors were negative for pRB. Multivariate analysis clarified that both TNM staging and DNA ploidy were prognostic factors after surgery. In 39 recurrent cases, the SPF value was inversely correlated with disease-free interval. With only supportive care after recurrence, high SPF tumors and pRB-negative tumors progressed rapidly, whereas active treatment yielded an equivalent effect on recurrent tumors regardless of the SPF or pRB expression. DNA ploidy is related to the risk of recurrence, while SPF is related to tumor growth rate and the impact of active treatment on recurrence. The utility of pRB expression was limited. The combination of DNA ploidy and SPF allows practical stratification of the biologic aggressiveness of NSCLC.

Adult↗

Genomic Profiling, Risk Stratification, and Post-Transformation Treatment Outcomes in Patients with Transformed Small-Cell Lung Cancer: A Multicenter Analysis.

BACKGROUND: Transformed small-cell lung cancer (T-SCLC) is an increasingly recognized resistance mechanism in EGFR-mutant lung adenocarcinoma. This study aimed to identify early predictors of histologic transformation and evaluate post-transformation treatment outcomes. METHODS: We retrospectively collected 163 T-SCLC patients from five Chinese centers. Next-generation sequencing was performed on 60 EGFR-mutant patients, including 47 paired primary-transformed samples. Integrated genomic and clinical analyses were conducted to delineate molecular features and survival outcomes. RESULTS: Among 150 EGFR-mutant patients, the median time to SCLC transformation was 25.8 months and median post-transformation overall survival (OS) was 14.2 months. Clinical and survival data for the 13 EGFR wild-type patients are reported descriptively given the limited sample size. Among 108 treatment-evaluable patients, first-line EGFR-TKI plus chemotherapy, chemotherapy alone, and immune checkpoint inhibitors (ICIs) plus chemotherapy yielded median progression-free survival (PFS) of 6.2, 5.30, and 4.07 months (P = 0.041) and median OS of 21.2, 27.6, and 13.6 months (P = 0.193). In later-line therapy, taxane-based regimens achieved a median PFS of 6.93 months, outperforming camptothecin-based (1.13 months) and other regimens (1.90 months; P = 0.049). High evolutionary diversity was associated with shorter post-transformation OS (6.77 vs. 11.10 months), with restricted cubic spline analysis showing a nonsignificant trend toward a nonlinear association (P = 0.055).Age, RB1/NTRK1 mutation, and secondary T790M mutation were identified as independent risk factors and integrated into a predictive model with high accuracy. CONCLUSIONS: This study establishes a clinically applicable model for early prediction and risk stratification of SCLC transformation. Taxane-based regimens emerge as a promising later-line therapeutic option for T-SCLC.

Humans↗

Copy Number-low/TP53-mutated Endometrial Cancer With Wild-type p53 Immunoexpression: Implications for Risk Stratification and Management When Using Next-generation Sequencing for Molecular Classification.

Endometrial cancers with the Cancer Genome Atlas (TCGA) molecular profile of TP53-mutated, POLE-wild-type, and microsatellite-stable generally exhibit a high burden of copy number (CN) alterations and carry an increased risk for adverse outcomes, meriting maximal adjuvant therapy. In contrast, the prognosis associated with a TP53 mutation that coexists with a POLE mutation or microsatellite instability aligns with that of ultramutated or hypermutated cancers, respectively. In this study, we characterized a rare molecular subclass of endometrial cancers defined by TP53 mutation but low burden of CN alterations, wild-type p53 immunoexpression (immunohistochemistry [IHC]), and low TP53 variant allele frequency (median 13% and maximum 47%). Among 723 consecutive endometrial cancers prospectively classified using next-generation sequencing, 16 (2.2%) were CN-low/TP53-mutated/p53 wild-type IHC. Two additional cases were identified in a separate retrospective cohort of 32 recurrent low-grade early-stage endometrial cancers, bringing the total to 18 cases. They affected postmenopausal patients, exhibited low-grade endometrioid histotype, and were mostly confined to the uterus without lymphovascular space invasion. The recurrence rate was 6.25% (1/16) in the prospective cohort, and none died, placing their prognosis closer to that of CN-low than CN-high cancers. We conclude that next-generation sequencing-based TCGA classification of TP53-mutated, POLE-wild-type, microsatellite-stable endometrial cancers with TP53 variant allele frequency < 50% requires further evaluation using CN analysis and/or p53 IHC to detect this rare molecular category. IHC-based TCGA classification, such as the ProMisE protocol, will not be able to detect these cases because the p53 IHC pattern is wild-type and there are no distinguishing morphological features; this may be of relevance for analyzing ProMisE protocol-based clinical trials and outcomes studies. Long-term outcome studies are needed to refine risk stratification and treatment decisions for this unique molecular class of endometrial cancers that further contributes to the evolving understanding that the clinical significance of TP53 mutation in endometrial cancer is complex and depends on coexisting molecular alterations.

Humans↗

Acute coronary syndromes: initial evaluation and risk stratification.

Chest pain, the second most frequent presenting complaint in the emergency department (ED), often poses a challenge to the physicians dealing with these patients owing to the wide spectrum of presentation of acute coronary syndromes (ACS). A majority of the patients presenting with chest pain are usually admitted to the hospital for further evaluation and management. Despite the availability of modern-day tools for diagnosis of acute myocardial infarction (AMI), about 5% of patients with AMI are missed in the ED with subsequent associated morbidity and mortality and legal consequences. Several centers have adapted critical pathways derived from American College of Cardiology/American Heart Association (ACC/AHA) guidelines for the management of patients presenting with ACS. We now have some evidence suggesting adherence to the critical pathways derived from ACC/AHA guidelines will optimize the quality of patient care and probably result in better patient outcomes. This article reviews initial evaluation and the importance of risk stratification of the patients presenting with chest pain using the currently available clinical and diagnostic tools. Critical pathways derived from the ACC/AHA guidelines for various presentations of ACS are also reviewed.

Acute Disease↗

The promise of pharmacogenetics: assessing the prospects for disease and patient stratification.

Pharmacogenetics is an emerging biotechnology concerned with understanding the genetic basis of drug response, and promises to transform the development, marketing and prescription of medicines. This paper is concerned with analysing the move towards segmented drug markets, which is implicit in the commercial development of pharmacogenetics. It is claimed that in future who gets a particular drug will be determined by their genetic make up. Drawing on ideas from the sociology of expectations we examine how pharmaceutical and biotechnology companies are constructing, responding to and realising particular 'visions' or expectations of pharmacogenetics and market stratification. We argue that the process of market segmentation remains uncertain, but that the outcome will be fashioned according to the convergence and divergence of the interests of key commercial actors. Qualitative data based both on interviews with industry executives and company documentation will be used to explore how different groups of companies are developing pharmacogenetics in distinct ways, and what consequences these different pathways might have for both clinical practice and health policy. In particular, the analysis will show a convergence of interests between biotechnology and pharmaceutical companies for creating segmented markets for new drugs, but a divergence of interest in segmenting established markets. Whilst biotechnology firms have a strong incentive to innovate, the pharmaceutical industry has no commercial interest in segmenting markets for existing products. This has important implications, as many of the claimed public health benefits of pharmacogenetics will derive from changing the prescribing of existing medicines. One significant implication of this is that biotechnology companies who wish to apply pharmacogenetics to existing medicines will have to explore an alternative convergence of interests with healthcare payers and providers (health insurers, HMOs, MCOs and national health systems). Healthcare providers may have a strong incentive to use pharmacogenetics to make the prescribing of existing medicine more cost-effective. However, we conclude by suggesting that a question mark hangs over their ability to provide the necessary economic and structural resources to bring such a vision to fruition.

Biotechnology↗

The health of nations in a global context: trade, global stratification, and infant mortality rates.

Despite the call for a better understanding of macro-level factors that affect population health, social epidemiological research has tended to focus almost exclusively on national-level factors, such as Gross Domestic Product per capita (GDP/c) or levels of social cohesion. Using a world-systems framework to examine cross-national variations in infant mortality, this paper seeks to emphasize the effects of global trade on national-level population health. Rather than viewing national-level health indicators as autonomous from broader global contexts, the study uses network analysis methods to examine the effects of international trade on infant mortality rates. Network data for countries were derived from international data on the trade of capital-intensive commodities in 2000. Using automorphic equivalence to measure the degree to which actors in a network perform similar roles, countries were assigned into one of six world-system blocks, each with its own pattern of trade. These blocks were dummy-coded and tested using ordinary least squares (OLS) regression. A key finding from this analysis is that after controlling for national-level factors, the two blocks with the lowest density in capital-intensive exchange, i.e., the periphery, are significantly and positively associated with national-level infant mortality rates. Results show the effects of peripherality and stratification on population health, and highlight the influence of broader macro-level factors such as trade and globalization on national health.

Commerce↗