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At least 595 records · Page 33Linked to original sources
PubMed2026

Dynamic evolution of chaperone-mediated autophagy is associated with tumor microenvironment remodeling and prognostic stratification in lung adenocarcinoma: insights from single-cell transcriptomics, ensemble machine learning, and experimental validation.

BACKGROUND: Lung adenocarcinoma (LUAD) shows prognostic heterogeneity, and tumor-node-metastasis (TNM) staging is limited for individualized management. Chaperone-mediated autophagy (CMA) maintains proteostasis, but its role during adenocarcinoma in situ (AIS)-minimally invasive adenocarcinoma (MIA)-invasive adenocarcinoma (IAC) progression remains unclear. METHODS: Single-cell RNA sequencing (scRNA-seq) data from GSE189357 and bulk transcriptomes from The Cancer Genome Atlas (TCGA)-LUAD and Gene Expression Omnibus (GEO) cohorts were integrated. CMA activity, cell-cell communication, weighted gene co-expression network analysis (WGCNA), tumor-normal differential expression, machine-learning survival modeling, tumor microenvironment (TME) features, drug sensitivity, and EPC1 function were analyzed. RESULTS: CMA-high tumor epithelial cells increased from AIS (58.1%) to MIA (65.7%) but declined in IAC (44.4%; p < 0.001). CMA-low cells preferentially received fibroblast-derived extracellular matrix cues. A CMA-negatively correlated module identified 69 core genes. Random survival forest (RSF) performed best among 117 machine-learning combinations (mean concordance index > 0.873). High-risk patients had worse survival across cohorts, and the risk score was independently associated with overall survival (hazard ratio = 16.013, 95% confidence interval: 9.579-26.768, p < 0.001). High-risk tumors showed proliferative activation and M0 macrophage enrichment, whereas low-risk tumors showed stronger immune-related signaling. EPC1 overexpression suppressed malignant phenotypes in A549 cells. CONCLUSION: CMA dynamics are associated with stromal and immune remodeling during LUAD progression. A CMA-based model provides robust prognostic stratification and may offer a basis for future TME-guided studies.

Chaperone-mediated autophagy↗
PubMed2026

Lactylation-related immune-metabolic dysregulation defines prognostic and therapeutic stratification in lung adenocarcinoma.

BACKGROUND: Lactylation links lactate metabolism with inflammatory signaling and immune regulation in tumors. However, its cellular distribution and translational value in lung adenocarcinoma (LUAD) remain unclear. METHODS: Single-cell RNA-sequencing datasets GSE189357 and GSE171145 were integrated to characterize lactylation-related activity, intercellular communication, and malignant epithelial cell states in LUAD. Single-cell-derived lactylation-related differentially expressed genes were mapped to TCGA-LUAD and multiple GEO cohorts. Univariate Cox regression and machine learning algorithms were used to construct a lactylation-related prognostic signature (LRPS). The associations of LRPS with prognosis, immunotherapy response, drug sensitivity, genomic alterations, immune infiltration, and inflammation- and metabolism-related pathways were evaluated. KRT7 was further validated using virtual knockout analysis, spatial transcriptomics, and in vitro and in vivo experiments. RESULTS: lactylation-related transcriptional activity showed heterogeneous distribution across LUAD cell populations and was associated with altered cell-cell communication. In malignant epithelial cells, LRTS-high and LRTS-low states exhibited distinct metabolic, inflammatory, and tumor-related pathway activities. LRPS showed stable prognostic performance in TCGA-LUAD and multiple GEO cohorts and remained an independent prognostic factor. Low LRPS was associated with greater potential benefit from immunotherapy, whereas different LRPS groups displayed distinct drug sensitivity, genomic alteration, and immune microenvironment patterns. KRT7 was highly expressed in LUAD and associated with poor prognosis. KRT7 knockdown suppressed LUAD cell proliferation, migration, invasion, colony formation, and tumor growth in vivo. CONCLUSIONS: This study identifies lactylation-related immune-metabolic dysregulation as a clinically relevant feature of LUAD and develops a single-cell-guided LRPS for prognosis and therapeutic stratification. KRT7 emerged as an LRPS-related functional candidate with experimentally supported roles in malignant LUAD phenotypes.

Immunotherapy↗
PubMed2005

Laminar cortical dynamics of 3D surface perception: stratification, transparency, and neon color spreading.

The 3D LAMINART neural model is developed to explain how the visual cortex gives rise to 3D percepts of stratification, transparency, and neon color spreading in response to 2D pictures and 3D scenes. Such percepts are sensitive to whether contiguous image regions have the same contrast polarity and ocularity. The model predicts how like-polarity competition at V1 simple cells in layer 4 may cause these percepts when it interacts with other boundary and surface processes in V1, V2, and V4. The model also explains how: the Metelli Rules cause transparent percepts, bistable transparency percepts arise, and attention influences transparency reversal.

Color Perception↗
PubMed1996

Dipyridamole technetium 99m sestamibi myocardial tomography for preoperative cardiac risk stratification before major or minor nonvascular surgery.

The value of dipyridamole technetium 99m sestamibi (MIBI) tomography for preoperative cardiac risk stratification was assessed in 285 consecutive patients being considered for nonvascular surgery. A "major" (n = 140) or "minor" (n = 89) nonvascular procedure was later done in 229 of these patients < or = 4 months after dipyridamole testing. Perioperative cardiac events (unstable angina, acute ischemic pulmonary edema, nonfatal myocardial infarction, or cardiac death) occurred in 11 (8%) patients undergoing major nonvascular surgery and 1 (1%) undergoing a minor procedure. The only clinical or scintigraphic variables associated with significantly increased perioperative cardiac risk in patients having major surgery were Goldman class > or = II, an abnormal MIBI scan, and a fixed perfusion defect. In these patients, cardiac events occurred in 1% of those who had a normal MIBI study, 14% of those with an abnormal scan (p < 0.01), 12% with a reversible MIBI defect (p = 0.29), and 17% with a fixed MIBI defect (p < 0.01). In the 60 patients whose Goldman class was > or = II, only an abnormal MIBI study and a fixed perfusion defect were associated with incremental risk of a perioperative cardiac event. The incidence of perioperative cardiac events in these patients was 4% with a normal MIBI scan, 27% with an abnormal study (p < 0.05), 24% with a reversible MIBI defect (p = 0.45), and 37% with a fixed defect (p < 0.01). Event rates were low in patients having minor nonvascular surgery; none of the 25 with a normal MIBI study and only 1 of the 64 with an abnormal scan had a perioperative cardiac event (p = not significant (NS). We conclude that dipyridamole MIBI tomography can provide important prognostic information in patients having major nonvascular surgery. A normal MIBI study indicates a low risk of perioperative cardiac events, whereas an abnormal study in patients with Goldman class > or = II undergoing major surgery is associated with significantly increased risk. The prognostic value of MIBI tomography in patients at low clinical risk undergoing minor surgery is limited.

Aged↗
PubMed2000

An ischemia-guided approach for risk stratification in patients with acute coronary syndromes.

The optimal management approach for patients with non-ST-segment elevation acute coronary syndromes continues to be an issue of debate. An ischemia-guided strategy appears to be effective as an alternative to either a very conservative "wait-and-see" approach or a very aggressive routine revascularization approach. The need for another approach is supported by the lack of conclusive evidence-based results favoring an early routine invasive treatment strategy. In the Thrombolysis in Myocardial Infarction (TIMI) IIIB trial, there were no differences in the incidence of death or myocardial infarction (MI) between patients treated with an early invasive approach and those treated with a conservative approach to treatment. Significantly worse outcomes were shown in patients assigned to an early invasive strategy in the Veterans Affairs Non-Q-Wave Infarction Strategies in Hospital (VANQWISH) trial at 1-year follow-up (111 clinical events in the invasive group vs 85 in the conservative group; p = 0.05). Registry information, including that from the Organization to Assess Strategies for Ischemic Syndromes (OASIS), which included approximately 8,000 patients with unstable angina or suspected MI, has even suggested an excess hazard with a routine invasive approach. Patients with non-ST-segment elevation MI observed in the Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes (GUSTO)-IIB and Platelet IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trials also fared better with an ischemia-guided strategy. Even the recent FRagmin and Fast Revascularization during InStability in Coronary artery disease (FRISC II) trial investigators had to be very selective relative to eliminating high-risk patients in the first week and treating with intense anti-ischemic therapy and 5-7 days of low-molecular-weight heparin therapy to show an advantage for assigned revascularization. A careful clinical evaluation with attention to early risk stratification is essential in the ischemia-guided approach. The Braunwald classification for unstable angina helps identify independent clinical predictors of a poor outcome; high risk is clearly associated with Braunwald class III and type C. Electrocardiographic and biochemical markers for myocardial necrosis (cardiac troponin T or I) are important tools for assessing the presence and degree of ischemia and associated risk for adverse outcome. Noninvasive evaluation of left ventricular ejection fraction is essential for identifying those at high risk due to impaired contractile function. When these conventional markers do not provide conclusive information, noninvasive stress testing is most helpful to further identify those at highest risk for revascularization.

Angina, Unstable↗
PubMed2002

Usefulness of fractional flow reserve for risk stratification of patients with multivessel coronary artery disease and an intermediate stenosis.

Intracoronary-derived, pressure-based fractional flow reserve (FFR) is important for clinical decision-making in patients with 1-vessel coronary artery disease (CAD). In the present study, we investigated the prognostic value of FFR in patients with intermediate stenoses and multivessel CAD. Therefore, we analyzed 107 patients with stable angina pectoris who underwent myocardial perfusion scintigraphy and showed no perfusion defects in the region of the intermediate lesion. At angiography, FFR was determined distal to the intermediate lesion. FFR was abnormal (i.e., <0.75) in 15 of 107 stenoses (14%). Angioplasty of the intermediate stenosis was deferred based on the absence of a perfusion defect. Patients were followed for 1 year to document major cardiac events related to the intermediate lesion. At 1-year follow-up, a total of 12 (11%: no deaths, 3 myocardial infarctions, 2 coronary bypass operations, 7 coronary angioplasties) events occurred in the entire group that were related to the intermediate lesion. The event rate was significantly higher when angioplasty was deferred despite FFR <0.75 compared with the group with FFR > or = 0.75 (4 of 15 [27%] vs 8 of 92 [9%]; p <0.041). The relative risk of FFR for predicting cardiac events (mainly revascularization procedures) was 3.1 (95% confidence interval 1.1 to 8.9; p <0.05). In conclusion, deferral of angioplasty of intermediate coronary narrowings is safe based on FFR > or = 0.75 in this patient cohort; this coincides with previous reports in patients with 1-vessel CAD. Furthermore, these results suggest that FFR is more useful than single-photon emission computed tomography for clinical decision-making and risk stratification in patients with multivessel CAD.

Adult↗
PubMed2002

Risk stratification using a combination of cardiac troponin T and brain natriuretic peptide in patients hospitalized for worsening chronic heart failure.

We prospectively evaluated whether the combination of admission measurements of a marker for myocardial cell injury and a marker for left ventricular overload would effectively risk stratify patients with acutely decompensated heart failure. We measured serum concentrations of cardiac troponin T (cTnT) using a second-generation assay, as well as serum cardiac troponin I (cTnI) and plasma atrial and brain natriuretic peptide (BNP) concentrations on admission in 98 consecutive patients hospitalized for worsening chronic heart failure (mean age 69 years; 5 patients were in New York Heart Association functional class II, 35 were in class III, and 58 patients were in class IV). During a mean follow-up period of 451 days, there were 37 cardiac events, including 21 cardiac deaths (14 in-hospital deaths) and 16 readmissions for worsening heart failure. In a stepwise Cox regression analysis, including these biochemical markers, age, sex, functional class, and left ventricular ejection fraction, cTnT, and BNP were found to be significantly independent predictors of both cardiac death (p <0.05) and cardiac events (p <0.01). A cTnT >0.033 microg/L and/or a BNP >440 pg/ml on admission was correlated with an incremental increase in in-hospital cardiac mortality, overall cardiac mortality, and cardiac event rate. Kaplan-Meier analysis revealed that this combination could reliably stratify the patients into low-, intermediate-, and high-risk groups for cardiac events. Measuring the combination of admission concentrations of cTnT and BNP may be a highly effective means of risk stratification of patients hospitalized for worsening chronic heart failure.

Adult↗
PubMed1996

A metaanalysis of predischarge risk stratification after acute myocardial infarction with stress electrocardiographic, myocardial perfusion, and ventricular function imaging.

We assessed the relation of abnormal predischarge non-invasive test results to outcomes in postmyocardial infarction patients. We included series published from 1980 to 1995 containing only myocardial infarction patients, enrolling most patients after 1980, testing within 6 weeks of infarction, having follow-up rates > 80%, and having 2 x 2 frequency outcome rates for test results, that were the latest of multiple reports. Sensitivity, specificity, and predictive values were calculated for test results for 1-year outcomes (cardiac death, cardiac death or reinfarction). Univariable and summary odds were calculated for test results. Reports (n = 54) included a total of 19,874 patients and were primarily retrospective (76%) and small series (35% of reports included < 5 deaths). One-year mortality ranged from 2.5% for pharmacologic stress echocardiography to 9.3% for exercise radionuclide angiography. Positive predictive values for most noninvasive risk markers were < 0.10 for cardiac death and < 0.20 for death or reinfarction. Electrocardiographic, symptomatic, and scintigraphic risk markers of ischemia (ST-segment depression, angina, a reversible defect) were less sensitive (< or = 44%) for identifying morbid and fatal outcomes than markers of left ventricular dysfunction or heart failure (exercise duration, impaired systolic blood pressure response, and peak left ventricular ejection fraction). The positive predictive value of predischarge noninvasive testing is low. Markers of left ventricular dysfunction appear to be better predictors than markers of ischemia. Limitations of the literature-small samples and widely varying event rates-impede our ability to discern the accuracy of pre-discharge noninvasive testing. More rigorous, controlled trials are required to elucidate the relative value of these tests for risk stratification.

Diagnostic Imaging↗
PubMed1996

Use of ventricular premature complexes for risk stratification after acute myocardial infarction in the thrombolytic era.

The independent predictive role of ventricular premature complex (VPC) frequency in the stratification of mortality risk after acute myocardial infarction (AMI) was established in the prethrombolytic era by extensive multicenter trials. Thrombolysis has lead to important changes in the natural history of patients after AMI, so that reassessment of established risk factors is now required. The prognostic significance of VPCs was assessed in 680 patients, of whom 379 received early thrombolytic therapy. All patients underwent 24-hour Holter monitoring in a drug-free state between 6 and 10 days after AMI. Patients were followed up for 1 to 8 years. During the first year of follow-up, cardiac death occurred in 33 patients, sudden death in 24, and sustained ventricular tachycardia in 20. Mean VPC frequency was significantly higher in patients who died of cardiac causes, in those who died suddenly, and in those with arrhythmic events during the first year of follow-up. This was also true when patients who did and did not undergo thrombolysis were considered separately. The positive predictive accuracy of VPC frequency in predicting adverse cardiac events was greater in patients who did than did not undergo thrombolysis. At a sensitivity level of 40%, the positive predictive accuracy for cardiac mortality and arrhythmic events for the group with thrombolysis was 19.4% and 25.8%, respectively, compared with 16% and 16% for those without thrombolysis. Moreover, the highest VPC frequency for the dichotomy of patients into high-and low-risk groups was 25 VPCs/hour for patients without thrombolysis. VPC frequency appears to be more highly predictive of prognosis after AMI in patients who have undergone thrombolysis than in those who have not, but the optimal frequency for dichotomy is higher in the former.

Adult↗
PubMed1997

Risk stratification and clinical outcome of minimally symptomatic and asymptomatic patients with nonsustained ventricular tachycardia and coronary disease: a prospective single-center study.

The Multicenter Automatic Defibrillator Implantation Trial (MADIT) showed improved survival with defibrillator therapy but was restricted to coronary artery disease patients with nonsustained ventricular tachycardia (NSVT) and inducible nonsupressible VT. The outcome of patients without inducible VT or inducible but suppressed VT still remains unclear. We performed risk stratification at electrophysiologic (EP) study in 111 consecutive unselected patients with nonsustained VT and coronary artery disease and randomized them to drug or device therapy. Follow-up on selected therapy was 1-71 (mean 27 +/- 20) months. Of 111 patients, 39 patients (35%) had inducible sustained VT at baseline EP study and were stratified to a "higher" risk group (group 1) for sudden death. In 9 of these patients (group 1A), sustained VT was suppressed with class IA antiarrhythmic drugs; in the remaining 30 patients (group 1B) sustained VT was not suppressed with class IA antiarrhythmic drugs. The other 72 of 111 patients (65%) had no inducible sustained VT at EP study and were stratified to a "lower"-risk group (group 2) for sudden death. Mean LVEF in group 1 was 30 +/- 10% versus 37 +/- 9% in group 2 (p = 0.001). Selected therapy in group 1 was an implantable cardioverter defibrillator (16 patients) or guided drug therapy (electrophysiologically guided class I antiarrhythmic drugs = 7 patients; Holter-guided class III antiarrhythmic drugs = 16 patients). In group 2, empiric drug therapy included beta blockers in 29 patients or Holter-guided class III antiarrhythmic drugs in 17 patients, with no antiarrhythmic drug therapy being administered in 26 patients. Mean LVEF tended to be lower in patients receiving class III antiarrhythmic drug therapy (34 +/- 12%) than in patients receiving beta blockers (40 +/- 10%, p = 0.06). Three-year total survival was comparable in group 1 (70%) and in group 2 (81%), but sudden cardiac death mortality tended to be lower in group 1 versus group 2 (0 vs 9%, p = 0.09). Patients receiving class III antiarrhythmic therapy had significantly higher 3-year all cause (40%, p = 0.04) and sudden death (25%, p = 0.06) mortality than patients receiving beta blockers (17% and 8% respectively) or no antiarrhythmic drug therapy (4% and 0%, respectively). The following conclusions can be drawn from this analysis: (1) Electrophysiologically guided drug therapy and implantable defibrillators can minimize the risk of sudden cardiac death in patients with coronary artery disease and inducible sustained VT stratified to higher risk of sudden death. A comparable outcome with respect to sudden death prevention in drug-suppressed or drug-refractory patients suggests limited prognostic benefit of class IA drug testing. (2) Lower-risk patients with severely depressed LVEF and minimal or no symptoms do not have a favorable outcome with respect to sudden and all-cause mortality on Holter-guided class III drug therapy. However, asymptomatic patients with mildly depressed left ventricular function have low sudden death event rates on beta blocker or no antiarrhythmic drug therapy.

Aged↗
PubMed1997

Noninvasive risk stratification in unstable coronary artery disease: exercise test and biochemical markers. FRISC Study Group.

Early risk assessment is essential for the application of appropriate treatment and further management in patients with unstable coronary artery disease, i.e., unstable angina or non-Q-wave myocardial infarction. In this article, the use of exercise testing and biochemical markers for identification of high- and low-risk patients is discussed, with special reference to experiences from the FRISC (Fragmin During Instability in Coronary Artery Disease) trial. It is concluded that a symptom-limited predischarge exercise test (provided all relevant information obtained is considered) and determination of troponin T are inexpensive, widely applicable, and useful methods for early risk stratification in both men and women after an episode of unstable coronary artery disease.

Biomarkers↗
PubMed1996

Short- and long-term assessment of heart rate variability for risk stratification after acute myocardial infarction.

Depressed heart rate variability (HRV) has been shown to be a powerful and independent risk factor in patients following acute myocardial infarction (AMI). A detailed comparison of the predictive values between short- and long-term HRV has not been made. The predictive value of short-term HRV for 1-year total cardiac mortality was studied in 700 consecutive patients after AMI. All patients underwent 24-hour Holter monitoring before discharge from the hospital (5 to 8 days after AMI) and were followed up for 1 year. Short-term HRV was computed as the standard deviation of all normal RR intervals (SDNN) from a 5-minute stationary period selected from 24-hour Holter electrocardiographic recordings. Long-term HRV was computed as an HRV index over the entire 24 hours. There was a significant but relatively poor correlation between SDNN and HRV index (r = 0.51, p <0.001). The positive predictive accuracy of SDNN for 1-year mortality (13% to 18%) was lower than the HRV index (17% to 43%) over a range of sensitivity of 25% to 75%. Assessment of HRV index in > or = 35% of the patients preselected by the lowest SDNN was able to achieve predictive power similar to that of HRV index assessed in all the patients. These data suggest that lower predischarge short-term HRV is associated with increased 1-year total cardiac mortality in patients after AMI. Analysis of long-term HRV for postinfarction risk stratification can safely be limited to patients preselected by depressed short-term HRV measures.

Analysis of Variance↗
PubMed1998

Risk stratification in patients with dilated cardiomyopathy: contribution of Doppler-derived left ventricular filling.

Dilated cardiomyopathy (DCM) is a major cause of mortality among patients with heart failure. The aim of the present study was to investigate the independent contribution of Doppler-derived left ventricular (LV) filling to the prediction of survival in patients with DCM, of either ischemic or nonischemic origin, and to derive a simple risk stratification score based on easily available clinical and echocardiographic parameters. We followed 197 consecutive patients (159 men, mean age 60+/-13 years) with an echocardiographic diagnosis of DCM (LV end-diastolic dimension >60 mm, fractional shortening <25%) over an average period of 62+/-13 months. The presumed etiology of DCM was ischemic in 52% of the patients. During follow up, 69 patients died of cardiac causes and 41 required transplantation. At 5 years, overall cardiac event-free survival was 55% and freedom from death or heart transplantation was 43% (compared with 86% for the 5-year age- and sex-adjusted survival rate in our country). Kaplan-Meier survival curves generated for different thresholds of the peak E velocity and the E/A ratio indicated significant worsening of prognosis with increasing values of these parameters in both ischemic and nonischemic patients. Using Cox stepwise regression analyses, age (chi-square to remove 24.4; p <0.001), peak E velocity (chi-square to remove=18.9; p <0.001), LV ejection fraction (chi-square to remove 6.4; p <0.011), and systolic blood pressure (chi-square to remove 4.5; p=0.034) independently predicted cardiac deaths, whereas New York Heart Association (NYHA) functional class (chi-square to remove 48.5; p < 0.001), LV ejection fraction (chi-square to remove 19.1; p <0.001), E/A ratio (chi-square to remove 10.8; p <0.001), and systolic blood pressure (chi-square to remove 5.8; p <0.016) were independently associated with cardiac death or need for transplantation. Based on these parameters, a risk score was elaborated, which allowed appropriate classification of each individual patient into low- (5-year survival rate of 72%), intermediate- (46% survival rate), and high-risk groups (11% survival rate). In conclusion, our data show that among the noninvasive parameters commonly available in patients with either ischemic or nonischemic DCM, age, the NYHA functional class, the LV ejection fraction, the systolic blood pressure, the peak E velocity, and the E/A ratio provide relevant and independent information regarding the risk of cardiac death or the need for heart transplantation.

Cardiomyopathy, Dilated↗
PubMed1998

Risk stratification of patients with medically treated unstable angina using exercise echocardiography.

Functional testing is recommended for risk stratification of medically treated patients with unstable angina. Exercise echocardiography is used in this situation, but its safety and prognostic value are not well defined. The objective of this study was to assess the incremental prognostic value of exercise echocardiography in 226 consecutive patients (128 men, age 59+/-13 years) with medically treated unstable angina, who underwent exercise echocardiography from 1991 to 1996. Clinical risk was designated as low in 108 patients, intermediate in 116, and high in 2 patients according to the unstable angina practice guidelines. There were no major complications from the stress tests. The exercise electrocardiogram was nondiagnostic in 57 patients (25%). Ischemia was identified by exercise electrocardiography in 33 patients and exercise echocardiography in 55 patients. Patients were followed for 29+/-18 months. After exclusion of 38 patients who underwent early revascularization, 28 patients had cardiac death, nonfatal infarction, and late (>3 months) revascularization. Ischemia at exercise echocardiography was associated with a 24-month event-free survival of 81%, compared to 95% with negative exercise echocardiography (p=0.02). A positive exercise electrocardiogram was associated with a 24-month event-free survival of 84%, compared to 93% with negative exercise electrocardiograms (p=0.08). In a Cox regression model, event-free survival was predicted by ischemia at exercise echocardiography (relative risk 2.8, confidence interval: 1.3 to 6.3, p=0.05), but not at exercise electrocardiography (relative risk 2.1, confidence interval 0.7 to 5.8, p=0.16).

Aged↗
PubMed1999

Relative contributions of a single-admission 12-lead electrocardiogram and early 24-hour continuous electrocardiographic monitoring for early risk stratification in patients with unstable coronary artery disease.

Patients with unstable coronary syndromes are a heterogeneous group with varying degrees of ischemia and prognosis. The present study compares the prognostic value of a standard electrocardiogram (ECG) obtained at admission to the hospital with the information from 24-hour continuous electrocardiographic monitoring obtained immediately after admission. The admission ECGs and 24 hours of vectorcardiographic (VCG) monitoring from 308 patients admitted with unstable coronary artery disease were analyzed centrally regarding standard electrocardiographic ST-T changes, ST-vector magnitude (ST-VM), and ST change vector magnitude episodes. End points were death, acute myocardial infarction, and refractory angina pectoris within a 30-day follow-up period. ST-VM episodes (> or = 50 microV for > or = 1 minute) during VCG monitoring was the only independent predictor of death or acute myocardial infarction by multivariate analysis. ST-VM episodes during vectorcardiography was associated with a relative risk of 12.7 for having a cardiac event, hypertension was associated with a relative risk of 1.7, and ST depression on the admission ECG was associated with a relative risk of 5.7. Patients with ST depression at admission had an event rate (death or acute myocardial infarction) of 17% at 30-day follow-up. Patients without ST depression could further be risk stratified by 24 hours of VCG monitoring into a subgroup with ST-VM episodes at similar (8%) risk and a subgroup without ST-VM episodes at low (1%) risk (p = 0.00005). Continuous VCG monitoring provides important information for evaluating patients with unstable coronary artery disease. It is recommended that patients not initially estimated at high risk based on the admission ECG are referred for 24 hours of VCG monitoring for further risk stratification.

Aged↗
PubMed1999

Usefulness of hospital admission risk stratification for predicting nonfatal acute myocardial infarction or death six months later in unstable angina pectoris. RESCATE Study Group. Resources Used in Acute Coronary Syndromes and Delays in Treatment.

The aim of this study was to assess the clinical course of unstable angina and the prognostic value of clinical and electrocardiographic variables measured during admission in a prospective, multicenter cohort study with 6-month follow-up. The population corresponds to 4 general teaching hospitals in Catalonia, Spain. The clinical course was analyzed in 839 consecutive patients aged up to 80 years with primary unstable angina, without myocardial infarction or previous coronary bypass. The main outcome measures were cardiac mortality and nonfatal myocardial infarction. Patients involved in the present analysis belonged to the Resources Used in Acute Coronary Syndromes and Delays in Treatment (RESCATE) study. Six-month overall mortality, cardiac mortality, and nonfatal myocardial infarction rates were 4.6%, 4.1%, and 3.9%, respectively. Six-month cardiac mortality or myocardial infarction rate did not differ among clinical forms of presentation. Peripheral artery disease (RR 3.5, 95% confidence interval [CI] 1.88 to 6.50, p = 0.0001), ST-T-wave electrocardiographic changes on admission (RR 2.22, 95% CI 1.13 to 4.36, p = 0.0203), and age >65 years (RR 1.74, 95% CI 1.04 to 2.91, p = 0.0356) independently predicted 6-month cardiac mortality or nonfatal myocardial infarction. Their positive predictive values were 21%, 10%, and 11%, respectively, whereas their negative predictive value was > or = 93% in all cases. Prevalences were 9%, 70%, and 41%, respectively. In this prospective study, patients with unstable angina without prior myocardial infarction have a relatively low, although not negligible, 6-month severe complication rate. Stratification risk can easily be established with clinical and electrocardiographic characteristics measured during admission. Their absence almost rules out future adverse events, while their presence does not necessarily imply bad prognosis.

Adult↗
PubMed2001

Exercise echocardiography for the prognostic stratification of patients with low pretest probability of coronary artery disease.

PURPOSE: The aim of this study was to determine whether exercise echocardiography provides incremental data for risk stratification of patients with a low pretest probability of coronary artery disease. PATIENTS AND METHODS: The study included patients referred for exercise echocardiography whose probability of coronary artery disease was 25% or less. We calculated an exercise wall motion score index (on a 1-5 scale), an indicator of the extent and severity of exercise-induced abnormalities. The primary outcomes of the study were subsequent cardiac events (cardiac death and nonfatal myocardial infarction). RESULTS: We studied 571 men and 1047 women; their mean (+/- SD) age was 55 +/- 13 years. During a median follow-up of 3 years, there were 19 cardiac events (6 cardiac deaths and 13 nonfatal myocardial infarctions); an additional 37 patients underwent coronary revascularization. In a multivariate analysis of clinical, exercise electrocardiographic, and echocardiographic parameters, exercise wall motion score index (hazard ratio [HR] = 2.1 per 0.5 units; 95% confidence interval [CI]: 1.3 to 3.4), and age (HR = 2.0 per decade; 95% CI: 1.2-2.8) were independently associated with the risk of cardiac events. Although exercise echocardiographic variables contributed significantly (P = 0.01) to a model of the risk of adverse events, only 9 (47%) of the 19 patients with cardiac events were identified by an abnormal exercise echocardiogram. CONCLUSION: Among patients with low pretest probability of coronary artery disease by clinical criteria, exercise echocardiography identifies some, but not all, patients at risk of future events. Because of the low event rate, routine application of exercise echocardiography in a patient with a low pretest probability does not appear to be cost-effective and therefore cannot be recommended.

Adult↗
PubMed1996

Risk stratification in coronary artery disease and special populations.

In patients with coronary artery disease (CAD), left ventricular (LV) function, the number of diseased vessels, and the severity of myocardial ischemia are important determinants of survival. These factors can be used to identify subsets of high-risk patients who are candidates for aggressive intervention. Among patients with LV dysfunction, those with left main CAD, three-vessel disease, and one- or two-vessel disease with inducible ischemia are at highest risk. High-risk subsets among those with preserved LV function include patients with left main CAD and those with inducible ischemia and either three-vessel disease or two-vessel disease with involvement of the proximal left anterior descending coronary artery. Thus, exercise testing, assessment of ventricular function and, in selected patients, coronary angiography to determine coronary anatomy are valuable tools in risk stratification. In the primary-care setting, patient characteristics such as gender, race, age, and concomitant medical conditions may also be most useful in identifying high-risk patients. Although women in general have some primary protection against premature CAD, especially prior to the menopause, coronary risk in women who have experienced a cardiovascular event is similar to that in men. Coronary mortality is increased in minority populations, and the presence of other risk factors, such as diabetes and hyperlipidemia, can further increase this risk. Up to 80% of diabetic patients die of cardiovascular disease, 75% of which is CAD. The risk in this population is exacerbated by the abnormalities in lipid metabolism associated with the diabetic state. CAD mortality increases with aging, but it is recommended that elderly patients with CAD also receive risk factor intervention, such as cholesterol-lowering therapy. Consideration of the impact of such therapy on quality of life is especially important in initiating such interventions in the older population.

Black or African American↗