Enhanced antitumor effect of L-buthionine sulfoximine or ionizing radiation by copper complexes with 2,2´-biquinoline and sulfonamides on A549 2D and 3D lung cancer cell models.

Two ternary copper(II) complexes with 2,2'-biquinoline (BQ) and with sulfonamides: sulfamethazine (SMT) or sulfaquinoxaline (SDQ) whose formulae are Cu(SMT)(BQ)Cl and Cu(SDQ)(BQ)Cl·CH3OH, in what follows SMTCu and SDQCu, respectively, induced oxidative stress by increasing ROS level from 1.0 µM and the reduction potential of the couple GSSG/GSH2. The co-treatment with L-buthionine sulfoximine (BSO), which inhibits the production of GSH, enhanced the effect of copper complexes on tumor cell viability and on oxidative damage. Both complexes generated DNA strand breaks given by-at least partially-the oxidation of pyrimidine bases, which caused the arrest of the cell cycle in the G2/M phase. These phenomena triggered processes of apoptosis proven by activation of caspase 3 and externalization of phosphatidylserine and loss of cell integrity from 1.0 µM. The combination with BSO induced a marked increase in the apoptotic population. On the other hand, an improved cell proliferation effect was observed when combining SDQCu with a radiation dose of 2 Gy from 1.0 µM or with 6 Gy from 1.5 µM. Finally, studies in multicellular spheroids demonstrated that even though copper(II) complexes did not inhibit cell invasion in collagen gels up to 48 h of treatment at the higher concentrations, multicellular resistance outperformed several drugs currently used in cancer treatment. Overall, our results reveal an antitumor effect of both complexes in monolayer and multicellular spheroids and an improvement with the addition of BSO. However, only SDQCu was the best adjuvant of ionizing radiation treatment.

High response rate and improved exercise capacity and quality of life with a new regimen of darbepoetin alfa with or without filgrastim in lower-risk myelodysplastic syndromes: a phase II study by the GFM.

Darbepoetin (DAR), with or without granulocyte colony-stimulating factor (G-CSF), has proved effective in treating anemia in patients with lower-risk myelodysplastic syndrome (MDS), but its effects on quality of life (QoL) and exercise functioning are less well established. In this phase II study (no. NCT00443339), lower-risk MDS patients with anemia and endogenous erythropoietin (EPO) level <500 IU/L received DAR 500 µg once every 2 weeks for 12 weeks, with G-CSF added at week 12 in non-responders. Physical performance was assessed with the 6-min walking test and, for fit patients, maximal oxygen consumption (VO2max). QoL was evaluated using SF-36 and FACT-An tests. In 99 patients, erythroid response rate according to IWG 2006 criteria was 48 and 56 % at 12 and 24 weeks, respectively. Addition of G-CSF rescued 22 % of non-responders. In 48 % of the responders, interval between darbepoetin injections could be increased for maintenance treatment. Serum EPO level was the only independent predictive factor of response at 12 weeks, and its most discriminant cutoff value was 100 IU/L. QoL and VO2max showed improvement over time in responders, compared with non-responders. With a median follow-up of 52 months, median response duration was not reached, and 3-year cumulative incidence of acute myeloid leukemia and overall survival (OS) was 14.5 and 70 %, respectively. Baseline transfusion dependence, International Prognostic Score System (IPSS), and Revised IPSS accurately predicted OS from treatment onset. Tolerance of darbepoetin was good. In conclusion, this regimen of darbepoetin every 2 weeks yielded high response rates and prolonged response duration. Objective improvement in exercise testing and in patient-reported QoL confirms the clinical relevance of anemia correction with erythropoiesis-stimulating agents.

Construction and validation of a dose-response curve using the comet assay to determine human radiosensitivity to ionizing radiation.

Individual radiosensitivity is an individual characteristic associated with an increased reaction to ionizing radiation. The purpose of our work is to establish a dose-response curve useful to classify individuals as radiosensitive or radioresistant. Thus, a dose-response curve was constructed by measuring in vitro responses to increasing doses (0 to 8 Gy) of gamma radiation in the comet assay. The obtained curve fit well with a linear equation in the range of 0 to 8 Gy. The overall dose-response curve was constructed for percent DNA in tail, as a measure of the genetic damage induced by irradiation. To probe the goodness of the constructed curve, a validation study was carried out with whole blood from two donors in a blind study. Results show that, for the two applied doses (2 and 6 Gy), the obtained values fit well inside the interval of confidence of the curve. In conclusion, our results demonstrate the usefulness of the comet assay in determining individual responses to defined doses of gamma radiation. The standard dose-response curve constructed may be used to detect individuals departing from reference values.

Detection of excision repaired DNA damage in the comet assay by using Ara-C and hydroxyurea in three different cell types.

Because of its characteristics, the comet assay has been used to evaluate the ability of virtually any type of eukaryotic cell to repair different kinds of DNA damage, including double and single strand breaks and base damage. The ability to detect excision repair sites using the alkaline version can be enhanced by the inclusion of repair inhibitors, DNA synthesis inhibitors, or chain terminators. In this sense, we evaluated the ability of hydroxyurea (HU) and cytosine arabinoside (Ara-C), for detecting lesions produced by the alkylating agents ethyl methanesulfonate (EMS) and methyl methanesulfonate (MMS) in three different cell systems. Two hundred cells for experimental point were analyzed in the alkaline version of the comet assay, and the results are evidences of the utility of the assay to detect alkylation of bases in the cells lines MRC-5 and TK-6, as the treatment with HU +Ara-C significantly increases both the basal and induced frequency of DNA damage. The use of whole blood, although it detected the effects of MMS, with and without repair inhibitors, failed to detect the effect of the selected dose of EMS and does not permit detection increases in the background level.

Genetic instability induced by low doses of x-rays in hamster cells.

PURPOSE: Genomic instability involves time delayed events and can be manifested as elevated rates of heritable changes in the progeny of irradiated cells. To study the induction of chromosomal instability by very low doses of radiation Chinese Hamster Ovary (CHO) cells were exposed to 10-50 milisieverts (mSv) (approximately 10-50 miligrays (mGy)) of x-rays. MATERIALS AND METHODS: Control and irradiated cell populations were assayed for chromosomal aberrations and assessed using a micronucleus test and anaphase-telophase analysis at the first cell division post-irradiation and at every four population doublings thereafter up to 16 population doublings post-irradiation. RESULTS: Frequencies of micronuclei, anaphase-telophase alterations and chromosomal aberrations were increased when the cells were analysed immediately after x-ray exposure. Micronuclei and anaphase-telophase alterations showed significantly increased frequencies when they were analysed at 12 and 16 population doublings after exposure to 50 mSv. Chromosomal aberrations increased significantly at 12 and 16 population doublings after exposure to 10 mSv and 50 mSv. CONCLUSIONS: Our results are consistent with the presence of a phenomenon by which the initial DNA damage in the surviving cells is memorized. Micronuclei and achromatic lessions were the main cytogenetic damage observed in cells exposed to very low doses of x-rays, indicating that these low doses are able to induce genetic instability.

Extramedullary relapse in acute promyelocytic leukemia treated with all-trans retinoic acid and chemotherapy.

We analyzed the incidence, presenting features, risk factors of extramedullary (EM) relapse occurring in acute promyelocytic leukemia (APL) treated with all-trans retinoic acid (ATRA) and chemotherapy by using a competing-risk method. In total, 740/ 806 (92%) patients included in three multicenter trials (APL91, APL93 trials and PETHEMA 96) achieved CR, of whom 169 (23%) relapsed, including 10 EM relapses. Nine relapses involved the central nervous system (CNS) and one the skin, of which two were isolated EM relapse. In patients with EM disease, median WBC count was 26950/mm3 (7700-162000). The 3-year cumulative incidence of EM disease at first relapse was 5.0%. Univariate analysis identified age <45 years (P=0.05), bcr3 PML-RARalpha isoform (P= 0.0003) and high WBC counts (> or = 10,000/ mm3) (P<0.0001) as risk factors for EM relapse. In multivariate analysis, only high WBC count remained significant (P= 0.001). Patients with EM relapse had a poorer outcome since median survival from EM relapse was 6.7 months as compared to 26.3 months for isolated BM relapse (P=0.04). In conclusion, EM relapse in APL occurs more frequently in patients with increased WBC counts (> or = 10,000/mm3) and carries a poor prognosis. Whether CNS prophylaxis should be systematically performed in patients with WBC > or = 10,000/mm3 at diagnosis remains to be established.

[Acquired alpha-thalassemia as early sign for myelodysplastic syndrome (refractory anaemia) with secondary haemochromatosis]. / Alpha-thalassémie acquise révélatrice d'un syndrome myélodysplasique de type anémie réfractaire avec hémochromatose secondaire.

We report the case of a 59 year old man presenting a regenerative microcytic hypochromic anaemia. The investigations revealed the presence of haemoglobin H, suggesting abnormalities in the alpha-globin chains synthesis. Alpha-thalassemia was thus suspected. The patient had no personal or familial history. The association with aniso-poïkilocytosis and a marked iron overload (ferritinemia > 1,500 microg/L) suggested a myelodysplastic syndrome, which was confirmed with a bone marrow aspiration. The pattern was consistent with the Acquired alpha-Thalassemia-Myelodysplastic Syndrome (ATMDS). About a hundred cases are listed worldwidely and collected in an international registry. The causes of ATMDS are ignored, but recent reports indicate that the ATRX gene may be implicated in the pathogenesis. ATRX is a chromatin-associated protein, involved in the transcription of several genes. The alpha globin genes could be one of the targets of the ATRX protein.

Autologous and allogeneic stem-cell transplantation as salvage treatment of acute promyelocytic leukemia initially treated with all-trans-retinoic acid: a retrospective analysis of the European acute promyelocytic leukemia group.

PURPOSE: To retrospectively determine the outcome of acute promyelocytic leukemia (APL) patients who underwent autologous or allogeneic stem-cell transplantation (SCT) during second complete remission. PATIENTS AND METHODS: Of 122 relapsing patients included in two successive multicenter APL trials who achieved hematological second complete remission (generally after a salvage regimen of all-trans-retinoic acid [ATRA] combined with chemotherapy), 73 (60%) received allogeneic (n = 23) or autologous (n = 50) SCT. RESULTS: Seven-year relapse-free survival (RFS), event-free survival (EFS), and overall survival (OS) in the autologous SCT group were 79.4%, 60.6%, and 59.8%, respectively, with a transplant-related mortality (TRM) of 6%. Of the 28 and two patients autografted with negative and positive, respectively, reverse transcriptase-polymerase chain reaction before auto SCT, three (11%) and one relapsed, respectively. In the allogeneic SCT group, 7-year RFS, EFS, and OS were 92.3%, 52.2%, and 51.8%, respectively, with 39% TRM. OS was significantly better in the autologous SCT group than in the allogeneic SCT group (P = .04), whereas RFS and EFS did not differ significantly (P = .19 and P = .11, respectively). In patients not receiving transplantation, 7-year RFS, EFS, and OS were 38%, 30.4%, and 39.5%, respectively. CONCLUSION: These retrospective data suggest that autologous SCT is very effective in APL relapsing after treatment with ATRA if performed in molecular remission. Allogeneic SCT yields few relapses, but it is associated with high TRM when performed after salvage with very intensive chemotherapy. Salvage with arsenic trioxyde, which has lower toxicity, should further improve the outcome of relapsing APL, especially before allogeneic SCT.

Prognostic implication of FLT3 and Ras gene mutations in patients with acute promyelocytic leukemia (APL): a retrospective study from the European APL Group.

Internal tandem duplications (ITDs) of the FLT3 gene have been observed in about 35% of APL cases. If FLT3-ITD is associated with a worse outcome in patients with acute myeloid leukemia (AML) in general, its prognostic value in acute promyelocytic leukemia (APL) is still a matter of debate. We investigated incidence, associated clinical features, and prognostic implication of FLT3-ITD, but also FLT3-D835 point mutation and N-Ras or K-Ras mutations in 119 APL patients, all prospectively enrolled in the two consecutive APL-93 and APL-2000 trials. Mutation incidences were 38, 20, and 4%, for FLT3-ITD, FLT3-D835, and Ras, respectively. The presence of FLT3-ITD was associated with high white blood cell count, high Sanz index, M3-variant subtype, and V/S PML-RAR alpha isoforms. Complete remission (CR), induction death, and death in CR rates were not affected by FLT3 or Ras mutations, as well as cumulative incidence of relapse. However, a trend for a shorter overall survival (P=0.09) was observed in FLT3-ITD patients, because of a very poor postrelapse survival (P=0.02). This feature, which has been also reported in patients with AML in general, is suggestive of an underlying genetic instability in FLT3-ITD patients, leading to the acquisition of additional unknown bad-prognosis gene mutations at relapse.

Outcome of acute promyelocytic leukemia treated with all trans retinoic acid and chemotherapy in elderly patients: the European group experience.

We analyzed the outcome of patients aged more than 60 included in a multicenter trial in newly diagnosed acute promyelocytic leukemia (APL93 trial), which tested the role of early addition of chemotherapy to all trans retinoic acid (ATRA) and of maintenance with ATRA and/or low-dose chemotherapy. In total, 129/533 (24.2%) patients included in this trial were older than 60. The CR rate was 86% in patients older than 60 as compared to 94.5% in younger patients (P=0.0014), due to a higher incidence of early deaths in elderly patients. The 4-year incidence of relapse was 15.6% in adults older than 60 and 23.2% in younger adults although most elderly patients received less intensive consolidation chemotherapy. However, 18.6% of the patients older than 60 years who achieved CR died in CR, mainly from sepsis during consolidation course or maintenance treatment, as compared to 5.7% of younger adults (P<0.001). Thus, overall 4-year survival of elderly patients was 57.8% as compared to 78% in younger adults (P<0.0001). APL in elderly patients appears as sensitive to ATRA-Chemotherapy based regimen as in younger adults. Less favorable outcome is mainly due to an increase of early deaths and to toxicity of consolidation treatment, strongly suggesting a beneficial role for less intensive consolidation chemotherapy and possibly introduction of arsenic derivates in the treatment of APL in the elderly.

Early reinfarction after fibrinolysis: experience from the global utilization of streptokinase and tissue plasminogen activator (alteplase) for occluded coronary arteries (GUSTO I) and global use of strategies to open occluded coronary arteries (GUSTO III) trials.

BACKGROUND: Trials report a 2% to 6% incidence of reinfarction after fibrinolysis for acute myocardial infarction (MI). We combined the Global Utilization of Streptokinase and Tissue plasminogen activator (alteplase) for Occluded coronary arteries (GUSTO I) and Global Use of Strategies To Open occluded coronary arteries (GUSTO III) populations to better define frequency, timing, and clinical predictors of in-hospital reinfarction. METHODS AND RESULTS: In 55 911 patients with ST-segment elevation myocardial infarction (MI) who were receiving fibrinolysis, we compared baseline characteristics and mortality rate by reinfarction incidence and developed multivariable logistic regression models to predict in-hospital reinfarction and composite of death or reinfarction. Reinfarction occurred in 2258 patients (4.3%) a median of 3.8 days after fibrinolysis; rates did not differ between GUSTO I (4.0%) and GUSTO III (4.2%) or by fibrinolytic assignment (streptokinase, 4.1%; alteplase, 4.3%; reteplase, 4.5%; combined streptokinase and alteplase, 4.4%; P=0.55). Advanced age, shorter time to fibrinolysis, non-US enrollment, nonsmoking status, prior MI or angina, female sex, anterior MI, and lower systolic blood pressure were associated significantly with reinfarction. Patients with reinfarction had higher mortality at 30 days (11.3% versus 3.5% without reinfarction; odds ratio, 3.5; P<0.001) and from 30 days to 1 year (4.7% versus 3.2%; hazard ratio, 1.5; P<0.001). Significant multivariate predictors of in-hospital death or reinfarction included age, Killip class, systolic and diastolic blood pressures, heart rate, anterior MI, smoking status, prior MI, sex, and country of enrollment (all P<0.001). CONCLUSIONS: Reinfarction occurs infrequently after fibrinolysis but confers increased risk of 30-day and 1-year mortality. Some predictors of reinfarction differ from known predictors of death after MI. Improved treatment and prevention strategies for reinfarction deserve study.

Management of patients with acute coronary syndromes in the United States by platelet glycoprotein IIb/IIIa inhibition. Insights from the platelet glycoprotein IIb/IIIa in unstable angina: receptor suppression using integrilin therapy (PURSUIT) trial.

BACKGROUND: A multinational, randomized, placebo-controlled trial (Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy, PURSUIT) demonstrated that the platelet glycoprotein IIb/IIIa receptor antagonist eptifibatide reduced the incidence of death or myocardial infarction among patients with acute ischemic syndromes without ST-segment elevation. Because of expected differences in practice patterns, a prospectively planned analysis of outcomes as a function of regions of the world was performed. The current study provides a detailed assessment of eptifibatide among the subgroup of patients enrolled within the United States. METHODS AND RESULTS: Patients presenting with chest pain within the previous 24 hours and ischemic ECG changes or creatine kinase-MB elevation were eligible for enrollment. Of the 10 948 patients randomized worldwide, 4035 were enrolled within the United States. Patients were allocated to placebo or eptifibatide infusion for up to 72 to 96 hours. Other medical therapies and revascularization strategies were at the discretion of the treating physician. Eptifibatide reduced the rate of the primary end point of death or myocardial infarction by 30 days from 15.4% to 11.9% (P=0.003) among patients in the United States. The treatment effect was achieved early and maintained over a period of 6 months (18.9% versus 15.2%; P=0.004). Bleeding events were more common in patients receiving eptifibatide but were predominantly associated with invasive procedures. The magnitude of clinical benefit from eptifibatide was greater among patients in the United States than elsewhere in the world. CONCLUSIONS: Platelet glycoprotein IIb/IIIa receptor blockade with eptifibatide reduces the incidence of death or myocardial infarction among patients treated for acute ischemic syndromes without ST-segment elevation within the United States.

Therapy-related acute promyelocytic leukemia.

PURPOSE: To analyze patient cases of therapy-related acute promyelocytic leukemia (tAPL), occurring after chemotherapy (CT), radiotherapy (RT) or both for a prior disorder, diagnosed during the last 20 years in three European countries. PATIENTS AND METHODS: The primary disorder and its treatment, interval from primary disorder to tAPL, characteristics of tAPL, and its outcome were analyzed in 106 patients. RESULTS: Eighty of the 106 cases of tAPL were diagnosed during the last 10 years, indicating an increasing incidence of tAPL. Primary disorders were predominantly breast carcinoma (60 patients), non-Hodgkin's lymphoma (15 patients), and other solid tumors (25 patients). Thirty patients had received CT alone, 27 patients had received RT alone, and 49 patients had received both. CT included at least one alkylating agent in 68 patients and at least one topoisomerase II inhibitor in 61 patients, including anthracyclines (30 patients), mitoxantrone (28 patients), and epipodophyllotoxins (19 patients). Median interval from primary disorder to tAPL diagnosis was 25 months (range, 4 to 276 months). Characteristics of tAPL were generally similar to those of de novo APL. With treatment using anthracycline-cytarabine-based CT or all-trans-retinoic acid combined with CT, actuarial survival was 59% at 8 years. CONCLUSION: tAPL is not exceptional, and develops usually less than 3 years after a primary neoplasm (especially breast carcinoma) treated in particular with topoisomerase II-targeted drugs (anthracyclines or mitoxantrone and less often etoposide). Characteristics and outcome of tAPL seem similar to those of de novo APL.

Intermittent coronary sinus occlusion in dogs: reduction of infarct size 10 days after reperfusion.

Intermittent balloon occlusion of the coronary sinus was applied to 11 open chest dogs subjected to 3 hours of ligation of the left anterior descending coronary artery followed by 8 to 12 days of reperfusion. Anticoagulants were not given during the reperfusion period. Risk region was assessed by planimetry of autoradiographs made from ventricular slices. Infarct size was equivalent when assessed by planimetry of ventricular slices before and after staining with triphenyltetrazolium chloride. In the seven survivors, 30 +/- 8% of the risk region was infarcted. Seven of 11 control dogs survived (p = NS); 75 +/- 4% of the risk region was infarcted in the control animals (p less than 0.01 versus treated survivors). Light microscopic inspection of specimens stained with hematoxylin-eosin confirmed the border between necrotic and preserved myocardium. Thrombus was observed in the coronary sinus in all survivors in the treatment group. These findings confirm earlier short-term studies that demonstrated a potent anti-ischemic effect of intermittent coronary sinus occlusion. At the same time, coronary sinus thrombosis warrants caution in the application of this technique to myocardial ischemia in humans.

Prediction of coronary events with electron beam computed tomography.

OBJECTIVES: We sought to determine the prognostic accuracy of electron beam computed tomographic (EBCT) scanning of the coronary arteries at three to four years. BACKGROUND: Coronary artery calcium scores determined by EBCT correlate with the severity of coronary artery disease. However, previous reports of the prognostic accuracy of EBCT scanning for coronary events in asymptomatic individuals are conflicting. METHODS: Asymptomatic men and women undergoing coronary EBCT completed initial and follow-up evaluations, which included past medical history, the Rose angina questionnaire and interim cardiovascular events. Reported coronary events (death, nonfatal myocardial infarction [MI] and revascularization procedures) were confirmed without knowledge of the scan results. RESULTS: Information was obtained in 1,172 (99.6%) of 1,177 eligible subjects (baseline age 53 +/- 11 years, 71% men). During an average follow-up of 3.6 years, 39 subjects sustained coronary events: three coronary deaths, 15 nonfatal MIs and 21 coronary artery revascularization procedures. The mean coronary artery calcium score was 764 +/- 935 among subjects with events as compared with 135 +/- 432 among those without events (p < 0.0001). For the prediction of all coronary events and of nonfatal MIs and deaths, the areas under the receiver-operator characteristics curve were 0.84 and 0.86, respectively, and a coronary calcium score > or =160 was associated with odds ratios of 15.8 and 22.2, respectively. The odds ratios for all events remained high (14.3 to 20.2) after adjustment for self-reported cardiovascular risk factors. CONCLUSIONS: In asymptomatic adults, EBCT of the coronary arteries predicts coronary death and nonfatal MI and the need for revascularization procedures.

Preservation of ventricular function by treatment of ventricular fibrillation with phenylephrine.

Epinephrine promotes resuscitation from ventricular fibrillation because of its peripheral vasoconstrictive effects. However, the beta-adrenergic effects of epinephrine may be detrimental because of the stimulation of myocardial oxygen demand. To test whether functional recovery from fibrillation in hearts treated with a selective alpha-adrenergic agent is greater than in hearts treated with epinephrine, ventricular fibrillation was induced in eight isolated dog hearts while coronary perfusion pressure was maintained at 30 mm Hg. In random order, epinephrine (5 micrograms/min), phenylephrine (50 micrograms/min) or no drug was infused for 5 min. The heart was then defibrillated, the drug infusion stopped and coronary perfusion pressure increased to 100 mm Hg. Coronary blood flow (ml/min per 100 g), arteriovenous oxygen difference (ml O2/dl) and myocardial oxygen consumption (ml O2/min per 100 g) measured after 4 min of ventricular fibrillation were greater with epinephrine (mean +/- SD 30.9 +/- 11.7, 17.5 +/- 1.6 and 5.4 +/- 1.9, respectively) than with phenylephrine (24.4 +/- 6.0, 15.7 +/- 2.6 and 3.8 +/- 1.1, respectively) or no drug (19.8 +/- 5.2, 12.8 +/- 1.8 and 2.6 +/- 0.7, respectively) (p less than 0.05, p less than 0.05 and p less than 0.05, respectively). The slope of the end-systolic pressure-volume relation 10 min after defibrillation and restoration of normal coronary perfusion pressure was depressed (percent of prefibrillation value) most by epinephrine infusion (72 +/- 17%, n = 6), less by no drug infusion (82 +/- 12%, n = 4) and was increased after phenylephrine infusion (143 +/- 17%, n = 6) (p less than 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)

Cost and procedure implications of thrombolytic therapy for acute myocardial infarction.

A computer model was developed to analyze the costs to Medicare and the potential procedure volume associated with alternative strategies for treatment of acute myocardial infarction. The expected cost per case to Medicare for initial hospitalization was approximately $7,200 for conventional treatment, $7,900 for treatment with intravenous streptokinase and $8,400 for treatment with recombinant tissue-type plasminogen activator (rt-PA). The expected cost per case for use of streptokinase or rt-PA in combination with cardiac catheterization performed either emergently or at 48 h was in excess of $11,000. These cost estimates do not reflect the cost of thrombolytic drugs themselves because Medicare has not adjusted its hospital payment rates to take account of such costs. Although both streptokinase and rt-PA will increase costs to Medicare for hospitalizations for acute myocardial infarction, both agents will do so at a reasonably low cost per additional life saved--between $50,000 and $60,000. Emergency and 48 h catheterization strategies are considerably less cost-effective. Regarding procedures, this model suggests that for every 1,000 patients treatment with streptokinase will result in an additional 76 coronary angioplasty procedures and 26 coronary artery bypass operations, whereas treatment with rt-PA will result in an additional 122 angioplasty procedures and 43 bypass operations compared with conventional treatment. Thrombolytic treatment is thus likely to increase substantially the volume of cardiac catheterization, coronary angioplasty and coronary artery bypass surgery performed in the United States.

Aortic diameter and pressure-flow sequence identify mechanism of blood flow during external chest compression in dogs.

Aortic flow and pressure relations and aortic diameter were examined during sinus rhythm, internal cardiac massage, vest cardiopulmonary resuscitation, conventional manual cardiopulmonary resuscitation and high impulse manual cardiopulmonary resuscitation in 14 anesthetized large dogs. During sinus rhythm and during internal cardiac massage, ascending aortic flow and pressure increased simultaneously and the rise in ascending aorta pressure preceded the rise in descending aortic pressure by (mean +/- SEM) 28 +/- 4 and 30 +/- 1 ms, respectively. In contrast, during vest, conventional and high impulse cardiopulmonary resuscitation, ascending aortic flow lagged behind the initial rise in aortic pressure by 40 +/- 4 to 46 +/- 4 ms and ascending and descending aortic pressure increased simultaneously (p less than 0.001 for each external compression mode versus sinus rhythm and internal massage). The ratio of pulse pressure to stroke volume increased by an order of magnitude during all modes of external chest compression (p less than 0.001 versus sinus rhythm and internal massage) and aortic diameter decreased during vest and high impulse cardiopulmonary resuscitation (p less than 0.05 versus sinus rhythm and internal massage). The hemodynamics of external chest compression depart from the normal physiologic sequence of stroke volume-induced increase in aortic pressure and diameter. The rise in aortic pressure precedes flow into the aorta, stroke volume does not fully account for pulse pressure, and aortic diameter decreases during chest compression. These data support the hypothesis that blood flow is due to fluctuations in intrathoracic pressure for high impulse as well as vest and conventional cardiopulmonary resuscitation.

Comparison of electron beam computed tomography scanning and conventional risk factor assessment for the prediction of angiographic coronary artery disease.

OBJECTIVE: To determine whether electron beam computed tomography (CT) adds to conventional risk factor assessment in the prediction of angiographic coronary artery disease. BACKGROUND: Electron beam CT scanning can be used to predict the severity of coronary atherosclerosis, but whether it does so independently of conventional risk factors is unclear. METHODS: Electron beam CT scans were performed and conventional risk factors were measured in 290 men and women undergoing coronary arteriography for clinical indications. The association of the electron beam CT-derived coronary artery calcium score and conventional risk factors with the presence and severity of angiographically defined coronary atherosclerosis was analyzed by logistic regression and receiver-operator characteristics analysis. RESULTS: Age, the ratio of total cholesterol to high-density lipoprotein (HDL) cholesterol and the coronary calcium score were significantly and independently associated with the presence of any coronary disease and obstructive coronary disease. In association with any coronary disease, odds ratios for age, the ratio of total cholesterol to HDL cholesterol and calcium score, highest quartile vs. lowest quartile, were 6.01 (95% confidence interval 2.87 to 12.56), 3.14 (1.56 to 6.31) and 94.08 (21.06 to 420.12), respectively. For obstructive coronary disease, highest quartile vs. lowest quartile, the respective odds ratios for age, the ratio of total cholesterol to HDL and calcium score were 3.86 (1.86 to 8.00), 4.11 (1.98 to 8.52) and 34.12 (12.67 to 91.86). Male gender was also significantly associated with any coronary disease (odds ratio 2.19, p=0.04) and obstructive coronary disease (odds ratio 2.07, p=0.04). Cigarette smoking was significantly associated with any coronary disease (odds ratio=2.74, p=0.004), and diabetes was significantly associated with obstructive disease (odds ratio 3.16, p=0.01). After adjustment for the coronary calcium score and other risk factors, it was determined that triglycerides, family history and hypertension were not significantly associated with any disease state. A coronary calcium score >80 (Agatston method) was associated with an increased likelihood of any coronary disease regardless of the number of risk factors, and a coronary calcium score > or = 170 was associated with an increased likelihood of obstructive coronary disease regardless of the number of risk factors (p < 0.001). CONCLUSIONS: Electron beam CT scanning offers improved discrimination over conventional risk factors in the identification of persons with any angiographic coronary disease or angiographic obstructive coronary disease.

Recurrent ischemia after thrombolysis: importance of associated clinical findings. GUSTO-I Investigators. Global Utilization of Streptokinase and t-PA [tissue-plasminogen activator] for Occluded Coronary Arteries.

OBJECTIVES: We sought to assess the incidence and clinical relevance of examination data to recurrent ischemia within an international randomized trial. BACKGROUND: Ischemic symptoms commonly recur after thrombolysis for acute myocardial infarction. METHODS: Patients (n = 40,848) were prospectively evaluated for recurrent angina and transient electrocardiographic (ECG) or hemodynamic changes. Five groups were developed: Group 1, patients with no signs or symptoms of recurrent ischemia; Group 2, patients with angina only; Group 3, patients with angina and ST segment changes; Group 4, patients with angina and hemodynamic abnormalities; and Group 5, patients with angina, ST segment changes and hemodynamic abnormalities. Baseline clinical and outcome variables were compared among the five groups. RESULTS: Group 1 comprised 32,717 patients, and Groups 2 to 5 comprised 20% of patients (4,488 in Group 2; 3,021 in Group 3; 337 in Group 4; and 285 in Group 5). Patients with recurrent ischemia were more often female, had more cardiovascular risk factors and less often received intravenous heparin. Significantly more extensive and more severe coronary disease, antianginal treatment, angioplasty and coronary bypass surgery were observed as a function of ischemic severity. The 30-day reinfarction rate was 1.6% in Group 1, 6.5% in Group 2, 21.7% in Group 3, 13.1% in Group 4 and 36.5% in Group 5 (p < 0.0001); in contrast, the 30-day mortality rate was significantly lower (p < 0.0001) in Groups 1, 2 and 3 (6.6%, 5.4% and 7.7%, respectively) than in Groups 4 and 5 (21.8% and 29.1%). CONCLUSIONS: Postinfarction angina greatly increases the risk of reinfarction, especially when accompanied by transient ECG changes. However, mortality is markedly increased only in the presence of concomitant hemodynamic abnormalities.