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Dive into the research topics where Labros A. Karagounis is active.

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Featured researches published by Labros A. Karagounis.


Journal of the American College of Cardiology | 1996

Increased incidence of Chlamydia species within the coronary arteries of patients with symptomatic atherosclerotic versus other forms of cardiovascular disease.

Joseph B. Muhlestein; Elizabeth H. Hammond; John F. Carlquist; Ellen Radicke; Matthew J. Thomson; Labros A. Karagounis; Marion L. Woods; Jeffrey L. Anderson

OBJECTIVES The objectives of this study were to test prospectively for an association between Chlamydia and atherosclerosis by comparing the incidence of the pathogen found within atherosclerotic plaques in patients undergoing directional coronary atherectomy with a variety of control specimens and comparing the clinical features between the groups. BACKGROUND Previous work has suggested an association between Chlamydia pneumoniae infection and coronary atherosclerosis, based on the demonstration of increased serologic titers and the detection of bacteria within atherosclerotic tissue, but this association has not yet been regarded as established. METHODS Coronary specimens from 90 symptomatic patients undergoing coronary atherectomy were tested for the presence of Chlamydia species using direct immunofluorescence. Control specimens from 24 subjects without atherosclerosis (12 normal coronary specimens and 12 coronary specimens from cardiac transplant recipients with subsequent transplant-induced coronary disease) were also examined. RESULTS Coronary atherectomy specimens were definitely positive in 66 (73%) and equivocally positive in 5 (6%), resulting in 79% of specimens showing evidence for the presence of Chlamydia species within the atherosclerotic tissue. In contrast, only 1 (4%) of 24 nonatherosclerotic coronary specimens showed any evidence of Chlamydia. The statistical significance of this difference is a p value < 0.001. Transmission electron microscopy was used to confirm the presence of appropriate organisms in three of five positive specimens. No clinical factors except the presence of a primary nonrestenotic lesion (odds ratio 3.0, p = 0.057) predicted the presence of Chlamydia. CONCLUSIONS This high incidence of Chlamydia only in coronary arteries diseased by atherosclerosis suggests an etiologic role for Chlamydia infection in the development of coronary atherosclerosis that should be further studied.


Journal of the American College of Cardiology | 1996

An emergency department-based protocol for rapidly ruling out myocardial ischemia reduces hospital time and expense: Results of a randomized study (ROMIO)

Miguel A. Gomez; Jeffrey L. Anderson; Labros A. Karagounis; Joseph B. Muhlestein; F. Bruce Mooders

OBJECTIVES We tested the hypothesis that an emergency department-based protocol for rapidly ruling out myocardial ischemia would reduce hospital time and expense but maintain diagnostic accuracy. BACKGROUND Patients with a missed diagnosis of myocardial infarction have a high mortality rate; however, providing routine hospital care to low risk patients may not be time- or cost-effective. METHODS One hundred low risk patients were entered into the study and randomized either to an emergency department-based rapid rule-out protocol (n = 50) or to routine hospital care (n = 50). Patients receiving routine care were managed by their attending physicians. The rapid protocol included serum enzyme testing at 0, 3, 6 and 9h, serial electrocardiograms with continuous ST segment monitoring and, if results were negative, a predischarge graded exercise test. Study patients were also compared with 160 historical control subjects. RESULTS Myocardial infarction or unstable angina occurred in 6% of patients within 30 days; no diagnoses were missed. By intention to treat analysis (n = 50 in each group), the hospital stay was shorter and charges were lower with the rapid protocol than with routine care (p = 0.001). Among patients in whom ischemia was ruled out, those assigned to the rapid protocol had a shorter hospital stay (median 11.9 vs. 22.8 h, p = 0.0001) and lower initial (


Circulation | 1993

TIMI perfusion grade 3 but not grade 2 results in improved outcome after thrombolysis for myocardial infarction. Ventriculographic, enzymatic, and electrocardiographic evidence from the TEAM-3 Study.

Jeffrey L. Anderson; Labros A. Karagounis; Lewis C. Becker; Sherman G. Sorensen; Ronald L. Menlove

893 vs


Circulation | 1994

Reduction in QT interval dispersion by successful thrombolytic therapy in acute myocardial infarction. TEAM-2 Study Investigators.

Fidela Moreno; T Villanueva; Labros A. Karagounis; Jeffrey L. Anderson

1,349, p = 0.0001) and 30-day (


Journal of the American College of Cardiology | 1992

Does thrombolysis in myocardial infarction (TIMI) perfusion grade 2 represent a mostly patent artery or a mostly occluded artery? Enzymatic and electrocardiographic evidence from the TEAM-2 study

Labros A. Karagounis; Sherman G. Sorensen; Ronald L. Menlove; Fidela Moreno; Jeffrey L. Anderson

898 vs.


American Heart Journal | 1995

Intravenous sotalol for the termination of supraventricular tachycardia and atrial fibrillation and flutter: A multicenter, randomized, double-blind, placebo-controlled study

Ruey J. Sung; Hanno L. Tan; Labros A. Karagounis; James J. Hanyok; Rodney H. Falk; Edward V. Platia; Gopal Das; Sterling Hardy

1,522, p = 0.0001) hospital charges than did patients given routine care. In historical control subjects, the hospital stay was longer (median 34.5 h, p = 0.001 vs. either group) and charges greater (median


American Journal of Cardiology | 1998

Prognostic significance of echocardiographically estimated right ventricular shortening in advanced heart failure

George Karatasakis; Labros A. Karagounis; Periklis A Kalyvas; Athanassios Manginas; George Athanassopoulos; Stefanos Aggelakas; Dennis V. Cokkinos

2,063, p = 0.001, vs rapid protocol, p = 0.02, vs. routine care group). CONCLUSIONS In low risk patients who present to the emergency department with chest pain, the rapid protocol ruled out myocardial infarction and unstable angina more quickly and cost-effectively than did routine hospital care.


Circulation | 1994

Apolipoprotein polymorphisms fail to define risk of coronary artery disease. Results of a prospective, angiographically controlled study.

Hiram W. Marshall; Linda Morrison; L L Wu; Jeffrey L. Anderson; P S Corneli; D M Stauffer; Ann Allen; Labros A. Karagounis; Ryk Ward

BackgroundCoronary patency has been used as a measure of thrombolysis success after acute myocardial infarction. The Thrombolysis in Myocardial Infarction (TIMI) Study Group perfusion grades have gained wide acceptance, with grades 0 (no distal flow) and 1 perfusion (minimal flow) being designated as thrombolysis failures and grades 2 (partial perfusion) and 3 (complete perfusion) as thrombolysis successes. However, the significance of the individual TIMI grades on clinical outcome has not been adequately assessed Methods and ResultsTo evaluate the functional significance of TIMI perfusion grades, we compared 1-day coronary patency status with ventriculographic, enzymatic, and ECG indexes of acute myocardial infarction in 298 patients treated with anistreplase or alteplase within 4 hours of myocardial infarction symptom onset. Radionuclide ejection fraction was determined at 1 week and at 1 month. Perfusion grades for the entire study population were distributed as 12% (n=37) grades 0/1, 13% (n=40) grade 2, and 74% (n=221) grade 3. Patency profile did not differ between the two thrombolytic regimens. Further coronary interventions were performed after the 1-day patency determination in 43% of patients (43%, 48%, 42%, respectively, in grades 0/1, 2, and 3 patients). The outcome of grade 2 patients did not differ from grades 0/1 patients in ejection fraction, enzyme peaks, ECG markers, or morbidity index. In contrast, grade 3 patients, compared with grades 0-2 patients, showed 1) a greater global ejection fraction at 1 week (54% versus 49%, p=0.006) and at 1 month (54% versus 49%, p=0.01), 2) a greater infarct zone ejection fraction at 1 week (41% versus 33%, p=0.003) and at 1 month (42% versus 32%, p=0.003), 3) smaller enzyme peaks, significant for lactate dehydrogenase, and shorter times to enzyme peaks, significant for all four enzymes, 4) a smaller QRS score at discharge and at 1 month, and 5) a trend toward a lower morbidity index. ConclusionGrade 3 flow predicts significantly better outcomes than lesser grades of flow and represents an important measure of reperfusion success.


American Journal of Cardiology | 1993

Effect of cigarette smoking on coronary patency after thrombolytic therapy for myocardial infarction

Miguel A. Gomez; Labros A. Karagounis; Ann Allen; Jeffrey L. Anderson

QT dispersion (QTd, equals maximal minus minimal QT interval) on a standard ECG has been shown to reflect regional variations in ventricular repolarization and is significantly greater in patients with than in those without arrhythmic events. Methods and ResultsTo assess the effect of thrombolytic therapy on QTd, we studied 244 patients (196 men; mean age, 57±10 years) with acute myocardial infarction (AMI) who were treated with streptokinase (n= 115) or anistreplase (n=129) at an average of 2.6 hours after symptom onset. Angiograms at 2.4±1 hours after thrombolytic therapy showed reperfusion (TIMI grade ≥ 2) in 75% of patients. QT was measured in 10±2 leads at 9±5 days after AMI by using a computerized analysis program interfaced with a digitizer. QTd, QRSd, JT (QT minus QRS), and JT dispersion (JTd, equals maximal minus minimal JT interval) were calculated with a computer. There were significant differences in QTd (96±31, 88±25, 60±22, and 52±19 milliseconds; P < .0001) and in JTd (97±32, 88±31, 63±23, and 58±21 milliseconds; P = .0001) but not in QRSd (25±10, 22±7, 28±9, and 24±9 milliseconds; P = .24) among perfusion grades 0, 1, 2, and 3, respectively. Similar results were obtained comparing TIMI grades 0/1 with 2/3 and 0/1/2 with 3. Patients with left anterior descending (versus right and left circumflex) coronary artery occlusion showed significantly greater QTd (70±29 versus 59±27 milliseconds, P = .003) and JTd (74±30 versus 63±27 milliseconds, P = .004). Similarly, patients with anterior (versus inferior/lateral) AMI showed significantly greater QTd (69±30 versus 59±27 milliseconds, P = .006) and JT d (73±30 versus 63±27 milliseconds, P = .007). Results did not change when Bazetts QTc, or JTc, was substituted for QT or JT or when ANOVA included adjustments for age, sex, drug assignment, infarct site, infarct vessel, and number of measurable leads. On ANCOVA, the relation of QTd or JTd and perfusion grade was not influenced by heart rate. ConclusionsSuccessful thrombolysis is associated with less QTd and JTd in post-AMI patients. The results are equally significant when either QT or JT is used for analysis. These data support the hypothesis that QTd after AMI depends on reperfusion status as well as infarct site and size. Reduction in QTd and its corresponding risk of ventricular arrhythmia may be mechanisms of benefit of thrombolytic therapy.


American Journal of Cardiology | 2000

Relation of Dispersion of QRS and QT in Patients With Advanced Congestive Heart Failure to Cardiac and Sudden Death Mortality

Maria Anastasiou-Nana; John N. Nanas; Labros A. Karagounis; Eleftheria P. Tsagalou; George Alexopoulos; Savas Toumanidis; Sophia Gerali; Stamatios F. Stamatelopoulos; Spyridon D. Moulopoulos

One measure of the success of thrombolysis is the early patency status of the infarct-related coronary artery. The Thrombolysis in Myocardial Infarction (TIMI) study group designated patency grades 0 (occluded) or 1 (minimal perfusion) as thrombolysis failure and grade 2 (partial perfusion) or 3 (complete perfusion) as success. To evaluate their true functional significance, perfusion grades were compared with enzymatic and electrocardiographic (ECG) indexes of myocardial infarction in 359 patients treated within 4 h with anistreplase (APSAC) or streptokinase. Serum enzymes and ECGs were assessed serially. Patency was determined at 90 to 240 min (median 2.1 h) and graded by an observer who had no knowledge of patient data. Results for the two drug arms were similar and combined. Distribution of patency was grade 0 = 20%, n = 72; grade 1 = 8% n = 27; grade 2 = 16%, n = 58 and grade 3 = 56%, n = 202. Interventions were performed after angiography but within 24 h in 51% (n = 37), 70% (n = 19), 41% (n = 24) and 14% (n = 28) of patients with grades 0, 1, 2 and 3, respectively. Outcomes were compared among the four patency groups by the orthogonal contrast method. Patients with perfusion grade 2 did not differ significantly from those with grade 0 or 1 in enzymatic peaks, time to peak activity and evolution of summed ST segments, Q waves and R waves (contrast 2). Conversely, comparisons of patients with grade 3 perfusion with those with grades 0 to 2 yielded significant differences for enzymatic peaks and time to peak activity for three of the four enzymes (p = 0.02 to 0.0001) and ECG indexes of myocardial infarction (p = 0.02 to 0.0001) (contrast 3). Thus, patients with grade 2 flow have indexes of myocardial infarction similar to those in patients with an occluded artery (grades 0 and 1 flow). Only early grade 3 flow results in a significantly better outcome than that of the other grades. Because early achievement of grade 2 flow does not appear to lead to optimal myocardial salvage, the frequency of achieving grade 3 perfusion alone may best measure the reperfusion success of thrombolytic therapy.

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Joseph B. Muhlestein

Intermountain Medical Center

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John N. Nanas

National and Kapodistrian University of Athens

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Maria Anastasiou-Nana

National and Kapodistrian University of Athens

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