Browsing by Author "Bitar, Abbas"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Caffeine Consumption and Heart Rate and Blood Pressure Response to Regadenoson
    (Public Library of Science, 2015) Bitar, Abbas; Mastouri, Ronald; Kreutz, Rolf P.; Department of Medicine, IU School of Medicine
    BACKGROUND: Current guidelines recommend that caffeinated products should be avoided for at least 12 hours prior to regadenoson administration. We intended to examine the effect of caffeine consumption and of timing of last dose on hemodynamic effects after regadenoson administration for cardiac stress testing. METHODS: 332 subjects undergoing regadenoson stress testing were enrolled. Baseline characteristics, habits of coffee/caffeine exposure, baseline vital signs and change in heart rate, blood pressure, percent of maximal predicted heart rate, and percent change in heart rate were prospectively collected. RESULTS: Non-coffee drinkers (group 1) (73 subjects) and subjects who last drank coffee >24 hours (group 3) (139 subjects) prior to regadenoson did not demonstrate any difference in systolic blood pressure, heart rate change, maximal predicted heart rate and percent change in heart rate. Systolic blood pressure change (15.2±17.1 vs. 7.2±10.2 mmHg, p = 0.001), heart rate change (32.2±14 vs. 27.3±9.6 bpm, p = 0.038) and maximal predicted heart rate (65.5±15.6 vs. 60.7±8.6%, p = 0.038) were significantly higher in non-coffee drinkers (group 1) compared to those who drank coffee 12-24 hours prior (group 2) (108 subjects). Subjects who drank coffee >24 hours prior (group 3) exhibited higher systolic blood pressure change (13±15.8 vs. 7±10.2, p = 0.007), and heart rate change (32.1±15.3 vs. 27.3±9.6, p = 0.017) as compared to those who drank coffee 12-24 hours prior to testing (group 2). CONCLUSIONS: Caffeine exposure 12-24 hours prior to regadenoson administration attenuates the vasoactive effects of regadenoson, as evidenced by a blunted rise in heart rate and systolic blood pressure. These results suggest that caffeine exposure within 24 hours may reduce the effects of regadenoson administered for vasodilatory cardiac stress testing.
  • Thumbnail Image
    Item
    Celiac disease in Middle Eastern and North African countries: A new burden?
    (Baishideng Publishing Group, 2010-03-28) Barada, Kassem; Bitar, Abbas; Mokadem, Mohamad Abdul-Razak; Hashash, Jana Ghazi; Green, Peter; Medicine, School of Medicine
    Celiac disease (CD) is now recognized as a common disorder among Middle Eastern (ME) and North African (NA) populations. The aim of this review is to assess the available data regarding CD in the ME and NA and to compare this information with that of Western countries. A literature review was performed using the electronic databases PubMed and Medline (1950-2008) as search engines, and “celiac disease” was used as a Mesh term. The search was limited to ME and NA countries. The prevalence of CD in ME and NA countries among low risk populations is similar to that of Western countries, but is higher in high risk populations such as those with type 1 diabetes. It is underestimated because of lack of clinical suspicion and lack of patient awareness. Clinical presentations in term of gastrointestinal, hematologic, skeletal, and liver manifestations are similar between both populations except for a high prevalence of short stature in some ME and NA countries. Few studies have addressed atypical or silent CD. As in the West, diagnosis is initially made by serological tests and is confirmed by small intestinal biopsies. Gluten-free diet is the main mode of treatment with a higher apparent adherence rate than in the West. Most disease complications result from malabsorption. The disease is strongly associated with HLA DQ2 and to a lesser extent with HLA DQ8 alleles. In conclusion, CD prevalence is underestimated, with little data available about its malignant complications. Disease parameters in the ME and NA are otherwise similar to those in Western countries.
  • Thumbnail Image
    Item
    Factor XIII Val34Leu polymorphism and recurrent myocardial infarction in patients with coronary artery disease
    (Springer, 2014-10) Kreutz, Rolf P.; Bitar, Abbas; Owens, Janelle; Desta, Zeruesenay; Breall, Jeffrey A.; von der Lohe, Elisabeth; Sinha, Anjan; Vatta, Matteo; Nystrom, Perry; Flockhart, David A.; Department of Medicine, IU School of Medicine
    Factor XIII (FXIII) is necessary for cross linking of fibrin strands and generation of stable fibrin clot. FXIII Val34Leu is a common genetic single nucleotide polymorphism that has been associated with accelerated fibrin stabilization and reduced rate of fibrinolysis. The contribution of Val34Leu to long term risk of recurrent myocardial infarction (MI) in patients with coronary stenting has not been conclusively established. The objective of the study was to examine the effects of Val34Leu on fibrin generation, platelet aggregation, and long term clinical outcomes in patients with coronary artery disease treated with dual antiplatelet therapy. Patients with angiographically documented coronary artery disease who were treated with aspirin and clopidogrel were enrolled (n = 211). Light transmittance aggregometry and plasma fibrin clot formation using thrombelastography (TEG) were determined. Genotyping of Val34Leu was performed using Taqman assay. Clinical events during follow up were recorded. Homozygous carriers of 34Leu variant had significantly shorter fibrin clot formation time as compared to wild type individuals (TEG K: 1.27 ± 0.3 vs. 1.68 ± 1.1 min, p = 0.011). The Val34Leu variant was associated with gene dose dependent increased risk of MI (log rank, p = 0.002) or occurrence of composite of MI and CV death (log rank, p = 0.005) with highest event rates observed in homozygous carriers of 34Leu. In summary, FXIII Val34Leu polymorphism was associated with increased rate of fibrin stabilization in homozygous carriers of the variant and may increase risk of recurrent MI and death in patients with angiographically established coronary artery disease treated with dual antiplatelet therapy.