Are you Kent G Meredith?

Claim your profile

Publications (4)24.1 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Aims: The role of anticoagulation during percutaneous coronary intervention has been well established. However, the role of anticoagulation during diagnostic coronary angiography remains unclear. Prothrombin fragment1+2 (PF1+2) and D-dimer (DD) have been reported to be useful in evaluating thrombotic phenomena. This study was designed to determine whether activation of coagulation occurs during diagnostic coronary angiography as measured by DD and PF1+2.Methods and results: Patients not on anticoagulation (except for aspirin) and with no documented coagulopathy undergoing elective diagnostic coronary angiography were enrolled in this prospective study. Blood samples for DD and PF1+2 were obtained serially after the femoral arterial sheath was placed. Peripheral venous blood was drawn along with an initial arterial blood sample from the sheath; thereafter, arterial blood samples from the sheath were obtained every 10 minutes for a maximum of 60 minutes or until the procedure was completed or when anticoagulation was initiated. A final venous sample was drawn at the end of the procedure. The data were analysed in time interval correlation to the DD and PF1+2 level.Forty-two patients were enrolled in this study, 15 were female (35%). There were 25 (59%) patients with diabetes. The mean fluoroscopic time was 8.8+/-7.81 minutes and the average time for the procedure was 29+/-22.70 minutes. There were 192 blood samples analysed. 67% of patient completed the procedure within 20 minutes and 91% within 30 minutes. Mean venous PF1+2 level was 0.20 nmol/L at baseline and 0.39 nmol/L (p=0.06) at the final interval, while the mean arterial PF1+2 level was significantly elevated. There was an increase of 0.2 nmol/L of arterial PF1+2 every 10 minutes (p<0.001). Mean venous DD at baseline and final levels were 0.41 ug/mL and 0.45 ug/mL respectively (p=0.68). There was a significant change in arterial DD with an increase of 0.02ug/ml every 10 minutes (p=0.023).Conclusions: In diagnostic coronary angiography, there is an early rise in PF1+2 levels in blood drawn through the arterial sheath suggesting that the procedure triggers local activation of coagulation that is not observed systemically. Prophylactic anticoagulation may not be necessary in stable patients without other known risk factors who will be undergoing elective diagnostic coronary angiography for less than 30 minutes. For procedures that are prolonged, or anticipated to be prolonged greater than 30 minutes, it may be advisable to administer anticoagulation to prevent thrombus formation. These findings may not be pertinent to patients with thrombophilia.
    EuroIntervention: journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society of Cardiology 11/2007; 3(3):345-9. · 3.17 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Coronary artery bypass surgery (CABG) and percutaneous coronary intervention with stenting (PCI-S) are both safe and effective approaches for revascularization in patients with multivessel coronary artery disease. However, conflicting information exists when comparing the efficacy of the two methods. In this study, we examined the outcomes of major adverse cardiovascular events and death for subgroups of typical "real-world" patients undergoing coronary revascularization in the modern era. Patients were included if they were revascularized by CABG or PCI-S, had > or = 5 years of follow-up, and had > or = 2-vessel disease. Patients were followed for an average of 7.0+/-3.2 years for incidence of death and major adverse cardiovascular events (death, myocardial infarction, or repeat revascularization). Multivariate regression models were used to correct for standard cardiac risk factors including age, sex, hyperlipidemia, diabetes mellitus, family history of coronary artery disease, smoking, hypertension, heart failure, and renal failure. Subgroup analyses were also performed, stratified by age, sex, diabetes, ejection fraction, and history of PCI-S, CABG, or myocardial infarction. A total of 6369 patients (CABG 4581; PCI-S 1788) were included. Age averaged 66+/-10.9 years, 76% were male, and 26% were diabetic. Multivariate risk favored CABG over PCI-S for both death (hazard ratio 0.85; P=0.001) and major adverse cardiovascular events (hazard ratio 0.51; P<0.0001). A similar advantage with CABG was also found in most substrata, including diabetes. In this large observational study of patients undergoing revascularization for multivessel coronary artery disease, a long-term benefit was found, in relationship to both death and major adverse cardiovascular events, for CABG over PCI-S regardless of diabetic status or other stratifications.
    Circulation 09/2007; 116(11 Suppl):I226-31. · 15.20 Impact Factor
  • Anwar Tandar, Kent G Meredith, Jeffrey L Anderson
    [Show abstract] [Hide abstract]
    ABSTRACT: Left ventricular (LV) diverticulum is a rare congenital abnormality for which the etiology, management, and natural history are very poorly understood. Although most often observed as a single diverticulum, we report a case of multiple LV diverticuli in an asymptomatic adult referred for coronary evaluation due to an abnormal electrocardiogram. LV diverticuli are often associated with other congenital malformations, but can also be found in isolation. Cardiac magnetic resonance imaging provides enhanced ability to determine size, location, and morphological characteristics, which may improve lesion assessment and management. A review of the condition and reported complications is discussed.
    Catheterization and Cardiovascular Interventions 03/2007; 69(3):453-8. · 2.51 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although previous studies have demonstrated that various "statins" decrease levels of high-sensitivity C-reactive protein (hs-CRP), the dose-response relation for lowering hs-CRP by the clinically important drug simvastatin compared with lipid lowering is unclear. A 16-week, randomized, double-blind study was performed in patients with stable coronary artery disease and high hs-CRP levels (>3 mg/L). Subjects were randomized to placebo, 20 mg of simvastatin, or 80 mg of simvastatin for 12 weeks. Those currently on a statin first underwent a 4-week washout. Of the 107 total patients randomized, 96 completed the trial, and 89 were able to be evaluated for efficacy. Changes in hs-CRP differed across simvastatin and placebo groups (change score +1.6 vs -0.6 mg/L, p = 0.004), but no dose response was observed when comparing 80 with 20 mg/day (-0.6 vs -0.5 mg/L, respectively). A strong dose response was observed for changes in total (p <0.01) and low-density lipoprotein (p <0.001) cholesterol. hs-CRP changes did not correlate with low-density lipoprotein changes. In conclusion, this randomized trial in patients with chronic stable coronary artery disease showed a strong dose response for simvastatin for total and low-density lipoprotein cholesterol lowering but not for hs-CRP.
    The American Journal of Cardiology 02/2007; 99(2):149-53. · 3.21 Impact Factor