Impact of anticoagulation on ionic and nonionic contrast media effect on thrombogenesis and fibrinolysis: The PEPCIT study.

OBJECTIVES: The effect of ionic low osmolar contrast media (ICM) and nonionic iso-osmolar CM (NICM) on acute thrombotic complications of percutaneous coronary intervention (PCI) is subject to controversies possibly related to a potential interaction with anticoagulation regimens. We sought to compare physical and morphological properties of fibrin clots made in the presence of ioxaglate (ICM), iodixanol (NICM) versus control and to evaluate the effect of four anticoagulants used in PCI. METHODS AND RESULTS: Maximum platelet aggregation (MPA%), maximum elastic modulus (EM, dyne/cm(2) ) fiber density (n/10(-5) /µm(2) ), and lysis front velocity (nm/sec) of fibrin rich clot (FRC) were measured simultaneously using peripheral blood from 12 patients undergoing elective PCI. We compared the effects of adding iodixanol or ioxaglate or saline (control) to blood with enoxaparin, unfractionated heparin, fondaparinux, and bivalirudin. Iodixanol and ioxaglate led to nonsignificant reduction in MPA compared to control (33.6% ± 16.9%, 28.2% ± 18.9%, and 40.7% ± 13.9%, respectively, P = ns). Fibrin formed with iodixanol was stiffer (42.7 ± 41.9, 18.7 ± 3.7, and 15.9 ± 9 dyne/cm(2) , P < 0.01) and displayed more fibrin fibers (1089 ± 175, 260 ± 108, and 456 ± 131 n/10(-5) /µm(2) , respectively, P < 0.01) than with ioxaglate or control. This resulted in a profound reduction in the lysis front velocity (191 ± 95, 261 ± 112, and 360 ± 153 nm/sec). None of the four anticoagulants displayed any significant interaction on the effect of contrast media. CONCLUSIONS: The prothrombogenic effect of iodixanol is related primarily to an increase in fibrin stiffness with subsequent delayed fibrinolysis, something not seen with ioxaglate. Anticoagulation does not appear to have any impact on this fibrin clot abnormalities.

Left atrial volume predicts abnormal exercise left ventricular filling pressure.

AIMS: Latent heart failure at rest can be observed in a number of patients upon exercise. Considering left atrial (LA) remodelling as the reflection of the cumulative effects of the LV filling pressure (FP) over time, our aim was to investigate whether the LA volume would predict abnormal exercise LVFP. METHODS AND RESULTS: Ninety patients (58.6 ± 10.8 years, 74 men) underwent exercise echocardiography. The LA maximal volume was measured by the Simpson method and indexed to body surface area. LVFP was assessed by the ratio between early peak diastolic velocities of mitral inflow and the septal annular mitral plane (E/e'). Exercise E/e' >13 was used as a threshold to define abnormal LVFP. Indexed LA volume was correlated with E/e' at rest (r = 0.37, P = 0.003), but the correlation was better with exercise E/e' (r = 0.54, P < 0.0001). In multivariate analysis, age, LV end-diastolic volume index, LVEF, and exercise E/e' were the independent determinants of LA volume index (R(2) = 0.47, P < 0.0001). Eleven patients had exercise E/e' >13; compared with the rest of the population, these patients were older and achieved a milder effort. LA volume index >33 mL/m(2) predicted an abnormal exercise LVFP with a 91% sensitivity and a 78% specificity. None of the patients with an LA volume index <26 mL/m(2) (n = 31, 34%) had an exercise E/e' >13. CONCLUSION: Exercise LVFP is a determinant of LA size. LA volume index seems to be helpful for predicting abnormal exercise LVFP. The potential use of LA remodelling to identify the patients benefitting most from exercise echocardiography should be investigated in larger studies.