Head-to-head comparison of exercise stress testing, pharmacologic stress echocardiography, and perfusion tomography as first-line examination for chest pain in patients without history of coronary artery disease.

BACKGROUND: To overcome the relatively low accuracy of exercise stress testing (EST) in detecting coronary artery disease (CAD), both echocardiography and perfusion scintigraphy have been evaluated in conjunction with pharmacologic stress, but there is still uncertainty of the relative value of these tests as possible first-line examinations for suspected CAD. This study evaluated the accuracy of EST, dipyridamole and dobutamine stress echocardiography (DIP-ECHO, DOB-ECHO), and dipyridamole and dobutamine technetium 99m sestamibi tomography (DIP-MIBI, DOB-MIBI) for the detection of CAD in patients evaluated for the first time because of chest pain. METHODS AND RESULTS: Sixty patients underwent EST, DIP-ECHO, DOB-ECHO, DIP-MIBI, and DOB-MIBI. Echocardiographic images were acquired simultaneously with sestamibi injections, and the scintigraphic images were collected 1 hour later. Coronary angiography was performed within 15 days. Out of 33 patients with significant (>70%) coronary stenoses, 19 (58%) were correctly identified by EST, 18 (55%) by DIP-ECHO, 20 (61%) by DOB-ECHO, 32 (97%) by DIP-MIBI, and 30 (91%) by DOB-MIBI (p < 0.005 for MIBI vs EST and ECHO). The specificity of EST was 67% (p < 0.05 vs ECHO and MIBI), 96%, 96%, 89%, and 81%, respectively. Of the 62 stenotic coronary arteries, 20 (32%) were correctly identified by DIP-ECHO, 24 (39%) by DOB-ECHO, 48 (77%) by DIP-MIBI, and 45 (73%) by DOB-MIBI. The sensitivity of the imaging techniques in predicting the presence of multivessel disease was 14% and 29% for DIP and DOB-ECHO compared with 48% and 57% for DIP and DOB-MIBI. CONCLUSIONS: Our results confirm the limited reliability of EST in detecting CAD and the good diagnostic value of DIP and DOB-MIBI. Conversely, the lower sensitivity and the poorer capability to recognize multivessel CAD do not support the role of either DIP or DOB-ECHO as first-line examination for suspected CAD.

[Modifications of hemorheologic parameters in the course of hemodialysis in chronic renal insufficiency]. / Modifications de paramètres hémorhéologiques au cours de l'hémodialyse chez l'insuffisant rénal chronique.

The influence of haemodialysis (HD) was assessed in 72 patients, undergoing a thrice weekly routine HD for chronic renal failure (CRF). Some of them received human recombinant erythropoietin (Eprex). Measurements were performed before and after the HD session: the erythrocyte aggregation (EA) was carried out by a laser backscattering technique with determination of the aggregation time (AT) and of the dissociation thresholds. Plasma viscosity (PV) was evaluated in an automatic capillary viscometer. Fibrinogen (Fg) levels, haematological features (blood cell count), serum proteins, creatinine, and some other biochemical parameters, were also determined. Anaemia was a common feature. Our results compared to those of a control group, confirmed the erythrocyte hyperaggregation before HD which increased during HD. PV also elevated before HD, further increased after HD; the same finding was observed for Fg. Some of these results might be related to the haemoconcentration. Significant correlations were noted between AT and PV, AT and Fg with closer correlations after HD, suggesting a strong cohesion of RBC aggregates, which enhanced during HD. Correlations were highly significant between relative variations of AT and relative variations of PV, Fg, proteins and body weight, before and after HD. Special attention was given to the group of patients under long term treatment with Eprex compared to non-treated dialysed patients: no significant difference was found between both groups. Our results are in agreement with a blood and plasma viscosity syndrome due to increased EA and with a tendency, to thrombosis reported in those patients.