Novel assay demonstrates that coronary artery disease patients have heightened procoagulant platelet response

Essentials Procoagulant platelets can be detected using GSAO in human whole blood. Stable coronary artery disease is associated with a heightened procoagulant platelet response. Agonist-induced procoagulant platelet response is not inhibited by aspirin alone. Collagen plus thrombin induced procoagulant platelet response is partially resistant to clopidogrel.

SUMMARY

Background Procoagulant platelets are a subset of highly activated platelets with a critical role in thrombin generation. Evaluation of their clinical utility in thrombotic disorders, such as coronary artery disease (CAD), has been thwarted by the lack of a sensitive and specific whole blood assay. Objectives We developed a novel assay, utilizing the cell death marker, GSAO [(4-(N-(S-glutathionylacetyl)amino)phenylarsonous acid], and the platelet activation marker, P-selectin, to identify procoagulant platelets in whole blood by flow cytometry. Patients/Methods Using this assay, we characterized the procoagulant platelet population in healthy controls and a cohort of patients undergoing elective coronary angiography. Results In patients with CAD, compared with patients without CAD, there was a heightened procoagulant platelet response to thrombin (25.2% vs. 12.2%), adenosine diphosphate (ADP) (7.8% vs. 2.7%) and thrombin plus collagen (27.2% vs. 18.3%). The heightened procoagulant platelet potential in CAD patients was not associated with other markers of platelet function, including aggregation, dense granule release and activation of α2b β3 integrin. Although dual antiplatelet therapy (DAPT) was associated with partial suppression of procoagulant platelets, this inhibitory effect on a patient level could not be predicted by aggregation response to ADP and was not fully suppressed by clopidogrel. Conclusions We report for the first time that procoagulant platelets can be efficiently detected in a few microliters of whole blood using the cell death marker, GSAO, and the platelet activation marker, P-selectin. A heightened procoagulant platelet response may provide insight into the thrombotic risk of CAD and help identify a novel target for antiplatelet therapies in CAD.

The value of transvaginal color Doppler in the assessment of pelvic inflammatory disease

This study compares transvaginal color and pulsed Doppler (TVCD), laparoscopic and clinical findings in 102 women with proven pelvic inflammatory disease (PID). Seventy-two (72) of them had acute symptoms, 11 presented with chronic pelvic pain and 19 patients were infertility cases suspected of tubal etiology. Uterine sonographic findings were demonstrated in 72 patients (70.6%). Free fluid in the cul-de-sac was demonstrated in 39 (38.2%) patients. Ovarian enlargement as the only finding was demonstrated in 6 (5.9%) patients, 22 (21.6%) presented with tubular adnexal structure, while in 74 (72.5%) patients it was of a complex nature. Color flow was obtained in all 6 patients presenting with ovarian enlargement, in 12 (54.5%) of those presenting with tubular adnexal structure, and in 56 (75.7%) of those with complex adnexal mass. Ovarian morphology was clearly delineated from adnexal mass in 59 patients (55.9%). The ipsilateral ovarian flow was altered in 50 of them (84.7%). The mean resistance index (RI) in patients with acute symptoms was 0.53 +/- 0.09 (+/-SD). It significantly differed from those obtained in patients with chronic pelvic pain (RI = 0.71 +/- 0.07) and infertility cases (RI = 0.73 +/- 0.09). We concluded that transvaginal color Doppler is useful additional tool in diagnosis and treatment monitoring in patients with PID.