P35 Heparin-coated cardiopulmonary bypass circuit with low-dose heparin reduces postoperative bleeding early

Poster and thrombosis. Hence platelets may circulate in not completely but partially activated a status. A novel aggregometer (AG-10, Kowa, Japan) employing a laser light scattering works advantageously in detection of microaggregates which could not be observed in a conventional light transmission method. Using AG-10, accelerated spontaneous platelet aggregation (SPA) was observed under a stirring condition without any agonist in susceptible status, e.g., diabetes mellitus. We have focused and investigated the relation-ship between the intensity of SPA and various kinds of pathological condition. In this study, we evaluated the alteration of SPA, whole blood platelet aggregation (WBPA) with an impedance method (C-560, Chrono-Log, USA) and plasma concentration of glycocalicin (GC. a proteolytic fragment of platelet membrane glycoprotein Iba) as a marker of membrane injury to elucidate an influence of CPB. [Patients and Methods] Citrated blood samples were taken at predicted points of time perioperatively from successive 10 cases of coronary artery bypass grafting respectively. Platelet rich plasma (PRP) prepared by centrifugation (1,000 rpm, 10 min) was applied in SPA measurement with AG-10. WBPA was measured induced by collagen (lO~g/ml). GC was measured according to the method improved by our collaborator. [Results and Discussion] SPA increased gradually during (‘PB and stayed accelerated after operation. WBPA reduced after heparin neutralization. GC showed that there existed ;I certain degree of platelet membrane injury during (X’B. WC have reported, according to WBPA results, that circulating platelet is a ‘reserved’ portion for further hemostatis after consumption related with CPB. Our results in this study suggested such platelets were ‘irritable’ and easy LO hc fully activated. It is expected that further modification anti application of AG-IO may become valuable for analysis of the relationship of platelet function with various kind< of pathological condition. estimation of thrombogenehis and monitoring of anti-platelet therapy. [Conclusion] Using AG-10, it was indicated that platelets after CPB were easy to bc activated and to form resulting SPA. Further application of AG-10 should be expected to investigate platclot function.

P34 Surgical Assessment of Valvular Heart Disease Associated with Left Ventricular Dysfunction N. Cl7~11KI, T. SUGIMOTO, M. OKADA, Kobe, Japan In this paper. we reviewed operated cases with valvular heart disease (VHD) associated with left ventricular (LV) dysfunclion. [Patients] Thirty-one patients of VHD (32-71, average 50 years) with “C fractional shortening (%FS) of below 2.5 were subjected to this study. Aortic valve diseases were in 5 patients, mitral valve diseases in 18 and the combined valve diseases in 8. No patient had coronary artery disease. Patients were divided into 2 groups; group I: IX patients with postopcrativc improvement of %FS, group II: 13 patients without it. [Results] 1) The preoperative rest variates did not show significant difference between these groups. 2) In preopera-

CARDIOVASCULAR

SURGERY

SEPTEMBER

1997

Presentations

tive Dobutamine infusion test patients in group 1 showed greater than 9% increase, of %FS. whcrcas group II, showed lass than 9% increase. 3) In preoperative mqocardial scintigram, the decrease of the phonton uptakes initially appears in the posterior-inferior LV wall, and cxtendrd to the lateral-anterior wall with progression of LV dysfunction. Defect score, the visual hemiquantitative mcth~~tl with 301Tl. 99mTc-MIBI and 1231-BMIPP single-phonton cmissiall computed tomography, showed higher with progression 01 LV dysfunction. [Conclusion] Preoperative Dobutaminr: inlusion tchts in echocardiogram and myocardial scintigram m&ding defect score were very useful to predict the postopcrativt: improvement of LV function.

P35 Heparin-Coated Cardiopulmonary Bypass Circuit with Low-Dose Heparin Reduces Postoperative Bleeding Early T. SHIBATA, S. SUEHIRO, K. HA’fTOK1, M. FUJIOKA. H. KU.MANO, M. HC~SON(~, It KINOLSHIT4, (hka, JNIXIII Heparin-coated cardiopulomnary bypass (C’BF’) has a good biocompatibility. III this retorspectivc study. WC:investigated whether the heparin-coated CPB circuit with low--dose heparin can reduce the postoperative bleeding. Patients: 150 patients who underwent open heart surgery using 031 longer than 90 minutes were the subjects ot‘ this study. They were divided into two groups; nonheparin coated circuit with normal-dose heparin (NC‘ group, n .--.7.5) and heparincoated circuit with low-dose heparin (Ht’ group II = 77). Patients in NC group had more than 2.5 rngikg hcparin (2.9+ 0.3 mg/kg, mean & SD) bcforc Ihc initiation of CPB. and those in HCgroup had Icsh t ban I.5 mg/kg heparin (1.2 f 0.3 mgfkg). Additional heparin was given IO keep the activated clotting time more than 400 minutes in NC group and 300 minutes in HC group. Kesults: CPB time was 147 + 32 minutes m NC group anti 14) !. 35 minutes in HC group. Operation time was significantly shori in HC group (300 & 72 minutes vs 337 i 70 minrrles). Kc-opening of chest due to bleeding was done in ti~c patients of NC D“roup t 7”~ ) aiid in iioiic of iic’ gro11~9. Thtw iivc paticiits wcrc excluded from the: statistical ;inalysis tiul the ;unlo~~nt 01 hhs in 12 poatoprrative bleeding. The ;~~~wu~it o< iAml hours after operation was 322 :t 172 nil 10 NC’ group and 257 +- 150 ml in HC group (p c. 0.01) ‘I’hc ;rmclunt 4 blectling within 71 hours was 455 rt 110 ml ill NC’ group and 307 rfr 2.5 ml in HC group (n.s.). C‘onclusion: Heparin-coated CPB circuit with low-dose hcparin (Icss thau I..5 mg/kg) shortened operation lime after CJ’R anti rctluccd bleeding in the early postoperative pcrioci.

P36 Reoperation or PTCA after Myocardisl Revascularization T. MURAKKA Ml. 7: FUJIWARA, K. ~‘NDOH, s19