Role of thrombin in coronary artery bypass grafting

Thrombin is a multifunctional protease, which has a central role in the development and progression of coronary atherosclerotic lesions and it is a possible mediator of myocardial ischemia-reperfusion injury. Its generation and procoagulant activity are greatly upregulated during cardiopulmonary bypass (CPB). On the other hand, activated protein C, a physiologic anticoagulant that is activated by thrombomodulin-bound thrombin, has been beneficial in various models of ischemia-reperfusion. Therefore, our aim in this study was to test whether thrombin generation or protein C activation during coronary artery bypass grafting (CABG) associate with postoperative myocardial damage or hemodynamic changes. To further investigate the regulation of thrombin during CABG, we tested whether preoperative thrombophilic factors associate with increased CPB-related generation of thrombin or its procoagulant activity. We also measured the anticoagulant effects of heparin during CPB with a novel coagulation test, prothrombinase-induced clotting time (PiCT), and compared the performance of this test with the present standard of laboratory-based anticoagulation monitoring. One hundred patients undergoing elective on-pump CABG were studied prospectively. A progressive increase in markers of thrombin generation (F1+2), fibrinolysis (D-dimer), and fibrin formation (soluble fibrin monomer complexes) was observed during CPB, which was further distinctly propagated by reperfusion after myocardial ischemia, and continued to peak after the neutralization of heparin with protamine. Thrombin generation during reperfusion after CABG associated with postoperative myocardial damage and increased pulmonary vascular resistance. Activated protein C levels increased only slightly during CPB before the release of the aortic clamp, but reperfusion and more significantly heparin neutralization caused a massive increase in activated protein C levels. Protein C activation was clearly delayed in relation to both thrombin generation and fibrin formation. Even though activated protein C associated dynamically with postoperative hemodynamic performance, it did not associate with postoperative myocardial damage. Preoperative thrombophilic variables did not associate with perioperative thrombin generation or its procoagulant activity. Therefore, our results do not favor routine thrombophilia screening before CABG. There was poor agreement between PiCT and other measurements of heparin effects in the setting of CPB. However, lower heparin levels during CPB associated with inferior thrombin control and high heparin levels during CPB associated with fewer perioperative transfusions of blood products. Overall, our results suggest that hypercoagulation after CABG, especially during reperfusion, might be clinically important.Trombiini on hyytymisjärjestelmän keskeinen entsyymi, jolla on tärkeä osuus sepelvaltimotaudin synnyssä ja etenemisessä. Lisäksi trombiini on mahdollinen välittäjäaine hapen puutteeseen ja sen jälkeiseen verenkierron palautumiseen liittyvässä sydänlihasvauriossa. Trombiinin tuotanto ja veren hyytymistä aiheuttava vaikutus lisääntyvät voimakkaasti kehon ulkoisen verenkierron aikana. Aktivoitu proteiini C puolestaan on elimistön luonnollinen hyytymistä estävä aine, eli antikoagulantti, joka aktivoituu trombiinin vaikutuksesta. Tutkimuksen tarkoituksena oli selvittää, liittyvätkö trombiinin tuotanto tai proteiini C:n aktivoituminen sepelvaltimo-ohitusleikkauksen jälkeiseen sydänlihasvaurioon tai verenkierron muutoksiin. Trombiinin säätelyn selvittämiseksi tutkimme lisäksi, lisääntyykö trombiinin tuotanto tai sen vaikutukset potilailla, joilla on veren hyytymistä lisääviä tekijöitä, sekä vertasimme uutta hyytymistutkimusta [prothrombinase-induced clotting time (PiCT)] vakiintuneisiin laboratoriomenetelmiin kliinisesti sydänleikkauksessa käytetyn antikoagulantin, hepariinin, vaikutusten mittaamisessa. Tutkimusaineistona oli sata elektiivistä potilasta, joille tehtiin sepelvaltimo-ohitusleikkaus sydämen pysäytystä ja kehon ulkoista verenkiertoa käyttäen. Trombiinin tuotannon, trombiinin hyytymistä aiheuttavan vaikutuksen ja fibrinolyysin merkkiaineiden (protombiinin fragmenttien F1+2, liukoisten fibriinimonomeerikompleksien ja D-dimeerin) pitoisuudet lisääntyivät voimakkaasti leikkauksen aikana erityisesti sydämen verenkierron palauttamisen jälkeen. Tämän ns. reperfuusiovaiheen trombiinin tuotanto liittyi leikkauksen jälkeiseen keuhkoverenkierron vastuksen kohoamiseen ja leikkauksen jälkeen todettuun sydänlihasvaurioon. Proteiini C aktivoitui viiveellä trombiinin tuotantoon nähden ja aktivoitu proteiini C liittyi leikkauksen jälkeiseen verenkierrolliseen toipumiseen eri tavoin leikkausta edeltävästi ja sen eri vaiheissa. Vaikka perinnöllinen veren hyytymisalttius lisää yleisesti veritulppariskiä, leikkausta edeltävissä tutkimuksissa todettuun hyytymisalttiuteen ei liittynyt lisääntynyttä leikkauksen aikaista hyytymisaktivaatiota. Siitä huolimatta, että erilaisten hepariinin vaikutusten mittaamisessa käytettyjen laboratoriomenetelmien tulosten vastaavuus oli huono, osoitettiin heparinisaation asteen liittyvän kääntäen verensiirtojen tarpeeseen ja hyytymisaktivaatioon. Kaikkiaan tutkimuksessa osoitettiin hyytymisaktivaatiolla olevan haitallisia vaikutuksia sydänleikkauksen yhteydessä

Hiippaläppävuodon leikkaushoito

Vertaisarvioitu.Primaarisen degeneratiivisen hiippaläppävuodon vuoksi tehdyn hiippaläppäplastian pitkäaikaistulokset ovat erikoistuneissa keskuksissa erinomaiset. Onnistunut potilaan oman läpän korjaava leikkaushoito poistaa vaikeasta hiippaläppävuodosta aiheutuvan ylimääräisen kuolemanriskin. Hoitosuositukset tukevatkin oireettoman hiippaläppävuodon leikkaushoitoa silloin, kun on todennäköistä, että hiippaläppäplastia voidaan tehdä niin, että pitkäaikaistulos on hyvä ja leikkausriski on pieni. Sekundaarisen hiippaläppävuodon ennuste on yleensä huono ja toimenpidehoidon pitkän aikavälin hyöty vielä epäselvä.Peer reviewe

TAVI vai avosydänleikkaus aorttastenoosipotilaalle?

Teema : aortt

Effects of lifelong ethanol consumption on brain monoamine transmitters in alcohol-preferring Alko Alcohol (AA) rats

Peer reviewe

Transition from BOS to RAS impairs prognosis after lung transplantation-CLAD subtype analysis by CT volumetry

Peer reviewe

Keuhkosiirteen kehonulkoinen perfuusio

Teema : elinsiirrot. English summar

Heparin Dose and Point-of-Care Measurements of Hemostasis in Cardiac Surgery-Results of a Randomized Controlled Trial

Objective: High heparin doses during cardiopulmonary bypass (CPB) have been suggested to reduce thrombin activation and consumption coagulopathy and consequently bleeding complications. The authors investigated the effect of a high heparin dose during CPB on point-of-care measurements of coagulation. The authors hypothesized that during CPB a high heparin dose compared with a lower heparin dose would reduce thrombin generation and platelet activation and tested whether this would be reflected in the results of rotational thromboelastometry (TEM) and platelet aggregation, measured with multiple electrode aggregometry (MEA). Design: Prospective, randomized, controlled, open single-center study. Setting: University teaching hospital. Participants: Sixty-three consecutive patients undergoing elective coronary artery bypass grafting with CPB were enrolled. Interventions: Patients were randomly assigned to receive either a high (600 IU/kg, n = 32) or a low (300 IU/kg, n = 31) initial dose of heparin. Target levels of activated clotting time during CPB were >600 seconds in the high heparin dose group and >400 seconds in the low heparin dose group. Measurements and Main Results: Blood samples were collected (1) preoperatively after induction of anesthesia, (2) 10 minutes after aortic declamping, (3) 30 minutes after protamine administration, and (4) 3 hours after protamine administration. TEM and MEA were then measured. There was no difference in blood loss up to 18 hours postoperatively (median 735 mL for high dose v 610 mL for low dose; p <0.056) or transfusions between the groups. Total median heparin dose (54,300 IU v 27,000 IU; p = 0.001) and median antifactor Xa levels during CPB (9.38 U/mL v 5.04 U/mL; p = 0.001) were greater in the high than in the low heparin dose group. However, neither TEM nor MEA results differed significantly between the groups. Conclusions: Compared with a lower dose of heparin during CPB, a high dose of heparin had little effect on the point-of-care measurements of hemostasis, TEM, and MEA. Based on the similarity of platelet and coagulation activity assessments, the higher heparin dose does not appear to offer benefit during CPB. (C) 2020 Elsevier Inc. All rights reserved.Peer reviewe

Early experience with robotic mitral valve repair with intra-aortic occlusion

Objective: To report the learning curve and early results of robotic mitral valve repairs in comparison with propensity score-matched sternotomy controls after the adoption of a robotic mitral valve surgery program in a university teaching hospital. Methods: A total of 142 patients underwent robotic mitral valve repair due to degenerative mitral regurgitation between May 2011 and December 2015. Control patients operated on via the conventional sternotomy approach were selected by the use of propensity score analysis resulting in 2 well-matched study groups. Results: Valve repair rate was 98.6% and 97.9% in the robotic and sternotomy groups, respectively. Operation length, cardiopulmonary bypass, aortic crossclamp, and ventilation times were shorter in the sternotomy group. All of these times were statistically significantly reduced within the robotic group during the learning curve. Even though there was no statistically significant difference in the rate of perioperative complications between the groups, 3 patients in the robotic group required postoperative extracorporeal membrane oxygenation due to low cardiac output, and 1 patient in the robotic group died. In the robotic and sternotomy groups, 86.3% versus 84.7% of patients had grade Conclusions: The present series reports the entire early learning curve related to the introduction of robotic mitral valve repair in our institution. In all, repair rate and early durability were acceptable, but more patients in the robotic group had serious complications. Early major robotic complications that occurred may have been related to the simultaneous use of intra-aortic occlusion.Peer reviewe

13-year single-center experience with the treatment of acute type B aortic dissection

Background. Acute type B aortic dissection (TBAD) is catastrophic event associated with significant mortality and lifelong morbidity. The optimal treatment strategy of TBAD is still controversial. Methods. This analysis includes patients treated for TBAD at the Helsinki University Hospital, Finland in 2007-2019. The endpoints were early and late mortality, and intervention of the aorta. Results. There were 205 consecutive TBAD patients, 59 complicated and 146 uncomplicated patients (mean age of 66 +/- 14, females 27.8%). In-hospital and 30-day mortality rates were higher in complicated patients compared with uncomplicated patients with a statistically significant difference (p = 0.035 and p = 0.015, respectively). After a mean follow-up of 4.9 +/- 3.8 years, 36 (25.0%) and 22 (37.9%) TBAD -related adverse events occurred in the uncomplicated and complicated groups, respectively (p = 0.066). Freedom from composite outcome was 83 +/- 3% and 69 +/- 6% at 1 year, 75 +/- 4% and 63 +/- 7% at 5 years, 70 +/- 5% and 59 +/- 7% at 10 years in the uncomplicated group and in the complicated group, respectively (p = 0.052). There were 25 (39.1%) TBAD-related deaths in the overall series and prior aortic aneurysm was the only risk factor for adverse aortic-related events in multivariate analysis (HR 3.46, 95% CI 1.72-6.96, p < 0.001). Conclusion. TBAD is associated with a significant risk of early and late adverse events. Such a risk tends to be lower among patients with uncomplicated dissection, still one fourth of them experience TBAD-related event. Recognition of risk factors in the uncomplicated group who may benefit from early aortic repair would be beneficial.Peer reviewe

Outcome of valve sparing root replacement for diverse indications

Objectives We report the mid-term outcomes of valve-sparing aortic root replacement (VSRR) in a cohort including patients with bicuspid aortic valve (BAV), connective tissue disorder (CTD), aortic dissection (AD), and congenital heart disease (CHD). Design. From 2005 to 2017, 174 patients underwent VSRR with the reimplantation technique. The mean age was 46 +/- 14 years. The mean follow-up time was 4.8 +/- 2.8 years. The indication for operation was aortic aneurysm for 127 (73%), aortic insufficiency (AI) for 38 (22%), and AD for 9 patients (5%). Preoperatively, 53 patients (31%) had >= moderate AI. BAV, CTD (Marfan or Loyes-Dietz), previous Ross procedure, or CHD was present in 57 (33%), 28 (16%), 7 (4%) and 12 patients (7%), respectively. Concomitant aortic valve repair was performed for 103 patients (59%). Results. Thirty-day mortality was zero. Four patients underwent aortic valve replacement (AVR) during follow-up. Kaplan-Meier estimates for survival, freedom from AVR, and freedom from >= moderate AI or reoperation were 96, 98, and 97% at 5 years. There was no difference in survival, freedom from AVR, or freedom from >= moderate AI or reoperation in patients with and without BAV, CTD, leaflet repair, or preoperative >= moderate AI. In Cox regression analysis, BAV, CTD, aortic valve repair, preoperative >= moderate AI, or aortic dimension were not risk factors for reoperation or valve dysfunction. Conclusions. Mid-term outcomes of VSRR for patients with diverse indications in terms of survival, reoperation rate, and valve dysfunction rate were excellent in a center with a limited annual volume of VSSR.Peer reviewe