Asbjørn Karevold

Prophylactic treatment with desmopressin does not reduce postoperative bleeding after coronary surgery in patients treated with aspirin before surgery

The synthetic vasopressin analog desmopressin has hemostatic properties and may reduce postoperative bleeding after coronary artery bypass grafting (CABG). A study on the effects of recent aspirin ingestion on platelet function in cardiac surgery showed a greater impairment of platelet function in patients treated with aspirin <2 days before the operation. We evaluated the effects of desmopressin on postoperative bleeding in CABG patients who were treated with aspirin 75 or 160 mg until the day before surgery. The study was a prospective, randomized, double-blinded, placebo-controlled, parallel group trial. One-hundred patients were included and divided into two groups. One group received desmopressin 0.3 &mgr;g/kg and the other received placebo (0.9% NaCl) after the neutralization of heparin with protamine sulfate. Postoperative blood loss was recorded for 16 h. The mean (sd) bleeding was 606 (237) mL in the desmopressin group and 601 (301) mL in the placebo group (P = 0.93), representing no significant difference (95% confidence interval, −107 to 117 mL). We conclude that desmopressin does not reduce postoperative bleeding in CABG patients treated with aspirin until the day before surgery.

Guiding Surgical Cannulation of the Inferior Vena Cava with Transesophageal Echocardiography

We studied 150 adult cardiac surgery patients to assess visualization of the venous cannula and the venous system by intraoperative transesophageal echocardiography and to register the incidence of cannulation of hepatic veins. The quality of images, the dimensions of the venous system, the position of the venous cannula, and the adequacy of venous return were registered. Acceptable image quality of the inferior vena cava and the right hepatic vein (RHV) was obtained in 95% and 87% of cases, respectively. Considerable individual variations were found in the dimensions of the venous system. The cannula position could be determined in 99% of the cases. Ten percent of venous cannulae were primarily placed in the RHV. A short distance between the eustachian valve and the RHV possibly predisposes to cannulation of the RHV. No other patient-related factors were associated with cannula position. Placement of the cannula deep in the inferior vena cava was associated with reduced venous return and may be a more important cause of reduced return than a cannula positioned in a hepatic vein.

Effect of clopidogrel on midterm graft patency following off-pump coronary revascularization surgery.

OBJECTIVE The aim of the study was to evaluate the effect of clopidogrel on midterm graft patency following off-pump coronary revascularization surgery. DESIGN Ninety-four consecutive patients who underwent off-pump coronary artery bypass grafting between 1997 and 2002 were studied (58 men, 36 women; 61.7 +/- 9.8 years). The initial 36 patients (control group) received 75 to 160 mg acetyl salicylic acid (ASA) as an antiplatelet agent, whereas the consecutive 58 patients (clopidogrel group) received 75 mg clopidogrel postoperatively in addition to ASA. Intraoperatively, graft flow was assessed with transit-time flowmetry in all patients and the peripheral anastomoses were assessed with epicardial ultrasound in 28 patients. Sixty-two patients underwent angiography after a mean of 185 +/- 92 days. A total of 82 grafts were evaluated angiographically. Grafts with TIMI flow 2 and 3 were assessed as patent. RESULTS At angiographic follow-up, the overall graft patency rate was 84% (31/37) in the control group and 93% (42/45) in the clopidogrel group (P value was not significant [ns]). Graft patency rates for left internal mammary artery (LIMA) grafts were 92% (23/25) versus 96% (28/29) (ns), and for saphenous vein grafts were 66% (7/11) versus 87% (14/16) (ns), respectively. CONCLUSION The observed trend toward higher patency rates in patients treated with clopidogrel did not reach statistical significance. Further larger studies are necessary to confirm these preliminary results.

Bleeding following Coronary Surgery after Preoperative Low-Molecular-Weight Heparin:

Low-molecular-weight heparin and acetyl salicylic acid have become an established treatment for unstable angina. A retrospective study on our database of one year was carried out to see what impact preoperative low-molecular-weight heparin versus none had on the postoperative course of 473 patients having coronary surgery exclusively. Apart from the fact that the low-molecular-weight heparin patients had a higher New York Heart Association classification and marginally more grafts, longer bypass and cross-clamp time, the preoperative characteristics and surgery of the two groups were similar. The low-molecular-weight heparin group had twice as many (9.7% versus 4.7%) re-operations for bleeding, 46% versus 26% had blood transfusion and 22.3% versus 12.6% plasma transfusion. The postoperative outcome was otherwise similar. Preoperative treatment of unstable angina with low-molecular-weight heparin carries a definite risk of postoperative bleeding. Although this study did not reveal any serious consequences, bleeding, transfusions and re-operations are associated with infections, wound healing problems and death. The indications and length of treatment with low-molecular-weight heparin in unstable angina patients have to be appropriate and the perioperative management of these patients has to address the bleeding tendency.

Clinical and echocardiographic assessment of the Medtronic ADVANTAGE aortic valve prosthesis: the Scandinavian multicentre, prospective study

Objective: The aim of this report is the prospective, multicentre evaluation of clinical results and haemodynamic performance of the Medtronic Advantage aortic valve prosthesis. Methods: From April 2001 to June 2003, 166 patients (male:female 125:41; mean (SD) age 61.8 (11.8) years) received an aortic advantage valve prosthesis. Complete cumulative follow-up was 242.7 patient-years (maximum 3.2; mean 1.6 years). Postoperatively, patients underwent early (within 30 days) and 1 year transthoracic echocardiography. Results: 30 day mortality was 2.4% (n = 4). Kaplan–Meier estimates of freedom from complications and linearised rates were as follows: 96.9 (1.6)% survival; 94.7 (1.3)% (2.06 patients/year) thrombo-embolism; 99.4 (0.6)% (0.4 patients/year) bleeding; 98.8 (0.9)% (0.8 patients/year) non-structural valve dysfunction; 98.8 (0.9)% (0.8 patients/year) reoperation. Valvular mean pressure gradients ranged from 16 (3) mm Hg for size 19 to 7 (2) mm Hg for size 27 and the corresponding effective orifice areas ranged from 1.2 (0.25) to 3.2 (0.66) cm2. In all, left ventricular mass significantly decreased (p<0.001) and fractional shortening increased (p<0.001) from postoperative to 1 year echocardiography. Conclusions: Haemodynamic performance and early clinical results of Medtronic advantage in the aortic position were satisfactory and comparable with those of other bileaflet valves in current clinical use.

Human cardiomyocyte calcium handling and transverse tubules in mid-stage of post-myocardial-infarction heart failure

Cellular processes in the heart rely mainly on studies from experimental animal models or explanted hearts from patients with terminal end‐stage heart failure (HF). To address this limitation, we provide data on excitation contraction coupling, cardiomyocyte contraction and relaxation, and Ca2+ handling in post‐myocardial‐infarction (MI) patients at mid‐stage of HF.