Detection of intraoperative myocardial dysfunction by accelerometer during aortic valve replacement.

OBJECTIVES: Myocardial dysfunction may occur during weaning from cardiopulmonary bypass (CPB). Epicardial accelerometers have been shown to be useful in continuous monitoring of myocardial ischaemia during beating-heart surgery. We aimed to investigate whether an accelerometer can detect myocardial dysfunction during weaning from CPB. METHODS: In 23 patients undergoing isolated aortic valve replacement (AVR), a three-axis accelerometer was attached to the left ventricle and 3D velocity was calculated from the signals. Peak early systolic velocity (Vsys) and velocity at aortic valve closure (Vavc) were measured. Measurements were undertaken during normothermia with 50% bypass flow and atrial pacing (90 beats/min) before aortic cross-clamping and after cross-clamp removal. Myocardial dysfunction was defined as Vsys < Vavc, and patients were classified as having normal function or dysfunction. Left ventricular (LV) stroke work via pulmonary artery catheter and systolic velocity by echocardiography were compared between groups and used as reference methods. RESULTS: The accelerometer identified a substantial proportion of patients with myocardial dysfunction during weaning from CPB, 56% of patients compared with 11% before aortic cross-clamping. Patients classified with normal myocardial function during weaning significantly improved their LV stroke work and systolic velocity by echocardiography in response to AVR, whereas those classified with dysfunction did not. Accelerometer classification of normal function predicted an increase in echocardiographic systolic velocity [r = 0.63, regression coefficient 1.98, 95% CI (0.57, 3.40) (P < 0.01)]. CONCLUSIONS: The accelerometer detected myocardial dysfunction during weaning from CPB in accordance with measures obtained by echocardiography and pulmonary artery catheter. Clinical Trials identifier: NCT01926067. https://clinicaltrials.gov/.

Heparinized cardiopulmonary bypass circuits and low systemic anticoagulation: an analysis of nearly 6000 patients undergoing coronary artery bypass grafting.

OBJECTIVE: Heparin coating of cardiopulmonary bypass circuits reduces the inflammatory response and increases the thromboresistance during extracorporeal circulation. These properties enables a lower systemic heparin dose, which has been shown to reduce the need for blood transfusions. Experience with this technique accumulated over 11 years has been analyzed. METHODS: All patients underwent on-pump coronary artery bypass grafting with heparin-coated circuits. Apart from some patients receiving a high intraoperative dose of aprotinin, the systemic heparin dose was reduced, with a lower level of an activated clotting time of 250 seconds during extracorporeal circulation. The overall strategy aimed at a fast-track regimen, with early extubation, minimal use of blood transfusions, and rapid postoperative recovery. RESULTS: Altogether, 5954 patients were included; 1131 (19.0%) were female (median age, 70 years), and 4823 were male (median age, 65 years). The median additive EuroSCORE was 3 (range, 0-14; mean 3.5 ± 2.5). No significant signs of clotting were seen in any part of the extracorporeal circuit. Bank blood products were given to 427 (7.2%) patients. Median extubation time was 1.7 hours. The stroke rate was 1.0%, transient neurologic deficits occurred in 0.7%, and perioperative myocardial infarction occurred in 1.2%. On the fifth day, 88.1% of the patients were physically rehabilitated and ready for discharge. Thirty-day mortality was 0.9% (54 patients). CONCLUSIONS: The experience with this patient cohort including mostly low- to medium-risk patients with a relatively short cardiopulmonary bypass time indicates that coronary artery bypass grafting performed with heparin-coated circuits and reduced level of systemic heparinization is safe and results in a very satisfactory clinical course. No signs of clotting or other technical incidents were recorded.

Cold blood versus cold crystalloid cardioplegia: a prospective randomised study of 345 aortic valve patients.

OBJECTIVE: Although experimental studies have indicated that blood cardioplegia may be superior to crystalloid cardioplegia for myocardial protection, clinical data still remain uncertain. In a previous randomised study from our institution, including 1440 patients undergoing coronary artery bypass grafting (CABG), no beneficial effects of blood cardioplegia were seen in any relevant outcome variables. The investigation was therefore extended to a patient population having longer pump times and ischaemic periods. METHODS: Over a 48-month period, all patients undergoing aortic valve replacement with or without CABG performed by two surgeons, were prospectively randomised to receive either intermittent cold retrograde blood cardioplegia (group B) or intermittent cold retrograde crystalloid cardioplegia (group C) during aortic cross-clamping. RESULTS: A total of 345 patients aged 28-90 years (median, 72 years) entered the study (group B, n=172, group C, n=173). All relevant demographic and operative variables were similar for both groups. As for the clinical course, no statistically significant differences were seen concerning spontaneous sinus rhythm after aortic declamping, use of inotropic drugs, duration of ventilatory support, bleeding and rate of allogeneic blood transfusions, perioperative myocardial infarction, episodes of atrial fibrillation, stroke or minor neurological dysfunction, renal function, infections, physical rehabilitation or mortality. Further, in the patients with the longest ischaemic times, no statistically significant differences between the groups could be demonstrated. CONCLUSIONS: There were no indications that retrograde cold blood cardioplegia was superior to retrograde cold crystalloid cardioplegia patients undergoing aortic valve replacement, with or without CABG.

Low postoperative dose of aprotinin reduces bleeding and is safe in patients receiving clopidogrel before coronary artery bypass surgery. A prospective randomized study.

Clopidogrel (Plavix) given before the operation increases bleeding complications following coronary artery bypass grafting (CABG). High perioperative doses of aprotinin (Trasylol) are known to reduce bleeding and transfusions after cardiac surgery, but may increase the risk of thrombosis, renal impairment, and mortality. The aim of the study was to evaluate the clinical effects of aprotinin given in high doses intra- and postoperatively vs. a low postoperative dose in patients on clopidogrel. Patients admitted for first-time CABG and receiving clopidogrel with or without aspirin, were prospectively randomized either to receive a total of 75,000 kallikrein inhibitor unit (KIU)/kg aprotinin given intra- and postoperatively or 25,000 KIU/kg aprotinin after the operation. Three hundred and ninety-nine patients aged 32-87 years (median 67 years) were included. Postoperative bleeding was slightly different, but moderate in both groups. The transfusion rate was similar, as were the incidences of postoperative neurological disturbances and myocardial infarction. Renal impairment and need for inotropic drugs were more frequent in the high dose group. Thirty-day mortality was similar (high dose 2%, low dose 0.5%, P=0.22). A low postoperative dose of aprotinin in patients receiving clopidogrel is safe and has comparable effects regarding postoperative bleeding complications as a high dose.

Cold blood cardioplegia versus cold crystalloid cardioplegia: a prospective randomized study of 1440 patients undergoing coronary artery bypass grafting.

OBJECTIVES: A large number of experimental studies have indicated that blood cardioplegia might be superior to crystalloid cardioplegia for myocardial protection during ischemic arrest. However, no prospectively randomized studies of large patient series have been undertaken to prove potential differences in clinical course. METHODS: Over a 52-month period, all patients undergoing on-pump coronary artery bypass operated on by 2 surgeons were prospectively randomized to receive either cold crystalloid cardioplegia (group C) or cold blood cardioplegia (group B) during aortic crossclamping. RESULTS: Altogether, 1440 patients aged 37 to 89 years (median, 66 years) entered the study (group C, n = 719; group B, n = 721). The groups were comparable in all major demographic, preoperative, and operative variables. The clinical course turned out to be nearly identical for both groups. No statistically significant differences were seen concerning spontaneous sinus rhythm after aortic declamping, use of inotropic drugs or intra-aortic balloon pumping, postoperative ventilatory support, bleeding and rate of allogeneic blood transfusions, perioperative myocardial infarction, episodes of atrial fibrillation, stroke or minor neurologic dysfunction, renal function, infections, physical rehabilitation, or mortality. Also, in subgroups of patients at higher operative risk (female sex, age >70 years, unstable angina, diabetes, emergency operation, ejection fraction <0.50, crossclamping time >50 minutes, and EuroSCORE >4), no statistically significant differences could be demonstrated between the groups. CONCLUSIONS: There were no significant differences whether myocardial protection was performed with cold blood cardioplegia or cold crystalloid cardioplegia during aortic crossclamping in patients undergoing coronary artery bypass grafting. The extra costs related to blood cardioplegia might be saved.

Heparin-coated circuits and reduced systemic anticoagulation applied to 2500 consecutive first-time coronary artery bypass grafting procedures.

BACKGROUND: In contrast to the widespread popularity of off-pump techniques for coronary artery bypass grafting, our institution has chosen a different strategy, emphasizing improvements in the technology for extracorporeal circulation, as well as simplifying surgical and clinical management. The clinical short-term results of this approach were analyzed. METHODS: The on-pump strategy includes routine use of heparin-coated circuits combined with low systemic heparinization (activated coagulation time of more than 250 seconds), intention of total revascularization within limited ischemic times and pump times, minimal use of blood transfusions, early extubation, and rapid postoperative recovery. The data from the first 2,500 consecutive first-time coronary artery bypass grafting patients (January 1998 to February 2002) treated with this protocol were retrospectively analyzed. RESULTS: There were 487 female (median age 68 years) and 2013 male (median age 64 years) patients. A median of four (one to nine) (mean 4.5 +/- 1.2) distal anastomoses were created, and the median aortic cross-clamp time and pump time were 34 and 54 minutes, respectively. At least one internal mammary artery was used in 99.7% of the patients. Blood or bank blood products were given to 118 patients (4.7%). Median extubation time was 1.5 hours. The stroke rate was 0.8%, transient neurologic deficits occurred in 0.6% of the patients, and the incidence of perioperative myocardial infarction was 1.1%. By the fifth day, 91% of the patients were ready for discharge. Seven patients (0.28%) died during their hospital stay. CONCLUSIONS: Coronary artery bypass grafting with heparin-coated cardiopulmonary bypass circuits and reduced systemic anticoagulation resulted in excellent clinical results, with minimal blood transfusions and rapid postoperative mobilization. The high number of grafted coronary arteries indicates complete revascularization in most patients, which is known to be a significant predictor of long-term event-free survival.

Universal fresh frozen plasma (Uniplas): a safe product in open-heart surgery.

OBJECTIVE: To test the tolerability and safety of the universal plasma Uniplas [solvent/detergent (SD)-treated plasma], infused regardless of the patient's blood group. DESIGN: Prospective, parallel group, controlled and observer-blinded study, randomized with respect to patients requiring plasma transfusion. SETTING: Cardiothoracic operating room and ICU in a university hospital. PATIENTS: Eighty-four patients undergoing open-heart surgery comparing three parallel treatment groups and one control group. INTERVENTIONS: The Uniplas treatment group was subdivided into patients with blood group A, B or AB, and group O. The treatment group receiving Octaplas of type AB, was not subdivided. Patients who did not require any plasma transfusion served as control. MEASUREMENTS: Complement activation (C3bc, TCC), direct antiglobulin test (DAT) and other immunohaematological tests, tests for haemolysis, and relevant clinical observations during treatment phase. Blood samples were collected again after 6 months for evaluation of viral safety. RESULTS: Of the 84 patients, 29 served as control group. Uniplas was transfused in 36 of the patients (1-23 units). Octaplas was transfused in 19 patients (1-11 units). During the study no clinical adverse events related to plasma transfusion were observed. The degree of complement activation C3bc and TCC, a recommended test for biocompatibility, did not show any increased activation after Uniplas or Octaplas transfusion. No haemolytic reactions, positive DAT-tests or viral transmissions were observed after Uniplas transfusion. CONCLUSION: In open-heart surgery, Uniplas, which can be transfused regardless of a patient's blood group, was well-tolerated and gave no adverse drug reactions.

Universal solvent/detergent-treated fresh frozen plasma (Uniplas--rationale and clinical properties.

Transfusions with incompatible blood products including plasma are a well-known problem. The present study was performed to test the effects of Uniplas, universal plasma that can be transfused regardless of a patient's blood group, with respect to bleeding and hemostatic activity. The study comprised 84 adult patients scheduled for elective openheart surgery. A total of 55 patients received plasma transfusions, while 29 patients not requiring plasma served as controls. If plasma transfusion was indicated during operation or over the two following days, patients were randomised 2:1 to receive Uniplas or Octaplas of blood group AB. Relevant clinical observations were recorded and blood tests taken repeatedly. The transfused patient groups were comparable, and no significant differences were observed with respect to activated clotting time (ACT), activated partial thromboplastin time (APTT) or postoperative bleeding into chest drains. The median number of transfused units of Uniplas was 3, with a range of 1-23, while the median for Octaplas was 2 with a range of 1-11. These differences were not significant.Thus, Uniplas has a similar effect as Octaplas in the treatment of bleeding in patients undergoing openheart surgery. Uniplas can therefore substitute for Octaplas and eliminate the risk of ABO-incompatible transfusions.