Bas A.J.M. de Mol

Pharmacological strategies to decrease excessive blood loss in cardiac surgery: a meta-analysis of clinically relevant endpoints.

BACKGROUND Excessive bleeding may complicate cardiac surgery, and is associated with increased morbidity and mortality. Pharmacological strategies to decrease perioperative bleeding have been investigated in a large number of controlled trials, most of which have shown a decrease in blood loss. However, most studies lacked sufficient power to detect a beneficial effect on clinically more relevant outcomes. We did a meta-analysis of all randomised, controlled trials of the three most frequently used pharmacological strategies to decrease perioperative blood loss (aprotinin, lysine analogues [aminocaproic acid and tranexamic acid], and desmopressin). METHODS Studies were included if they reported at least one clinically relevant outcome (mortality, rethoracotomy, proportion of patients receiving a transfusion, or perioperative myocardial infarction) in addition to perioperative blood loss. In addition, a separate meta-analysis was done for studies concerning complicated cardiac surgery. FINDINGS We identified 72 trials (8409 patients) that met the inclusion criteria. Treatment with aprotinin decreased mortality almost two-fold (odds ratio 0.55 [95% CI 0.34-0.90]) compared with placebo. Treatment with aprotinin and with lysine analogues decreased the frequency of surgical re-exploration (0.37 [0.25-0.55], and 0.44 [0.22-0.90], respectively). These two treatments also significantly decreased the proportion of patients receiving any allogeneic blood transfusion. By contrast, the use of desmopressin resulted in a small decrease in perioperative blood loss, but was not associated with a beneficial effect on other clinical outcomes. Aprotinin and lysine analogues did not increase the risk of perioperative myocardial infarction; however, desmopressin was associated with a 2.4-fold increase in the risk of this complication. Studies in patients undergoing complicated cardiac surgery showed similar results. INTERPRETATION Pharmacological strategies that decrease perioperative blood loss in cardiac surgery, in particular aprotinin and lysine analogues, also decrease mortality, the need for rethoracotomy, and the proportion of patients receiving a blood transfusion.

Oral anticoagulation self-management and management by a specialist anticoagulation clinic: a randomised cross-over comparison

BACKGROUND Vitamin K antagonist treatment is effective for prevention and treatment of thromboembolic events but frequent laboratory control and dose-adjustment are essential. Small portable devices have enabled patient self-monitoring of anticoagulation and self-adjustment of the dose. We compared this self-management of oral anticoagulant therapy with conventional management by a specialist anticoagulation clinic in a randomised cross-over study. METHODS 50 patients on long-term oral anticoagulant treatment were included in a randomised controlled crossover study. Patients were self-managed or were managed by the anticoagulation clinic for a period of 3 months. After this period the alternative strategy was followed for each patient. Prothrombin time (expressed as international normalised ratio [INR]) were measured at intervals of 1-2 weeks in both periods without knowledge of type of management. The primary endpoint was the number of measurements within the therapeutic range (therapeutic target value +/-50.5 INR units). FINDINGS There was no significant difference in the overall quality of control of anticoagulation between the two study periods. Patients were for 55% and for 49% of the treatment period within a range of +/-0.5 from the therapeutic target INR during self-management and anticoagulation clinic management, respectively (p=0.06). The proportion of patients who spent most time in the therapeutic target range was larger during self-management than during anticoagulation clinic-guided management. The odds ratio for a better control of anticoagulation (defined as the period of time in the therapeutic target range) during self-management compared with anticoagulation clinic-guided management was 4.6 (95% CI 2.1-10.2). A patient-satisfaction assessment showed superiority of self-management over conventional care. INTERPRETATION Self-management of INR in the population in this study is feasible and appears to result in control of anticoagulation that is at least equivalent to management by a specialist anticoagulation clinic. It is also better appreciated by patients. Larger studies are required to assess the effect of this novel management strategy on the incidence of thromboembolic or bleeding complications.

Noninvasive continuous arterial blood pressure monitoring with Nexfin

Background: If invasive measurement of arterial blood pressure is not warranted, finger cuff technology can provide continuous and noninvasive monitoring. Finger and radial artery pressures differ; Nexfin® (BMEYE, Amsterdam, The Netherlands) measures finger arterial pressure and uses physiologic reconstruction methodologies to obtain values comparable to invasive pressures. Methods: Intra-arterial pressure (IAP) and noninvasive Nexfin arterial pressure (NAP) were measured in cardiothoracic surgery patients, because invasive pressures are available. NAP-IAP differences were analyzed during 30 min. Tracking was quantified by within-subject precision (SD of individual NAP-IAP differences) and correlation coefficients. The ranges of pressure change were quantified by within-subject variability (SD of individual averages of NAP and IAP). Accuracy and precision were expressed as group average ± SD of the differences and considered acceptable when smaller than 5 ± 8 mmHg, the Association for the Advancement of Medical Instrumentation criteria. Results: NAP and IAP were obtained in 50 (34–83 yr, 40 men) patients. For systolic, diastolic, mean arterial, and pulse pressure, median (25–75 percentiles) correlation coefficients were 0.96 (0.91–0.98), 0.93 (0.87–0.96), 0.96 (0.90–0.97), and 0.94 (0.85–0.98), respectively. Within-subject precisions were 4 ± 2, 3 ± 1, 3 ± 2, and 3 ± 2 mmHg, and within-subject variations 13 ± 6, 6 ± 3, 9 ± 4, and 7 ± 4 mmHg, indicating precision over a wide range of pressures. Group average ± SD of the NAP-IAP differences were −1 ± 7, 3 ± 6, 2 ± 6, and −3 ± 4 mmHg, meeting criteria. Differences were not related to mean arterial pressure or heart rate. Conclusion: Arterial blood pressure can be measured noninvasively and continuously using physiologic pressure reconstruction. Changes in pressure can be followed and values are comparable to invasive monitoring.

Factors associated with cardiac conduction disorders and permanent pacemaker implantation after percutaneous aortic valve implantation with the CoreValve prosthesis

BACKGROUND Cardiac conduction disorders and requirement for permanent pacemaker implantation (PPI) are not uncommon after surgical aortic valve replacement and have important clinical implications. We aimed to investigate the incidence of cardiac conduction disorders after percutaneous aortic valve implantation (PAVI) and to identify possible clinical factors associated with their development. METHODS We studied 34 patients (mean age 80 +/- 8 years, 18 male) who underwent PAVI with the CoreValve bioprosthesis (Corevalve Inc, Irvine, CA). Electrocardiographic evaluation was performed pre- and postprocedurally, and at 1-week and 1-month follow-up. Other clinical variables were obtained from the medical history, echocardiography, and angiography. RESULTS After PAVI, 7 patients required PPI, all of whom developed total atrioventricular block within 3 days postprocedurally. A smaller left ventricular outflow tract diameter (20.3 +/- 0.5 vs 21.6 +/- 1.8 cm, P = .01), more left-sided heart axis (-20 degrees +/- 29 degrees vs 19 degrees +/- 36 degrees , P = .02), more mitral annular calcification (10 +/- 1 vs 5 +/- 4 mm, P = .008), and a smaller postimplantation indexed effective orifice area (0.86 +/- 0.20 vs 1.10 +/- 0.26 cm(2)/m(2), P = .04) were associated with PPI. The incidence of new left bundle-branch block (LBBB) was 65% and was associated with a deeper implantation of the prosthesis: 10.2 +/- 2.3 mm in the new-LBBB group versus 7.7 +/- 3.1 mm in the non-LBBB group (P = .02). CONCLUSIONS Percutaneous aortic valve implantation with the CoreValve prosthesis results in a high incidence of total atrioventricular block requiring PPI and new-onset LBBB. Preexisting disturbance of cardiac conduction, a narrow left ventricular outflow tract, and the severity of mitral annular calcification predict the need for permanent pacing, whereas the only factor shown to be predictive for new-onset LBBB is the depth of prosthesis implantation.

Collapse of a stent-graft following treatment of a traumatic thoracic aortic rupture.

Purpose: To report a collapsed stent-graft used to treat a traumatic aortic rupture. Case Report: A Gore TAG stent-graft was placed in a 20-year-old man with multiple injuries. Postimplantation computed tomographic angiography (CTA) demonstrated no contrast extravasation and total exclusion of the traumatic rupture. Routine CTA 3 months after implantation revealed a collapsed stent-graft located in the outer curve of the distal aortic arch. A Talent stent-graft was placed successfully within the collapsed prosthesis. Postimplantation CTA demonstrated no contrast extravasation and good apposition of the endograft to the aortic wall. At 6 months, the repair remains secure; there is no sign of graft collapse or endoleak. Conclusions: Collapse of stent-grafts can occur after treatment for traumatic aortic ruptures; endovascular methods can be used to restore a satisfactory luminal contour.

Left ventricular unloading in acute ST-segment elevation myocardial infarction patients is safe and feasible and provides acute and sustained left ventricular recovery

To the Editor: Unloading the left ventricle (LV) after ST-segment elevation myocardial infarction (STEMI) in addition to reperfusion therapy may reduce infarct size and may give the myocardium time to recuperate from ischemic stunning ([1][1]). This may be particularly true in STEMI patients with

Blood transfusions recruit the microcirculation during cardiac surgery.

BACKGROUND: Perioperative red blood cell transfusions are commonly used in patients undergoing cardiac surgery to correct anemia caused by blood loss and hemodilution associated with cardiopulmonary bypass circulation. The aim of this investigation was to test the hypothesis that blood transfusion has beneficial effects on sublingual microcirculatory density, perfusion, and oxygenation. To this end, sidestream dark field (SDF) imaging and spectrophotometry were applied sublingually before and after blood transfusion during cardiac surgery.

Reduced renal failure following thoracoabdominal aortic aneurysm repair by selective perfusion

OBJECTIVES Renal failure and visceral ischemia are feared complications following thoracoabdominal aortic aneurysm (TAAA) repair, significantly contributing to mortality. This prospective study describes volume- and pressure-controlled perfusion of the renal and visceral arteries during TAAA surgery. METHODS In 73 consecutive patients (mean age 59 years), TAAA repair (27 type I, 28 type II, 8 type III and 10 type IV) was performed, using retrograde and selective organ perfusion. Sixteen patients had impaired renal function with blood creatinine higher than 100 mmol/l. During the thoracic part of the procedure, the mean distal aortic pressure was kept above 60 mm Hg by means of left-heart bypass. After opening the abdominal aorta, the renal and visceral arteries were individually perfused by means of perfusion catheters (9 French) in the first 33 patients (group I). Volume flow through each catheter was assessed with ultrasound flow meters and maintained at least at 60 ml/min. In addition to volume flow measurements, catheters with pressure sensors were used in the last 40 patients (group II), allowing pressure-controlled selective perfusion. The extent of the aneurysm was comparable in both groups. RESULTS Mean cross-clamp time for the thoracic part was 46 min, including proximal anastomosis and reattachment of intercostal arteries. Mean cross-clamp time for the abdominal part was 74 min, including re-implantation of intestinal and renal arteries and selective dacron grafts to the celiac-axis arteries (n = 5), superior mesenteric arteries (n = 8) and renal arteries (n = 25), through which the catheters guaranteed continuous perfusion during the time the anastomosis was performed. Urine output was uninterrupted in all patients, irrespective of cross-clamp time. In group I, one patient (3%) developed renal failure and three patients (9%) required temporary peritoneal dialysis. In group II, no patients developed renal failure and two patients (5%) required temporary peritoneal dialysis. Thirteen patients with pre-existing renal impairment did not deteriorate. No patients developed visceral ischemia or multiple-organ failure. Total in-hospital mortality was 6/73 (8%) and was related to cardiopulmonary complications. CONCLUSIONS Renal and visceral ischemia can be reduced significantly by continuous perfusion during cross-clamping in TAAA repair. Not only sufficient volume flow but also adequate arterial pressure appears to be essential in maintaining renal function.

Comparable Systemic Ventricular Function in Healthy Adults and Patients With Unoperated Congenitally Corrected Transposition Using MRI Dobutamine Stress Testing

BACKGROUND Failure of the systemic right ventricle (RV) often complicates adult survival in unoperated or physiologically repaired congenitally corrected transposition of the great arteries (CCTGA). Healthy controls schematically represent an optimal outcome of anatomic repair, which is increasingly performed to treat CCTGA. Magnetic resonance imaging dobutamine stress testing measures cardiac reserve, and sets to compare the left ventricle of controls with the systemic RV of unoperated and physiologically repaired patients with CCTGA. METHODS Baseline and stress magnetic resonance imaging (maximum dobutamine dose, 15 microg/kg/min) assessed systemic RV function in 13 minimally or asymptomatic adult patients with CCTGA (unoperated, n = 7; physiologically repaired, n = 6). The left ventricles of 11 healthy age-matched adults served as controls. RESULTS Baseline and stress end-diastolic volumes similar between the systemic RV of unoperated patients and the left ventricle of controls, as well as base end-systolic volumes. Stress ejection fraction was lower in unoperated and physiologically repaired patients (70 +/- 6% and 60 +/- 5%, respectively, vs healthy controls (84 +/- 8%). However, comparable with healthy controls, both subsets of CCTGA patients responded appropriately to dobutamine stress, as illustrated by similar RV stroke volume, heart rate, mean blood pressure, and cardiac index. CONCLUSIONS Compared with the left ventricles of healthy controls, both patient groups had larger systemic RV volumes, diminished ejection fraction, but an appropriate response to dobutamine stress. Values of unoperated patients are closer to normal than physiologically repaired patients. Magnetic resonance imaging dobutamine may help to define the subgroups of CCTGA patients with favorable anatomy, whereby asymptomatic adult survival could be anticipated without the need for an operation.

Effects of mechanical left ventricular unloading by Impella on left ventricular dynamics in high-risk and primary percutaneous coronary intervention patients

Objectives: We studied online left ventricular (LV) dynamic effects of mechanical LV unloading directly after percutaneous coronary intervention (PCI). Background: Limited clinical information is available on the direct LV dynamic consequences of LV unloading in patients undergoing high‐risk PCI and primary PCI for acute ST‐elevation myocardial infarction. Methods: The effects of the Impella LP2.5 device on LV dynamics were studied in 11 patients (elective high‐risk PCI, n = 6; primary PCI, n = 5). LV pressure and volume were continuously assessed by a pressure‐conductance catheter at 4 different support levels of the Impella, from 0 L/min at baseline to 2.5 L/min at maximal support. Results: The response to increased LV unloading was not different between both groups of patients. The pooled data showed no change on global and systolic LV function during increased LV unloading, while diastolic function showed improvement as indicated by an increased LV compliance in all patients. There was a decrease in end‐diastolic pressure from 22 ± 12 to 13 ± 9 mm Hg (P = 0.0001), in end‐diastolic elastance from 0.134 ± 0.060 to 0.091 ± 0.064 mm Hg/mL (P = 0.009), and in end‐diastolic wall stress from 84 ± 50 to 47 ± 39 mm Hg (P = 0.004). Conclusions: LV unloading decreases end‐diastolic wall stress and improves diastolic compliance dose‐dependently. Our results indicate beneficial LV unloading effects of Impella during high‐risk and primary PCI.