Laboratory diagnosis of heparin-induced thrombocytopenia: A retrospective experience.

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is a severe complication of heparin therapy associated with thrombosis that requires a quick diagnosis. Therefore, laboratory assays must provide an accurate and swift answer. This work aims to evaluate the performances of an ELISA assay, especially when combined with 4T risk score, and a functional assay. METHODS: Data were collected for 894 patients treated by heparin who underwent anticoagulant switch because of HIT suspicion and were examined by a multidisciplinary expert team who confirmed or ruled out HIT diagnosis. All patients were tested for anti-PF4 IgG with Asserachrom HPIA IgG (ELISA), and 307 were tested with a platelet aggregation test done on platelet-rich plasma (PRP-PAT). The 4T risk score was available for 607 of them. RESULTS: HIT was diagnosed in 232 patients. 4T risk score had a 94.2% negative predictive value (NPV) for risk scores ≤3 and 77.3% for risk scores ≤5. The sensitivity of ELISA was 90.9%, its specificity 79.0%, and its NPV 96.1%. When combined with 4T risk score, its NPV reached 100% and 97% for risk scores ≤3 and ≤5, respectively. PRP-PAT sensitivity was 70.4%, and its specificity was 92.3%. Combination of ELISA and PRP-PAT had a 0.7% false-negative rate. CONCLUSION: This study shows that ELISA can rule out HIT with an excellent NPV, especially when combined with the 4T risk score. Nonetheless, it has low specificity; hence, it needs to be associated with a functional assay.

Left ventricular assist device-associated infections: incidence and risk factors.

BACKGROUND: Left ventricular assist device (LVAD)-associated infections are major complications that can lead to critical outcomes. The aims of this study were to assess the incidence of and to determine the risk factors for LVAD-associated infections. METHODS: We included all consecutive patients undergoing LVAD implantation between January 1, 2010, and January 1, 2019, in a single institution. Infection-related data were retrospectively collected by review of patient's medical files. LVAD-associated infections were classified into three categories: percutaneous driveline infections, pocket infections and pump and/or cannula infections. RESULTS: We enrolled 72 patients. Twenty-one (29.2%) patients presented a total of 32 LVAD-associated infections. Eight (38.1%) patients had more than one infection. Five (62.5%) pocket infections and one (50.0%) pump and/or cannula infection were preceded by a driveline infection. The median delay between the operation and LVAD-associated infection was 6.5 (1.4-12.4) months. The probability of having a LVAD-associated infection at one year after receiving an implant was 26.6% (95% CI: 17.5-40.5%). Percutaneous driveline infections represented 68.7% of all LVAD-associated infections. Staphylococcus aureus and coagulase-negative staphylococci were the predominant bacteria in LVAD-associated infections (53.1% and 15.6%, respectively). Hospital length of stay (sdHR =1.22 per 10 days; P=0.001) and postoperative hemodialysis (sdHR =0.17; P=0.004) were statistically associated with infection. Colonization with multidrug-resistant bacteria was more frequent in patients with LVAD-associated infections than in others patients (42.9% vs. 15.7%; P=0.013). CONCLUSIONS: LVAD-associated infections remain an important complication and are mostly represented by percutaneous driveline infections. Gram-positive cocci are the main pathogens isolated in microbiological samples. Patients with LVAD-associated infections are more frequently colonized with multidrug-resistant bacteria.

Decompressive hemicraniectomy for acute ischemic stroke in a patient implanted with a left ventricular assist device: a case report.

BACKGROUND: Thromboembolic ischemic stroke (IS) is one of the most feared complications of left ventricular assist device (LVAD) placement and represents a challenge to surgical management because of concomitant anticoagulant therapy. CASE PRESENTATION: A 39-year-old man presented with cardiogenic shock following an out-of-hospital cardiac arrest. After a period of stabilization, the patient was referred for LVAD placement. Upon recovery from anesthesia, he presented with acute neurological deficits suggestive of IS. A brain computed tomography confirmed the diagnosis, and an emergency decompressive hemicraniectomy (DHC) was performed. Anticoagulation was managed empirically. The patient's neurological status progressively improved and he was referred for heart transplantation at five months from DHC. One month later, cranioplasty was performed. CONCLUSIONS: This report suggests an anticoagulation management approach in combination with decompressive craniectomy after IS in a patient with LVAD placement was successful. An optimized anticoagulation management and collaborative team-based practice may contribute to successful outcomes in complex cases.

Outcomes after extracorporeal membrane oxygenation for the treatment of high-risk pulmonary embolism: a multicentre series of 52 cases.

Aims: The role of extracorporeal membrane oxygenation (ECMO) remains ill defined in pulmonary embolism (PE). We investigated outcomes in patients with high-risk PE undergoing ECMO according to initial therapeutic strategy. Methods and results: From 01 January 2014 to 31 December 2015, 180 patients from 13 Departments in nine centres with high-risk PE were retrospectively included. Among those undergoing ECMO, we compared characteristics and outcomes according to adjunctive treatment strategy (systemic thrombolysis, surgical embolectomy, or no reperfusion therapy). Primary outcome was all-cause 30-day mortality. Secondary outcome was 90-day major bleeding. One hundred and twenty-eight patients were treated without ECMO; 52 (mean age 47.6 years) underwent ECMO. Overall 30-day mortality was 48.3% [95% confidence interval (CI) 41-56] (87/180); 43% (95% CI 34-52) (55/128) in those treated without ECMO vs. 61.5% (95% CI 52-78) (32/52) in those with ECMO (P = 0.008). In patients undergoing ECMO, 30-day mortality was 76.5% (95% CI 57-97) (13/17) for ECMO + fibrinolysis, 29.4% (95% CI 51-89) (5/17) for ECMO + surgical embolectomy, and 77.7% (95% CI 59-97) (14/18) for ECMO alone (P = 0.004). Among patients with ECMO, 20 (38.5%, 95% CI 25-52) had a major bleeding event in-hospital; without significant difference across groups. Conclusion: In patients with high-risk PE, those with ECMO have a more severe presentation and worse prognosis. Extracorporeal membrane oxygenation in patients with failed fibrinolysis and in those with no reperfusion seems to be associated with particularly unfavourable prognosis compared with ECMO performed in addition to surgical embolectomy. Our findings suggest that ECMO does not appear justified as a stand-alone treatment strategy in PE patients, but shows promise as a complement to surgical embolectomy.

Effect of Xenon Anesthesia Compared to Sevoflurane and Total Intravenous Anesthesia for Coronary Artery Bypass Graft Surgery on Postoperative Cardiac Troponin Release: An International, Multicenter, Phase 3, Single-blinded, Randomized Noninferiority Trial.

BACKGROUND: Ischemic myocardial damage accompanying coronary artery bypass graft surgery remains a clinical challenge. We investigated whether xenon anesthesia could limit myocardial damage in coronary artery bypass graft surgery patients, as has been reported for animal ischemia models. METHODS: In 17 university hospitals in France, Germany, Italy, and The Netherlands, low-risk elective, on-pump coronary artery bypass graft surgery patients were randomized to receive xenon, sevoflurane, or propofol-based total intravenous anesthesia for anesthesia maintenance. The primary outcome was the cardiac troponin I concentration in the blood 24 h postsurgery. The noninferiority margin for the mean difference in cardiac troponin I release between the xenon and sevoflurane groups was less than 0.15 ng/ml. Secondary outcomes were the safety and feasibility of xenon anesthesia. RESULTS: The first patient included at each center received xenon anesthesia for practical reasons. For all other patients, anesthesia maintenance was randomized (intention-to-treat: n = 492; per-protocol/without major protocol deviation: n = 446). Median 24-h postoperative cardiac troponin I concentrations (ng/ml [interquartile range]) were 1.14 [0.76 to 2.10] with xenon, 1.30 [0.78 to 2.67] with sevoflurane, and 1.48 [0.94 to 2.78] with total intravenous anesthesia [per-protocol]). The mean difference in cardiac troponin I release between xenon and sevoflurane was -0.09 ng/ml (95% CI, -0.30 to 0.11; per-protocol: P = 0.02). Postoperative cardiac troponin I release was significantly less with xenon than with total intravenous anesthesia (intention-to-treat: P = 0.05; per-protocol: P = 0.02). Perioperative variables and postoperative outcomes were comparable across all groups, with no safety concerns. CONCLUSIONS: In postoperative cardiac troponin I release, xenon was noninferior to sevoflurane in low-risk, on-pump coronary artery bypass graft surgery patients. Only with xenon was cardiac troponin I release less than with total intravenous anesthesia. Xenon anesthesia appeared safe and feasible.

Impact of prosthesis-patient mismatch on early haemodynamic status after aortic valve replacement.

OBJECTIVES: Prosthesis-patient mismatch (PPM) has been reported to impact early haemodynamic status and early mortality after prosthetic aortic valve replacement (AVR) in patients with aortic stenosis (AS). The aim of this study was to assess the impact of PMM on early haemodynamic status after AVR using vasoactive-inotropic dependency index (VDI), postoperative pressures and end-organ perfusion. METHODS: A total of 183 patients with AS were included in this prospective cohort study, and underwent elective AVR with or without combined coronary artery bypass graft surgery. PPM was defined as a projected indexed effective orifice area of ≤0.85 cm2/m2, and was present in 27.9% of the patients. The primary end-point was the VDI [VDI = vasoactive-inotropic score/mean arterial pressure] measured upon admission to the intensive care unit (POD0) and on the morning of the first postoperative day (POD1). The secondary end-points were the following: mean left atrial pressure, mean central venous pressure, fluid balance, brain natriuretic peptide, troponin I, glomerular filtration rate and lactate levels on POD0 and POD1. RESULTS: No significant differences in VDI were observed between the no PPM and PPM groups on POD0 (0.08 ± 0.48 vs 0.05 ± 0.13, respectively, P = 0.622) or on POD1 (0.09 ± 0.40 vs 0.06 ± 0.13, respectively; P = 0.583). The mean arterial pressure, mean left atrial pressure, central venous pressure, troponin I, glomerular filtration rate and lactate levels did not differ between the two groups on POD0 and POD1, as well as fluid balance and brain natriuretic peptide on POD1. CONCLUSIONS: PPM is not associated with early haemodynamic status impairment and end-organ perfusion after AVR. CLINICAL TRIAL NUMBER: ClinicalTrials.gov number, NCT00699673.

Plasma fibrinogen level on admission to the intensive care unit is a powerful predictor of postoperative bleeding after cardiac surgery with cardiopulmonary bypass.

INTRODUCTION: Evidence regarding the behavior of fibrinogen levels and the relation between fibrinogen levels and postoperative bleeding is limited in cardiac surgery under cardiopulmonary bypass (CPB). To evaluate perioperative fibrinogen levels as a predictor of postoperative bleeding in patients undergoing cardiac surgery with CPB. MATERIALS AND METHODS: In this prospective, single-center, observational cohort study of 1956 patients following cardiac surgery with CPB, fibrinogen level was measured perioperatively. Excessive bleeding group was defined as patients with a 24-h chest tube output (CTO) exceeded the 90th percentile of distribution. RESULTS: The median 24-h CTO was 728.6±431.1ml. A total of 189 patients (9.7%) were identified as having excessive bleeding. At admission to the intensive care (Day 0), the fibrinogen levels were 2.5±0.8g/l and 2.1±0.8g/l in the control and excessive bleeding groups, respectively (P<0.0001). The fibrinogen level on Day 0 was significantly correlated with the 24-h CTO (rho=-0.237; P<0.0001). Multivariate analysis demonstrated that the fibrinogen level at Day 0 was the best perioperative standard laboratory test to predict excessive bleeding (P=0.0001; odds ratio, 0.5), whereas preoperative fibrinogen level was not a predictor. Using receiver operating characteristics curve analyses, the best Day 0 fibrinogen level cutoff to predict postoperative bleeding was 2.2g/l. CONCLUSIONS: In this large prospective study, the fibrinogen level upon admission to the intensive care unit after CPB predicted the risk of postoperative bleeding. Our data add to the concern regarding the fibrinogen level threshold that might require fibrinogen concentrate infusion to reduce postoperative blood loss.

Exclusive low-molecular-weight heparin as bridging anticoagulant after mechanical valve replacement.

BACKGROUND: Unfractionated heparin has been the standard anticoagulant used immediately after mechanical heart valve replacement (MHVR). The purpose of this study was to assess a postoperative anticoagulation protocol with low-molecular-weight heparin (LMWH) immediately after MHVR without the use of unfractionated heparin or anti-factor Xa monitoring. METHODS: We performed a prospective, single-center, observational study of 1,063 consecutive patients undergoing elective MHVR with postoperative LMWH anticoagulation treatment. The exclusion criteria were as follows: renal failure, intraaortic balloon counterpulsation, critical perioperative state, or a recent neurologic event. The postoperative anticoagulation protocol used subcutaneous enoxaparin as a bridging anticoagulant treatment beginning on the first postoperative day and continuing until vitamin K antagonist treatment was fully effective. Patients were followed for 6 weeks. The primary endpoints were the incidence of thromboembolic or major bleeding events. RESULTS: Eleven (1%) thromboembolic events occurred. Ten of these events were transient or permanent strokes. Major bleeding events occurred in 44 patients (4.1%), 7 of which were observed before the enoxaparin treatment period. At the time of discharge, 570 patients (53.6%) were no longer receiving LMWH treatment due to achieving the target international normalized ratio. The mean length of hospital stay was 8.5 ± 2.9 days. There were no deaths during the 6-week follow-up period. CONCLUSIONS: In our highly selected population, after MHVR, postoperative anticoagulation using LMWH is associated with a low rate of thromboembolic and major bleeding events. This large observational study demonstrates that the use of LMWH as an anticoagulant is effective and safe after MHVR.