Intravenous ivabradine versus placebo in patients with low cardiac output syndrome treated by dobutamine after elective coronary artery bypass surgery: a phase 2 exploratory randomized controlled trial.

BACKGROUND: Low cardiac output syndrome (LCOS) is a severe condition which can occur after cardiac surgery, especially among patients with pre-existing left ventricular dysfunction. Dobutamine, its first-line treatment, is associated with sinus tachycardia. This study aims to assess the ability of intravenous ivabradine to decrease sinus tachycardia associated with dobutamine infused for LCOS after coronary artery bypass graft (CABG) surgery. METHODS: In a phase 2, multi-center, single-blind, randomized controlled trial, patients with left ventricular ejection fraction below 40% presenting sinus tachycardia of at least 100 beats per minute (bpm) following dobutamine infusion for LCOS after CABG surgery received either intravenous ivabradine or placebo (three ivabradine for one placebo). Treatment lasted until dobutamine weaning or up to 48 h. The primary endpoint was the proportion of patients achieving a heart rate (HR) in the 80- to 90-bpm range. Secondary endpoints were invasive and non-invasive hemodynamic parameters and arrhythmia events. RESULTS: Nineteen patients were included. More patients reached the primary endpoint in the ivabradine than in the placebo group (13 (93%) versus 2 (40%); P = 0.04). Median times to reach target HR were 1.0 h in the ivabradine group and 5.7 h in the placebo group. Ivabradine decreased HR (112 to 86 bpm, P <0.001) while increasing cardiac index (P = 0.02), stroke volume (P <0.001), and systolic blood pressure (P = 0.03). In the placebo group, these parameters remained unchanged from baseline. In the ivabradine group, five patients (36%) developed atrial fibrillation (AF) and one (7%) was discontinued for sustained AF; two (14%) were discontinued for bradycardia. CONCLUSION: Intravenous ivabradine achieved effective and rapid correction of sinus tachycardia in patients who received dobutamine for LCOS after CABG surgery. Simultaneously, stroke volume and systolic blood pressure increased, suggesting a beneficial effect of this treatment on tissue perfusion. TRIAL REGISTRATION: European Clinical Trials Database: EudraCT 2009-018175-14 . Registered February 2, 2010.

Diagnostic Performance of a New Rapid Lateral Flow Immunoassay in Patients Suspected of Heparin-Induced Thrombocytopenia and Its Clinical Consequences.

We prospectively evaluated the diagnostic accuracy of a new rapid assay (STic Expert HIT) alone or in combination with a clinical score in 90 HIT-suspected patients. The 4Ts score was calculated, and ELISA and serotonin-release assay (SRA) were performed; the average time taken for test results were 2 and 5 days for ELISA and SRA, respectively. The STic test was performed in our laboratory as an evaluation exercise and the result was available in 1 hour, but results were not communicated to the clinicians so as to not influence management. Diagnostic performance of STic test was assessed, alone and in combination with 4Ts score. HIT was diagnosed in 19 patients. The sensitivity, specificity, and positive and negative predictive values for the STic test alone were 95%, 92%, 75%, and 98%, respectively, with an accuracy of 92%. The likelihood ratio for positive and negative results with the STic test was 11.2 and 0.06. The combination of the 4Ts score and the STic test results had a negative predictive value of 100% and a negative likelihood ratio of 0. The favorable performance of the STic test may allow for the rapid exclusion of HIT in combination with a low to intermediate pretest clinical probability. During the subsequent year, using the STic test in real time to rapidly exclude the diagnosis, we observed a 50% reduction in danaparoid administration in HIT-suspected patients.

Decreased right ventricular lateral wall velocities early after cardiac surgery.

BACKGROUND: Right ventricular (RV) function is less often monitored than left ventricular (LV) function and might influence the postoperative period in patients undergoing coronary bypass or heart valve surgery. Our objective was to compare RV lateral wall velocities before and soon after heart surgery. METHODS: We examined 87 patients before and at a median time of 5 days after surgery with tissue Doppler echocardiography. On-pump coronary artery bypass grafting was performed in 40 patients, and valvular surgery in 47 patients. The pulsed Doppler sample was positioned at the midportion of the RV lateral wall, on the septum and on the LV lateral wall to record peak systolic (S), early (E) and late (A) diastolic tissue Doppler velocities. RESULTS: We observed lower values of LV end diastolic volume and left atrial area (P < 0.001) but no differences in RV fractional area change as well as LV ejection fraction between before and after surgery. RV S, E, and A were dramatically lower in the postoperative group (P < 0.001 between before and after surgery), as well as septal S, E, and A (P < 0.005 between before and after). No change occurred on LV lateral S and A, whereas LV lateral wall E velocity was slightly higher in the postoperative group (P < 0.05). CONCLUSIONS: Tissue Doppler velocities of the RV free wall are reduced significantly after cardiac surgery despite no reduction in RV fractional area change.

Tissue Doppler echocardiographic and color M-mode estimation of left atrial pressure in infants.

OBJECTIVES: Using recorded flow and tissue Doppler, we evaluated the relation of peak velocity of early transmitral Doppler filling (E)/early diastolic velocity of the lateral mitral annulus (Ea) ratio and of E/flow propagation velocity (Vp) ratio to mean left atrial pressure in infants after surgery for congenital heart disease. DESIGN: Experimental design. SETTING: Pediatric intensive care unit. PATIENTS: Thirty-seven infants aged 4 (3-8) months. INTERVENTIONS: Patients underwent postoperative invasive hemodynamic monitoring with simultaneously obtained Doppler measurements. MEASUREMENTS AND MAIN RESULTS: Values are expressed as median (25th-75th percentiles). Heart rate was 145 (135-157) beats/min. Left atrial pressure was 10 (8-12) mm Hg with E/Ea 16 (12-19) and E/Vp 1.9 (1.3-2.4). E/Ea and E/Vp ratios were higher in patients with left atrial pressure >10 mm Hg (n = 18), than in patients with left atrial pressure < or =10 mm Hg (n = 19) (E/Ea, 16 [15-25] vs. 12 [9-17], p = .01; E/Vp, 2.3 [1.9-2.8] vs. 1.4 [1-1.9]. respectively, p = .001). At a cutoff point of 15, E/Ea sensitivity for left atrial pressure >10 mm Hg was 17 of 18 (94%) with specificity 13 of 18 (72%). At a cutoff point of 2, E/Vp sensitivity for left atrial pressure >10 mm Hg was 15 of 18 (83%) with specificity 16 of 18 (89%). Areas under the receiver operating characteristic curves were 0.76 (E/Ea) and 0.83 (E/Vp). CONCLUSIONS: Doppler ratios might be considered as promising noninvasive tools for left atrial pressure evaluation in infants after cardiac surgery.

Pulmonary artery dissection and rupture associated with aortopulmonary window.

A 31-year-old man with uncorrected aortopulmonary window and fixed pulmonary hypertension experienced dissection of the pulmonary artery, rapidly complicated by a fatal spontaneous rupture into the pericardium. In the setting of pulmonary hypertension, the diagnosis of dissection and rupture of the pulmonary artery should be considered in cases of thoracic pain or cardiogenic shock.

Left main artery dissection during 4 French coronary angiography in elderly patient with severe aortic stenosis: "speedy recovery" using emergency primary stenting.

A 70-year-old woman was referred due to a symptomatic severe calcific aortic stenosis. An iatrogenic dissection of the left main artery with total occlusion and arrest (asystole) occurred during preoperative 4Fr coronography. "Speedy recovery" is achieved with a strategy of percutaneous primary stenting revascularization combined with cardiopulmonary maneuvers.