Sibel Altintas

Hemolysis is associated with acute kidney injury during major aortic surgery

Hemolysis is an inevitable side effect of cardiopulmonary bypass resulting in increased plasma free hemoglobin that may impair tissue perfusion by scavenging nitric oxide. Acute kidney injury after on-pump cardiovascular surgery arises from a number of causes and severely affects patient morbidity and mortality. Here, we studied the effect of acute hemolysis on renal injury in 35 patients undergoing on-pump surgical repair of thoracic and thoracoabdominal aortic aneurysms of whom 19 experienced acute kidney injury. During surgery, plasma free hemoglobin increased, as did urinary excretion of the tubular injury marker N-acetyl-beta-D-glucosaminidase, in patients with and without acute kidney injury, reaching peak levels at 2 h and 15 min, respectively, after reperfusion. Furthermore, plasma free hemoglobin was independently and significantly correlated with the urine biomarker, which, in turn, was independently and significantly associated with the later postoperative increase in serum creatinine. Importantly, peak plasma free hemoglobin and urine N-acetyl-beta-D-glucosaminidase concentrations had significant predictive value for postoperative acute kidney injury. Thus, we found an association between increased plasma free hemoglobin and renal injury casting new light on the pathophysiology of acute kidney injury. Therefore, free hemoglobin is a new therapeutic target to improve clinical outcome after on-pump cardiovascular surgery.

Trends in the occurrence of new conduction abnormalities after transcatheter aortic valve implantation

The aim of the study was to investigate trends over time in the occurrence of left bundle branch block (LBBB) and permanent pacemaker implantation (PPI) after transcatheter aortic valve implantation (TAVI) with the Medtronic CoreValve System (MCS) and Edwards SAPIEN Valve (ESV). Background: TAVI‐induced conduction abnormalities (TAVI‐CAs) such as LBBB and the need for PPI are frequent postoperative complication. New techniques, procedural refinements, and increased awareness are focused on the reduction of these abnormalities.

Coronary CT angiography using low concentrated contrast media injected with high flow rates: Feasible in clinical practice.

PURPOSE Aim of this study was to test the hypothesis that peak injection pressures and image quality using low concentrated contrast media (CM) (240 mg/mL) injected with high flow rates will be comparable to a standard injection protocol (CM: 300 mg/mL) in coronary computed tomographic angiography (CCTA). MATERIAL AND METHODS One hundred consecutive patients were scanned on a 2nd generation dual-source CT scanner. Group 1 (n=50) received prewarmed Iopromide 240 mg/mL at an injection rate of 9 mL/s, followed by a saline chaser. Group 2 (n=50) received the standard injection protocol: prewarmed Iopromide 300 mg/mL; flow rate: 7.2 mL/s. For both protocols, the iodine delivery rate (IDR, 2.16 gI/s) and the total iodine load (22.5 gI) were kept identical. Injection pressure (psi) was continuously monitored by a data acquisition program. Contrast enhancement was measured in the thoracic aorta and all proximal and distal coronary segments. Subjective and objective image quality was evaluated between both groups. RESULTS No significant differences in peak injection pressures were found between both CM groups (121 ± 5.6 psi vs. 120 ± 5.3 psi, p=0.54). Flow rates of 9 mL/s were safely injected without any complications. No significant differences in contrast-to-noise ratio, signal-to-noise ratio and subjective image quality were found (all p>0.05). No significant differences in attenuation levels were found in the thoracic aorta and all segments of the coronary arteries (all p>0.05). CONCLUSION Usage of low iodine concentration CM and injection with high flow rates is feasible. High flow rates (9 mL/s) of Iopromide 240 were safely injected without complications and should not be considered a drawback in clinical practice. No significant differences in peak pressure and image quality were found. This creates a doorway towards applicability of a broad variety in flow rates and IDRs and subsequently more individually tailored injection protocols.

High-Sensitivity Cardiac Troponin Concentrations in Patients with Chest Discomfort: Is It the Heart or the Kidneys As Well?

Background High-sensitivity cardiac troponins (hs-cTn) are the preferred biomarkers to detect myocardial injury, making them promising risk-stratifying tools for patients with symptoms of chest pain. However, circulating hs-cTn are also elevated in other conditions like renal dysfunction, complicating appropriate interpretation of low-level hs-cTn concentrations. Methods A cross-sectional analysis was performed in 1864 patients with symptoms of chest discomfort from the cardiology outpatient department who underwent cardiac computed tomographic angiography (CCTA). Serum samples were analyzed using hs-cTnT and hs-cTnI assays. Renal function was measured by the estimated glomerular filtration rate (eGFR), established from serum creatinine and cystatin C. On follow-up, the incidence of adverse events was assessed. Results Median hs-cTnT and hs-cTnI concentrations were 7.2(5.8–9.2) ng/L and 2.6(1.8–4.1) ng/L, respectively. Multivariable regression analysis revealed that both assay results were more strongly associated with eGFR (hs-cTnT:stβ:-0.290;hs-cTnI:stβ:-0.222) than with cardiac imaging parameters, such as coronary calcium score, CCTA plaque severity score and left ventricular mass (all p<0.01). Furthermore, survival analysis indicated lower relative risks in patients with normal compared to reduced renal function for hs-cTnT [HR(95%CI), 1.02(1.00–1.03) compared to 1.07(1.05–1.09)] and hs-cTnI [1.01(1.00–1.01) compared to 1.02(1.01–1.02)] (all p<0.001). Conclusion In patients with chest discomfort, we identified an independent influence of renal function on hs-cTn concentrations besides CAD, that affected the association of hs-cTn concentrations with adverse events. Estimating renal function is therefore warranted when interpreting baseline hs-cTn concentrations.

Patient Comfort During Contrast Media Injection in Coronary Computed Tomographic Angiography Using Varying Contrast Media Concentrations and Flow Rates: Results From the EICAR Trial.

PurposePain sensation and extravasation are potential drawbacks of contrast media (CM) injection during computed tomographic angiography. The purpose was to evaluate safety and patient comfort of higher flow rates in different CM protocols during coronary computed tomographic angiography. MethodsTwo hundred consecutive patients of a double-blind randomized controlled trial (NCT02462044) were analyzed. Patients were randomized to receive 94 mL of prewarmed iopromide 240 mg I/mL at 8.3 mL/s (group I), 75 mL of 300 mg I/mL at 6.7 mL/s (group II), or 61 mL of 370 mg I/mL at 5.4 mL/s (group III), respectively. Iodine delivery rate (2.0 g I/s) and total iodine load (22.5 g I) were kept identical. Outcome was defined as intravascular enhancement, patient comfort during injection, and injection safety, expressed as the occurrence of extravasation. Patients completed a questionnaire for comfort, pain, and stress during CM injection. Comfort was graded using a 5-point scale, 1 representing “very bad” and 5 “very well.” Pain was graded using a 10-point scale, 0 representing “no pain” and 10 “severe pain.” Stress was graded using a 5-point scale, 1 representing “no stress” and 5 “unsustainable stress.” ResultsMean enhancement levels within the coronary arteries were as follows: 437 ± 104 Hounsfield units (HU) (group I), 448 ± 111 HU (group II), and 447 ± 106 HU (group III), with P ≥ 0.18. Extravasation occurred in none of the patients. Median (interquartile range) for comfort, pain, and stress was, respectively, 4 (4–5), 0 (0–0), and 1 (1–2), with P ≥ 0.68. ConclusionsHigh flow rates of prewarmed CM were safely injected without discomfort, pain, or stress. Therefore, the use of high flow rates should not be considered a drawback for CM administration in clinical practice.

Contrast Enhancement of the Right Ventricle during Coronary CT Angiography--Is It Necessary?

Purpose It is unclear if prolonged contrast media injection, to improve right ventricular visualization during coronary CT angiography, leads to increased detection of right ventricle pathology. The purpose of this study was to evaluate right ventricle enhancement and subsequent detection of right ventricle disease during coronary CT angiography. Materials and Methods 472 consecutive patients referred for screening coronary CT angiography were retrospectively evaluated. Every patient underwent multidetector-row CT of the coronary arteries: 128x 0.6mm coll., 100-120kV, rot. time 0.28s, ref. mAs 350 and received an individualized (P3T) contrast bolus injection of iodinated contrast medium (300 mgI/ml). Patient data were analyzed to assess right ventricle enhancement (HU) and right ventricle pathology. Image quality was defined good when right ventricle enhancement >200HU, moderate when 140-200HU and poor when <140HU. Results Good image quality was found in 372 patients, moderate in 80 patients and poor in 20 patients. Mean enhancement of the right ventricle cavity was 268HU±102. Patients received an average bolus of 108±24 ml at an average peak flow rate of 6.1±2.2 ml/s. In only three out of 472 patients (0.63%) pathology of the right ventricle was found (dilatation) No other right ventricle pathology was detected. Conclusion Right ventricle pathology was detected in three out of 472 patients; the dilatation observed in these three cases may have been picked up even without dedicated enhancement of the right ventricle. Based on our findings, right ventricle enhancement can be omitted during screening coronary CT angiography.