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Signs of coronary steal during apnea after hyperventilation in awake patients with coronary artery disease
S24
1
University of Glasgow, Department of Anaesthesia, Pain and Critical Care Medicine, Glasgow, UK, 2Golden Jubilee National Hospital, Clydebank, UK Introduction. Existing studies indicate that right ventricular (RV) dysfunction occurs following lung resection, predisposing patients to post-operative complications and long term morbidity. RV assessment is difficult however; it’s complex shape, marked load dependence and retrosternal position mean there are no reliable, noninvasive methods of assessment. Previous work in this patient group has focused on the use of the Volumetric Pulmonary Artery Catheter, the reliability of which has been challenged. Concerns regarding the validity of these reports, and their inconsistent findings mean the extent and mechanism of post-operative RV dysfunction remains incompletely understood. Cardiac Magnetic Resonance (CMR) is the gold standard for non-invasive assessment of RV volumes and has become a standard tool for assessment of RV structure and function in many clinical settings. CMR has potential challenges in this population however; scanning takes 30 minutes, requires participants to lie flat, and necessitates repeated short (approx 10 second) breath holds during imaging. CMR has not previously been used to assess the RV response to lung resection. Method. With ethical approval and informed consent 27 patients undergoing open lung resection by thoracotomy underwent serial CMR; pre-op, on post-operative day (POD) 2 and at 2-month follow-up. Ventricular volumes and ejection fraction were determined offline, using commercially available software by dual reported analysis of randomised and anonymised images (Argus, Siemens, Germany). Results. Twenty-two patients (81.5%) completed CMR imaging on POD2. For assessment of RV end diastolic and end systolic volumes there was good inter-observer (Intra Class Correlation coefficient [ICC] 0.85 and 0.84 respectively) and intra-observer variability (ICC 0.92 and 0.94 respectively). Mean (95%CI) absolute right ventricular ejection fraction (RVEF) fell from 49.7% (46.3-53.0) pre-op, to 45.5% (43.5-47.5) on POD2 (po0.001, Fig. 1). In the quartile of patients with the largest change on POD2, RVEF dropped by 11.9% (8.9-15.7). Right ventricular ejection fraction remained depressed at 2-months (Fig. 1). There were no changes in left ventricular ejection fraction over the same time periods (p40.39).
Fig. 1 Mean Right Ventricle Ejection Fraction (RVEF) over time. Bars represent 95% Confidence Intervals. (*po0.001, **p¼0.02, Paired ttest). Discussion. CMR was well tolerated in the post-op period and is reproducible with low inter and intra-observer variability. This study demonstrates a reduction in RVEF in patients undergoing
ABSTRACT PRESENTATIONS
lung resection. Whilst RVEF for the whole study cohort fell by a modest 4.2%, one quarter of patients
Best Abstract Presentations 207 Thursday, May 12, 2016 12:00-13:00, Auditorium OP-29 Signs of coronary steal during apnea after hyperventilation in awake patients with coronary artery disease Dominik Guensch1,2, K. Fischer1, K. Yamaji3, B. Jung2, J. Heverhagen2, S. Windecker3, M. Friedrich4, B. Eberle1 1
Department of Anesthesiology and Pain Therapy, Inselspital, Bern University Hospital, University of Bern, Switzerland, 2Institute for Diagnostic, Interventional and Paediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Switzerland, 3Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Switzerland, 4Departments of Cardiology and Diagnostic Radiology, McGill University, Montreal, QC, Canada Introduction. Induction of general anaesthesia is frequently accompanied by hyperventilation and subsequent apnea, e.g., prior to intubation. Both respiratory maneuvers can affect myocardial oxygenation [1]. So far it remains unclear whether patients with coronary artery disease (CAD) are at risk of myocardial ischemia by sequential hyperventilatory vasoconstriction and apnea-induced vasodilation. We hypothesized that in CAD patients, hyperventilation followed by a maximal voluntary breath-hold decreases oxygenation in myocardium subtended by a relevant stenosis, which can be measurable by oxygenation-sensitive (OS) cardiovascular magnetic resonance (CMR). Methods. With ethics committee approval and informed consent, six healthy volunteers and seven CAD patients (stenosis of 50-70% by quantitative coronary angiography) underwent an MRI exam using an OS-CMR protocol. Baseline OS images (two left ventricular short axis slices) were obtained before subjects were asked to first hyperventilate at a rate of 30 breaths/min and then hold their breath. Throughout the apneic period, serial OS images were obtained. The temporal change in myocardial signal intensity was expressed as %-change from baseline, and was compared between healthy and CAD subjects immediately after hyperventilation and at 30 s of apnea. Results and Discussion. Myocardial oxygenation in healthy volunteers significantly decreased with hyperventilation, and increased with apnea (fig., *po0.05). These effects were significantly attenuated in CAD patients (po0.05), indicating a diminished coronary reactivity to the blood gas changes associated with both maneuvers. Within-patient comparison showed that myocardial segments perfused by normal coronaries (remote) showed a small oxygenation increase during apnea. In contrast, segments subtended by a stenosed vessel (affected) showed a net oxygenation decrease in OS-CMR. This can be explained by coronary steal induced by the breathing manoeuvre. Oxygenation at 30-s of the breath-hold was significantly lower in affected than in remote myocardium of CAD patients, and much lower than in healthy subjects. Conclusion(s). Our results indicate that in awake CAD patients, hyperventilation followed by apnea may induce coronary steal with a measurable decrease of oxygenation in myocardium at risk. This may explain transient signs of myocardial ischemia in CAD patients with steal-prone anatomy.
S25
ABSTRACT PRESENTATIONS
REFERENCE 1. Fischer K, et al: Response of myocardial oxygenation to breathing manoeuvres and adenosine infusion. Eur Heart J Cardiovasc Imaging. 16:395–401, 2015.
OP-30 Plasma neutrophil gelatinase-associated lipocalin for early detection of acute kidney injury after cardiac surgery
REFERENCES 1. Perrotti A, Miltgen G, Chevet-Noel A, Durst C, Vernerey D, Bardonnet K, Davani S, Chocron S: Neutrophil gelatinaseassociated lipocalin as early predictor of acute kidney injury after cardiac surgery in adults with chronic kidney failure. Ann Thorac Surg. 99:864-9, 2015. 2. Ho J, Tangri N, Komenda P, Kaushal A, Sood M, Brar R, Gill K, Walker S, MacDonald K, Hiebert BM, Arora RC, Rigatto C: Urinary, Plasma, and Serum Biomarkers’ Utility for Predicting.
Camilla L’Acqua1, C. Beverini1, G. Introcaso2, F. Veglia3, C. Brambillasca1, L. Salvi1 1
IRCCS Centro Cardiologico Monzino, Anaesthesia and Postoperative Intensive Care Unit, Milano, Italy, 2IRCCS Centro Cardiologico Monzino, Laboratory Medicine Service, Milano, Italy, 3IRCCS Centro Cardiologico Monzino, Statistics Service, Milano, Italy
OP-31 Factors influencing urinary NAG-excretion during cardiopulmonary bypass Lukas Lannemyr, G. Bragadottir, B. Redfors, S-E. Ricksten
Introduction. Acute kidney injury (AKI) is one of the most frequent complications after cardiac surgery, with time delay between clinical impairment of kidney function and the worsening in blood creatinine levels. Neutrophil gelatinase-associated lipocalin (NGAL) has been proposed for early detection of AKI1,2, but its clinical utility in immediate postoperative period is still debated. In our study we evaluated whether plasma NGAL (plNGAL) could predict early AKI after cardiac surgery. Methods. All consecutive adult patients with at least 2 of the following risk criteria of developing renal impairment: age470 years, glomerular filtration rate o 60 ml/min, ejection fraction o 41%, redo procedure, combined procedures, were enrolled in the study. AKI was defined following the www. akinet.org indications. We measured plNGAL immediately before (pre) and after (post) surgery in EDTA tubes, serum creatinine the day before surgery and at postoperative day 1st, 2nd and 3rd. Plasma NGAL samples were stored at -801C and was determined using an NGAL test: Triage (Alere Medical Inc., San Diego, CA, USA). Wilcoxon matched-pairs rank test, logistic regression and ROC curves were used for data analysis. Results. plNGAL samples on 82 patients (164 samples analyzed) were collected. Patients who not developed AKI were 53 (64%), mild (1) AKI occurred in 15 patients (18%), moderate (2) AKI in 8 patients (10%) and severe (3) AKI in 6 patients (8%). plNGAL significantly increased in AKI group compared to non AKI group, p¼ 0.0029. Discussion. In our study plNGAL was able to early detect AKI after cardiac surgery in adults. ROC curve showed postoperative plNGAL was able to early detect AKI: AUC¼ 0.7118, 95%CI¼ 0.6019 to 0.8217, p value¼ 0.0016, OR¼24.55. We detected postoperative plNGAL cut off: 154 ng/ml as potential interest to discriminate AKI threshold, with sensitivity 0.79 and specificity 0.58. As secondary endopoint postoperative plNGAL was weakly correlated with cardiopulmonary bypass time, p¼0.03, r¼0.15.
Department of Cardiothoracic Anaesthesia and Intensive Care, Sahlgrenska University Hospital, Gothenburg, Sweden
Introduction. Acute kidney injury (AKI) is a common complication with major impact on morbidity and mortality after cardiopulmonary bypass (CPB) (1). The pathogenesis is not fully understood, and serum creatinine, has poor specificity and sensitivity in early AKI (2). NAG (N-acetyl-b-D-glucosaminidase), a lysosomal enzyme excreted in urine after renal tubular cell damage, is a candidate biomarker for early detection of AKI. To increase the understanding of CPB-related AKI, we studied the influence of perioperative factors on urinary NAG-excretion. Method. The Gothenburg Regional Ethics Committee approved the study protocol. 65 patients undergoing complex cardiac surgery with an expected CPB-time 4 120 minutes were included after informed consent. Perioperative data were recorded and urine samples for NAG excretion corrected for urine creatinine were taken at specified times as indicated in figure. An ANOVA for repeated measurements followed by Fisher’s PLSD test were used to assess changes in NAG excretion over time. Bi- and multivariate linear regression analyses were performed to establish clinical variables associated with renal tubular injury. Results. Figure shows mean urinary NAG/creatinine ratio ⫾ SEM. * p o 0.05, *** p o 0.001. NAG excretion increased significantly early after start of CPB and peaked at ICU arrival, 89⫾ 5.5 minutes after weaning from CPB. Multiple regression using NAG excretion as the dependent variable was significant at p o 0.001, (adjusted R2 ¼ 0.329).
B ⫾ SEM
ß p-value
0.002 ⫾ 0.001 -0.008 ⫾ 0.002
0.293 0.001 -0.397 0.002
Preoperative eGFR (ml min-1)
0.004 ⫾ 0.002
0.286 0.013
Diabetes mellitus
0.254 ⫾ 0.125
0.212 0.047
Coefficient CPB time (minutes) Fluid administered during CPB (mL kg-1)
Discussion. Intra-operative fluid load, CPB time and diabetes mellitus were independently associated with tubular injury. Preoperative eGFR was positively associated with NAG excretion, suggesting that the release of tubular injury markers durig/after CPB must be adjusted for preoperative renal function, i.e. the number of functioning nephrons
1
University of Glasgow, Department of Anaesthesia, Pain and Critical Care Medicine, Glasgow, UK, 2Golden Jubilee National Hospital, Clydebank, UK Introduction. Existing studies indicate that right ventricular (RV) dysfunction occurs following lung resection, predisposing patients to post-operative complications and long term morbidity. RV assessment is difficult however; it’s complex shape, marked load dependence and retrosternal position mean there are no reliable, noninvasive methods of assessment. Previous work in this patient group has focused on the use of the Volumetric Pulmonary Artery Catheter, the reliability of which has been challenged. Concerns regarding the validity of these reports, and their inconsistent findings mean the extent and mechanism of post-operative RV dysfunction remains incompletely understood. Cardiac Magnetic Resonance (CMR) is the gold standard for non-invasive assessment of RV volumes and has become a standard tool for assessment of RV structure and function in many clinical settings. CMR has potential challenges in this population however; scanning takes 30 minutes, requires participants to lie flat, and necessitates repeated short (approx 10 second) breath holds during imaging. CMR has not previously been used to assess the RV response to lung resection. Method. With ethical approval and informed consent 27 patients undergoing open lung resection by thoracotomy underwent serial CMR; pre-op, on post-operative day (POD) 2 and at 2-month follow-up. Ventricular volumes and ejection fraction were determined offline, using commercially available software by dual reported analysis of randomised and anonymised images (Argus, Siemens, Germany). Results. Twenty-two patients (81.5%) completed CMR imaging on POD2. For assessment of RV end diastolic and end systolic volumes there was good inter-observer (Intra Class Correlation coefficient [ICC] 0.85 and 0.84 respectively) and intra-observer variability (ICC 0.92 and 0.94 respectively). Mean (95%CI) absolute right ventricular ejection fraction (RVEF) fell from 49.7% (46.3-53.0) pre-op, to 45.5% (43.5-47.5) on POD2 (po0.001, Fig. 1). In the quartile of patients with the largest change on POD2, RVEF dropped by 11.9% (8.9-15.7). Right ventricular ejection fraction remained depressed at 2-months (Fig. 1). There were no changes in left ventricular ejection fraction over the same time periods (p40.39).
Fig. 1 Mean Right Ventricle Ejection Fraction (RVEF) over time. Bars represent 95% Confidence Intervals. (*po0.001, **p¼0.02, Paired ttest). Discussion. CMR was well tolerated in the post-op period and is reproducible with low inter and intra-observer variability. This study demonstrates a reduction in RVEF in patients undergoing
ABSTRACT PRESENTATIONS
lung resection. Whilst RVEF for the whole study cohort fell by a modest 4.2%, one quarter of patients
Best Abstract Presentations 207 Thursday, May 12, 2016 12:00-13:00, Auditorium OP-29 Signs of coronary steal during apnea after hyperventilation in awake patients with coronary artery disease Dominik Guensch1,2, K. Fischer1, K. Yamaji3, B. Jung2, J. Heverhagen2, S. Windecker3, M. Friedrich4, B. Eberle1 1
Department of Anesthesiology and Pain Therapy, Inselspital, Bern University Hospital, University of Bern, Switzerland, 2Institute for Diagnostic, Interventional and Paediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Switzerland, 3Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Switzerland, 4Departments of Cardiology and Diagnostic Radiology, McGill University, Montreal, QC, Canada Introduction. Induction of general anaesthesia is frequently accompanied by hyperventilation and subsequent apnea, e.g., prior to intubation. Both respiratory maneuvers can affect myocardial oxygenation [1]. So far it remains unclear whether patients with coronary artery disease (CAD) are at risk of myocardial ischemia by sequential hyperventilatory vasoconstriction and apnea-induced vasodilation. We hypothesized that in CAD patients, hyperventilation followed by a maximal voluntary breath-hold decreases oxygenation in myocardium subtended by a relevant stenosis, which can be measurable by oxygenation-sensitive (OS) cardiovascular magnetic resonance (CMR). Methods. With ethics committee approval and informed consent, six healthy volunteers and seven CAD patients (stenosis of 50-70% by quantitative coronary angiography) underwent an MRI exam using an OS-CMR protocol. Baseline OS images (two left ventricular short axis slices) were obtained before subjects were asked to first hyperventilate at a rate of 30 breaths/min and then hold their breath. Throughout the apneic period, serial OS images were obtained. The temporal change in myocardial signal intensity was expressed as %-change from baseline, and was compared between healthy and CAD subjects immediately after hyperventilation and at 30 s of apnea. Results and Discussion. Myocardial oxygenation in healthy volunteers significantly decreased with hyperventilation, and increased with apnea (fig., *po0.05). These effects were significantly attenuated in CAD patients (po0.05), indicating a diminished coronary reactivity to the blood gas changes associated with both maneuvers. Within-patient comparison showed that myocardial segments perfused by normal coronaries (remote) showed a small oxygenation increase during apnea. In contrast, segments subtended by a stenosed vessel (affected) showed a net oxygenation decrease in OS-CMR. This can be explained by coronary steal induced by the breathing manoeuvre. Oxygenation at 30-s of the breath-hold was significantly lower in affected than in remote myocardium of CAD patients, and much lower than in healthy subjects. Conclusion(s). Our results indicate that in awake CAD patients, hyperventilation followed by apnea may induce coronary steal with a measurable decrease of oxygenation in myocardium at risk. This may explain transient signs of myocardial ischemia in CAD patients with steal-prone anatomy.
S25
ABSTRACT PRESENTATIONS
REFERENCE 1. Fischer K, et al: Response of myocardial oxygenation to breathing manoeuvres and adenosine infusion. Eur Heart J Cardiovasc Imaging. 16:395–401, 2015.
OP-30 Plasma neutrophil gelatinase-associated lipocalin for early detection of acute kidney injury after cardiac surgery
REFERENCES 1. Perrotti A, Miltgen G, Chevet-Noel A, Durst C, Vernerey D, Bardonnet K, Davani S, Chocron S: Neutrophil gelatinaseassociated lipocalin as early predictor of acute kidney injury after cardiac surgery in adults with chronic kidney failure. Ann Thorac Surg. 99:864-9, 2015. 2. Ho J, Tangri N, Komenda P, Kaushal A, Sood M, Brar R, Gill K, Walker S, MacDonald K, Hiebert BM, Arora RC, Rigatto C: Urinary, Plasma, and Serum Biomarkers’ Utility for Predicting.
Camilla L’Acqua1, C. Beverini1, G. Introcaso2, F. Veglia3, C. Brambillasca1, L. Salvi1 1
IRCCS Centro Cardiologico Monzino, Anaesthesia and Postoperative Intensive Care Unit, Milano, Italy, 2IRCCS Centro Cardiologico Monzino, Laboratory Medicine Service, Milano, Italy, 3IRCCS Centro Cardiologico Monzino, Statistics Service, Milano, Italy
OP-31 Factors influencing urinary NAG-excretion during cardiopulmonary bypass Lukas Lannemyr, G. Bragadottir, B. Redfors, S-E. Ricksten
Introduction. Acute kidney injury (AKI) is one of the most frequent complications after cardiac surgery, with time delay between clinical impairment of kidney function and the worsening in blood creatinine levels. Neutrophil gelatinase-associated lipocalin (NGAL) has been proposed for early detection of AKI1,2, but its clinical utility in immediate postoperative period is still debated. In our study we evaluated whether plasma NGAL (plNGAL) could predict early AKI after cardiac surgery. Methods. All consecutive adult patients with at least 2 of the following risk criteria of developing renal impairment: age470 years, glomerular filtration rate o 60 ml/min, ejection fraction o 41%, redo procedure, combined procedures, were enrolled in the study. AKI was defined following the www. akinet.org indications. We measured plNGAL immediately before (pre) and after (post) surgery in EDTA tubes, serum creatinine the day before surgery and at postoperative day 1st, 2nd and 3rd. Plasma NGAL samples were stored at -801C and was determined using an NGAL test: Triage (Alere Medical Inc., San Diego, CA, USA). Wilcoxon matched-pairs rank test, logistic regression and ROC curves were used for data analysis. Results. plNGAL samples on 82 patients (164 samples analyzed) were collected. Patients who not developed AKI were 53 (64%), mild (1) AKI occurred in 15 patients (18%), moderate (2) AKI in 8 patients (10%) and severe (3) AKI in 6 patients (8%). plNGAL significantly increased in AKI group compared to non AKI group, p¼ 0.0029. Discussion. In our study plNGAL was able to early detect AKI after cardiac surgery in adults. ROC curve showed postoperative plNGAL was able to early detect AKI: AUC¼ 0.7118, 95%CI¼ 0.6019 to 0.8217, p value¼ 0.0016, OR¼24.55. We detected postoperative plNGAL cut off: 154 ng/ml as potential interest to discriminate AKI threshold, with sensitivity 0.79 and specificity 0.58. As secondary endopoint postoperative plNGAL was weakly correlated with cardiopulmonary bypass time, p¼0.03, r¼0.15.
Department of Cardiothoracic Anaesthesia and Intensive Care, Sahlgrenska University Hospital, Gothenburg, Sweden
Introduction. Acute kidney injury (AKI) is a common complication with major impact on morbidity and mortality after cardiopulmonary bypass (CPB) (1). The pathogenesis is not fully understood, and serum creatinine, has poor specificity and sensitivity in early AKI (2). NAG (N-acetyl-b-D-glucosaminidase), a lysosomal enzyme excreted in urine after renal tubular cell damage, is a candidate biomarker for early detection of AKI. To increase the understanding of CPB-related AKI, we studied the influence of perioperative factors on urinary NAG-excretion. Method. The Gothenburg Regional Ethics Committee approved the study protocol. 65 patients undergoing complex cardiac surgery with an expected CPB-time 4 120 minutes were included after informed consent. Perioperative data were recorded and urine samples for NAG excretion corrected for urine creatinine were taken at specified times as indicated in figure. An ANOVA for repeated measurements followed by Fisher’s PLSD test were used to assess changes in NAG excretion over time. Bi- and multivariate linear regression analyses were performed to establish clinical variables associated with renal tubular injury. Results. Figure shows mean urinary NAG/creatinine ratio ⫾ SEM. * p o 0.05, *** p o 0.001. NAG excretion increased significantly early after start of CPB and peaked at ICU arrival, 89⫾ 5.5 minutes after weaning from CPB. Multiple regression using NAG excretion as the dependent variable was significant at p o 0.001, (adjusted R2 ¼ 0.329).
B ⫾ SEM
ß p-value
0.002 ⫾ 0.001 -0.008 ⫾ 0.002
0.293 0.001 -0.397 0.002
Preoperative eGFR (ml min-1)
0.004 ⫾ 0.002
0.286 0.013
Diabetes mellitus
0.254 ⫾ 0.125
0.212 0.047
Coefficient CPB time (minutes) Fluid administered during CPB (mL kg-1)
Discussion. Intra-operative fluid load, CPB time and diabetes mellitus were independently associated with tubular injury. Preoperative eGFR was positively associated with NAG excretion, suggesting that the release of tubular injury markers durig/after CPB must be adjusted for preoperative renal function, i.e. the number of functioning nephrons