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Device Geometry Does Not Predict Pump Thrombosis in HeartMate II Patients
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The Journal of Heart and Lung Transplantation, Vol 34, No 4S, April 2015
Conclusion: cLVAD patients had CMBs more frequently than small infarction. Careful attentions have to be paid for hemorrhagic cerebrovascular complications as well as ischemic complications. 5( 83) Device Geometry Does Not Predict Pump Thrombosis in HeartMate II Patients J.J. Han ,1 A.C. Gaffey,1 R. Sooppan,1 G. Hung,1 C.M. Venkataraman,1 E. Phillips,1 J.L. Howard,1 M.A. Acker,1 J. Eduardo Rame,2 P. Atluri.1 1Surgery, University of Pennsylvania, Philadelphia, PA; 2Cardiology, Hospital of the University of Pennsylvania, Philadelphia, PA. Purpose: Pump thrombosis (PT) is a common and potentially life-threatening complication among HeartMate II (HMII; Thoratec, Pleasanton, CA) patients. There have been efforts to correlate HMII geometry with higher risk of PT. The aim of this study was to test the validity of using HMII inflow cannula angle (ICA) and pump pocket depth (PPD) to predict PT. Methods: We performed a retrospective analysis of patients implanted with HMII left ventricular assist devices (LVAD) from January 2011 to March 2014 at our institution. Three blinded reviewers measured ICA and PPD from chest x-rays at post-implantation and most recent follow-up time points. The diagnosis of PT was visually confirmed upon device explantation. Results: HMII was implanted in 90 patients. Sixteen (20%) patients experienced PT. There was no statistical difference between PT and non-PT patients in their initial ICA (56.0° ± 10.1 vs. 54.6° ± 10.8, p = 0.63) and PPD (86.7 ± 24.9 mm vs. 81.1 ± 32.2 mm, p = 0.46). Prediction of PT using ICA and PPD by receiving operating characteristic (ROC) was poor (AUC= 0.54, 0.55, respectively) (Figure 1). Changes in HMII geometry were measured over 112.5 (IQR = 34.3-337.3) days. A decrease in PPD was observed (p = 0.0001). Initial ICA was a significant predictor of future angle change and suggested a convergence towards the median (55.3°) (ANOVA p = 0.005) (Figure 2). Conclusion: Post-operative ICA and PPD do not appear to predict PT in HMII patients in our experience. HMII geometry changes over time secondary to remodeling with a decrease in PPD and a convergence towards the median in ICA. Further investigation into the role of geometric VAD conformation post-implant may be warranted.
5( 84) Left Ventricular Dimension Decrement Index Early After LVAD Implantation: A Novel Risk Marker for Late Pump Thrombosis E. Joyce ,1 G.C. Stewart,1 M. Hickey,1 J. Rivero,1 I. Gosev,2 M. Leacche,2 M.M. Givertz,1 G.S. Couper,2 M.R. Mehra.1 1Cardiovascular Division, Department of Medicine, Brigham and Womens Hospital, Boston, MA; 2Division of Cardiac Surgery, Brigham and Womens Hospital, Boston, MA. Purpose: Early risk stratification for pump thrombosis in continuous-flow left ventricular assist device (LVAD) therapy remains challenging. We hypothesized that the decrement in LV size prior to discharge after device implantation is associated with increased risk of pump thrombosis. Methods: In 65 patients (age 59±11 years, 79% men, 45% destination therapy) discharged alive without evidence of thrombosis or other device malfunction following first HeartMate II LVAD implantation (January 2011-June 2014), LV dimensions in end-diastole (LVIDd) and end-systole (LVIDs) were compared between pre-implantation and optimal set speed predischarge echocardiography. LV dimension decrement indices (preoperative dimension - optimal set speed dimension divided by preoperative dimension x100) for LVIDd [LVIDdDI] and LVIDs [LVIDsDI] were calculated. Patients were followed for occurrence of confirmed or suspected (lactate dehydrogenase > 1000IU/l or 2.5x upper limit of normal ± evidence of pump dysfunction) LVAD thrombosis for the duration of therapy through November 2014. Results: Incidence of pump thrombosis was 0.07 per-patient-year (n= 18 patients overall). Median time to event was 8 (IQR 2, 17) months. Baseline preoperative LVIDd (p= 0.73) and LVIDs (p= 0.84) were similar between patients with and without LVAD thrombosis. Mean set speed (9240±300 vs. 9190±380 rpms, p= 0.60), other ramp parameters, and change in right heart indices between preoperative and set speed studies did not differ between groups. However, LVIDdDI (18±13 vs. 25±11%, p= 0.04) and LVIDsDI (16±16 vs. 28±13%, p= 0.006) were significantly lower in the pump thrombosis compared to no thrombosis group. On ROC curve analysis, AUC for association with LVAD thrombosis was 0.67 (0.52-0.82, p= 0.04) for LVIDdDI and 0.69 (0.55-0.83, p= 0.02) for LVIDsDI. A cut-off value of ≤ 15% for both indices had sensitivities of 82% (LVIDdDI) and 84% (LVIDsDI) for predicting pump thrombosis (specificities 41% and 35% respectively). Conclusion: LV Dimension Decrement Index measured at optimized speed setting on predischarge echocardiography is predictive of late pump thrombosis. This novel marker reflects intrinsic limitations to optimization of the LVAD/patient interface and identifies patients in whom more intensive surveillance for pump thrombosis may be indicated. 5( 85) Change of Left Atrial Pressure, LAP Measured With a Wireless Implantable Pressure Sensor (Titan Sensor) During Echocardiographic RAMP-Test in HeartMate II Patients L. Hubbert ,1 J. Baranowski,2 B. Delshad,3 H. Ahn.3 1Department of Cardiology, and Department of Medical and Health Sciences, Linkoping University, Linkoping, Sweden; 2Department of Clinical Physiology and Department of Medical and Health Sciences, Linköping University, Linkoping, Sweden; 3Department of Thoracic and Vascular Surgery, and Department of Medical and Health Sciences, Linkoping University, Linkoping, Sweden. Purpose: At implantation and in the initial postoperative course patients undergoing implantation of a Heart Mate II™ (HMII) are routinely monitored by a standard fluid filled catheter measuring the left atrial pressure (LAP) which is of special interest when following the balance between preload of the pump and unloading of the LV. After discharge from the intensive care units, Echocardiography is used to estimate the filling pressure of the left ventricle and optimizing the pump speed. The purpose of this study was to evaluate a new device for long-term wireless monitoring of LAP and evaluate its correspondence with Echocardiographic RAMP-test and pulmonary wedge pressure 10 weeks after implantation of HertMate II and the device. Methods: A wireless microelectromechanical pressure sensor, (Titan™, ISSYS Inc. Ypsilanti, MI, USA) was placed in the left atrium (LA) while
The Journal of Heart and Lung Transplantation, Vol 34, No 4S, April 2015
Conclusion: cLVAD patients had CMBs more frequently than small infarction. Careful attentions have to be paid for hemorrhagic cerebrovascular complications as well as ischemic complications. 5( 83) Device Geometry Does Not Predict Pump Thrombosis in HeartMate II Patients J.J. Han ,1 A.C. Gaffey,1 R. Sooppan,1 G. Hung,1 C.M. Venkataraman,1 E. Phillips,1 J.L. Howard,1 M.A. Acker,1 J. Eduardo Rame,2 P. Atluri.1 1Surgery, University of Pennsylvania, Philadelphia, PA; 2Cardiology, Hospital of the University of Pennsylvania, Philadelphia, PA. Purpose: Pump thrombosis (PT) is a common and potentially life-threatening complication among HeartMate II (HMII; Thoratec, Pleasanton, CA) patients. There have been efforts to correlate HMII geometry with higher risk of PT. The aim of this study was to test the validity of using HMII inflow cannula angle (ICA) and pump pocket depth (PPD) to predict PT. Methods: We performed a retrospective analysis of patients implanted with HMII left ventricular assist devices (LVAD) from January 2011 to March 2014 at our institution. Three blinded reviewers measured ICA and PPD from chest x-rays at post-implantation and most recent follow-up time points. The diagnosis of PT was visually confirmed upon device explantation. Results: HMII was implanted in 90 patients. Sixteen (20%) patients experienced PT. There was no statistical difference between PT and non-PT patients in their initial ICA (56.0° ± 10.1 vs. 54.6° ± 10.8, p = 0.63) and PPD (86.7 ± 24.9 mm vs. 81.1 ± 32.2 mm, p = 0.46). Prediction of PT using ICA and PPD by receiving operating characteristic (ROC) was poor (AUC= 0.54, 0.55, respectively) (Figure 1). Changes in HMII geometry were measured over 112.5 (IQR = 34.3-337.3) days. A decrease in PPD was observed (p = 0.0001). Initial ICA was a significant predictor of future angle change and suggested a convergence towards the median (55.3°) (ANOVA p = 0.005) (Figure 2). Conclusion: Post-operative ICA and PPD do not appear to predict PT in HMII patients in our experience. HMII geometry changes over time secondary to remodeling with a decrease in PPD and a convergence towards the median in ICA. Further investigation into the role of geometric VAD conformation post-implant may be warranted.
5( 84) Left Ventricular Dimension Decrement Index Early After LVAD Implantation: A Novel Risk Marker for Late Pump Thrombosis E. Joyce ,1 G.C. Stewart,1 M. Hickey,1 J. Rivero,1 I. Gosev,2 M. Leacche,2 M.M. Givertz,1 G.S. Couper,2 M.R. Mehra.1 1Cardiovascular Division, Department of Medicine, Brigham and Womens Hospital, Boston, MA; 2Division of Cardiac Surgery, Brigham and Womens Hospital, Boston, MA. Purpose: Early risk stratification for pump thrombosis in continuous-flow left ventricular assist device (LVAD) therapy remains challenging. We hypothesized that the decrement in LV size prior to discharge after device implantation is associated with increased risk of pump thrombosis. Methods: In 65 patients (age 59±11 years, 79% men, 45% destination therapy) discharged alive without evidence of thrombosis or other device malfunction following first HeartMate II LVAD implantation (January 2011-June 2014), LV dimensions in end-diastole (LVIDd) and end-systole (LVIDs) were compared between pre-implantation and optimal set speed predischarge echocardiography. LV dimension decrement indices (preoperative dimension - optimal set speed dimension divided by preoperative dimension x100) for LVIDd [LVIDdDI] and LVIDs [LVIDsDI] were calculated. Patients were followed for occurrence of confirmed or suspected (lactate dehydrogenase > 1000IU/l or 2.5x upper limit of normal ± evidence of pump dysfunction) LVAD thrombosis for the duration of therapy through November 2014. Results: Incidence of pump thrombosis was 0.07 per-patient-year (n= 18 patients overall). Median time to event was 8 (IQR 2, 17) months. Baseline preoperative LVIDd (p= 0.73) and LVIDs (p= 0.84) were similar between patients with and without LVAD thrombosis. Mean set speed (9240±300 vs. 9190±380 rpms, p= 0.60), other ramp parameters, and change in right heart indices between preoperative and set speed studies did not differ between groups. However, LVIDdDI (18±13 vs. 25±11%, p= 0.04) and LVIDsDI (16±16 vs. 28±13%, p= 0.006) were significantly lower in the pump thrombosis compared to no thrombosis group. On ROC curve analysis, AUC for association with LVAD thrombosis was 0.67 (0.52-0.82, p= 0.04) for LVIDdDI and 0.69 (0.55-0.83, p= 0.02) for LVIDsDI. A cut-off value of ≤ 15% for both indices had sensitivities of 82% (LVIDdDI) and 84% (LVIDsDI) for predicting pump thrombosis (specificities 41% and 35% respectively). Conclusion: LV Dimension Decrement Index measured at optimized speed setting on predischarge echocardiography is predictive of late pump thrombosis. This novel marker reflects intrinsic limitations to optimization of the LVAD/patient interface and identifies patients in whom more intensive surveillance for pump thrombosis may be indicated. 5( 85) Change of Left Atrial Pressure, LAP Measured With a Wireless Implantable Pressure Sensor (Titan Sensor) During Echocardiographic RAMP-Test in HeartMate II Patients L. Hubbert ,1 J. Baranowski,2 B. Delshad,3 H. Ahn.3 1Department of Cardiology, and Department of Medical and Health Sciences, Linkoping University, Linkoping, Sweden; 2Department of Clinical Physiology and Department of Medical and Health Sciences, Linköping University, Linkoping, Sweden; 3Department of Thoracic and Vascular Surgery, and Department of Medical and Health Sciences, Linkoping University, Linkoping, Sweden. Purpose: At implantation and in the initial postoperative course patients undergoing implantation of a Heart Mate II™ (HMII) are routinely monitored by a standard fluid filled catheter measuring the left atrial pressure (LAP) which is of special interest when following the balance between preload of the pump and unloading of the LV. After discharge from the intensive care units, Echocardiography is used to estimate the filling pressure of the left ventricle and optimizing the pump speed. The purpose of this study was to evaluate a new device for long-term wireless monitoring of LAP and evaluate its correspondence with Echocardiographic RAMP-test and pulmonary wedge pressure 10 weeks after implantation of HertMate II and the device. Methods: A wireless microelectromechanical pressure sensor, (Titan™, ISSYS Inc. Ypsilanti, MI, USA) was placed in the left atrium (LA) while