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Maximal oxygen uptake improvements with long-term LVAD support
The Journal of Heart and Lung Transplantation Volume 24, Number 2S
culture conditions (⫹37°C, 5% CO2) over a period of 7 days. Changes of the COLL I and III synthesis were analyzed using immunohistochemical staining methods. COLL I and III content was quantified using a fluorescence confocal laser scanning microscope and special analysis software. Compared to CM exposed to 0 A (control), COLL I synthesis of CM showed no significant change after exposure to a MC magnitude of 50 A but a highly significant mean decrease (20.6 %) if exposed to 100 A. COLL III revealed a mean increase at 50 A of 29.7 % and a decrease of 25.2 % at 100 A exposure. The results suggest that MC is able to modulate the synthesis of COLL. In dependency of the current magnitude COLL I can be up- or down-regulated. COLL I is responsible for the stiffness and the degree of dilatation of the heart. It can be envisaged that this method - if applied clinically - may help to improve cardiac function, as it helps to heal bone fractures. 198 LONG-TERM OUTCOME IN PATIENTS WITH IDIOPATHIC DILATED CARDIOMYOPATHY AFTER WEANING FROM LEFT VENTRICULAR ASSIST DEVICES M. Dandel,1 Y. Weng,1 H. Siniawski,1 E. Potapov,1 R. Hetzer,1 1 Cardiothoracic and Vascular Surgery, Deutsches Herzzentrum Berlin, Berlin, Germany Purpose: Since our first successful weaning from left ventricular assist device (LVAD) of a patient with idiopathic dilated cardiomyopathy (DCM) in 1995 we have shown that for selected patients with DCM weaning is a feasible option. After 9 years of experience we assessed the long-term results of all weaned patients. Methods: We evaluated all patients with DCM weaned between 3/1995–3/2004 with regard to preservation of stable cardiac function without LVAD support and survival after weaning. Results: The 33 weaned DCM patients showed survival of 85% at 5 years after LVAD removal. Sustained cardiac recovery for ⬎2 years after weaning was documented in 64.3%. At 5 years after LVAD removal, despite worsening of cardiac function in some patients, 75% still had their native hearts, without any need for transplantation or another LVAD. Recurrence of heart failure (HF) within the first 2 years occurred in only 32.3% of patients. Only one patient died after weaning due to HF; the other patients with HF recurrence were successfully transplanted. Three patients (9.6%) died after weaning due to non-cardiac causes. LV enddiastolic diameter (LVEDD) and ejection fraction (LVEF) obtained during final “off pump” trials before weaning appeared predictable for long-term outcome after weaning. Thus LVEDD ⱕ55mm associated with LVEF ⱖ 45% together with a history of ⬍5 years were predictive of good long-term cardiac function (positive predictive value for stable function beyond 3 years after weaning 92.3%). “Off pump” LVEDD ⬎55mm and/or LVEF ⬍ 45% were predictive for short-term HF recurrence after weaning. Conclusions: For selected patients with DCM, weaning from LVADs is a clinical option with potentially successful results over more than 5 years and should therefore be considered in all patients with sufficient recovery of cardiac function after LVAD implantation. Echocardiographic data obtained during “off pump” trials are reliable for detection of LV recovery and prediction of long-term optimal cardiac function after weaning. 199 MAXIMAL OXYGEN UPTAKE IMPROVEMENTS WITH LONGTERM LVAD SUPPORT J.C. Matthews,1 F.D. Pagani,2 S. Wright,2 M. Daly-Myers,2 D.B. Dyke,1 1Division of Cardiovascular Medicine, The University of Michigan, Ann Arbor, MI; 2Section of Adult Cardiac Surgery, The University of Michigan, Ann Arbor, MI
Abstracts
S107
Background: LVAD support is known to improve maximal oxygen consumption (VO2max) for patients awaiting heart transplant. The purpose of this study was to demonstrate the magnitude and time course of change in VO2max during serial cardiopulmonary exercise testing (CPX) during LVAD support. This information may help define a time period of optimal fitness for transplant in patients who undergo long-term LVAD support. Methods: A prospectively collected database of clinical variables has been established for all LVAD recipients at the University of Michigan. Analysis of change in VO2max was performed on patients who underwent ⱖ3 CPX tests during LVAD support. Statistical analysis was performed with paired-sample t test and repeated-measures ANOVA with Bonferroni adjustment for multiple comparisons. Results: Between 1996 and the present time, 142 LVADs (135 Thoratec HeartMate devices, 7 other) have been implanted. A total of 48 patients have been evaluated with CPX testing. The mean initial VO2max was 13.0⫾3.1 ml/kg/min at 7.5⫾5.7 weeks post-op. Of these patients, 17 underwent CPX testing at 6.1⫾2.7, 18.3⫾4.8, and 32.0⫾7.4 weeks post-op during full LVAD support. VO2max improved from 13.7⫾3.9 to 15.7⫾5.0 to 16.3⫾4.5 across the three measurements (p⫽0.003). Post-hoc analysis demonstrates a statistically significant difference between the first two measurements (p⫽0.013), and a non-significant trend between the second and third measurements (p⫽0.31). Conclusions: VO2max continues to improve up to 8 months after LVAD implantation. The majority of this improvement is seen within the first 18 weeks. For patients who survive the high-risk period immediately following LVAD implantation, deferring on transplant for the first 4 months allows for more complete functional recovery. This may translate into better transplant outcomes despite the risk incurred by long-term LVAD support. 200 IMPROVEMENT OF SYMPATHETIC NERVE ACTIVITY RATHER THAN MYOCARDIAL FIBROSIS MAY CONTRIBUTE TO FUNCTIONAL RECOVERY OF IDIOPATHIC CARDIOMYOPATHY DURING PROLONGED MECHANICAL VENTRICULAR SUPPORT G. Matsumiya,1 O. Monta,1 Y. Sawa,1 N. Fukushima,1 H. Matsuda,1 1Department of Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan Objectives: To elucidate the change of sympathetic nerve activity and myocardial fibrosis during a prolonged LVAS support and analyze their role in the functional recovery of idiopathic dilated cardiomyopathy (DCM). Methods: From 2000 to 2003, 11 patients (age; 21 to 38, mean of 27.9, 10 male) with end-stage heart failure secondary to DCM were supported with implantable LVAS for at least 6 months. All the patients had pharmachological treatment including beta-blocker. Myocardial specimen was obtained both at LVAS implant and explant. Iodine-125-metaiodobenzylguanidine (MIBG) scintigraphy was obtained serially to assess the sympathetic nerve activity. Results: During 239 to 663 (mean 453) days of LVAS support, 5 patients had significant recovery of cardiac function and successfully underwent LVAS removal. All of these patients have remained in NYHA class 1 during 6 to 26 months of follow-up. The other 6 patients did not have significant recovery and either underwent transplantation (n⫽1) or expired (n⫽5) after 244 to 648 (mean 470) days of support. Myocardial fibrosis worsened during the LVAS support in all the patients. However, fibrosis was significantly less severe in the recovered group (% fibrosis 17.7⫾8.2 % at LVAS implant vs. 20.1⫾5.2% at explant) in comparison to the non-recovered group (30.5⫾13.2 % at implant vs. 48.4⫾5.1% at explant) both at pre- and post-LVAS. Heart-to-mediastinum activity
culture conditions (⫹37°C, 5% CO2) over a period of 7 days. Changes of the COLL I and III synthesis were analyzed using immunohistochemical staining methods. COLL I and III content was quantified using a fluorescence confocal laser scanning microscope and special analysis software. Compared to CM exposed to 0 A (control), COLL I synthesis of CM showed no significant change after exposure to a MC magnitude of 50 A but a highly significant mean decrease (20.6 %) if exposed to 100 A. COLL III revealed a mean increase at 50 A of 29.7 % and a decrease of 25.2 % at 100 A exposure. The results suggest that MC is able to modulate the synthesis of COLL. In dependency of the current magnitude COLL I can be up- or down-regulated. COLL I is responsible for the stiffness and the degree of dilatation of the heart. It can be envisaged that this method - if applied clinically - may help to improve cardiac function, as it helps to heal bone fractures. 198 LONG-TERM OUTCOME IN PATIENTS WITH IDIOPATHIC DILATED CARDIOMYOPATHY AFTER WEANING FROM LEFT VENTRICULAR ASSIST DEVICES M. Dandel,1 Y. Weng,1 H. Siniawski,1 E. Potapov,1 R. Hetzer,1 1 Cardiothoracic and Vascular Surgery, Deutsches Herzzentrum Berlin, Berlin, Germany Purpose: Since our first successful weaning from left ventricular assist device (LVAD) of a patient with idiopathic dilated cardiomyopathy (DCM) in 1995 we have shown that for selected patients with DCM weaning is a feasible option. After 9 years of experience we assessed the long-term results of all weaned patients. Methods: We evaluated all patients with DCM weaned between 3/1995–3/2004 with regard to preservation of stable cardiac function without LVAD support and survival after weaning. Results: The 33 weaned DCM patients showed survival of 85% at 5 years after LVAD removal. Sustained cardiac recovery for ⬎2 years after weaning was documented in 64.3%. At 5 years after LVAD removal, despite worsening of cardiac function in some patients, 75% still had their native hearts, without any need for transplantation or another LVAD. Recurrence of heart failure (HF) within the first 2 years occurred in only 32.3% of patients. Only one patient died after weaning due to HF; the other patients with HF recurrence were successfully transplanted. Three patients (9.6%) died after weaning due to non-cardiac causes. LV enddiastolic diameter (LVEDD) and ejection fraction (LVEF) obtained during final “off pump” trials before weaning appeared predictable for long-term outcome after weaning. Thus LVEDD ⱕ55mm associated with LVEF ⱖ 45% together with a history of ⬍5 years were predictive of good long-term cardiac function (positive predictive value for stable function beyond 3 years after weaning 92.3%). “Off pump” LVEDD ⬎55mm and/or LVEF ⬍ 45% were predictive for short-term HF recurrence after weaning. Conclusions: For selected patients with DCM, weaning from LVADs is a clinical option with potentially successful results over more than 5 years and should therefore be considered in all patients with sufficient recovery of cardiac function after LVAD implantation. Echocardiographic data obtained during “off pump” trials are reliable for detection of LV recovery and prediction of long-term optimal cardiac function after weaning. 199 MAXIMAL OXYGEN UPTAKE IMPROVEMENTS WITH LONGTERM LVAD SUPPORT J.C. Matthews,1 F.D. Pagani,2 S. Wright,2 M. Daly-Myers,2 D.B. Dyke,1 1Division of Cardiovascular Medicine, The University of Michigan, Ann Arbor, MI; 2Section of Adult Cardiac Surgery, The University of Michigan, Ann Arbor, MI
Abstracts
S107
Background: LVAD support is known to improve maximal oxygen consumption (VO2max) for patients awaiting heart transplant. The purpose of this study was to demonstrate the magnitude and time course of change in VO2max during serial cardiopulmonary exercise testing (CPX) during LVAD support. This information may help define a time period of optimal fitness for transplant in patients who undergo long-term LVAD support. Methods: A prospectively collected database of clinical variables has been established for all LVAD recipients at the University of Michigan. Analysis of change in VO2max was performed on patients who underwent ⱖ3 CPX tests during LVAD support. Statistical analysis was performed with paired-sample t test and repeated-measures ANOVA with Bonferroni adjustment for multiple comparisons. Results: Between 1996 and the present time, 142 LVADs (135 Thoratec HeartMate devices, 7 other) have been implanted. A total of 48 patients have been evaluated with CPX testing. The mean initial VO2max was 13.0⫾3.1 ml/kg/min at 7.5⫾5.7 weeks post-op. Of these patients, 17 underwent CPX testing at 6.1⫾2.7, 18.3⫾4.8, and 32.0⫾7.4 weeks post-op during full LVAD support. VO2max improved from 13.7⫾3.9 to 15.7⫾5.0 to 16.3⫾4.5 across the three measurements (p⫽0.003). Post-hoc analysis demonstrates a statistically significant difference between the first two measurements (p⫽0.013), and a non-significant trend between the second and third measurements (p⫽0.31). Conclusions: VO2max continues to improve up to 8 months after LVAD implantation. The majority of this improvement is seen within the first 18 weeks. For patients who survive the high-risk period immediately following LVAD implantation, deferring on transplant for the first 4 months allows for more complete functional recovery. This may translate into better transplant outcomes despite the risk incurred by long-term LVAD support. 200 IMPROVEMENT OF SYMPATHETIC NERVE ACTIVITY RATHER THAN MYOCARDIAL FIBROSIS MAY CONTRIBUTE TO FUNCTIONAL RECOVERY OF IDIOPATHIC CARDIOMYOPATHY DURING PROLONGED MECHANICAL VENTRICULAR SUPPORT G. Matsumiya,1 O. Monta,1 Y. Sawa,1 N. Fukushima,1 H. Matsuda,1 1Department of Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan Objectives: To elucidate the change of sympathetic nerve activity and myocardial fibrosis during a prolonged LVAS support and analyze their role in the functional recovery of idiopathic dilated cardiomyopathy (DCM). Methods: From 2000 to 2003, 11 patients (age; 21 to 38, mean of 27.9, 10 male) with end-stage heart failure secondary to DCM were supported with implantable LVAS for at least 6 months. All the patients had pharmachological treatment including beta-blocker. Myocardial specimen was obtained both at LVAS implant and explant. Iodine-125-metaiodobenzylguanidine (MIBG) scintigraphy was obtained serially to assess the sympathetic nerve activity. Results: During 239 to 663 (mean 453) days of LVAS support, 5 patients had significant recovery of cardiac function and successfully underwent LVAS removal. All of these patients have remained in NYHA class 1 during 6 to 26 months of follow-up. The other 6 patients did not have significant recovery and either underwent transplantation (n⫽1) or expired (n⫽5) after 244 to 648 (mean 470) days of support. Myocardial fibrosis worsened during the LVAS support in all the patients. However, fibrosis was significantly less severe in the recovered group (% fibrosis 17.7⫾8.2 % at LVAS implant vs. 20.1⫾5.2% at explant) in comparison to the non-recovered group (30.5⫾13.2 % at implant vs. 48.4⫾5.1% at explant) both at pre- and post-LVAS. Heart-to-mediastinum activity