ASAIO Journal 2014
Brief Communication
Clinical Indications for Implantation of the Total Artificial Heart Kristin L. Thanavaro,* Daniel G. Tang,† Vigneshwar Kasirajan,† and Keyur B. Shah*
We studied 66 consecutive patients implanted with the CardioWest TAH (Syncardia, Tucson, AZ) at our institution from 2006 to 2012. A retrospective chart review was performed to abstract laboratory and clinical data from the medical record. Based on independent review by two investigators (K.L.T. and K.B.S.), the indication for TAH was categorized as biventricular heart failure (BiVHF; cardiomyopathy with right ventricular dysfunction prohibiting LVAD implantation) or ALT pathology. Invasive hemodynamic measurements, echocardiography, and clinical notes were reviewed to determine if BiVHF was present. Patients in the ALT group were categorized into six groups by indication for device—hypertrophic cardiomyopathy, refractory arrhythmias, postinfarction shock, ventricular rupture, LVAD failure, and cardiac allograft failure. The institutional review board at the Virginia Commonwealth University approved this project.
The total artificial heart (TAH) is effective for bridging patients with biventricular heart failure (BiVHF) to transplantation. It consists of two pneumatic pumps with four mechanical valves that replace nearly the entire myocardium, thus also making it effective therapy for heart failure from alternative (ALT) anatomical and pathophysiological causes that preclude left ventricular assist device (LVAD). This report reviews the clinical indications and outcomes for TAH implantation at our institution from 2006 to 2012. We sought to characterize and compare survival to transplant for patients with BiVHF to those with ALT indications. The overall survival to transplant for all patients was 86% (57/66). There was a trend towards decreased survival to transplantation in the ALT group compared with the BiVHF group (77% vs. 93%, HR 0.42 [95% confidence interval 0.1, 1.7], log-rank test: p = 0.2). This was likely driven by certain high risk subgroups of allograft failure, LVAD failure, and acute postinfarct shock. ASAIO Journal 2014; 60:594–596.
Results Demographics and laboratory values are listed in Table 1. Forty patients (61%) had BiVHF, and twenty-six had ALT indications. In the ALT group, two patients had hypertrophic cardiomyopathy (8%), eight had refractory arrhythmias (31%), six had postinfarction shock (23%), two had ventricular rupture (8%), three had LVAD failure (11%), and five had cardiac allograft failure (19%). More patients in the ALT group were Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile 1 (50% vs. 35%), although this was not statistically significant (p = 0.2). There was a trend towards fewer implantations for BiVHF after 2009 when a continuous flow (CF) LVAD became available at our institution (75% to 54%). The mean number of days on device was 103.6 ± 99.6 for BiVHF group and 168 ± 180.8 for the ALT group (p = 0.11). Three patients in the BiVHF group (7.5%) died, compared with six in the ALT group (23%). There was a trend towards decreased survival to transplantation in the ALT group that was not statistically significant (93% vs. 77%, HR 0.42 [95% confidence interval 0.1, 1.7], log-rank test: p = 0.2). Survival for each indication is presented in Table 2, and a Kaplan–Meier survival curve is presented in Figure 1. Of the three deaths in BiVHF group, one occurred in the immediate postoperative period from hypoxic encephalopathy (on day 6). The other deaths occurred from intracranial hemorrhage and multisystem organ failure (day 62 and 81). The six deaths in the ALT group occurred in patients with allograft rejection (n = 2), postinfarct shock (n = 2), LVAD failure (n = 1), and shock/progressive heart failure (n = 1). Two of the deaths occurred perioperatively (on day 1 and 3) in patients who had been bridged from extracorporeal membrane oxygenation. Two of the deaths were from persistent infection (on day 79 and 162), one was from an intracranial bleed (on day 32), and one was from circulatory collapse after malfunction of a portable driver (on day 169).
Key Words: mechanical circulatory support, heart transplantation, total artificial heart
Total heart replacement is an effective bridge to transplanta-
tion for patients with severe biventricular heart failure.1 Total artificial heart replacement (TAH) may also be considered for patients with conditions other than biventricular failure, where coexisting medical or anatomical conditions make left ventricular assist device (LVAD) implantation less desirable including ventricular rupture, small ventricular cavities (restrictive/hypertrophic cardiomyopathies), complex heart congenital disease, refractory arrhythmias, or allograft failure. We sought to characterize and compare survival to transplant for TAH patients in these two groups. It is our institutional practice to select the TAH rather than biventricular assist device (BiVAD) support for durable mechanical circulatory support with the intention for heart transplantation.
From the *Division of Cardiology, Virginia Commonwealth University Medical Center, Richmond, Virginia; and †Division of Cardiothoracic Surgery, Virginia Commonwealth University Medical Center, Richmond, Virginia. Submitted for consideration January 2014; accepted for publication in revised form May 2014. Disclosures: Dr. Kasirajan is a consultant for Syncardia, is the principal investigator for the Freedom Trial for Syncardia, and has institutional research grants from Thoratec Corp and Syncardia. Dr. Shah has institutional grants from Thoratec Corp. Correspondence: Kristin L. Thanavaro, Division of Cardiology, Virginia Commonwealth University, MCV Campus, P.O. Box 980204, Richmond, VA 23298-0204. Email: [email protected]. Copyright © 2014 by the American Society for Artificial Internal Organs DOI: 10.1097/MAT.0000000000000111
594
INDICATION FOR THE TOTAL ARTIFICIAL HEART
595
Table 1. Baseline Characteristics
Variable
Biventricular Heart Failure N = 40
Alternative Indication N = 26
p
Male gender Ischemic cardiomyopathy Age (years) BMI (kg/m2) BSA (m2) Hgb (g/dl) Creatinine (mg/dl) AST (IU/l) ALT (IU/l) Total bilirubin (mg/dl) INR Mean RA (mm Hg) Mean PAP (mm Hg) PCWP (mm Hg) Cardiac output (Fick) Cardiac index (Fick) INTERMACS profile 1 Days alive on TAH
81% (21) 23% (6) 48.8 ± 12.3 29.1 ± 5.5 2.14 10.9 ± 1.8 1.7 ± 2.0 148.2 ± 350.4 152.3 ± 381.6 1.8 ± 1.1 1.4 ± 0.5 19.3 ± 8.6 39.8 ± 9.5 28.8 ± 7.8 3.8 ± 1 1.8 ± 0.5 35% (14) 103.6 ± 99.6
90% (36) 20% (8) 48.7 ± 11.1 29.0 ± 6.4 2.08 10.4 ± 2.3 1.6 ± 0.9 494.2 ± 1184.7 225.6 ± 462.1 1.5 ± 1.0 1.5 ± 0.4 15.9 ± 7.4 31.9 ± 15.0 23.6 ± 10.1 3.9 ± 1.3 1.9 ± 0.6 50% (13) 168 ± 180.8
0.3 0.8 0.8 0.9 0.3 0.4 0.7 0.2 0.5 0.2 0.5 0.2 0.07 0.08 0.9 0.9 0.2 0.1
ALT, alanine aminotransferase; AST, aspartate aminotransferase; BMI, body mass index; BSA, body surface area; Hgb, hemoglobin; INR, international normalized ratio; INTERMACS, Interagency Registry for Mechanically Assisted Circulatory Support; PAP, pulmonary artery pressure; PCWP, pulmonary capillary wedge pressure; RA, right atrial; TAH, total artificial heart.
Discussion We found that the TAH was effective for bridging patients with indications other than BiVHF to transplantation. Although there was a trend towards decreased survival in the ALT group, 77% still survived to transplantation. This less favorable survival is likely driven by certain high risk subgroups that were implanted with the TAH under emergent, life-threatening conditions (acute shock, LVAD/allograft failure). This is reflected in the greater number of patients in the ALT group who were INTERMACS profile 1 compared with patients in the BiVHF group, who tended towards less sick profiles. Although our data were underpowered to analyze survival by individual indication, other centers have also reported poorer survival depending on indication for implantation. Copeland found that patients with BiVHF had a 79% survival to transplant on the TAH, compared with 50% for those with off-protocol indications1 (LVADs, hemodialysis, and previous heart transplantation). The La Pitié group similarly found that from 1997 to 2001 survival to transplant for patients with dilated cardiomyopathy was 74%, compared with 50% for Table 2. Survival to Transplant for Biventricular Heart Failure and Alternative Patients Indication for Total Artificial Heart
Survival to Transplant
Biventricular heart failure Alternative indication (total) Hypertrophic cardiomyopathy Acute shock Refractory arrhythmias Ventricular rupture LVAD failure Allograft failure
37/40 (93%) 20/26 (77%) 2/2 (100%) 3/6 (50%) 8/8 (100%) 2/2 (100%) 2/3 (67%) 3/5 (60%)
Figure 1. Kaplan–Meier curves for alternative and BiVHF group showing survival to transplantation. BiVHF, biventricular heart failure; TAH, total artificial heart.
patients with alternative indications (graft failure/rejection, multioperated valvular disease, acute myocardial infarction, hypertrophic cardiomyopathy, and congenital disease).2 However, the German Bad Oeynhausen group found that patients with acute postinfarct shock and postcardiotomy heart failure actually had better survival at the end of the study compared with those patients with chronic progressive heart failure (73% vs. 21%).3 The authors attribute this to the fact that patients in the former group became ill acutely and had less end-organ failure than the chronic heart failure patients who had hypoperfusion for months before transplant. However, it should be noted that in this study, 50% (2/4) of patients with fulminant myocarditis and 100% (2/2) of patients with allograft failure died. The survival to transplant on the TAH (93% for BiVHF and 77% for ALT) is higher than the documented survival published for durable extracorporeal BiVADs. In Germany, Brehm and colleagues investigated survival to transplant for 39 acute and chronic heart failure patients on the paracorporeal ventricular assist device (Thoratec Corporation, Pleasanton, CA). They found that patients with acute heart failure, about half of whom had myocarditis, had a 53% survival to transplant compared with only 13% for patients with chronic heart failure.4 A Toronto group examined survival of patients implanted with the ABIOMED BVS 5000 (ABIOMED Inc, CA). Ten of the 18 patients (55%) survived to device explant or transplantation.5 Thirteen were bridged to recovery, two were bridged to a more permanent device, and three were bridged to transplantation. Of note, the mean duration on device for this study was only 6 days (range 1–10). A group from Cedars-Saini Medical Center examined patients implanted with the Thoratec BiVAD for heart failure refractory to medical therapy. These patients had high preoperative morbidity, with 89% requiring an intraaortic balloon pump, 68% mechanically ventilated, and 84% requiring
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THANAVARO et al.
three or more inotropes.6 Of the 17 patients, 10 (59%) survived to transplantation. Another notable finding was the decreasing proportion of patients receiving the TAH for BiVHF since the introduction of CF LVADs. We observed a rise in LVAD implantation with the introduction of more durable and compact CF technologies. With the greater availability of temporary right ventricular support devices and improved identification of patients at high risk for postoperative right ventricular failure, we have implanted the TAH in a smaller proportion of patients with BiVHF in the CF LVAD era (54% vs. 75%). In the continuous flow LVAD era, more patients with BiVHF are now managed successfully with LVAD centered strategies (LVAD + temporary right ventricular assist device or LVAD + prolonged inotropes), leading to an increased reliance on TAH implantation for patients who may have anatomical contraindications for an LVAD. Our study has noteworthy limitations. Although this is one of the larger contemporary experiences with the TAH, it is underpowered to distinguish differences in outcomes by subgroups. With a larger sample size, our results may reach statistical significance. This was a retrospective study prone to misclassification of patients into BiVHF/ALT groups, although the categorizations were adjudicated by two investigators. Our center’s experience demonstrates that the TAH is an effective bridge to transplantation for patients with pure biventricular failure as well as patients with alternative indications, with 86% of all patients surviving to transplantation. The
decreased survival in the ALT group compared with the BiVHF group is driven by certain high risk conditions such as allograft failure, LVAD failure, and postinfarct shock but surpasses previously published data on the TAH and BiVADs. Acknowledgment The authors thank Dr. Michael Hess and Dr. Richard Cooke for their help and support.
References 1. Copeland JG, Smith RG, Arabia FA, et al: CardioWest total artificial heart investigators. N Engl J Med 351: 859–867, 2004. 2. Leprince P, Bonnet N, Rama A, et al: Bridge to Transplantation with the Jarvik-7 (CardioWest) total artifical heart: A single-center 15-year experience. J Heart Lung Transplant 22: 1296–1303, 2003. 3. El-Banayosy A, Arusoglu L, Morshuis M, et al: CardioWest total artificial heart: Bad Oeyenhausen experience. Ann Thorac Surg 80: 548–552, 2005. 4. Brehm K, Heilmann C, Siepe M, Benk C, Beyersdorf F, Schlensak C: Thoratec paracorporeal biventricular assist device therapy: The Freiburg experience. Eur J Cardiothorac Surg 41: 207–212, 2012. 5. Lad V, Elhenawy A, Harwood S, et al: Mechanical circulatory support with the ABIOMED BVS 5000: The Toronto General Hospital experience. Can J Cardiol 26: 467–470, 2010. 6. Magliato KE, Kleisli T, Soukiasian HJ, et al: Biventricular support in patients with profound cardiogenic shock: A single center experience. ASAIO J 49: 475–479, 2003.
Brief Communication
Clinical Indications for Implantation of the Total Artificial Heart Kristin L. Thanavaro,* Daniel G. Tang,† Vigneshwar Kasirajan,† and Keyur B. Shah*
We studied 66 consecutive patients implanted with the CardioWest TAH (Syncardia, Tucson, AZ) at our institution from 2006 to 2012. A retrospective chart review was performed to abstract laboratory and clinical data from the medical record. Based on independent review by two investigators (K.L.T. and K.B.S.), the indication for TAH was categorized as biventricular heart failure (BiVHF; cardiomyopathy with right ventricular dysfunction prohibiting LVAD implantation) or ALT pathology. Invasive hemodynamic measurements, echocardiography, and clinical notes were reviewed to determine if BiVHF was present. Patients in the ALT group were categorized into six groups by indication for device—hypertrophic cardiomyopathy, refractory arrhythmias, postinfarction shock, ventricular rupture, LVAD failure, and cardiac allograft failure. The institutional review board at the Virginia Commonwealth University approved this project.
The total artificial heart (TAH) is effective for bridging patients with biventricular heart failure (BiVHF) to transplantation. It consists of two pneumatic pumps with four mechanical valves that replace nearly the entire myocardium, thus also making it effective therapy for heart failure from alternative (ALT) anatomical and pathophysiological causes that preclude left ventricular assist device (LVAD). This report reviews the clinical indications and outcomes for TAH implantation at our institution from 2006 to 2012. We sought to characterize and compare survival to transplant for patients with BiVHF to those with ALT indications. The overall survival to transplant for all patients was 86% (57/66). There was a trend towards decreased survival to transplantation in the ALT group compared with the BiVHF group (77% vs. 93%, HR 0.42 [95% confidence interval 0.1, 1.7], log-rank test: p = 0.2). This was likely driven by certain high risk subgroups of allograft failure, LVAD failure, and acute postinfarct shock. ASAIO Journal 2014; 60:594–596.
Results Demographics and laboratory values are listed in Table 1. Forty patients (61%) had BiVHF, and twenty-six had ALT indications. In the ALT group, two patients had hypertrophic cardiomyopathy (8%), eight had refractory arrhythmias (31%), six had postinfarction shock (23%), two had ventricular rupture (8%), three had LVAD failure (11%), and five had cardiac allograft failure (19%). More patients in the ALT group were Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile 1 (50% vs. 35%), although this was not statistically significant (p = 0.2). There was a trend towards fewer implantations for BiVHF after 2009 when a continuous flow (CF) LVAD became available at our institution (75% to 54%). The mean number of days on device was 103.6 ± 99.6 for BiVHF group and 168 ± 180.8 for the ALT group (p = 0.11). Three patients in the BiVHF group (7.5%) died, compared with six in the ALT group (23%). There was a trend towards decreased survival to transplantation in the ALT group that was not statistically significant (93% vs. 77%, HR 0.42 [95% confidence interval 0.1, 1.7], log-rank test: p = 0.2). Survival for each indication is presented in Table 2, and a Kaplan–Meier survival curve is presented in Figure 1. Of the three deaths in BiVHF group, one occurred in the immediate postoperative period from hypoxic encephalopathy (on day 6). The other deaths occurred from intracranial hemorrhage and multisystem organ failure (day 62 and 81). The six deaths in the ALT group occurred in patients with allograft rejection (n = 2), postinfarct shock (n = 2), LVAD failure (n = 1), and shock/progressive heart failure (n = 1). Two of the deaths occurred perioperatively (on day 1 and 3) in patients who had been bridged from extracorporeal membrane oxygenation. Two of the deaths were from persistent infection (on day 79 and 162), one was from an intracranial bleed (on day 32), and one was from circulatory collapse after malfunction of a portable driver (on day 169).
Key Words: mechanical circulatory support, heart transplantation, total artificial heart
Total heart replacement is an effective bridge to transplanta-
tion for patients with severe biventricular heart failure.1 Total artificial heart replacement (TAH) may also be considered for patients with conditions other than biventricular failure, where coexisting medical or anatomical conditions make left ventricular assist device (LVAD) implantation less desirable including ventricular rupture, small ventricular cavities (restrictive/hypertrophic cardiomyopathies), complex heart congenital disease, refractory arrhythmias, or allograft failure. We sought to characterize and compare survival to transplant for TAH patients in these two groups. It is our institutional practice to select the TAH rather than biventricular assist device (BiVAD) support for durable mechanical circulatory support with the intention for heart transplantation.
From the *Division of Cardiology, Virginia Commonwealth University Medical Center, Richmond, Virginia; and †Division of Cardiothoracic Surgery, Virginia Commonwealth University Medical Center, Richmond, Virginia. Submitted for consideration January 2014; accepted for publication in revised form May 2014. Disclosures: Dr. Kasirajan is a consultant for Syncardia, is the principal investigator for the Freedom Trial for Syncardia, and has institutional research grants from Thoratec Corp and Syncardia. Dr. Shah has institutional grants from Thoratec Corp. Correspondence: Kristin L. Thanavaro, Division of Cardiology, Virginia Commonwealth University, MCV Campus, P.O. Box 980204, Richmond, VA 23298-0204. Email: [email protected]. Copyright © 2014 by the American Society for Artificial Internal Organs DOI: 10.1097/MAT.0000000000000111
594
INDICATION FOR THE TOTAL ARTIFICIAL HEART
595
Table 1. Baseline Characteristics
Variable
Biventricular Heart Failure N = 40
Alternative Indication N = 26
p
Male gender Ischemic cardiomyopathy Age (years) BMI (kg/m2) BSA (m2) Hgb (g/dl) Creatinine (mg/dl) AST (IU/l) ALT (IU/l) Total bilirubin (mg/dl) INR Mean RA (mm Hg) Mean PAP (mm Hg) PCWP (mm Hg) Cardiac output (Fick) Cardiac index (Fick) INTERMACS profile 1 Days alive on TAH
81% (21) 23% (6) 48.8 ± 12.3 29.1 ± 5.5 2.14 10.9 ± 1.8 1.7 ± 2.0 148.2 ± 350.4 152.3 ± 381.6 1.8 ± 1.1 1.4 ± 0.5 19.3 ± 8.6 39.8 ± 9.5 28.8 ± 7.8 3.8 ± 1 1.8 ± 0.5 35% (14) 103.6 ± 99.6
90% (36) 20% (8) 48.7 ± 11.1 29.0 ± 6.4 2.08 10.4 ± 2.3 1.6 ± 0.9 494.2 ± 1184.7 225.6 ± 462.1 1.5 ± 1.0 1.5 ± 0.4 15.9 ± 7.4 31.9 ± 15.0 23.6 ± 10.1 3.9 ± 1.3 1.9 ± 0.6 50% (13) 168 ± 180.8
0.3 0.8 0.8 0.9 0.3 0.4 0.7 0.2 0.5 0.2 0.5 0.2 0.07 0.08 0.9 0.9 0.2 0.1
ALT, alanine aminotransferase; AST, aspartate aminotransferase; BMI, body mass index; BSA, body surface area; Hgb, hemoglobin; INR, international normalized ratio; INTERMACS, Interagency Registry for Mechanically Assisted Circulatory Support; PAP, pulmonary artery pressure; PCWP, pulmonary capillary wedge pressure; RA, right atrial; TAH, total artificial heart.
Discussion We found that the TAH was effective for bridging patients with indications other than BiVHF to transplantation. Although there was a trend towards decreased survival in the ALT group, 77% still survived to transplantation. This less favorable survival is likely driven by certain high risk subgroups that were implanted with the TAH under emergent, life-threatening conditions (acute shock, LVAD/allograft failure). This is reflected in the greater number of patients in the ALT group who were INTERMACS profile 1 compared with patients in the BiVHF group, who tended towards less sick profiles. Although our data were underpowered to analyze survival by individual indication, other centers have also reported poorer survival depending on indication for implantation. Copeland found that patients with BiVHF had a 79% survival to transplant on the TAH, compared with 50% for those with off-protocol indications1 (LVADs, hemodialysis, and previous heart transplantation). The La Pitié group similarly found that from 1997 to 2001 survival to transplant for patients with dilated cardiomyopathy was 74%, compared with 50% for Table 2. Survival to Transplant for Biventricular Heart Failure and Alternative Patients Indication for Total Artificial Heart
Survival to Transplant
Biventricular heart failure Alternative indication (total) Hypertrophic cardiomyopathy Acute shock Refractory arrhythmias Ventricular rupture LVAD failure Allograft failure
37/40 (93%) 20/26 (77%) 2/2 (100%) 3/6 (50%) 8/8 (100%) 2/2 (100%) 2/3 (67%) 3/5 (60%)
Figure 1. Kaplan–Meier curves for alternative and BiVHF group showing survival to transplantation. BiVHF, biventricular heart failure; TAH, total artificial heart.
patients with alternative indications (graft failure/rejection, multioperated valvular disease, acute myocardial infarction, hypertrophic cardiomyopathy, and congenital disease).2 However, the German Bad Oeynhausen group found that patients with acute postinfarct shock and postcardiotomy heart failure actually had better survival at the end of the study compared with those patients with chronic progressive heart failure (73% vs. 21%).3 The authors attribute this to the fact that patients in the former group became ill acutely and had less end-organ failure than the chronic heart failure patients who had hypoperfusion for months before transplant. However, it should be noted that in this study, 50% (2/4) of patients with fulminant myocarditis and 100% (2/2) of patients with allograft failure died. The survival to transplant on the TAH (93% for BiVHF and 77% for ALT) is higher than the documented survival published for durable extracorporeal BiVADs. In Germany, Brehm and colleagues investigated survival to transplant for 39 acute and chronic heart failure patients on the paracorporeal ventricular assist device (Thoratec Corporation, Pleasanton, CA). They found that patients with acute heart failure, about half of whom had myocarditis, had a 53% survival to transplant compared with only 13% for patients with chronic heart failure.4 A Toronto group examined survival of patients implanted with the ABIOMED BVS 5000 (ABIOMED Inc, CA). Ten of the 18 patients (55%) survived to device explant or transplantation.5 Thirteen were bridged to recovery, two were bridged to a more permanent device, and three were bridged to transplantation. Of note, the mean duration on device for this study was only 6 days (range 1–10). A group from Cedars-Saini Medical Center examined patients implanted with the Thoratec BiVAD for heart failure refractory to medical therapy. These patients had high preoperative morbidity, with 89% requiring an intraaortic balloon pump, 68% mechanically ventilated, and 84% requiring
596
THANAVARO et al.
three or more inotropes.6 Of the 17 patients, 10 (59%) survived to transplantation. Another notable finding was the decreasing proportion of patients receiving the TAH for BiVHF since the introduction of CF LVADs. We observed a rise in LVAD implantation with the introduction of more durable and compact CF technologies. With the greater availability of temporary right ventricular support devices and improved identification of patients at high risk for postoperative right ventricular failure, we have implanted the TAH in a smaller proportion of patients with BiVHF in the CF LVAD era (54% vs. 75%). In the continuous flow LVAD era, more patients with BiVHF are now managed successfully with LVAD centered strategies (LVAD + temporary right ventricular assist device or LVAD + prolonged inotropes), leading to an increased reliance on TAH implantation for patients who may have anatomical contraindications for an LVAD. Our study has noteworthy limitations. Although this is one of the larger contemporary experiences with the TAH, it is underpowered to distinguish differences in outcomes by subgroups. With a larger sample size, our results may reach statistical significance. This was a retrospective study prone to misclassification of patients into BiVHF/ALT groups, although the categorizations were adjudicated by two investigators. Our center’s experience demonstrates that the TAH is an effective bridge to transplantation for patients with pure biventricular failure as well as patients with alternative indications, with 86% of all patients surviving to transplantation. The
decreased survival in the ALT group compared with the BiVHF group is driven by certain high risk conditions such as allograft failure, LVAD failure, and postinfarct shock but surpasses previously published data on the TAH and BiVADs. Acknowledgment The authors thank Dr. Michael Hess and Dr. Richard Cooke for their help and support.
References 1. Copeland JG, Smith RG, Arabia FA, et al: CardioWest total artificial heart investigators. N Engl J Med 351: 859–867, 2004. 2. Leprince P, Bonnet N, Rama A, et al: Bridge to Transplantation with the Jarvik-7 (CardioWest) total artifical heart: A single-center 15-year experience. J Heart Lung Transplant 22: 1296–1303, 2003. 3. El-Banayosy A, Arusoglu L, Morshuis M, et al: CardioWest total artificial heart: Bad Oeyenhausen experience. Ann Thorac Surg 80: 548–552, 2005. 4. Brehm K, Heilmann C, Siepe M, Benk C, Beyersdorf F, Schlensak C: Thoratec paracorporeal biventricular assist device therapy: The Freiburg experience. Eur J Cardiothorac Surg 41: 207–212, 2012. 5. Lad V, Elhenawy A, Harwood S, et al: Mechanical circulatory support with the ABIOMED BVS 5000: The Toronto General Hospital experience. Can J Cardiol 26: 467–470, 2010. 6. Magliato KE, Kleisli T, Soukiasian HJ, et al: Biventricular support in patients with profound cardiogenic shock: A single center experience. ASAIO J 49: 475–479, 2003.
