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Right ventricular stroke work index (RVSWI) predicts duration of inotropic support after left ventricular assist device implantation
S108
Abstracts
All patients were seen twice over a period of six months, at each clinic visit C0 and C2 were measured. Medical staff were blinded to C2 in Group A and to C0 in Group B. Results: the primary end-point will be the relative change of CyA dose under TDM with C2 and C0 during the study period of six months. Secondary end-points will be assessed including creatinine clearance, mortality, rejection episodes and infections. Conclusions: depending on the results we will be able to either recommend TDM of CyA with C2 instead of C0 or not.
197 OUTPATIENTS ON MECHANICAL CIRCULATORY SUPPORT: EXPERIENCE WITH OVER 80 PATIENTS T.N.H. Drews,1 M. Jurmann,1 D. Kemper,1 M. Pasic,1 Y. Weng,1 R. Hetzer,1 1German Heart Institute Berlin, Augustenburger Platz 1, Berlin, Germany As waiting periods for heart transplantation have lengthened, the application of long-term mechanical circulatory support (MCS) has become more common in patients presenting with cardiogenic shock. Anticipating increased long-term MCS, a policy to discharge patients home has been instituted. This study presents the results of outpatients on MCS. We report our 6-year experience with 85 patients on MCS discharged home. There were 12 patients on a biventricular assist device (Berlin Heart Excor), and 73 patients on a left ventricular assist device (24 Novacor, 21 Berlin Heart Excor LVAD, 17 Berlin Heart Incor, 10 DeBakey, one Lion Heart). The mean age was 49 years (15–72 years). They had a mean support time of 395 days (range 64–1215 days) and spent a mean of 255 days (range 3–1162 days) at home. Eight patients died from systemic infection, five from cerebral embolism, five from cerebral hemorrhage and two from underlying disease. Seventy-five patients (88%) required 242 readmissions to hospital due to wound infections (n ⫽ 44), coagulation disorder (n ⫽ 27), bleeding (n ⫽ 22), cerebral embolism (n ⫽ 20), technical problems (n ⫽ 16), for right heart catheterization (n ⫽ 8) and for non-cardiac reasons (n ⫽ 105). Our experience shows that MCS can be used in outpatients without increased mortality and with an acceptable rate of readmissions (2.8/patient). It integrates the patient into his normal environment, enables recovery from multiorgan failure and offers an acceptable quality of life.
198 AN AUTOMATIC SPEED ADAPTATION SYSTEM FOR IMPLANTABLE ROTARY BLOOD PUMPS AND ITS CLINICAL EVALUATION H. Schima,1,2 M. Vollkron,1 B. Benkowski,5 G. Morello,5 M. Quittan,3 M. Hiesmayr,4 E. Wolner,1 G. Wieselthaler,1 1Dept. of Cardiothoracic Surgery and LBI, Univ. of, Vienna, Austria; 2Dept. of Biomed. Eng., Univ. of, Vienna, Austria; 3Dept. of Physical Medicine, Univ. of, Vienna, Austria; 4Dept. of cardiovasc Anaesthesia, Univ. of, Vienna, Austria; 5Micromed Technology Inc, Houston, TX Purpose: To obtain automatic speed adaptation of rotary pumps to changes in venous return and to various levels of physical activity, an automatic control system was developed. In a first clinical trial, the safety and functionality of this algorithm has been evaluated under various patient conditions, including spiroergometry. Methods: A closed loop control system based on the MicroMedmonitoring equipment and a dSpace-PC-system was realized. Only
The Journal of Heart and Lung Transplantation February 2004
pump motor data and pump flow are used as control inputs. The physician can define “Desired flow levels” at rest and exercise, based on heart rate and general patient condition. Pump flow is analyzed continuously to determine if such flow can be achieved in consideration of potential suction and pump efficiency. The system has been tested in 40 tests in 14 patients, including conditions in the ICU, at the standard ward and in daily life, and in four tests also during spiroergometry with right heart catheterization. Results: The system reacted appropriate to every condition, including severe pathologic situations like right heart failure in early postoperative phase, chatecholamine switch or decompensation after exercise. It provided a massive increase of blood flow in case of physical activity without impairing the right heart function by septal shift, also at sudden hemodynamic changes such as posture, coughing and Valsalva action. During catheter ergometry at bicycle exercise, flow increased for 53% from baseline compared to only 27% at constant speed settings, with a decrease of pulmonary pressure at exercise from 31.5 ⫹⫺ 8,6 to 24.1 ⫹⫺ 6,3 mmHg and of wedge pressure from 20.7 ⫹⫺9,2 to 10,8 ⫹⫺5,2mmHg. The workload increased for 11%, and mean SvO2 for 10%. Conclusion: An automatic speed control system for rotary blood pumps based on pump flow interpretation was developed, which confirmed in a first clinical study its capability to adapt pump output to physiological demand, and its ability to increase the physical capacity of LVAD recipients.
199 RIGHT VENTRICULAR STROKE WORK INDEX (RVSWI) PREDICTS DURATION OF INOTROPIC SUPPORT AFTER LEFT VENTRICULAR ASSIST DEVICE IMPLANTATION S. Schenk,1 P.M. McCarthy,1 J. Feng,1 K.J. Hoercher,1 R.C. Starling,1 J.B. Young,1 L. Zhou,1 J.L. Navia,1 E.H. Blackstone,1 K. Fukamachi,1 1Biomedical Engineering, Cleveland Clinic Foundation, Cleveland, OH Background: Right ventricular dysfunction (RVD) after left ventricular assist device (LVAD) implantation, i.e., need for prolonged inotropic support (IS) or right ventricular assist device (RVAD) insertion, warrants careful evaluation. We examined incidence, prediction, and prognosis of prolonged IS. Methods: Between 1991 and 2002, LVAD’s were implanted into 259 patients at our institution. We excluded 52 patients with pre-LVAD circulatory support to allow for accurate assessment of hemodynamics. Factors associated with prolonged IS were identified with timerelated multivariable analysis. Results: Freedom from IS on day 7 and 14 was 41% and 68%, respectively. The lower RVSWI, the longer was the requirement for IS (p⬍0.01; Figure). Marginal predictors were longer pre-LVAD hospital admission and non-ischemic cardiomyopathy (both p ⫽ 0.08). Survival to transplantation (analyzed as competing risk) was compromised by prolonged IS and use for RVAD. Only 41% of non-RVAD patients with inotropic support ⬎14 days survived to transplantation as opposed to 89% of those with shorter inotropic support (p⬍0.0001). Eighteen patients (8.7%) required RVAD support and only 4 (22.2%) survived to transplantation. RVSWI was lower in patients who died of multi-organ failure, bleeding or infection (354 mmHg䡠ml/m2) than in those with cerebro-vascular events (569 mmHg䡠ml/m2 p⬍0.05). Conclusions: RVD affected many patients post LVAD insertion and was associated with poor survival. Low RVSWI predicted prolonged inotropic support and correlated with death pre-transplantation from multi-organ failure and related complications. We assess RVSWI prospectively when considering patients for biventricular support.
Abstracts
All patients were seen twice over a period of six months, at each clinic visit C0 and C2 were measured. Medical staff were blinded to C2 in Group A and to C0 in Group B. Results: the primary end-point will be the relative change of CyA dose under TDM with C2 and C0 during the study period of six months. Secondary end-points will be assessed including creatinine clearance, mortality, rejection episodes and infections. Conclusions: depending on the results we will be able to either recommend TDM of CyA with C2 instead of C0 or not.
197 OUTPATIENTS ON MECHANICAL CIRCULATORY SUPPORT: EXPERIENCE WITH OVER 80 PATIENTS T.N.H. Drews,1 M. Jurmann,1 D. Kemper,1 M. Pasic,1 Y. Weng,1 R. Hetzer,1 1German Heart Institute Berlin, Augustenburger Platz 1, Berlin, Germany As waiting periods for heart transplantation have lengthened, the application of long-term mechanical circulatory support (MCS) has become more common in patients presenting with cardiogenic shock. Anticipating increased long-term MCS, a policy to discharge patients home has been instituted. This study presents the results of outpatients on MCS. We report our 6-year experience with 85 patients on MCS discharged home. There were 12 patients on a biventricular assist device (Berlin Heart Excor), and 73 patients on a left ventricular assist device (24 Novacor, 21 Berlin Heart Excor LVAD, 17 Berlin Heart Incor, 10 DeBakey, one Lion Heart). The mean age was 49 years (15–72 years). They had a mean support time of 395 days (range 64–1215 days) and spent a mean of 255 days (range 3–1162 days) at home. Eight patients died from systemic infection, five from cerebral embolism, five from cerebral hemorrhage and two from underlying disease. Seventy-five patients (88%) required 242 readmissions to hospital due to wound infections (n ⫽ 44), coagulation disorder (n ⫽ 27), bleeding (n ⫽ 22), cerebral embolism (n ⫽ 20), technical problems (n ⫽ 16), for right heart catheterization (n ⫽ 8) and for non-cardiac reasons (n ⫽ 105). Our experience shows that MCS can be used in outpatients without increased mortality and with an acceptable rate of readmissions (2.8/patient). It integrates the patient into his normal environment, enables recovery from multiorgan failure and offers an acceptable quality of life.
198 AN AUTOMATIC SPEED ADAPTATION SYSTEM FOR IMPLANTABLE ROTARY BLOOD PUMPS AND ITS CLINICAL EVALUATION H. Schima,1,2 M. Vollkron,1 B. Benkowski,5 G. Morello,5 M. Quittan,3 M. Hiesmayr,4 E. Wolner,1 G. Wieselthaler,1 1Dept. of Cardiothoracic Surgery and LBI, Univ. of, Vienna, Austria; 2Dept. of Biomed. Eng., Univ. of, Vienna, Austria; 3Dept. of Physical Medicine, Univ. of, Vienna, Austria; 4Dept. of cardiovasc Anaesthesia, Univ. of, Vienna, Austria; 5Micromed Technology Inc, Houston, TX Purpose: To obtain automatic speed adaptation of rotary pumps to changes in venous return and to various levels of physical activity, an automatic control system was developed. In a first clinical trial, the safety and functionality of this algorithm has been evaluated under various patient conditions, including spiroergometry. Methods: A closed loop control system based on the MicroMedmonitoring equipment and a dSpace-PC-system was realized. Only
The Journal of Heart and Lung Transplantation February 2004
pump motor data and pump flow are used as control inputs. The physician can define “Desired flow levels” at rest and exercise, based on heart rate and general patient condition. Pump flow is analyzed continuously to determine if such flow can be achieved in consideration of potential suction and pump efficiency. The system has been tested in 40 tests in 14 patients, including conditions in the ICU, at the standard ward and in daily life, and in four tests also during spiroergometry with right heart catheterization. Results: The system reacted appropriate to every condition, including severe pathologic situations like right heart failure in early postoperative phase, chatecholamine switch or decompensation after exercise. It provided a massive increase of blood flow in case of physical activity without impairing the right heart function by septal shift, also at sudden hemodynamic changes such as posture, coughing and Valsalva action. During catheter ergometry at bicycle exercise, flow increased for 53% from baseline compared to only 27% at constant speed settings, with a decrease of pulmonary pressure at exercise from 31.5 ⫹⫺ 8,6 to 24.1 ⫹⫺ 6,3 mmHg and of wedge pressure from 20.7 ⫹⫺9,2 to 10,8 ⫹⫺5,2mmHg. The workload increased for 11%, and mean SvO2 for 10%. Conclusion: An automatic speed control system for rotary blood pumps based on pump flow interpretation was developed, which confirmed in a first clinical study its capability to adapt pump output to physiological demand, and its ability to increase the physical capacity of LVAD recipients.
199 RIGHT VENTRICULAR STROKE WORK INDEX (RVSWI) PREDICTS DURATION OF INOTROPIC SUPPORT AFTER LEFT VENTRICULAR ASSIST DEVICE IMPLANTATION S. Schenk,1 P.M. McCarthy,1 J. Feng,1 K.J. Hoercher,1 R.C. Starling,1 J.B. Young,1 L. Zhou,1 J.L. Navia,1 E.H. Blackstone,1 K. Fukamachi,1 1Biomedical Engineering, Cleveland Clinic Foundation, Cleveland, OH Background: Right ventricular dysfunction (RVD) after left ventricular assist device (LVAD) implantation, i.e., need for prolonged inotropic support (IS) or right ventricular assist device (RVAD) insertion, warrants careful evaluation. We examined incidence, prediction, and prognosis of prolonged IS. Methods: Between 1991 and 2002, LVAD’s were implanted into 259 patients at our institution. We excluded 52 patients with pre-LVAD circulatory support to allow for accurate assessment of hemodynamics. Factors associated with prolonged IS were identified with timerelated multivariable analysis. Results: Freedom from IS on day 7 and 14 was 41% and 68%, respectively. The lower RVSWI, the longer was the requirement for IS (p⬍0.01; Figure). Marginal predictors were longer pre-LVAD hospital admission and non-ischemic cardiomyopathy (both p ⫽ 0.08). Survival to transplantation (analyzed as competing risk) was compromised by prolonged IS and use for RVAD. Only 41% of non-RVAD patients with inotropic support ⬎14 days survived to transplantation as opposed to 89% of those with shorter inotropic support (p⬍0.0001). Eighteen patients (8.7%) required RVAD support and only 4 (22.2%) survived to transplantation. RVSWI was lower in patients who died of multi-organ failure, bleeding or infection (354 mmHg䡠ml/m2) than in those with cerebro-vascular events (569 mmHg䡠ml/m2 p⬍0.05). Conclusions: RVD affected many patients post LVAD insertion and was associated with poor survival. Low RVSWI predicted prolonged inotropic support and correlated with death pre-transplantation from multi-organ failure and related complications. We assess RVSWI prospectively when considering patients for biventricular support.