Intra-aortic balloon counterpulsation in decompensated cardiomyopathy patients: bridge to transplantation or assist device
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《血管的通路杂志》
Center of Anaesthesia, Intensive Care and Pain Management, Clinic of Heart Diseases, Vilnius University Hospital, Santariskiu Clinics, Santariskiu 2, Vilnius, Lithuania LT-08661
Presented at the 55th International Congress of the European Society for Cardiovascular Surgery, St. Petersburg, Russian Federation, May 11–14, 2006.
Abstract
Objective: The crucial decision to progress from pharmacological treatment of acute decompensated heart failure to institution of assist device or transplantation begins with evaluation of the chances for a successful recovery. We tested whether the intra-aortic balloon counterpulsation (IABP) could give us the necessary time for clinical decision-making and preserve adequate circulation until it is made. Methods: We assessed 11 dilated cardiomyopathy patients of NYHA class IV, listed for heart transplantation or a ventricular assist device (VAD), who had conventional IABP placed. Heart function prior to and after IABP insertion as well as hemodynamics, end-organ function (renal and hepatic), frequency of complications and clinical outcomes were assessed. Results: The duration of intra-aortic balloon pump insertion ranged from 72 to 360 h (mean 181.54±81.65). After 48 h of intra-aortic balloon pump support, there was a significant increase of mean systemic arterial pressure from 74.5±9.6 to 82.3±4.7 mmHg (P=0.02), and ejection fraction from 14.7±6.4 to 21.0±8.6 (P=0.014). Meanwhile improvement of cardiac index, pulmonary wedge pressure and end-organ perfusion markers did not reach statistical significance. Three patients were successfully weaned off the balloon and recovered without additional interventions, two patients were transplanted and three were supported with counterpulsation until the implantation of assist device. Three patients died due to progressive heart failure, two after IABP removal and one after VAD implantation. There was no incidence of infection, limb ischemia, thrombus, or embolic complications. Conclusions: Our data showed that intra-aortic balloon pump support may be successfully and safely used in the acute decompensated dilated cardiomyopathy patients, as an urgent measure of cardiac support, to stabilize the patient and maintain organ perfusion until transplant is available, VAD is placed or patient is weaned from IABP.
Key Words: Intra-aortic balloon counterpulsation; Assisted circulation; Bridge to transplant
1. Introduction
While the waiting period for cardiac transplantation continues to lengthen, each year around 35% of potential recipients are condemned to die before a heart becomes available. Therefore an effective therapy, which can improve functional capacity, quality of life and survival of decompensated heart failure (HF) patients, remains a challenge. Ventricular assist devices (VADs) are developed to meet these needs, becoming a bridge to transplant or destination therapy for a number of patients, who are not eligible for heart transplantation. Continued developments of VADs have made their wider application a reality. However, VAD implantation is usually reserved for patients thought to have better chances of survival according to criteria suggested by Farr et al. [1]. Besides, the operative procedure required for implantation has risks of its own. Unstable patient's condition, progressing end-organ insufficiency or infection could be obstacles not leaving a fair chance for recovery in the postoperative period. Therefore, stabilizing and bridging in critically ill potential recipients for transplantation or implantation of VAD is crucial in obtaining good postoperative results. Intra-aortic balloon counterpulsation (IABP) is a minimally invasive, the cheapest and most widely used assist device, the primary goal of which is to increase myocardial oxygen supply and decrease myocardial oxygen demand. Although the IABP is immensely useful in patients with cardiogenic shock, it has not generally been advocated as a part of the standard armamentarium for the treatment of acute decompensated dilated heart failure. The aim of our study was to evaluate the hemodynamic effect and bridging possibilities of IABP support in patients with dilatative cardiomyopathy, listed for urgent heart transplantation or implantation of VAD.
2. Materials and methods
2.1. Study population
We assessed adult patients with acute decompensated dilated cardiomyopathy, listed for urgent heart transplantation, who underwent percutaneous intra-aortic balloon pump therapy and were recorded in Benchmark Counterpulsation Outcomes Registry from September 2004 to December 2005. All patients met specific New York Heart Association (NYHA) class IV heart failure criteria and became refractory to all means of medical circulatory support. Inclusion criteria are presented in Table 1.
2.2. Hemodynamics
Hemodynamic function was assessed through values obtained by an arterial pressure line, central venous catheter and thermodilution catheter inserted in the pulmonary artery. Cardiac index and systemic vascular resistance index (SVRI) were calculated using standard formulae. Serial transthoracic echocardiographic studies were performed regularly for detailed assessiment of heart function. Once all the monitoring lines were removed, hemodynamic assessment was achieved by routinely evaluating the patient's vital signs and by performing echocardiographic studies when indicated.
2.3. IABP
The decision to start intra-aortic counterpulsation was made according to pharmacological thresholds, when standard maximal inotropic support (adrenalin/noradrenalin > 0.15 μg/kg/min) failed to restore hemodynamic stability. All patients had a 40-cc balloon and 8 Fr catheter inserted percutaneously through the femoral artery by the Seldinger sheathless technique. We used a 98 or CS100 Datascope counterpulsation system (Datascope Corporation, Oakland, NJ, USA). After IABP insertion and initial heparin bolus of 3000 units, anticoagulation was achieved by low dose heparin infusion, monitoring APTT (activated partial thromboplastin time) and maintaining it in a range of 48–71 s. In each case, we placed the catheter and initiated IABP without otherwise changing medical management. Patients were weaned from IABP if hemodynamic stability was maintained after decreasing the balloon inflation or the rate of counterpulsation. Hemodynamic weaning criteria were CI 2.1 l/min/m2 and mean arterial pressure 70 mmHg. Clinical criteria were defined as no inotropic support for 12 h and absence of end-organ hypoperfusion. Otherwise IABP was continued until heart transplantation or implantation of axial flow VAD (INCOR, Berlin Heart AG, Berlin, Germany) if no proper heart transplant donor was found. The balloon was removed by direct extraction in all patients and a local compression device prevented bleeding. Patients were followed for possible vascular, ischemic, and hemorrhagic complications, which were classified and distributed by severity according to Benchmark Counterpulsation Outcomes Registry criteria.
2.4. Data collection and statistical methods
Each patient's clinical data were collected in retrospective and concurrent manner, before IABP insertion and during IABP support. The hemodynamic parameters (mean arterial pressure (MAP), heart rate (HR), central venous pressure (CVP), pulmonary artery mean pressure (PA), pulmonary capillary wedge pressure (PCWP), cardiac index (CI), cardiac output (CO)) and clinical variables (serum creatinine, urea, lactic acid, bilirubin) were recorded for all IABP patients each day. Clinical data are reported as mean±S.D. for the numerical variables and as percentages for the categorical variables. Wilcoxon signed rank-test was used for paired comparisons, to determine significance of the difference between baseline values and the data obtained at specific intervals: 12, 24 and 48 h following IABP insertion. Differences were considered significant at P<0.05. Data were analyzed using the SPSS software program (SPSS for Windows 7.5; SPSS, Chicago, IL).
3. Results
We evaluated data of 11 patients, eight male and three female, mean age 43.9±13.8 years.
Baseline clinical and demographic characteristics are presented in Table 2. The duration of intra-aortic balloon pump insertion ranged from 72 to 360 h (mean 181.54± 81.65). The results of the hemodynamic parameters, transthoracic echoscopic data and laboratory variables before and during IABP support of all patients studied are shown in Table 3.
When the results obtained at baseline were compared to those during the IABP therapy, the following could be observed: there was an elevation of mean arterial pressure (MAP) from 74.5±9.6 to 77.09±9.02 (P=0.19) during the first 12 h, and further, significant increase up to 82.4± 4.8 mmHg (P=0.02) on the second day of IABP application. These changes were followed by diminished central venous pressure (CVP) from 13.5±6.4 to 7.7±2.1 mmHg (P=0.03) after 48 h of IABP application. Pulmonary artery mean pressure and pulmonary capillary wedge pressure decreased, respectively, from 52.1±15.3 to 33.2±10.7 mmHg (P= 0.10) and from 30.3±17.7 to 15.6±7.0 mmHg (P=0.11).
The baseline ejection fraction (mean±S.D.) was 14.7±6.3 (range: 10%–30%). After insertion of IABP it significantly increased by 30%, up to 21.0±8.6 (P=0.014) on the second day of IABP application.
The hemodynamic improvement after IABP insertion was accompanied not only by a progressive decrease in the need for inotropic drugs but also with concomitant decrease in serum lactate levels and reversal of metabolic acidosis. Serum lactate levels decreased from 4.47±2.7 to 2.4± 1.5 mmol/l (P=0.28) during the first 12 h after insertion of IABP. After 24 and 48 h, lactates were further decreasing, though the difference was not statistically significant. To evaluate restoration of organ perfusion, we assessed dynamics of such clinical and biochemical markers of organ injury as serum creatinine, blood urea and bilirubin. Serum creatinine decreased from 1.8±0.8 to 1.4±0.5 mg/dl (P= 0.23) during the first 12 h, and up to 1.3±0.3 mg/dl (P=0.26) on the second day of IABP application.
3.1. Outcomes
Outcomes are summarized in Table 4. Three patients (27%) were successfully weaned from IABP support. Three patients (27%) were supported by IABP until successful implantation of ventricular assist device. IABP served as a bridge to heart transplantation in two patients (18%). Three patients (27%) died. The first death occurred in a patient who had continuous IABP support for 648 h, but died after IABP removal of multisystem failure due to progressing heart failure, in spite of renal replacement therapy and resuscitation. Another patient died after removal of IABP, due to a cardiac arrhythmia episode. Worsening right ventricular failure, after implantation of VAD, caused death of a third patient. The average duration of IABP insertion ranged from 72 to 360 h (mean 181.54±81.65). None of the studied patients had adverse side effects that could justify the interruption of IABP support.
4. Discussion
Intra-aortic balloon counterpusation is routinely used in a wide range of various cardiovascular conditions, from hemodynamic stabilization of patients suffering complications of acute coronary syndromes, cardiogenic shock or low output syndrome to a support of high-risk patients undergoing cardiac surgery. The goal of IABP is to improve hemodynamics by increasing myocardial perfusion, reducing afterload and decreasing cardiac work. Rise of coronary perfusion pressure and preload of myocardial fibers are well-known primary effects of IABP influencing left ventricular mechanoenergetics [2]. Theoretically the improvement of ventricular systolic function with IABP is related to the fall in wall stress; particularly in the contractions following balloon deflation [3]. There are also some studies confirming that the use of IABP could also be beneficial due to left–right ventricle hemodynamic interactions [4].
Though the intra-aortic balloon pump is often used as a first line support for failing heart, when medical therapy becomes ineffective, it could not be considered as a true ‘assist device’. It has limitations of its own, which determine the success of this method upon patient selection. IABP support might be useless for patients with significant arrhythmias. Also institution of counterpulsation in patients with significant atherosclerotic disease of the femoral arteries and/or descending aorta could be the cause of disastrous complications. Moreover, standard IABP insertion through the femoral artery requires prolonged immobilization, which is associated with numerous side effects and influences increased morbidity and mortality.
Nevertheless, IABP has several advantages, if compared with other mechanical support systems. The presence of a balloon counterpulsation at the time of transplantation does not complicate native heart excision and facilitates weaning off from cardiopulmonary bypass in case of graft dysfunction. Compared to other ventricular assist systems, the IABP does not require a massive and specific anticoagulation therapy. And third, even if IABP is used as a short-term support for patients with acute cardiac deterioration, it gives us the necessary time for stabilization of a patient's condition before the application of more sophisticated mechanical support.
Over the last decades several reports have mentioned the use of IABP for supporting end-stage heart failure [5]. Some of the papers evaluate novel modifications of an ambulatory intra-aortic balloon pump technique used in patients with heart failure of ischemic origin as a bridge to transplant [6,7], some report on a specific population, like children awaiting heart transplantation [8]. Meanwhile, only a few authors analyze bridging possibilities of conventional IABP in adult patients with acute decompensated dilated cardiomyopathy [9,10]. In the present study we evaluated intra-aortic balloon pump counterpulsation as a bridge towards implantation of assist device or heart transplantation, focusing on changes of hemodynamic parameters and laboratory values reflecting end-organ perfusion.
Immediate circulatory improvement was obvious after a few hours following IABP insertion, though statistically significant difference of such important variables as mean arterial pressure or central venous pressure was seen only on the second day of IABP support. Increase of cardiac index, ejection fraction and diminished peripheral vascular resistance indicates that afterload reduction was achieved together with increased cardiac performance. Restoration of renal and hepatic blood supply reflected by a decrease in serum creatinin, urea and bilirubin, also proved that IABP insertion helped to prevent multi-organ failure. Moreover, our data confirmed that some patients actually showed an improvement in heart function and had the IABP successfully removed without any further invasive treatment. We did not notice any evidence of complications related to prolonged IABP support, which confirms previous study data, that improved sheathless insertion techniques [11] and higher catheter quality allow safe use of IABP for a longer period of time [12].
The present study is limited by the small size of its population. Full evaluation of conventional IABP support effect in acute decompensated dilatative cardiomyopathy requires a larger group of patients. Nevertheless, the data of our study confirm that conventional IABP therapy could be successfully used as an urgent measure of cardiac support, ensuring the stable patient condition, maintaining organ perfusion and giving the necessary time for therapeutical decision making. Moreover, improvement of right heart function, observed in our patients and reflected by diminishing of such parameters as central venous or pulmonary pressures, might be crucial in obtaining favorable postoperative results after implantation of VAD or heart transplant. Further studies with a larger population are needed to single out a group of heart failure patients, which could benefit most from using intra-aortic balloon counterpulsation as a supportive or bridge therapy.
References
Farrar DJ, Thoratec Investigators. Preoperative predictors of survival in patients with Thoratec ventricular assist device as a bridge to heart transplantation. J Heart Lung Traspl 1994; 13:93–101.
Kantrowitz A. Origins of intraaortic balloon pumping. Ann Thorac Surg 1990; 50:672–674.
Papaioannou TG, Stefanadis C. Basic principles of the intraaortic balloon pump and mechanisms affecting its performance. ASAIO J 2005; 51:296–300.
Khir AW, Price S, Heneyn MY, Parker KH, Pepper JR. Intra-aortic balloon pumping: effects on left ventricular diastolic function. Eur J Cardiothorac Surg 2003; 24:277–282.
Tenderich G, Koerner M, Bentheim N, Banayosy A, Kizner L, Arusoglu L, Hornik L, Wlost S, Minami K, Koerfer R. Heart failure in patients with idiopathic dilated cardiomyopathy: benefit of intra-aortic balloon counterpulsation. CVE 2000; 5:16–18.
H'Doubler J, H'Doubler WZ, Bien RC, Jansen DA. A novel technique for intraaortic balloon pump placement via the left axillary artery in patients awaiting cardiac transplantation. Cardiovasc Surg 2000; 8:463–465.
Cohran RP, Starkey TD, Panos AL, Kunzelman KS. Ambulatory intraaortic balloon pump use as bridge to heart transplant. Ann Thorac Surg 2002; 74:746–751.
Minich L, Tani LT, Hawkins JA, Orsmond GS, Russo G, Shaddy RE. Intra-aortic balloon pumping in children with dilated cardiomyopathy as a bridge to transplantation. J Heart Lung Transplant 2001; 20:750–754.
Rosenbaum AM, Murali S, Uretsky BF. Intra-aortic balloon counterpulsation as a ‘bridge’ to cardiac transplantation. Effects in nonischemic and ischemic cardiomyopathy. Chest 1994; 106:1683–1688.
Wang SH, Saiki Y, Singh G, Scherr K, Koshal A, Mullen JC, Modry Dl. Successful bridge to cardiac transplantation using conventional cardiac assist devices – University of Alberta experience. CVE 2001; 6:12–15.
Gol MK, Bayazit M, Emir M, Tasdemir O, Bayazit K. Vascular complications related to percutaneous insertion of intra-aortic balloon pumps. Ann Thorac Surg 1994; 58:1476–1480.
Oshima K, Morishita Y, Hinonara H. Prolonged use for at least 10 days of intraaortic balloon pumping (IABP) for heart failure. Int Heart J 2005; 46:1041–1047.(Ieva Norkiene, Donata Ringaitiene, Kestu)
Presented at the 55th International Congress of the European Society for Cardiovascular Surgery, St. Petersburg, Russian Federation, May 11–14, 2006.
Abstract
Objective: The crucial decision to progress from pharmacological treatment of acute decompensated heart failure to institution of assist device or transplantation begins with evaluation of the chances for a successful recovery. We tested whether the intra-aortic balloon counterpulsation (IABP) could give us the necessary time for clinical decision-making and preserve adequate circulation until it is made. Methods: We assessed 11 dilated cardiomyopathy patients of NYHA class IV, listed for heart transplantation or a ventricular assist device (VAD), who had conventional IABP placed. Heart function prior to and after IABP insertion as well as hemodynamics, end-organ function (renal and hepatic), frequency of complications and clinical outcomes were assessed. Results: The duration of intra-aortic balloon pump insertion ranged from 72 to 360 h (mean 181.54±81.65). After 48 h of intra-aortic balloon pump support, there was a significant increase of mean systemic arterial pressure from 74.5±9.6 to 82.3±4.7 mmHg (P=0.02), and ejection fraction from 14.7±6.4 to 21.0±8.6 (P=0.014). Meanwhile improvement of cardiac index, pulmonary wedge pressure and end-organ perfusion markers did not reach statistical significance. Three patients were successfully weaned off the balloon and recovered without additional interventions, two patients were transplanted and three were supported with counterpulsation until the implantation of assist device. Three patients died due to progressive heart failure, two after IABP removal and one after VAD implantation. There was no incidence of infection, limb ischemia, thrombus, or embolic complications. Conclusions: Our data showed that intra-aortic balloon pump support may be successfully and safely used in the acute decompensated dilated cardiomyopathy patients, as an urgent measure of cardiac support, to stabilize the patient and maintain organ perfusion until transplant is available, VAD is placed or patient is weaned from IABP.
Key Words: Intra-aortic balloon counterpulsation; Assisted circulation; Bridge to transplant
1. Introduction
While the waiting period for cardiac transplantation continues to lengthen, each year around 35% of potential recipients are condemned to die before a heart becomes available. Therefore an effective therapy, which can improve functional capacity, quality of life and survival of decompensated heart failure (HF) patients, remains a challenge. Ventricular assist devices (VADs) are developed to meet these needs, becoming a bridge to transplant or destination therapy for a number of patients, who are not eligible for heart transplantation. Continued developments of VADs have made their wider application a reality. However, VAD implantation is usually reserved for patients thought to have better chances of survival according to criteria suggested by Farr et al. [1]. Besides, the operative procedure required for implantation has risks of its own. Unstable patient's condition, progressing end-organ insufficiency or infection could be obstacles not leaving a fair chance for recovery in the postoperative period. Therefore, stabilizing and bridging in critically ill potential recipients for transplantation or implantation of VAD is crucial in obtaining good postoperative results. Intra-aortic balloon counterpulsation (IABP) is a minimally invasive, the cheapest and most widely used assist device, the primary goal of which is to increase myocardial oxygen supply and decrease myocardial oxygen demand. Although the IABP is immensely useful in patients with cardiogenic shock, it has not generally been advocated as a part of the standard armamentarium for the treatment of acute decompensated dilated heart failure. The aim of our study was to evaluate the hemodynamic effect and bridging possibilities of IABP support in patients with dilatative cardiomyopathy, listed for urgent heart transplantation or implantation of VAD.
2. Materials and methods
2.1. Study population
We assessed adult patients with acute decompensated dilated cardiomyopathy, listed for urgent heart transplantation, who underwent percutaneous intra-aortic balloon pump therapy and were recorded in Benchmark Counterpulsation Outcomes Registry from September 2004 to December 2005. All patients met specific New York Heart Association (NYHA) class IV heart failure criteria and became refractory to all means of medical circulatory support. Inclusion criteria are presented in Table 1.
2.2. Hemodynamics
Hemodynamic function was assessed through values obtained by an arterial pressure line, central venous catheter and thermodilution catheter inserted in the pulmonary artery. Cardiac index and systemic vascular resistance index (SVRI) were calculated using standard formulae. Serial transthoracic echocardiographic studies were performed regularly for detailed assessiment of heart function. Once all the monitoring lines were removed, hemodynamic assessment was achieved by routinely evaluating the patient's vital signs and by performing echocardiographic studies when indicated.
2.3. IABP
The decision to start intra-aortic counterpulsation was made according to pharmacological thresholds, when standard maximal inotropic support (adrenalin/noradrenalin > 0.15 μg/kg/min) failed to restore hemodynamic stability. All patients had a 40-cc balloon and 8 Fr catheter inserted percutaneously through the femoral artery by the Seldinger sheathless technique. We used a 98 or CS100 Datascope counterpulsation system (Datascope Corporation, Oakland, NJ, USA). After IABP insertion and initial heparin bolus of 3000 units, anticoagulation was achieved by low dose heparin infusion, monitoring APTT (activated partial thromboplastin time) and maintaining it in a range of 48–71 s. In each case, we placed the catheter and initiated IABP without otherwise changing medical management. Patients were weaned from IABP if hemodynamic stability was maintained after decreasing the balloon inflation or the rate of counterpulsation. Hemodynamic weaning criteria were CI 2.1 l/min/m2 and mean arterial pressure 70 mmHg. Clinical criteria were defined as no inotropic support for 12 h and absence of end-organ hypoperfusion. Otherwise IABP was continued until heart transplantation or implantation of axial flow VAD (INCOR, Berlin Heart AG, Berlin, Germany) if no proper heart transplant donor was found. The balloon was removed by direct extraction in all patients and a local compression device prevented bleeding. Patients were followed for possible vascular, ischemic, and hemorrhagic complications, which were classified and distributed by severity according to Benchmark Counterpulsation Outcomes Registry criteria.
2.4. Data collection and statistical methods
Each patient's clinical data were collected in retrospective and concurrent manner, before IABP insertion and during IABP support. The hemodynamic parameters (mean arterial pressure (MAP), heart rate (HR), central venous pressure (CVP), pulmonary artery mean pressure (PA), pulmonary capillary wedge pressure (PCWP), cardiac index (CI), cardiac output (CO)) and clinical variables (serum creatinine, urea, lactic acid, bilirubin) were recorded for all IABP patients each day. Clinical data are reported as mean±S.D. for the numerical variables and as percentages for the categorical variables. Wilcoxon signed rank-test was used for paired comparisons, to determine significance of the difference between baseline values and the data obtained at specific intervals: 12, 24 and 48 h following IABP insertion. Differences were considered significant at P<0.05. Data were analyzed using the SPSS software program (SPSS for Windows 7.5; SPSS, Chicago, IL).
3. Results
We evaluated data of 11 patients, eight male and three female, mean age 43.9±13.8 years.
Baseline clinical and demographic characteristics are presented in Table 2. The duration of intra-aortic balloon pump insertion ranged from 72 to 360 h (mean 181.54± 81.65). The results of the hemodynamic parameters, transthoracic echoscopic data and laboratory variables before and during IABP support of all patients studied are shown in Table 3.
When the results obtained at baseline were compared to those during the IABP therapy, the following could be observed: there was an elevation of mean arterial pressure (MAP) from 74.5±9.6 to 77.09±9.02 (P=0.19) during the first 12 h, and further, significant increase up to 82.4± 4.8 mmHg (P=0.02) on the second day of IABP application. These changes were followed by diminished central venous pressure (CVP) from 13.5±6.4 to 7.7±2.1 mmHg (P=0.03) after 48 h of IABP application. Pulmonary artery mean pressure and pulmonary capillary wedge pressure decreased, respectively, from 52.1±15.3 to 33.2±10.7 mmHg (P= 0.10) and from 30.3±17.7 to 15.6±7.0 mmHg (P=0.11).
The baseline ejection fraction (mean±S.D.) was 14.7±6.3 (range: 10%–30%). After insertion of IABP it significantly increased by 30%, up to 21.0±8.6 (P=0.014) on the second day of IABP application.
The hemodynamic improvement after IABP insertion was accompanied not only by a progressive decrease in the need for inotropic drugs but also with concomitant decrease in serum lactate levels and reversal of metabolic acidosis. Serum lactate levels decreased from 4.47±2.7 to 2.4± 1.5 mmol/l (P=0.28) during the first 12 h after insertion of IABP. After 24 and 48 h, lactates were further decreasing, though the difference was not statistically significant. To evaluate restoration of organ perfusion, we assessed dynamics of such clinical and biochemical markers of organ injury as serum creatinine, blood urea and bilirubin. Serum creatinine decreased from 1.8±0.8 to 1.4±0.5 mg/dl (P= 0.23) during the first 12 h, and up to 1.3±0.3 mg/dl (P=0.26) on the second day of IABP application.
3.1. Outcomes
Outcomes are summarized in Table 4. Three patients (27%) were successfully weaned from IABP support. Three patients (27%) were supported by IABP until successful implantation of ventricular assist device. IABP served as a bridge to heart transplantation in two patients (18%). Three patients (27%) died. The first death occurred in a patient who had continuous IABP support for 648 h, but died after IABP removal of multisystem failure due to progressing heart failure, in spite of renal replacement therapy and resuscitation. Another patient died after removal of IABP, due to a cardiac arrhythmia episode. Worsening right ventricular failure, after implantation of VAD, caused death of a third patient. The average duration of IABP insertion ranged from 72 to 360 h (mean 181.54±81.65). None of the studied patients had adverse side effects that could justify the interruption of IABP support.
4. Discussion
Intra-aortic balloon counterpusation is routinely used in a wide range of various cardiovascular conditions, from hemodynamic stabilization of patients suffering complications of acute coronary syndromes, cardiogenic shock or low output syndrome to a support of high-risk patients undergoing cardiac surgery. The goal of IABP is to improve hemodynamics by increasing myocardial perfusion, reducing afterload and decreasing cardiac work. Rise of coronary perfusion pressure and preload of myocardial fibers are well-known primary effects of IABP influencing left ventricular mechanoenergetics [2]. Theoretically the improvement of ventricular systolic function with IABP is related to the fall in wall stress; particularly in the contractions following balloon deflation [3]. There are also some studies confirming that the use of IABP could also be beneficial due to left–right ventricle hemodynamic interactions [4].
Though the intra-aortic balloon pump is often used as a first line support for failing heart, when medical therapy becomes ineffective, it could not be considered as a true ‘assist device’. It has limitations of its own, which determine the success of this method upon patient selection. IABP support might be useless for patients with significant arrhythmias. Also institution of counterpulsation in patients with significant atherosclerotic disease of the femoral arteries and/or descending aorta could be the cause of disastrous complications. Moreover, standard IABP insertion through the femoral artery requires prolonged immobilization, which is associated with numerous side effects and influences increased morbidity and mortality.
Nevertheless, IABP has several advantages, if compared with other mechanical support systems. The presence of a balloon counterpulsation at the time of transplantation does not complicate native heart excision and facilitates weaning off from cardiopulmonary bypass in case of graft dysfunction. Compared to other ventricular assist systems, the IABP does not require a massive and specific anticoagulation therapy. And third, even if IABP is used as a short-term support for patients with acute cardiac deterioration, it gives us the necessary time for stabilization of a patient's condition before the application of more sophisticated mechanical support.
Over the last decades several reports have mentioned the use of IABP for supporting end-stage heart failure [5]. Some of the papers evaluate novel modifications of an ambulatory intra-aortic balloon pump technique used in patients with heart failure of ischemic origin as a bridge to transplant [6,7], some report on a specific population, like children awaiting heart transplantation [8]. Meanwhile, only a few authors analyze bridging possibilities of conventional IABP in adult patients with acute decompensated dilated cardiomyopathy [9,10]. In the present study we evaluated intra-aortic balloon pump counterpulsation as a bridge towards implantation of assist device or heart transplantation, focusing on changes of hemodynamic parameters and laboratory values reflecting end-organ perfusion.
Immediate circulatory improvement was obvious after a few hours following IABP insertion, though statistically significant difference of such important variables as mean arterial pressure or central venous pressure was seen only on the second day of IABP support. Increase of cardiac index, ejection fraction and diminished peripheral vascular resistance indicates that afterload reduction was achieved together with increased cardiac performance. Restoration of renal and hepatic blood supply reflected by a decrease in serum creatinin, urea and bilirubin, also proved that IABP insertion helped to prevent multi-organ failure. Moreover, our data confirmed that some patients actually showed an improvement in heart function and had the IABP successfully removed without any further invasive treatment. We did not notice any evidence of complications related to prolonged IABP support, which confirms previous study data, that improved sheathless insertion techniques [11] and higher catheter quality allow safe use of IABP for a longer period of time [12].
The present study is limited by the small size of its population. Full evaluation of conventional IABP support effect in acute decompensated dilatative cardiomyopathy requires a larger group of patients. Nevertheless, the data of our study confirm that conventional IABP therapy could be successfully used as an urgent measure of cardiac support, ensuring the stable patient condition, maintaining organ perfusion and giving the necessary time for therapeutical decision making. Moreover, improvement of right heart function, observed in our patients and reflected by diminishing of such parameters as central venous or pulmonary pressures, might be crucial in obtaining favorable postoperative results after implantation of VAD or heart transplant. Further studies with a larger population are needed to single out a group of heart failure patients, which could benefit most from using intra-aortic balloon counterpulsation as a supportive or bridge therapy.
References
Farrar DJ, Thoratec Investigators. Preoperative predictors of survival in patients with Thoratec ventricular assist device as a bridge to heart transplantation. J Heart Lung Traspl 1994; 13:93–101.
Kantrowitz A. Origins of intraaortic balloon pumping. Ann Thorac Surg 1990; 50:672–674.
Papaioannou TG, Stefanadis C. Basic principles of the intraaortic balloon pump and mechanisms affecting its performance. ASAIO J 2005; 51:296–300.
Khir AW, Price S, Heneyn MY, Parker KH, Pepper JR. Intra-aortic balloon pumping: effects on left ventricular diastolic function. Eur J Cardiothorac Surg 2003; 24:277–282.
Tenderich G, Koerner M, Bentheim N, Banayosy A, Kizner L, Arusoglu L, Hornik L, Wlost S, Minami K, Koerfer R. Heart failure in patients with idiopathic dilated cardiomyopathy: benefit of intra-aortic balloon counterpulsation. CVE 2000; 5:16–18.
H'Doubler J, H'Doubler WZ, Bien RC, Jansen DA. A novel technique for intraaortic balloon pump placement via the left axillary artery in patients awaiting cardiac transplantation. Cardiovasc Surg 2000; 8:463–465.
Cohran RP, Starkey TD, Panos AL, Kunzelman KS. Ambulatory intraaortic balloon pump use as bridge to heart transplant. Ann Thorac Surg 2002; 74:746–751.
Minich L, Tani LT, Hawkins JA, Orsmond GS, Russo G, Shaddy RE. Intra-aortic balloon pumping in children with dilated cardiomyopathy as a bridge to transplantation. J Heart Lung Transplant 2001; 20:750–754.
Rosenbaum AM, Murali S, Uretsky BF. Intra-aortic balloon counterpulsation as a ‘bridge’ to cardiac transplantation. Effects in nonischemic and ischemic cardiomyopathy. Chest 1994; 106:1683–1688.
Wang SH, Saiki Y, Singh G, Scherr K, Koshal A, Mullen JC, Modry Dl. Successful bridge to cardiac transplantation using conventional cardiac assist devices – University of Alberta experience. CVE 2001; 6:12–15.
Gol MK, Bayazit M, Emir M, Tasdemir O, Bayazit K. Vascular complications related to percutaneous insertion of intra-aortic balloon pumps. Ann Thorac Surg 1994; 58:1476–1480.
Oshima K, Morishita Y, Hinonara H. Prolonged use for at least 10 days of intraaortic balloon pumping (IABP) for heart failure. Int Heart J 2005; 46:1041–1047.(Ieva Norkiene, Donata Ringaitiene, Kestu)