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Since 1986, 26 candidates were evaluated for mechanical support as a bridge to heart transplantation. Group 1 consisted of 15 patients who were accepted and who received support with a ventricular assist device (14 patients) or a total artificial heart (1 patient). Seven of the 15 patients received transplants and survived, whereas contraindications to transplant developed in seven patients while they were receiving support, and these seven died. One patient remains hospitalized after transplantation. Group 2 consisted of 11 patients rejected for circulatory support because of renal insufficiency or infection (9), pulmonary embolus (1), and cerebrovascular accident (1). Two group 2 patients underwent transplant procedures after their complications resolved, and one survived. One other group 2 patient who recovered without transplantation or mechanical support was discharged. There was no significant difference in age, gender, or cause of cardiogenic shock between the two groups. Four of five patients accepted for mechanical support on the first evaluation survived, and three of 10 accepted after the initial evaluation survived, indicating that delayed selection often results in complications that preclude transplantation and survival. Only one of the 26 patients survived without transplantation or support. These data emphasize the importance of patient selection on the outcome of bridging to transplantation.

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There is an increasing need to evaluate the psychologic impact of circulatory support because of the growing use of mechanical assist devices. Twenty-seven people, 12 survivors of mechanical circulatory assistance and 15 family members, were surveyed; nonsurvivors' families were not surveyed. The 12 survivors (ages 18 to 66 years; mean, 43 years) had been supported with Pierce-Donachy ventricular assist devices (nine patients) and the Novacor left ventricular assist system (one patient). One patient received a centrifugal pump, and one was supported with extracorporeal membrane oxygenation (ECMO). Duration of support ranged from 8 hours to 90 days (mean, 23 days). Ten people surveyed were spouses of these patients, and five were parents of children who had been supported with ECMO. Three patients were supported longer than 3 weeks, and four patients were awake and ambulatory during support. Financial worries were not a concern for 80% of the parents but were a concern for 80% of the spouses. Eighteen percent of the patients believed they were treated as an experiment, whereas 40% of their spouses thought they were. None of the parents thought their child was treated as an experiment. Sixty-seven percent of the patients stated that they have returned to a normal life-style, and 75% feel they have a brighter outlook on life. Six patients have returned to work, two are retired, two are disabled, and two have physical capabilities to work but choose not to. Eighty-nine percent of all those surveyed would recommend an assist device to someone who needed one. Although these procedures are often associated with severe medical and psychologic complications, 74% of the patients would agree to a second implant.

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In order to find hemodynamic parameters that can accurately predict whether patients can be successfully weaned from ventricular assist devices (VADs), we studied data from 17 patients supported with Pierce-Donachy VADs [11 left VAD (LVAD); 6 right VAD (RVAD)] following cardiogenic shock for periods from 1.3 to 22 days (mean 5.4). Myocardial recovery was determined by daily measurements of "pump on pump off" parameters, and the data from the 8 LVAD patients and 3 RVAD patients whose hearts recovered were compared to the data from those whose did not. In this study, daily pump on pump off hemodynamic measurements were found to be predictive of success for weaning patients from VADs. In particular, the most significant predictors were: increases in mixed venous oxygen saturation, cardiac index, mean arterial pressure and ventricular ejection fraction, as well as decreases in atrial pressures. An index for measuring hemodynamic function with the VAD off is proposed, as are models of recovery. Seventy percent of the patients weaned from VADs survived, indicating that patients appropriately weaned from VAD support have a reasonable chance for survival.

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Levels of T lymphocytes were measured in 20 consecutive patients, 18 men and two women, supported with ventricular assist devices or an artificial heart. Indications for support were bridge to transplantation (n = 10), postcardiotomy cardiogenic shock (n = 8), and acute myocardial infarction shock (n = 2). Control levels were from healthy volunteers not undergoing cardiac operation. Preoperatively, numbers of total lymphocytes and subclasses CD3, CD4, and CD8, as well as the interleukin-2 receptors (IL2R), were the same as controls (cells/microliters): lymphocytes, 1,940; CD3, 1,413 +/- 410; CD4, 894 +/- 318; CD8, 490 +/- 185; IL2R, 96. From implant to postoperative day 5, levels were below control values (p less than 0.001), reaching a nadir on postoperative day 2 (lymphocytes, 896 +/- 599; CD3, 489 +/- 267; CD4, 309 +/- 207; CD8, 183 +/- 107; IL2R, 43 +/- 47). Data from 10 patients (group 1) who survived (four weaned from cardiopulmonary bypass, six transplanted) were compared with those from 10 patients (group 2) who died of multiorgan failure, sepsis, or both. From preimplant through postoperative day 6, levels did not differ between groups. However, from postoperative day 7 to the last day of ventricular support (group 1, 24-90 days; group 2, 7-29 days), group 1 levels (lymphocytes, 2,364 +/- 618; CD3, 1,825 +/- 553; CD4, 1,013 +/- 187; CD8, 796 +/- 402) were significantly above (p less than 0.01) group 2 levels (lymphocytes, 1,290 +/- 463; CD3, 746 +/- 295; CD4, 534 +/- 253; CD8, 221 +/- 106). These data indicate that lymphocytes and particularly T cells 1) decrease after ventricular assist device insertion, reaching a nadir at postoperative day 2, 2) return to control values after patients whose clinical status improves, and 3) remain low in severely ill patients. T-cell depression in ventricular assist device patients is related to the severity of the patient's condition rather than the presence of the device.

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A multidisciplinary approach to circulatory support is discussed in this article. The clinical, educational, and investigational responsibilities of each team member are presented.

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Pierce-Donachy ventricular assist devices (VADs) were used to support 54 patients. None of the 27 patients supported less than 4 days had any visible thrombi in the VAD at explant. Of the 27 patients supported longer than 4 days, nine patients had visible thrombi. In this group of 27 patients, 19 received VAD support pending myocardial recovery, and anticoagulation consisted of dextran (4-15 days) and heparin during the weaning phase (1-2 days). The other eight patients had VADs implanted as bridges to cardiac transplantation. These patients also received dextran postoperatively (1-5 days), but were switched to a regimen of oral warfarin and dipyridamole. Duration of support for the nine patients in whom thrombi were found ranged from 4-27 days (mean, 12 days). The etiology of thrombus was probably related to mechanical problems in four patients, inadequate anticoagulation in two patients, sepsis in two patients, and unknown causes in one patient. Four of these patients suffered cerebral or peripheral injuries, which were probably embolic in two, and possibly embolic in two. One of these four patients survived, and two patients with thrombi but no emboli survived. One patient suffered a stroke, but no evidence of thrombi was found. Our incidence of thrombus with this VAD was 17%. Thrombi were related to inadequate anticoagulation, interrupted flow, or sepsis, but not to duration of support.

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Twenty-one patients (pts) were supported with mechanical devices as a bridge to cardiac transplantation (Tx). Ventricular function was assessed by a combination of angiography, echocardiography, nuclear scans, hemodynamics, and visual inspection at the time of device insertion. Twelve pts had biventricular failure (BVF) and 11 received biventricular support with extracorporeal membrane oxygenation (two pts), biventricular assist devices (VAD) (eight pts), or an artificial heart (one pt). One BVF pt received a left VAD (LVAD) and drug support for severe right ventricular failure (RVF), which resolved after 48 hr. The remaining nine pts had left ventricular failure (LVF), with only mild to moderate RVF, and received LVADs with minimal drugs. Eleven pts were tx, with nine survivors. A comparison of pts with LVF vs BVF revealed no differences in age, gender, device flows, duration of support, diagnosis, number tx, or number survived. The incidence of LVF was 43% vs 57% BVF in bridge-to-transplant pts. LVAD support alone is often successful in pts with mild or moderate BVF, but is rarely successful in pts with severe BVF.

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Four cardiac transplant candidates were supported with ventricular assist devices for periods ranging from 53 to 90 days (mean, 75 days). The patients were men who ranged in age from 36 to 49 years (mean, 44.5 years). Two patients had Pierce-Donachy biventricular assist devices (BVADs) and two patients had Novacor left ventricular assist systems (LVASs). Complications included infection (3 patients), development of antibodies (2 patients), bleeding (2 patients), and pump inflow obstruction (1 patient). All patients were maintained on an anticoagulation regimen which included warfarin and dipyridamole. They were extubated and ambulatory for most of the period of mechanical support. Thromboembolic complications did not develop in any of these patients, and they did not acquire infections which involved the mediastinum. They were successfully transplanted and discharged 11 to 25 days after transplantation. Although major complications were common in this small group of patients, all four patients achieved hemodynamic stability and became excellent candidates for cardiac transplantation. With proper patient selection and meticulous nursing care, current mechanical circulatory support technology is capable of maintaining patients consistently for periods of greater than 50 days.

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Although it is now possible to obtain, with mechanical circulatory support devices, survival of postcardiotomy patients who develop profound cardiogenic shock, their long-term functional status has not been firmly established. We studied 22 patients who survived cardiac operations by the use of circulatory support devices. Their ages ranged from 3 days to 69 years at the time of device support. Operations performed were coronary artery bypass (9 pts), valve replacement (4 pts), congenital defect correction (8 pts), and cardiac transplantation (1 pt). Ten patients were supported with a Pierce-Donachy ventricular assist device (VAD) (left 4, right 3, both 3), nine with extracorporeal membrane oxygenation (ECMO), and three with centrifugal pumps (left 2, both 1). Duration of support ranged from 22 to 189 hours (mean 84.4). There were four late deaths; two of the deaths were cardiac-related within 6 months and two were due to cancer at 46 and 53 months following discharge. The remaining 18 survivors were followed for 6 to 74 months (mean 29.9). Prior to operation three of the patients were New York Heart Association (NYHA) Class I, eight were Class II, six patients were Class III, and five were Class IV. Following discharge from the hospital 13 patients were Class I, two were Class II, and three were Class III; no patients were Class IV. Five patients work full-time, three are retired without limitation, four attend school, and three are pre-school. Only three patients suffer from moderate cardiac disability. These data suggest that patients surviving mechanical circulatory assistance for postoperative cardiogenic shock have an excellent chance for functional recovery.

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In order to determine if hemodynamic parameters can accurately predict whether patients can be successfully weaned from ventricular assists devices (VADs), we studied 24 patients supported with Pierce-Donachy VADs (11 left VAD; 6 right VAD; 7 biventricular VAD) following cardiogenic shock for periods from 1.3 to 22 days (mean 5.4). Myocardial recovery was determined by daily measurements of "pump on/pump off" parameters, and the data from seven LVAD patients (64%) and three RVAD patients (50%) whose hearts recovered were compared to the data from those whose did not. Additionally, data from the five patients (71%) weaned from biventricular support were compared to those weaned from only a single LVAD or RVAD. In this study, daily pump on/pump off hemodynamic measurements were found to be predictive of success for weaning patients from VADs. The most significant predictors were increases in mixed venous oxygen saturation, cardiac index, mean arterial pressure and ventricular ejection fraction, as well as decreases in atrial pressures. Seventy percent of the patients weaned from VADs survived, indicating that patients appropriately weaned from VAD support have a reasonable chance of survival.

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