Katharine A. Catanese

Right ventricular dysfunction and organ failure in left ventricular assist device recipients: a continuing problem

BACKGROUND Although right ventricular assist device (RVAD) use has declined with the introduction of inhaled nitric oxide and phosphodiesterase inhibitors (type III), right ventricular dysfunction (RVD) is still a serious problem in patients receiving left ventricular assist devices (LVAD). METHODS We retrospectively analyzed Thoratec Vented Electrical LVAD recipients between June 1996 and September 1999. RVD was defined as inotropic requirement 14 days or more or need for RVAD postoperatively, or both. RESULTS Sixty-nine LVAD recipients were analyzed. Twenty-one patients (30.4%) had RVD, with 1 patient requiring RVAD insertion, and there were 48 non-RVD patients. There were no significant differences between both groups for age, sex, etiology of congestive heart failure, days of support, and preoperative hemodynamics. Preoperative right ventricle stroke work index (mm Hg x m(-2) x L(-1)) had a trend toward being lower in the RVD group (4.1+/-3.2 versus 6.1+/-3.7, p = 0.06). A higher preoperative total bilirubin (mg/dL) was noticed in the RVD group (4.0+/-5.2 versus 2.1+/-1.7). The RVD group had a higher postoperative creatinine (2.2+/-1.4 mg/dL versus 1.5+/-0.8 mg/dL), incidence of continuous venovenous hemofiltration dialysis (73% versus 26%), transfusion of packed red blood cells (43.2+/-28.6 units versus 24.7+/-18.9 units), platelets (58.6+/-46.1 units versus 30.2+/-20.4 units), with longer intensive care unit length of stay (33.6+/-34.7 days versus 9.1+/-6.9) and higher mortality (42.8% versus 14.5%). When deaths were excluded, both intensive care unit and postoperative length of stay were significantly longer in the RVD group. CONCLUSIONS RVD in LVAD recipients remains poorly identified and is associated with a high transfusion rate and end organ failure that results in increased intensive care unit and hospital length of stay, and a high mortality rate. Preoperative identification of risk factors for RVD may select patients who would benefit from a biventricular assist device and prevent the subsequent end organ failure.

Use of aprotinin in LVAD recipients reduces blood loss, blood use, and perioperative mortality

Aprotinin, a bovine protease inhibitor, has been used extensively in patients undergoing cardiac surgical procedures in an effort to minimize blood loss and prevent the complications associated with blood replacement. We sought to evaluate the effect of aprotinin on postoperative blood loss, renal function, and the incidence of right ventricular failure in patients undergoing placement of a TCI Heartmate left ventricular assist device as a bridge to cardiac transplantation. Retrospective data analysis in 142 patients (42 receiving aprotinin and 100 untreated) demonstrated that the use of aprotinin was associated with a significant decrease in postoperative blood loss (p = 0.019) and in the intraoperative packed red blood cell transfusion (p = 0.019) and total blood product (p = 0.016) requirements. A transient, yet significant, increase in the postoperative creatinine level in the aprotinin group (p = 0.0006), but not in blood urea nitrogen level (p = 0.22), was noted. Interestingly, we noted an association between blood loss and the subsequent development of right ventricular failure; patients who required a right ventricular assist device bled significantly more than did those who did not suffer right ventricular failure (p = 0.02). Additionally, aprotinin recipients benefited by a reduction of nearly one half in the incidence of the need for a right ventricular assist device. The incidence of perioperative mortality was reduced in those receiving aprotinin compared with that in untreated patients, (p = 0.05). We conclude that aprotinin is safe and effective in decreasing postoperative blood loss and intraoperative blood product requirements, and in reducing perioperative mortality in patients undergoing left ventricular assist device placement as a bridge to cardiac transplantation.

Implantable Left Ventricular Assist Devices Provide an Excellent Outpatient Bridge to Transplantation and Recovery

OBJECTIVES Our recent experience with outpatient left ventricular assist device (LVAD) support is presented to demonstrate the possibilities and limitations of long-term outpatient mechanical circulatory assistance. BACKGROUND The experience with inpatient LVAD support as a bridge to transplantation has proved the efficacy of such therapy in improving circulatory hemodynamic status, restoring normal end-organ function and facilitating patient rehabilitation. With miniaturization of the power supplies and controllers, such mechanical circulatory support can now be accomplished in an outpatient setting. METHODS Between March 1993 and February 1997, 32 patients (26 male, 6 female, mean [+/-SEM] age 49 +/- 15 years) underwent implantation of the ThermoCardiosystems (TCI) Heartmate vented electric (VE) LVAD. The VE LVAD is powered by batteries worn on shoulder holsters and is operated by a belt-mounted system controller, allowing unrestricted patient ambulation and hospital discharge. RESULTS Mean duration of support was 122 +/- 26 days (range 3 to 605), with a survival rate to transplantation or explantation of 78%. Nineteen patients were discharged from the hospital on mean postoperative day 41 +/- 4 (range 17 to 68), for an outpatient support time of 108 +/- 30 days (range 2 to 466). Four patients underwent early transplantation and could not participate in the discharge program, and three patients currently await discharge. The complication rate was not statistically different from that encountered in our previous 52 patients with a pneumatic LVAD. CONCLUSIONS Outpatient LVAD support is safe and provides improved quality of life for patients awaiting transplantation. Wearable and totally implantable LVADs should be studied as permanent treatment options for patients who are not candidates for heart transplantation.

Malignant ventricular arrhythmias are well tolerated in patients receiving long-term left ventricular assist devices

OBJECTIVES We sought to quantitate the incidence of malignant ventricular arrhythmias and to identify subsequent hemodynamic changes and untoward events in patients who have received an implantable left ventricular circulatory assist device as an extended bridge to heart transplantation. BACKGROUND Implantable long-term mechanical circulatory assist devices have been used clinically with increasing frequency and success for the past 4 years. Previous investigators have suggested that patients with malignant ventricular arrhythmias receiving a left ventricular assist device will require both left and right ventricular assistance to maintain vital organ perfusion. METHODS We reviewed our 4-year experience with 21 patients who underwent implantation of a left ventricular assist device. Device flows and mean arterial pressure were used to assess systemic perfusion; central venous pressure provided a gauge of right ventricular function. Charts were screened for evidence of end-organ injury resulting from malignant ventricular arrhythmias. RESULTS Malignant ventricular arrhythmias occurred in 4 patients (19%) before device placement and in 9 patients (43%) during device support. The latter nine patients formed the final study group; their arrhythmias occurred 0 to 186 days after device implantation and had a duration of 10 min to 12 days. The patients reported weakness or palpitation; however, none reported syncope or dyspnea. Mean arterial pressure and central venous pressure were insignificantly changed by the arrhythmias. Device flow decreased by 1.4 +/- 0.6 liters/min (p < 0.05) at the onset of the arrhythmias but returned to normal after cardioversion. No thromboembolic events or significant end-organ dysfunction occurred. CONCLUSION Absence of right ventricular contraction during malignant ventricular arrhythmias is well tolerated in recipients of a left ventricular assist device. The diagnosis of malignant arrhythmia should be suspected if an unexplained decrease in left ventricular assist device flow occurs. Early electrical cardioversion is warranted to avoid both thrombus formation in the native heart and right ventricular myocardial injury from prolonged fibrillation.

Outpatient Left Ventricular Assist Device Support: A Destination Rather Than a Bridge

BACKGROUND To evaluate the feasibility and efficacy of outpatient left ventricular assist devices as a bridge to transplantation, we reviewed the initial clinical experience with this modality at our institution. METHODS During January 1993 to November 1995, 12 male and 2 female patients with an average age of 47 +/- 17 years were supported for an average of 117 +/- 24 days with the Thermo Cardiosystems VE wearable left ventricular assist device. Seven patients were discharged home an average of 35 +/- 4 days after implantation. RESULTS No device failures occurred, although 29 controller malfunctions were identified during 1,640 total support days. All patients were able to safely maintain their devices. Outflow graft bleeding and driveline infection were responsible for two readmissions. No long-term anticoagulation treatment was used; one small thromboembolic episode occurred, but without significant long-term sequelae. CONCLUSIONS None of the 7 patients released from the hospital died, and all were able to successfully maintain their devices at home. Hospital discharge of patients supported with left ventricular assist devices has allowed long-term evaluation of this technology, and the findings should prompt study of their use as a long-term alternative treatment to medical management for congestive heart failure.

Potential of left ventricular assist devices as outpatient therapy while awaiting transplantation

Left ventricular assist devices (LVADs) increasingly are being used as a bridge to transplantation. We studied changes in New York Heart Association class, mean arterial pressure, resting cardiac output, end-organ function, exercise oxygen consumption, and exercise cardiac output in 12 LVAD recipients. In addition, resting levels of neurohormonal factors were evaluated 4 to 16 weeks after implantation. Two of the 12 patients died of right heart failure and 1 of aspiration; all deaths occurred in the first 2 weeks after LVAD implantation. Of the other 9 patients, 8 improved to New York Heart Association class I and 1 to class II, all of whom were in class IV preoperatively. The 4 patients who underwent exercise testing achieved an exercise oxygen consumption of 15.0 +/- 2.7 mL.kg-1.min-1, which was paralleled by an increase in resting cardiac output from 3.07 +/- 0.9 L.min-1 preoperatively to 5.66 +/- 1.1 L.min-1 at 2 months, and mean arterial pressure from 60 +/- 8 to 91 +/- 10 mm Hg at 2 months, a benefit that was maintained for up to 10 months. End-organ function revealed comparable improvement at 2 months for both creatinine (1.68 +/- 0.7 to 1.0 +/- 0.19 mg.dL-1) and total bilirubin (1.37 +/- 1.17 to 0.54 +/- 0.26 mg.dL-1) levels. Levels of neurohormones were within normal limits. Adverse clinical events after the perioperative period were minimal, and no thromboembolic complications occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Six-year experience of caring for forty-four patients with a left ventricular assist device at home: safe, economical, necessary.

OBJECTIVE With increasing numbers of implantations, left ventricular assist device programs can put a financial strain on a hospital unless an efficient and safe outpatient program is developed. However, the left ventricular assist device is not widely recognized in the medical community as being reliable enough to support a patient at home. We reviewed our experience with these patients at home to assess the safety and the benefits of such a program. METHODS Our institutional 6-year experience with 90 consecutive recipients of a wearable left ventricular assist device was analyzed. RESULTS Forty-four (49%) of the 90 patients who received TCI vented-electric left ventricular assist devices (Thermo Cardiosystems, Inc, Woburn, Mass) were discharged, spending a total of 4546 days (12.5 years) at home with an average of 103 +/- 16 days of outpatient support (range 9-436 days). Of these 44 patients, all were successfully bridged to transplantation (42 patients, 96%) or planned explantation (2 patients, 4%). None of the outpatients died. The cumulative events per outpatient month were 0.020 for bleeding, 0.053 for device infection, 0.0068 for thromboembolus, and 0.020 for major malfunctions. Our estimated average cost to bridge a patient to transplantation or explantation once discharged is

Noncardiac surgery in long-term implantable left ventricular assist-device recipients

13,200 and as an inpatient over the same length of time, including only room and board, is

Fungal infections in left ventricular assist device recipients : incidence, prophylaxis, and treatment

165,200. Thirty percent of outpatients were able to return to work or school, 33% to sexual activity, and 44% to driving. All outpatients performed activities of daily living. CONCLUSION Current left ventricular assist device technology provides effective and economical outpatient support and is associated with limited morbidity and a satisfactory quality of life.

Asymptomatic microembolism in patients with long-term ventricular assist support

ObjectiveThe authors describe their experience with left ventricular assist-device (LVAD) recipients undergoing noncardiac surgery and delineate surgical, anesthetic, and logistic factors important in the successful intraoperative management of these patients. Summary Background DataLeft ventricular assist-devices have become part of the armamentarium in the treatment of end-stage heart failure. As the numbers of patients chronically supported with long-term implantable devices grows, general surgical problems that are commonly seen in other hospitalized patients are becoming manifest. Of particular interest is the intraoperative management of patients undergoing elective noncardiac surgical procedures. MethodsThe anesthesia records and clinical charts were reviewed for eight ventricular assist-device recipients undergoing general surgical procedures between August 1, 1990 and August 31, 1994. ResultsA total of 12 procedures were performed in 6 men and 2 women averaging 52.7 years of age. Mean time elapsed from device implantation to operation was 68 ± 35 days. Conventional inhalational and intravenous anesthetic techniques were well tolerated in these patients undergoing diverse surgical procedures. No perioperative mortality was observed. Five of eight patients went on to successful cardiac transplantation. ConclusionsHemodynamic recovery after LVAD insertion has defined a new group of patients who develop noncardiac surgical problems often seen in other critically ill patients. Recognition of the unique potential problems that the LVAD recipient may encounter in the perioperative period—in particular patient positioning, device limitations, and fluid and inotropic management—will ensure an optimal surged outcome for LVAD recipients undergoing noncardiac surgery.