Persistent anemia after implantation of the total artificial heart.

BACKGROUND: The total artificial heart (TAH) replaces the heart with 2 pneumatic pumps and 4 tilting disk mechanical valves. It was hypothesized that patients receiving TAH support have persistent hemolysis that resolves after heart transplantation (HT). METHODS AND RESULTS: Hematocrit (HCT) was compared in patients on TAH to left ventricular assist device (LVAD) support for bridge to HT. Data were compared with t tests. The TAH (n = 36; mean age 47 ± 13 years) and LVAD patients (n = 14; mean age 53 ± 12 years) were supported for a median of 83 (interquartile range [IQR] 43-115) and 106 days (IQR 84-134), respectively. Hematocrit was similar between the TAH and LVAD patients (34 ± 6% vs 37 ± 5%; P = .07) at baseline. After placement, TAH patients had lower HCT at 2 (20 ± 2% vs 24 ± 3%), 4 (22 ± 3% vs 26 ± 3%), 6 (22 ± 4% vs 30 ± 4%), and 8 weeks (23 ± 4% vs 33 ± 5%; P < .001 for all). There were no differences in HCT at 1 (30 ± 4% vs 29 ± 7%; P = .42) and 3 months (35 ± 7% vs 35 ± 4%; P = .98) after removal of the devices for HT. TAH patients had undetectable haptoglobin in 96% of assessments, increased lactate dehydrogenase (1,128 ± 384 units/L), and detectable plasma free hemoglobin in 40% of measurements (21 ± 15 mg/dL). High sensitivity C-reactive protein (52 ± 50 mg/dL) was elevated, and reticulocyte production index was decreased (1.6 ± 0.6). CONCLUSIONS: Patients implanted with a TAH have persistent anemia that resolves only after HT. The association of hemolysis, ineffective erythropoiesis, and inflammation with the TAH warrants further study.

Frequency and predictors of return to incentive spirometry volume baseline after cardiac surgery.

Incentive spirometry (IS) is routinely used in most clinical settings, but evaluation of patient efficacy of IS is not standardized. The purpose of this study was to describe the degree and predictors of return to preoperative IS volume after cardiac surgery. IS volumes were documented in 69 subjects (71% men; mean age, 59 years) undergoing cardiac surgery during the preoperative evaluation and twice daily postoperatively. Nineteen percent of subjects achieved their IS preoperative volume by hospital discharge. Based on highest volume achieved, subjects achieved an average of 75% of their preoperative volume by discharge, and only age and number of bypass grafts predicted return to preoperative IS volume. These data may assist nurses and patients to set realistic goals for postoperative IS volume achievement.

Implantable mechanical circulatory support: demystifying patients with ventricular assist devices and artificial hearts.

Engineering advancements have expanded the role for mechanical circulatory support devices in the patient with heart failure. More patients with mechanical circulatory support are being discharged from the implanting institution and will be seen by clinicians outside the immediate surgical or heart-failure team. This review provides a practical understanding of device design and physiology, general troubleshooting, and limitations and complications for implantable left ventricular assist devices (pulsatile-flow and continuous-flow pumps) and the total artificial heart.

Exercise blood pressure response during assisted circulatory support: comparison of the total artificial [corrected] heart with a left ventricular assist device during rehabilitation.

BACKGROUND: The total artificial heart (TAH) consists of two implantable pneumatic pumps that replace the heart and operate at a fixed ejection rate and ejection pressure. We evaluated the blood pressure (BP) response to exercise and exercise performance in patients with a TAH compared to those with a with a continuous-flow left ventricular assist device (LVAD). METHODS: We conducted a single-center, retrospective study of 37 patients who received a TAH and 12 patients implanted with an LVAD. We measured the BP response during exercise, exercise duration and change in tolerated exercise workload over an 8-week period. RESULTS: In patients with a TAH, baseline BP was 120/69 ± 13/13, exercise BP was 118/72 ± 15/10 and post-exercise BP was 120/72 ± 14/12. Mean arterial BP did not change with exercise in patients with a TAH (88 ± 10 vs 88 ± 11; p = 0.8), but increased in those with an LVAD (87 ± 8 vs 95 ± 13; p < 0.001). Although the mean arterial BP (MAP) was negatively correlated with metabolic equivalents (METs) achieved during exercise, the association was not statistically significant (ß = -0.1, p = 0.4). MAP correlated positively with METs achieved in patients with LVADs (MAP: ß = 0.26, p = 0.04). Despite the abnormal response to exercise, patients with a TAH participated in physical therapy (median: 5 days; interquartile range [IQR] 4 to 7 days) and treadmill exercise (19 days; IQR: 13 to 35 days) early after device implantation, with increased exercise intensity and duration over time. CONCLUSIONS: During circulatory support with a TAH, the BP response to exercise was blunted. However, aerobic exercise training early after device implantation was found to be safe and feasible in a supervised setting.