Pump Speed Optimization in Patients Implanted With the HeartMate 3 Device.

BACKGROUND: Pump speed optimization in patients implanted with a ventricular assist device represents a major challenge during the follow-up period. We present our findings on whether combined invasive hemodynamic ramp tests and cardiopulmonary exercise testing (CPX) can help optimize patient management. METHODS: Eighteen patients implanted with a HeartMate 3 (HM3) device underwent ramp tests with right heart catheterization (including central venous pressure [CVP], pulmonary artery pressure, pulmonary capillary wedge pressure [PCWP], and blood pressure) and echocardiography. Data were recorded at up to 4 speed settings. Speed changes were in steps of 200 revolutions/min (rpm). Evaluation of functional capacity by CPX was conducted according to the modified Bruce protocol. RESULTS: Only 30% of patients had normal PCWPs at their original rpm settings. In going from lowest to highest speeds, cardiac output improved by 0.25 ± 0.35 L/min/step (total change, 1.28 ± 0.3 L/min), and PCWP decreased by 1.9 ± 0.73 mm Hg/step (total change, 6 ± 1.6 mm Hg). CVP and systolic blood pressure did not change significantly with rpm. The rpm assessment was adjusted based on test results to achieve CVPs and PCWPs as close to normal limits as possible, which was feasible in all patients. On CPX, all patients demonstrated good performance (peak VO2, 16.8 ± 3.5 mL/kg/min). CONCLUSION: Hemodynamic ramp testing provides an objective means of optimizing rpm, and has the potential to provide good exercise tolerance.

Pulse Oximeter Usefulness for Blood Pressure Monitoring in Patients Implanted With Latest-Generation Continuous-Flow Device HeartMate 3.

INTRODUCTION: The measurement of blood pressure (BP) and the management of hypertension in patients with continuous-flow ventricular assist devices (CF-VADs) can present unique challenges. Patients with CF-VADs often do not have a palpable pulse, and therefore traditional blood pressure measurement by auscultation or automated cuff is less reliable. We tested the efficacy of blood pressure estimation using sphygmomanometry combined with finger pulse oximetry only after a hemodynamic optimization was effected to make the values estimated approximately similar to mean arterial pressure. METHODS: Fifteen consecutive patients with a mean age of 57.8 ± 11.2 years were implanted with HeartMate 3 between November 2015 and March 2017. All patients underwent pump speed optimization by conducting a ramp test during right heart catheterization. The patients were prospectively studied during the follow-up period and mean arterial pressure was estimated using 3 different methodologies: Doppler ultrasound, pulse oximeter, and automated blood pressure cuff. For each method 3 consecutive evaluations were conducted during 3 follow-up visits. RESULTS: For each patient, 9 different evaluations were obtained (3 for each method). The overall success rate was 100% for blood pressure assessment conducted with Doppler ultrasound and pulse oximeter and 80%-87% for automated monitor evaluations. The first 2 methodologies were 100% successful, while the third was 60% successful. Pearson's correlation analyses for the Doppler ultrasound and pulse oximeter measurements showed a good correlation when evaluations conducted with the same method were compared. A high variability emerged between estimations obtained by using an automated monitor and a poor correlation was found when this method was compared to the Doppler ultrasound and pulse oximeter measurements. CONCLUSION: According to our results, the pulse oximeter method showed a high success rate and a good correlation level with the standard procedure. Our data encourage the use of oximeters for domiciliary blood pressure assessment in patients implanted with a continuous flow device.

Mechanical circulatory support in advanced heart failure: single-center experience.

BACKGROUND: Currently, ventricular assist device (VAD) or total artificial heart (TAH) mechanical support provides an effective treatment of unstable patients with advanced heart failure. We report our single-center experience with mechanical circulatory support therapy. METHODS: From March 2002 to December 2012, 107 adult patients (mean age, 56.8 ± 9.9 y; range, 31-76 y) were primarly supported on temporary or long-term VAD or TAH support as treatment for refractory heart failure at our institution. Temporary extracorporeal radial VAD support (group A) was established in 49 patients (45.7%), and long-term paracorporeal and intracorporeal VAD or TAH (group B) in 58 patients (54.2%). Left ventricular (LVAD) support was established in 55 patients (51.4%; n = 33, Heartmate II; n = 6, Heartmate I XVE; n = 4, Heartware HVAD; and n = 12, Centrimag) and biventricular (BVAD/TAH) support (group B) in 28 patients (26.1%; n = 10, Thoratec paracorporeal; n = 2, Heartware HVAD, n = 1, Thoratec implantable; n = 1, Syncardia TAH; and n = 14, Centrimag). The temporary Centrimag was the only device adopted as isolated right ventricular (RVAD) support, and it was inserted in 24 patients (22.4%). RESULTS: In group A, overall mean support time was 10.2 ± 6.6 days (range, 3-43 d). In group B, LVAD mean support time was 357 ± 352.3 days (range, 1-902 d) and BVAD/TAH support time was 98 ± 82.6 days (range, 8-832 d). In group A, the overall success rate was 55.1% (27 patients). In group B, LVAD overall success rate was 74.4% (32 patients) and BVAD/TAH success rate was 50% (7 patients). Overall heart transplantation rate for both groups was 27.1% (n = 2, group A; n = 27, group B). Overall 1-year and 5-year survivals after heart transplantation were 72.4% (n = 21) and 58.6% (n = 17), respectively. CONCLUSIONS: Mechanical circulatory support is an effective strategy even in cases of end-stage heart failure according to our experience. Further improvement of VAD and TAH technologies may support their adoption as an encouraging alternative to heart transplantation in the near future.