D. Rodgers

Hemodynamic Ramp Tests in Patients With Left Ventricular Assist Devices

OBJECTIVES This study tested whether combined invasive hemodynamic and echocardiographic ramp tests can help optimize patient management. BACKGROUND Guidelines for optimizing speed and medications in continuous flow ventricular assist device (cfLVAD) patients are mainly based on expert opinion. METHODS Thirty-five cfLVAD patients (21 HeartMate II [Thoratec, Pleasanton, California] and 14 HVAD [HeartWare International, Framingham, Massachusetts]) 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 9 speed settings. Speed changes were in steps of 400 revolutions per minute (RPM) for HeartMate II (8,000 to 12,000 RPM) and 100 RPM for HVAD (2,300 to 3,200 RPM) patients. RESULTS Only 42.9% of patients had normal CVPs and PCWPs at their original RPM settings. Going from lowest to highest speeds, cardiac output improved by 0.16 ± 0.19 l/min/step (total change 1.28 ± 1.41 l/min) and PCWP decreased by 1.23 ± 0.85 mm Hg/step (total change 9.9 ± 6.5 mm Hg). CVP and systolic blood pressure did not change significantly with RPM. RPM were adjusted based on test results to achieve CVPs and PCWPs as close to normal limits as possible, which was feasible in 56% of patients. For the remainder, results indicated which type of medical management should be pursued. CONCLUSIONS Use of combined hemodynamic and echocardiographic ramp tests in patients provides objective means of optimizing RPM, and has the potential to guide medical management. It remains to be tested whether this strategy has a beneficial impact on quality of life or clinical outcomes.

Clinical hemodynamic evaluation of patients implanted with a fully magnetically levitated left ventricular assist device (HeartMate 3)

BACKGROUND The HeartMate 3 (HM3) is a Conformiteé Européenne (CE) mark-approved left ventricular assist device (LVAD) with a fully magnetically levitated rotor with features consisting of a wide range of operational speeds, wide flow paths and an artificial pulse. We performed a hemodynamic and echocardiographic evaluation of patients implanted with the HM3 LVAD to assess the speed range for optimal hemodynamic support. METHODS Sixteen HM3 patients underwent pump speed ramp tests with right heart catheterization (including central venous pressure [CVP], pulmonary artery pressure, pulmonary capillary wedge pressure [PCWP] and blood pressure [BP]) and 3-dimensional echocardiography (3DE). Data were recorded at up to 13 speed settings. Speed changes were in steps of 100 revolutions per minute (rpm), starting at 4,600 rpm and ramping up to 6,200 rpm. RESULTS Mean original speed was 5,306 ± 148 rpm, with a majority of patients (10 of 16, 62.5%) having normal CVPs and PCWPs at their original rpm settings. Going from lowest to highest speeds, cardiac output improved at the rate of 0.08 ± 0.08 liter/min per 100 rpm (total change 1.25 ± 1.20 liters/min) and PCWP decreased at the rate of -0.48 ± 0.27 mm Hg per 100 rpm (total change -6.13 ± 3.72 mm Hg). CVP and systolic BP did not change significantly with changes in rpm. Left ventricular end-diastolic dimension (LVEDD) decreased at a rate of -0.15 ± 0.09 cm per 100 rpm. Number of rpm was adjusted based on test results to achieve CVPs and PCWPs as close to normal limits as possible, which was feasible in 13 (81.3%) patients. For the remaining 3 patients, medical management was pursued to optimize hemodynamic support. CONCLUSION Hemodynamic normalization of pressures was achieved in the majority of patients implanted with the HM3 pump within a narrow speed range.

Decoupling Between Diastolic Pulmonary Artery Pressure and Pulmonary Capillary Wedge Pressure as a Prognostic Factor After Continuous Flow Ventricular Assist Device Implantation

Background: A cohort of heart failure (HF) patients receiving left ventricular assist devices (LVADs) has decoupling of their diastolic pulmonary artery pressure and pulmonary capillary wedge pressure. However, the clinical implications of this decoupling remain unclear. Methods and Results: In this prospective study, patients with LVADs underwent routine invasive hemodynamic ramp testing with right heart catheterization, during which LVAD speeds were adjusted. Inappropriate decoupling was defined as a >5 mm Hg difference between diastolic pulmonary artery pressure and pulmonary capillary wedge pressure. The primary outcomes of survival and heart failure readmission rates after ramp testing were assessed. Among 63 LVAD patients (60±12 years old and 25 female [40%]), 27 patients (43%) had inappropriate decoupling at their baseline speed. After adjustment of their rotation speed during ramp testing, 30 patients (48%) had inappropriate decoupling. Uni/multivariable Cox analyses demonstrated that decoupling was the only significant predictor for the composite end point of death and heart failure readmission during the 1 year following the ramp study (total of 18 events; hazards ratio, 1.09; 95% confidence interval, 1.04–1.24; P<0.05). Furthermore, normalization of decoupling (n=8) during ramp testing was significantly associated with higher 1-year heart failure readmission–free survival rate compared with the non-normalized group (n=19, 100% versus 53%; P=0.035). Conclusions: The presence of inappropriate decoupling was associated with worse outcomes in patients with LVADs. Prospective, large-scale multicenter studies to validate the result are warranted.

The Hemodynamic Effects of Aortic Insufficiency in Patients Supported with Continuous-Flow Left Ventricular Assist Devices

BACKGROUND The impact of aortic insufficiency (AI) on the morbidity and mortality of left ventricular assist device (LVAD) patients remains controversial. This studys aim was to assess the hemodynamics of LVAD patients with at least mild AI, at baseline and in response to device speed changes. METHODS AND RESULTS Asymptomatic LVAD patients were prospectively enrolled and underwent a hemodynamic and echocardiographic ramp study. Hemodynamics at rest and in response to device speed changes were compared between patients with at least mild AI at their baseline speed and patients without AI. Fift-five patients were enrolled in the study, and 42% had AI. The AI group had higher baseline central venous pressure (11 ± 5 vs 8 ± 5 mm Hg; P = .03), higher pulmonary capillary wedge pressure (PCWP) (16 ± 6 vs 12 ± 6 mm Hg; P = .02) and lower pulmonary artery pulsatility index (PAPI) (2.3 ± 1.3 vs 3.6 ± 2.4; P = .01). Cardiac index (CI) increased and PCWP decreased in both groups by similar degrees during the ramp study. AI worsened in 78% of patients during the ramp study. CONCLUSIONS LVAD patients with at least mild AI have increased filling pressures and reduced PAPI. Normalization of filling pressures can be achieved by increasing LVAD speed; however, this concomitantly worsens AI severity. The long-term hemodynamic consequences of this approach are unknown.

Long-Acting Octreotide Reduces the Recurrence of Gastrointestinal Bleeding in Patients With a Continuous-Flow Left Ventricular Assist Device

BACKGROUND Recurrent gastrointestinal bleeding is one of the most significant adverse events in patients with left ventricular assist devices (LVADs). METHODS We enrolled LVAD patients who had received an intramuscular injection of 20 mg octreotide every 4 weeks as secondary prevention for recurrent gastrointestinal bleeding despite conventional medical therapies and repeated transfusions. The frequency of gastrointestinal bleeding and other associated clinical outcomes before and during octreotide therapy were compared. RESULTS Thirty LVAD patients (66.4 ± 8.8 years old, 16 men [53%]) received octreotide therapy for 498.8 ± 356.0 days without any octreotide-associated adverse events. The frequency of gastrointestinal bleeding was decreased significantly during octreotide therapy (from 3.4 ± 3.1 to 0.7 ± 1.3 events/year; P < .001), accompanied by significant reductions in red blood cell and flesh frozen plasma transfusions, days in hospital, and need for endoscopic procedures (P < .05 for all). CONCLUSIONS Octreotide therapy reduced the frequency of recurrent gastrointestinal bleeding and may be considered for secondary prevention.

Cannula and Pump Positions Are Associated With Left Ventricular Unloading and Clinical Outcome in Patients With HeartWare Left Ventricular Assist Device

BACKGROUND Cannula and pump positions are associated with clinical outcomes such as device thrombosis in patients with HeartMate II; however, clinical implications of HVAD (HeartWare International, Framingham, Massachusetts) cannula position are unknown. This study aims to assess the relationship among cannula position, left ventricular (LV) unloading, and patient prognosis. METHODS AND RESULTS Twenty-seven HVAD patients (60.0 ± 12.6 years of age and 19 males [70%]) underwent ramp test. Device position was quantified from chest X-ray parameters obtained at the time of the hemodyamic ramp test: (1) cannula coronal angle, (2) pump depth, (3) cannula sagittal angle, and (4) pump area. Lower cannula coronal angle was associated with LV unloading (as measured by smaller LV diastolic dimension and lower pulmonary capillary wedge pressure). Smaller pump area was associated with LV dynamic unloading, as assessed by steeper negative slopes of LV diastolic dimension and pulmonary capillary wedge pressure during incremental rotational speed change. Cannula coronal angle ≤65° was associated with reduced heart failure readmission rate (hazard ratio, 10.33; P = .007 by log-rank test). CONCLUSION HVAD cannula and pump positions are associated with LV unloading and improved clinical outcomes. Prospective studies evaluating surgical techniques to ensure optimal device positioning and its effects on clinical outcomes are warranted.

Increase in short-term risk of rejection in heart transplant patients receiving granulocyte colony-stimulating factor

BACKGROUND Neutropenia is a significant adverse event after heart transplantation (HT) and increases infection risk. Granulocyte colony-stimulating factor (G-CSF) is commonly used in patients with neutropenia. In this work, we assessed the adverse effects of G-CSF treatment in the setting of a university hospital. METHODS Data on HT patients from January 2008 to July 2016 were reviewed. Patients who received G-CSF were identified and compared with patients without a history of therapy. Baseline characteristics, rejection episodes, and outcomes were collected. Data were analyzed by incidence rates, time to rejection and survival were analyzed using Kaplan-Meier curves, and odds ratios were generated using logistic regression analysis. RESULTS Two hundred twenty-two HT patients were studied and 40 (18%) received G-CSF for a total of 85 total neutropenic events (0.79 event/patient year). There were no differences in baseline characteristics between the groups. In the 3 months after G-CSF, the incidence rate of rejection was 0.067 event/month. In all other time periods considered free of G-CSF effect, the incidence rate was 0.011 event/month. This rate was similar to the overall incidence rate in the non-GCSF group, which was 0.010 event/month. There was a significant difference between the incidence rates in the G-CSF group at 0 to 3 months after G-CSF administration and the non-GCSF group (p = 0.04), but not for the other time periods (p = 0.5). Freedom from rejection in the 3 months after G-CSF administration was 87.5% compared with 97.5% in the non-GCSF group (p = 0.006). CONCLUSIONS G-CSF administration was found to be associated with significant short-term risk of rejection. This suggests the need for increased surveillance during this time period.

Echocardiographic Predictors of Hemodynamics in Patients Supported With Left Ventricular Assist Devices

BACKGROUND The assessment of hemodynamics in patients supported with left ventricular assist devices (LVADs) is often challenging. Physical examination maneuvers correlate poorly with true hemodynamics. We assessed the value of novel transthoracic echocardiography (TTE)-derived variables to reliably predict hemodynamics in patients supported with LVAD. METHODS AND RESULTS A total of 102 Doppler-TTE images of the LVAD outflow cannula were obtained during simultaneous invasive right heart catheterization (RHC) in 30 patients supported with continuous-flow LVADs (22 HMII, 8 HVAD) either during routine RHC or during invasive ramp testing. Properties of the Doppler signal though the outflow cannula were measured at each ramp stage (RS), including the systolic slope (SS), diastolic slope (DS), and velocity time integral (VTI). Hemodynamic variables were concurrently recorded, including Doppler opening pressure (MAP), heart rate (HR), right atrial pressure, pulmonary artery pressure, pulmonary capillary wedge pressure (PCWP), Fick cardiac output (CO) and systemic vascular resistance (SVR). Univariate and multivariate regression analyses were used to explore the dependence of PCWP, CO, and SVR on DS, SS, VTI, MAP, HR, and RS. Multivariate linear regression analysis revealed significant contributions of DS on PCWP (PCWPpred = 0.164DS + 4.959; R = 0.68). Receiver operating characteristic (ROC) curve analysis revealed that PCWPpred could predict an elevated PCWP ≥18 mm Hg with a sensitivity (Sn) of 94% and specificity (Sp) of 85% (area under the ROC curve 0.88). CO could be predicted by RS, VTI, and HR (COpred = 0.017VTI + 0.016HR + 0.12RS + 2.042; R = 0.61). COpred could predict CO ≤4.5 L/min with Sn 73% and Sp 79% (AUC 0.81). SVR could be predicted by MAP, VTI, and HR (SVRpred = 15.44MAP - 5.453VTI - 6.349HR + 856.15; R = 0.84) with Sn 84% and Sp 79% (AUC 0.91) to predict SVR ≥1200 dyn-s/cm5. CONCLUSIONS Doppler-TTE variables derived from the LVAD outflow cannula can reliably predict PCWP, CO, and SVR in patients supported with LVADs and may mitigate the need for invasive testing.

Decoupling Between Diastolic Pulmonary Arterial Pressure and Pulmonary Arterial Wedge Pressure at Incremental Left Ventricular Assist Device (LVAD) Speeds Is Associated With Worse Prognosis After LVAD Implantation

BACKGROUND Decoupling between diastolic pulmonary arterial pressure (dPAP) and pulmonary arterial wedge pressure (PAWP) is an index of pulmonary vasculature remodeling and provides prognostic information. Furthermore, decoupling may change during incremental left ventricular assist device (LVAD) speed changes. METHODS AND RESULTS In this prospective study, patients underwent an echocardiographic and hemodynamic ramp test after LVAD implantation and were followed for 1 year. The change in decoupling (dPAP - PAWP) between the lowest and highest LVAD speeds during the ramp test was calculated. Survival and heart failure admission rates were assessed by means of Kaplan-Meier analysis. Eighty-seven patients were enrolled in the study: 54 had a Heartmate II LVAD (60.8 ± 9.3 years of age and 34 male) and 33 had an HVAD LVAD (58.6 ± 13.2 years of age and 20 male). Patients who experienced greater changes in decoupling (Δdecoupling >3 mm Hg) had a persistently elevated dPAP at incremental LVAD speed and had worse 1-year heart failure readmission-free survival compared with the group without significant changes in the degree of decoupling (41% vs 75%; P = .001). CONCLUSIONS An increase in decoupling between dPAP and PAWP at incremental LVAD speed changes was associated with worse prognosis in LVAD patients.