C. Juricek

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.

The Subclavian Intraaortic Balloon Pump: A Compelling Bridge Device for Advanced Heart Failure

BACKGROUND A subclavian intraaortic balloon pump (SC-IABP) can help to optimize patients with advanced congestive heart failure as a bridge to definitive therapy. We retrospectively reviewed our experience to assess the application and safety of this technique. METHODS We studied 88 patients with decompensated advanced congestive heart failure who received SC-IABP placement between January 2011 and December 2014. The SC-IABP was placed through a graft in the subclavian artery. The intended therapeutic goals for SC-IABP were bridge to transplant (n = 61), mechanical circulatory support (n = 21), or recovery (n = 6). Success was defined as stroke-free survival, achievement of therapeutic goal, and maintenance or improvement in renal function, hemodynamics, and physical conditioning through ambulation and rehabilitation. RESULTS Eighty patients were successfully bridged to the next therapy (transplant 93.4%, mechanical circulatory support 95.3%, recovery 50%). There was no mortality related to SC-IABP placement. Duration of SC-IABP support was 4 to 135 days (median 21). Failure was attributed to escalation of support (n = 5), stroke (n = 2), and sepsis (n = 1). Mean pulmonary artery pressure significantly improved from 33 ± 11 mm Hg to 28 ± 8 mm Hg (p < 0.05). Eighty-four patients (95.5%) ambulated more than 3 times a day. Two-minute step test demonstrated significant improvement, from 50 ± 9 steps to 90 ± 23 steps (n = 16, p < 0.001). Specific complications of SC-IABP included exchange/repositioning (n = 26, 29.5%), subclavian artery thrombosis (n = 1, 1.1%), and reexploration for hematoma (n = 4, 4.5%) and infection (n = 2, 2.3%). No distal thromboembolic events were observed. CONCLUSIONS The SC-IABP provided excellent hemodynamic support with minimal morbidity and mortality, allowed for extensive rehabilitation, and permitted more than 90% of patients to receive their intended therapy. Therefore, SC-IABP is a compelling bridge device for patients with advanced congestive heart failure.

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.

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.

Increased Risk of Bleeding in Left Ventricular Assist Device Patients Treated with Enoxaparin as Bridge to Therapeutic INR

Anticoagulation therapy is used to prevent thromboembolic events in patients with left ventricular assist devices (LVADs). This study aims to determine the safety of low molecular weight heparin (enoxaparin) for bridging subtherapeutic international normalized ratio (INR) in LVAD patients. In this retrospective single-center study, all patients who underwent LVAD implantation were examined between January 1, 2013, and December 31, 2014. Patients were divided into two groups: enoxaparin bridge and no bridge, with identification of major bleeding episodes (MBEs) and thrombotic events (TEs). Major bleeding episode and TE incidence was compared between the two groups, with subanalysis of incidence in the enoxaparin group between the periods on and off treatment. One hundred eighteen patients were included in this analysis. Fifty-five patients received enoxaparin, whereas 63 patients did not receive enoxaparin, with no significant difference between groups in all baseline characteristics. For the study period, enoxaparin patients had no increased incidence of MBEs (0.53 vs. 0.35 MBE per year; p = 0.12). However, there was a fourfold increase in MBEs during the bridged period in the enoxaparin group (2.02 vs. 0.45 MBE per year; p = 0.03). Major bleeding episodes on versus off enoxaparin had no major difference in transfusion requirements (2.7 ± 2.9 vs. 2.5 ± 3.4 units; p = 0.57) or mortality (p = 0.11). The enoxaparin group trended to a higher incidence of TEs (0.20 vs. 0.11 events per year; p = 0.08). Enoxaparin bridging in patients with subtherapeutic INR is associated with a significantly increased risk of MBEs. Prospective studies are needed to confirm these findings; however, until then, caution should be used with enoxaparin for bridging in LVAD patients.

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.

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.