Outcomes of Patients With Left Ventricular Assist Devices Requiring Intermittent Hemodialysis: Single-Center Cohort, Systematic Review, and Individual-Participant Data Meta-Analysis.

Patients with left ventricular assist devices (LVADs) who require intermittent hemodialysis (iHD) are considered to have a poor prognosis despite a paucity of supportive evidence, mostly from small single-center cohorts and extrapolations from studies of patients who received continuous renal replacement therapy but no iHD. We conducted a systematic review and individual-participant-data meta-analysis of the literature including our single-center cohort to examine the outcomes of patients initiated on iHD following LVAD implantation. Sixty-four patients from 5 cohorts met selection criteria (age 57.5 [46-64.5] years, 87% HeartMate II, mostly bridge to transplantation). Follow-up after iHD initiation was 87.5 (38.5-269.5) days, although it was considerably longer in our center than in other cohorts (601.5 [93-1559] days vs 65 [26-180] days, P = 0.0007). The estimated median survival was 308 (76-912.5) days and varied significantly among cohorts, ranging from 60 (57-65) to 838 (103-1872) days (P = 0.0096). Twelve (18.8%) patients achieved either heart transplantation (HT) or remission during follow-up. Patients who received HT had an 8-fold longer estimated median survival (1972 [799-1972] days vs 244 [64-838] days, P = 0.0112). Being from a more recent cohort was associated with better 1-year survival. Renal recovery occurred in eight patients (13.1%) at 30 days and its cumulative incidence increased to 73% (27/37 patients with available data) at 1 year. Most patients initiated on iHD after LVAD experienced renal recovery within the first year after implantation. Improved survival was observed for patients who received HT and in those from more recent cohorts. Some patients were able to survive on LVAD and iHD support for several years.

Preimplant Hyponatremia Does Not Predict Adverse Outcomes in Patients With Left Ventricular Assist Devices.

Hyponatremia is a well-established marker of adverse outcomes in chronic heart failure (HF) but not well studied in patients with left ventricular assist device (LVAD). This is a retrospective study, single center study of HM3 [Abbott, USA] LVAD implants. We divided our population based on their sodium prior to LVAD implantation - hyponatremia if <135 mEq/L and normal sodium if 135-145 mEq/L. We compared postoperative and long-term outcomes. A total of 195 patients were included, preimplant hyponatremia was present in 40% with a sodium of 132.1 ± 2.1 vs 137.8 ± 1.9 mEq/L in the normal sodium group. No differences were observed in the postoperative or long-term outcomes. Preimplant hyponatremia was not associated with mortality or HF admissions, likely due to adequate left ventricular unloading and resolution of the mechanisms that lead to hyponatremia. These results suggest that optimization of mild hyponatremia may not be critical and should not delay LVAD placement.

Cerebral protection during percutaneous intervention for left ventricular assist device outflow graft obstruction.

BACKGROUND: Left ventricular assist devices (LVAD) outflow graft obstruction is an uncommon complication but carries significant morbidity and mortality. Here we provide a case series of patients with LVAD intrinsic outflow graft obstruction who are deemed to be a high surgical risk for pump exchange and, therefore, underwent percutaneous intervention with the concomitant use of neuroprotective device-Sentinel cerebral protection system (CPS) (Boston Scientific) to prevent embolic stroke. METHODS: We retrospectively analyzed patients who underwent LVAD placement in our institution and developed LVAD outflow graft obstruction. The diagnosis of LVAD outflow graft obstruction was confirmed by utilizing various cardiac imaging modalities such as echocardiography and/or computed tomography angiography. All patients were treated with percutaneous intervention and a catheter-based CPS. RESULTS: From a total of 501 LVAD implants in our institute, 6 (1.2%) patients with LVAD outflow graft obstruction who underwent percutaneous treatment were included; 4 patients with HeartMate-III LVAD, 1 patient with HeartMate-II LVAD, and 1 patient with HeartWare (HVAD). The median age of patients was 56.5 years at the time of LVAD implantation. The median time from the LVAD implantation to the episode of LVAD outflow obstruction was 1343 days. Utilization of Sentinel CPS resulted in the capture and removal of thrombus/debris in all patients. CONCLUSIONS: Percutaneous intervention of LVAD outflow graft obstruction is less invasive than surgical pump exchange and an acceptable alternative in properly selected patients. In our experience, utilization of a catheter-based CPS can help in reducing the incidence of periprocedural embolic events.

Triple Antithrombotic Therapy in Patients With Left Ventricular Assist Devices.

Data on the efficacy and safety of the combination of warfarin and dual-antiplatelet therapy compared with warfarin and mono-antiplatelet therapy (MAPT) in patients with left ventricular assist devices (LVAD) remains scarce. Single-center study of 130 consecutive patients with durable LVAD. Baseline demographics, antithrombotic and antiplatelet regimen, and outcomes were compared between patients receiving warfarin plus dual-antiplatelet therapy (Group 1) and warfarin plus MAPT (Group 2). Antiplatelet therapy was assessed at hospital discharge post-LVAD implant and included aspirin, clopidogrel and dipyridamole. Outcomes at 1-year were assessed in each group. All patients were on aspirin and warfarin. No significant differences with regards to age, gender or ethnicity were noted at baseline between the two groups. Group 1 was more likely to have higher lactate dehydrogenase LDH levels at discharge and a history of stroke. No significant differences in international normalized ratio INR, hemoglobin or hematocrit were noted at discharge. During the study period, 48 patients had gastrointestinal bleeding events: 28 of 68 (41.2%) in Group 1 vs 20 of 62 (32.2%) in Group 2 (P = 0.293). At 1year, no statistically significant differences were noted in gastrointestinal bleeding (Group 1=27.90% vs Group 2 = 25.80, P = 0.784), ischemic stroke (Group 1 = 8.8% vs group 2 = 6.5%, P = 0.612), hemorrhagic stroke (Group 1 = 4.4% vs group 2 = 3.2%, P = 0.725) or mortality (Group 1 = 5.9% vs Group 2 = 1.6%, P = 0.206). Rates of pump thrombosis however were lower in Group 1 (Group 1 = 0% vs Group 2 = 6.5%, P = 0.033). Our study showed a high prevalence of triple-therapy antithrombotic use in LVAD patients with no significant differences in bleeding, stroke or survival. However, the risk for pump thrombosis was lower at 1-year when compared to patient receiving MAPT.

Feasibility and Safety of Coronary Angiography via Radial Approach in Cardiac Transplant Recipients: A Single Center Experience.

Coronary angiography remains the gold standard post-transplant screening test for cardiac allograft vasculopathy. This procedure has traditionally been performed via femoral approach. Data on safety and efficacy of radial approach in cardiac transplant patients remains scarce. Single center retrospective study including all cardiac transplant patients who underwent coronary angiography via transradial approach (TRA) or transfemoral approach (TFA). Safety and efficacy outcomes were compared between the 2 groups. Primary end points included major bleeding, vascular complications, crossover to femoral approach, contrast use and radiation exposure. A total of 201 patients were included. 96 patients (47.8%) underwent angiography via TRA. At baseline, no significant differences with regards to age, gender, or traditional risk factors such as HTN, DM, hyperlipidemia were noted between the 2 groups. Most patients underwent intravascular ultrasound (n = 179, 89%) with no statistically significant differences between the 2 groups (TRA: 90.6% vs TFA: 87.6%, P = 0.5). Additionally, there were no statistically significant differences in radiation exposure, amount of contrast use and fluoroscopy time between the 2 groups. Although there were trends toward increased bleeding among TFA group, these were not statistically significant and were mostly driven by access site hematomas. Use of TRA increased over time and Conversion from TRA to TFA was low (n = 4, 4.2%). Coronary angiography via the radial approach in cardiac transplant recipients is feasible, safe and is associated with low a risk of bleeding with no significant increase in radiation exposure when compared to the traditional femoral approach.

Outcomes of Asian-Americans Implanted With Left Ventricular Assist Devices: An Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) Analysis.

BACKGROUND: Studies have indicated differences between Asians and Whites in their propensity for stroke, coronary artery disease, heart failure, bleeding and thrombosis. We investigated whether Asian-Americans on durable left ventricular assist devices (LVADs) exhibit differential morbidity and mortality when compared to Whites. METHODS: We analysed prospectively collected data from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database to compare the outcomes after LVAD implantation of Asians versus Whites. RESULTS: In total, 7,018 patients were included, 130 were identified as Asian-Americans. Asian-Americans were younger, had lower body mass index, higher serum bilirubin and lower albumin levels. In a multivariable regression model, there was no difference in survival between the two groups. Asian-Americans had lower incidence of device malfunction and after adjusting for multiple factors this remained lower. The adjusted risk of a major safety composite outcome, including major bleeding, major infection, stroke and device malfunction, revealed no difference between the two groups. CONCLUSIONS: Although prior studies have reported worse cardiac surgery outcomes in Asians, in this INTERMACS analysis Asian-Americans appear to have similar survival and risk of adverse events as their White counterparts. The incidence of device malfunction was lower in the Asian-Americans, both in a univariate model and after adjusting for multiple clinical factors. Future, larger studies of Asian-Americans with end-stage heart failure and LVAD support are warranted to confirm these results.

Cardiac Rotational Mechanics As a Predictor of Myocardial Recovery in Heart Failure Patients Undergoing Chronic Mechanical Circulatory Support: A Pilot Study.

BACKGROUND: Impaired qualitative and quantitative left ventricular (LV) rotational mechanics predict cardiac remodeling progression and prognosis after myocardial infarction. We investigated whether cardiac rotational mechanics can predict cardiac recovery in chronic advanced cardiomyopathy patients. METHODS AND RESULTS: Sixty-three patients with advanced and chronic dilated cardiomyopathy undergoing implantation of LV assist device (LVAD) were prospectively investigated using speckle tracking echocardiography. Acute heart failure patients were prospectively excluded. We evaluated LV rotational mechanics (apical and basal LV twist, LV torsion) and deformational mechanics (circumferential and longitudinal strain) before LVAD implantation. Cardiac recovery post-LVAD implantation was defined as (1) final resulting LV ejection fraction ≥40%, (2) relative LV ejection fraction increase ≥50%, (iii) relative LV end-systolic volume decrease ≥50% (all 3 required). Twelve patients fulfilled the criteria for cardiac recovery (Rec Group). The Rec Group had significantly less impaired pre-LVAD peak LV torsion compared with the Non-Rec Group. Notably, both groups had similarly reduced pre-LVAD LV ejection fraction. By receiver operating characteristic curve analysis, pre-LVAD peak LV torsion of 0.35 degrees/cm had a 92% sensitivity and a 73% specificity in predicting cardiac recovery. Peak LV torsion before LVAD implantation was found to be an independent predictor of cardiac recovery after LVAD implantation (odds ratio, 0.65 per 0.1 degrees/cm [0.49-0.87]; P=0.014). CONCLUSIONS: LV rotational mechanics seem to be useful in selecting patients prone to cardiac recovery after mechanical unloading induced by LVADs. Future studies should investigate the utility of these markers in predicting durable cardiac recovery after the explantation of the cardiac assist device.

Clinical and histopathological effects of heart failure drug therapy in advanced heart failure patients on chronic mechanical circulatory support.

AIMS: Adjuvant heart failure (HF) drug therapy in patients undergoing chronic mechanical circulatory support (MCS) is often used in conjunction with a continuous-flow left ventricular assist device (LVAD), but its potential impact is not well defined. The objective of the present study was to examine the effects of conventional HF drug therapy on myocardial structure and function, peripheral organ function and the incidence of adverse events in the setting of MCS. METHODS AND RESULTS: Patients with chronic HF requiring LVAD support were prospectively enrolled. Paired myocardial tissue samples were obtained prior to LVAD implantation and at transplantation for histopathology. The Meds group comprised patients treated with neurohormonal blocking therapy (concurrent beta-blocker, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, and aldosterone antagonist), and the No Meds group comprised patients on none of these. Both the Meds (n = 37) and No Meds (n = 44) groups experienced significant improvements in cardiac structure and function over the 6 months following LVAD implantation. The degree of improvement was greater in the Meds group, including after adjustment for baseline differences. There were no differences between the two groups in arrhythmias, end-organ injury, or neurological events. In patients with high baseline pre-LVAD myocardial fibrosis, treatment with HF drug therapy was associated with a reduction in fibrosis. CONCLUSIONS: Clinical and histopathological evidence showed that adjuvant HF drug therapy was associated with additional favourable effects on the structure and function of the unloaded myocardium that extended beyond the beneficial effects attributed to LVAD-induced unloading alone. Adjuvant HF drug therapy did not influence the incidence of major post-LVAD adverse events during the follow-up period.

Impact of Ischemic Heart Failure Etiology on Cardiac Recovery During Mechanical Unloading.

BACKGROUND: Small-scale studies focused mainly on nonischemic cardiomyopathy (NICM) have shown that a subset of left ventricular assist device (LVAD) patients can achieve significant improvement of their native heart function, but the impact of ischemic cardiomyopathy (ICM) has not been specifically investigated. Many patients with acute myocardial infarction are discharged from their index hospitalization without heart failure (HF), only to return much later with overt HF syndrome, mainly caused by chronic remodeling of the noninfarcted region of the myocardium. OBJECTIVES: This study sought to prospectively investigate the effect of ICM HF etiology on LVAD-associated improvement of cardiac structure and function using NICM as control. METHODS: Consecutive patients (n = 154) with documented chronic and dilated cardiomyopathy (ICM, n = 61; NICM, n = 93) requiring durable support with continuous-flow LVAD were prospectively evaluated with serial echocardiograms and right heart catheterizations. RESULTS: In patients supported with LVAD for at least 6 months, we found that 5% of subjects with ICM and 21% of subjects with NICM achieved left ventricular ejection fraction ≥40% (p = 0.034). LV end-diastolic and end-systolic volumes and diastolic function were significantly and similarly improved in patients with ICM and NICM. CONCLUSIONS: LVAD-associated unloading for 6 months resulted in a substantial improvement in myocardial structure, and systolic and diastolic function in 1 in 20 ICM and 1 in 5 NICM patients. These specific incidence and timeline findings may provide guidance in clinical practice and research design for sequencing and prioritizing advanced HF and heart transplantation therapeutic options in patients with ICM and NICM.

Myocardial Structural and Functional Response After Long-Term Mechanical Unloading With Continuous Flow Left Ventricular Assist Device: Axial Versus Centrifugal Flow.

OBJECTIVES: The aim of this study was to assess the impact of continuous-flow left ventricular assist device (LVAD) type-axial flow (AX) versus centrifugal flow (CR)-on myocardial structural and functional response following mechanical unloading. BACKGROUND: The use of continuous-flow LVADs is increasing steadily as a therapeutic option for patients with end-stage heart failure who are not responsive to medical therapy. Whether the type of mechanical unloading influences the myocardial response is yet to be determined. METHODS: A total of 133 consecutive patients with end-stage heart failure implanted with continuous-flow LVADs (AX, n = 107 [HeartMate II Thoratec Corporation, Pleasanton, California]; CR, n = 26 [HeartWare, HeartWare International, Framingham, Massachusetts]) were prospectively studied. Echocardiograms were obtained pre-LVAD implantation and then serially at 1, 2, 3, 4, 6, 9, and 12 months post-implantation. RESULTS: The 2 pump types led to similar degrees of mechanical unloading as assessed by invasive hemodynamic status and frequency of aortic valve opening. Myocardial structural and functional parameters showed significant improvement post-LVAD in both AX and CR groups. Left ventricular ejection fraction increased significantly from a mean of 18% to 28% and 26% post-LVAD in the AX and CR groups, respectively. Left ventricular end-systolic volume index and left ventricular end-diastolic volume index decreased significantly as early as 30 days post-implantation in the 2 groups. The degree of myocardial structural or functional response between patients in the AX or CR groups appeared to be comparable. CONCLUSIONS: Long-term mechanical unloading induced by AX and CR LVADs, while operating within their routine clinical range, seems to exert comparable effects on myocardial structural and functional parameters.

Coronary computed tomography angiography for the detection of cardiac allograft vasculopathy: a meta-analysis of prospective trials.

OBJECTIVES: This study aimed to evaluate the diagnostic accuracy of coronary computed tomography angiography (CCTA) for detecting cardiac allograft vasculopathy (CAV) in comparison with conventional coronary angiography (CCAG) alone or with intravascular ultrasound (IVUS). BACKGROUND: CAV limits long-term survival after heart transplantation, and screening for CAV is performed on annual basis. CCTA is currently not recommended for CAV screening due to the limited accuracy reported by early studies. Technological advances, however, might have resulted in improved test performance and might justify re-evaluation of this recommendation. METHODS: A systematic review of Medline, Cochrane, and Embase for all prospective trials assessing CAV using CCTA was performed using a standard approach for meta-analysis for diagnostic test and a bivariate analysis. RESULTS: Thirteen studies evaluating 615 patients (mean age 52 years, 83% male) and 9,481 segments fulfilled inclusion criteria. Patient-based analyses comparing CCTA versus CCAG for the detection of any CAV (> luminal irregularities) and significant CAV (stenosis ≥50%), showed mean weighted sensitivities of 97% and 94%, specificities of 81% and 92%, a negative predictive value (NPV) of 97% and 99%, a positive predictive value (PPV) of 78% and 67%, and diagnostic accuracies of 88% and 94%, respectively. There was a strong trend toward improved sensitivity (97% vs. 91%, p = 0.06) and NPV (99% vs. 97%, p = 0.06) to detect significant CAV with 64-slice compared with 16-slice CCTA. A patient-based analysis of 64-slice CCTA versus IVUS showed a mean weighted sensitivity and specificity of 81% and 75% to detect CAV (intimal thickening >0.5 mm), whereas the PPV and NPV were 93% and 50%, respectively. CONCLUSIONS: CCTA using currently available technology is a reliable noninvasive imaging alternative to coronary angiography with an excellent sensitivity, specificity, and NPV for the detection of CAV.