Search

There is limited knowledge of pulmonary physiology and pulmonary function after continuous flow-left ventricular assist device (CF-LVAD) implantation. Therefore, this study investigated whether CF-LVAD influenced pulmonary circulation by assessing pulmonary capillary blood volume and alveolar-capillary conductance in addition to pulmonary function in patients with heart failure. Seventeen patients with severe heart failure who were scheduled for CF-LVAD implantation (HeartMate II, III, Abbott, Abbott Park, IL or Heart Ware, Medtronic, Minneapolis, MN) participated in the study. They underwent pulmonary function testing (measures of lung volumes and flow rates) and unique measures of pulmonary physiology using a rebreathe technique that quantified the diffusing capacity of the lungs for carbon monoxide (DLCO) and diffusing capacity of the lungs for nitric oxide before and 3 months after CF-LVAD implantation. After CF-LVAD, pulmonary function was not significantly changed (p >0.05). For lung diffusing capacity, alveolar volume (VA) was not changed (p = 0.47), but DLCO was significantly reduced (p = 0.04). After correcting for VA, DLCO/VA showed a trend toward reduction (p = 0.08). For the alveolar-capillary component, capillary blood volume (Vc) was significantly reduced (p = 0.04), and alveolar-capillary membrane conductance trended toward a reduction (p = 0.06). However, alveolar-capillary membrane conductance/Vc was not altered (p = 0.92). In conclusion, soon after CF-LVAD implantation, Vc is reduced likely because of pulmonary capillary derecruitment, which contributes to the decrease in lung diffusing capacity., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to declare., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Mechanical circulatory support is increasingly being used as bridge-to-transplant and destination therapy in patients with advanced heart failure. Technologic improvements have led to increased patient survival and quality of life, but infection remains one of the leading adverse events following ventricular assist device (VAD) implantation. Infections can be classified as VAD-specific, VAD-related, and non-VAD infections. Risk of VAD-specific infections, such as driveline, pump pocket, and pump infections, remains for the duration of implantation. While adverse events are typically most common early (within 90 days of implantation), device-specific infection (primarily driveline) is a notable exception. No diminishment over time is seen, with event rates of 0.16 events per patient-year in both the early and late periods postimplantation. Management of VAD-specific infections requires aggressive treatment and chronic suppressive antimicrobial therapy is indicated when there is concern for seeding of the device. While surgical intervention/hardware removal is often necessary in prosthesis-related infections, this is not so easily accomplished with VADs. This review outlines the current state of infections in patients supported with VAD therapy and discusses future directions, including possibilities with fully implantable devices and novel approaches to treatment., Competing Interests: Disclosure: The authors have no conflicts of interest to report., (Copyright © ASAIO 2023.)

The effects of left ventricular unloading on septal function in patients with left ventricular assist devices (LVADs) have not been well characterized in vivo. The purpose of this study was to evaluate the relationship between markers of septal function with echocardiography in relationship to RV dysfunction and late RV failure after LVAD implantation. A retrospective study was conducted of patients supported on centrifugal-flow LVADs implanted over a 10-year period. Echocardiographic data were collected pre-operatively and up to 2 years after implantation. Interventricular septum (IVS) measurements were taken at end-systole and end-diastole. Interventricular-septal output (ISO) was calculated using the formula: (IVSs-IVSd)×heart rate. A total of 110 patients were included. An immediate and sustained reduction in both lateral annulus systolic velocity (RVS') and TAPSE were observed after implant ( p < 0.0001). However, ISO gradually decreased over time ( p < 0.0001). While ISO was not predictive of late RV failure, a decrease in ISO by 25% or greater from pre-implant to hospital discharge was associated with late RV failure (OR 4.8; 95% CI, 1.4-16.5; p = 0.012) even after adjusting for relevant clinical variables ( p ≤ 0.01 for each model). RV function is known to be influenced by mechanical ventricular interdependence and we demonstrate that measurement of ISO may be a useful marker in assessing RV dysfunction and predicting RV failure in patients following LVAD implantation., Competing Interests: There are no conflicts of interest to disclose and no sources of funding., (Copyright © ASAIO 2022.)

Data on pre-implant hemodynamic optimization before continuous flow left ventricular assist device placement (CF-LVAD) with respect to patient-centered outcomes remain limited. Consecutive patients undergoing CF-LVAD implant between 2007 and 2017 were identified. Hemodynamic variables, trends, and laboratory studies were evaluated pre-LVAD implant in a logistic regression model to identify predictors of the primary composite endpoint: the need for right ventricular assist device therapy, the requirement for hemodialysis at 90 days, and 30-day mortality. Multivariate modeling identified three variables significantly associated with the primary endpoint: right ventricular stroke work index (RVSWI), right atrial pressure (RAP), and blood urea nitrogen (BUN); all immediately pre-LVAD, p < 0.01. Optimal dichotomization points were 500 mmHg*ml*m-2, 12 mmHg, and 40 mg/dL. The three-component model identified an AUC of 0.77 (p < 0.0001) for the composite endpoint. Optimization of 2/3 parameters, 1/3, and 0/3 was associated with odds ratios of 3.5 (95% CI, 1.1-11.7), 7.2 (95% CI, 2.1-24.2), and 20.6 (95% CI, 5.3-80.6), respectively, relative to those patients who were fully optimized (3/3 parameters). The number of optimized parameters was also associated with 1-year overall survival (p = 0.02). Low RVSWI, high RAP, and high BUN were independently associated with adverse outcomes after the CF-LVAD implant, demonstrating a stepwise association with severe postimplant adverse events., Competing Interests: Disclosure: Dr Behfar is a cofounder and is on the Board of Directors of Rion LLC. He holds stock in Sorento Therapeutics and shares in Deverra Therapeutics. The other authors have no conflicts of interest to report., (Copyright © ASAIO 2021.)

Background: Incident liver dysfunction after left ventricular assist device implantation has been previously associated with adverse outcomes, yet data on perioperative risk markers are sparse., Methods: We retrospectively reviewed consecutive patients undergoing continuous-flow left ventricular assist device implant between 2007 and 2017 at a single institution. Perioperative variables were evaluated by univariate modeling and adjusted for false discovery rate. Variables most significantly associated with incident Interagency Registry for Mechanically Assisted Circulatory Support-defined liver dysfunction (INT-LD) were evaluated using logistic regression and optimal cutpoints were defined. One-year survival was evaluated using Kaplan-Meier analysis., Results: We included 359 patients (79% male; mean age 59 ± 13 years; 46% ischemic; 64% destination therapy). Lower right ventricular stroke work index at the time of right heart catheterization, higher right atrial pressure 6 hours after right heart catheterization, higher preoperative total bilirubin, longer cardiopulmonary bypass time, and greater volume of intraoperative ultrafiltration were most strongly associated with incident INT-LD (adjusted P < .01 for each). Initial right ventricular stroke work index less than 460 mm Hg∗mL/m2 (odds ratio [OR] 4.6; 95% confidence interval [CI], 2.3 to 9.4), 6-hour right heart catheterization 14 mm Hg or greater (OR 4.3; 95% CI, 2.1 to 8.8), cardiopulmonary bypass time longer than 137 minutes (OR 3.3; 95% CI, 1.8 to 6.2; P < .01 for all), ultrafiltration more than 2.95 L (OR 3.7; 95% CI, 2 to 6.8), and total bilirubin greater than 1.4 mg/dL (OR 2.7; 95% CI, 1.4 to 5) were each strongly associated with risk of INT-LD, which was associated with decreased unadjusted 1-year survival (P < .001)., Conclusions: Right ventricular stroke work index, right heart catheterization, cardiopulmonary bypass time, and ultrafiltration were each more strongly associated with elevated risk of INT-LD after left ventricular assist device implant than total bilirubin. Therefore, optimization of right ventricular hemodynamics and minimizing cardiopulmonary bypass time and ultrafiltration could potentially reduce the risk of liver dysfunction, but these observations require prospective validation., (Copyright © 2021 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: To characterize the properties of the audible tones produced by current left ventricular assist device (LVAD) pumps approved for use, and to ascertain if changes in those may be present in the setting of pump thrombosis., Patients and Methods: From August 31, 2016, to January 16, 2020, LVAD recipients consented to have surface recordings obtained using a high-fidelity digital stethoscope. Audio data were analyzed using digital recording and editing software to produce an acoustic spectrogram by Fast Fourier transformation., Results: Recordings were obtained in 53 patient encounters (27 HeartMate II, 19 HeartWare and 7 HeartMate 3). In 12 patients (9 HeartMate II, 3 HeartWare) there was a clinical concern for pump thrombosis. In all patients and pump models, a fundamental frequency was noted, and the second and third harmonics were also clearly detectable. Where thrombosis occurred in the HeartMate II pump, the absolute (normal -46.9 [-57.5,-42.9] dB vs thrombosis -41.4 [-49.8,-26.8] dB; P=.08) and relative (normal 0.72 [0.62, 0.92] vs thrombosis 0.95 [0.86, 1.24]; P=.01) third harmonic frequencies were increased in amplitude. Where paired data were available, an increase in the absolute and relative third harmonic frequencies was observed in all patients. In the case of the HeartWare device, a consistent difference in harmonic amplitudes in the setting of thrombosis could not be identified., Conclusion: A consistent pattern of fundamental and harmonic frequencies is common to all LVADs currently approved for use. Alterations in the amplitude of higher order harmonics may signal the onset of pump thrombosis in axial flow LVADs., (Copyright © 2020 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.)

Left ventricular assist devices (LVAD) are used to support advanced heart failure patients who have failed optimal medical management, meet LVAD criteria, and are deemed to be appropriate surgical candidates. LVAD patients are further advised on symptoms that should prompt notification to the implanting center and are encouraged to contact their LVAD team with device questions and concerns due to morbidity risks unique to this patient population. Mechanical disruption of internal LVAD components is rare and typically requires hospitalization and potentially surgical intervention. External trauma to the LVAD resulting in driveline fracture, torn LVAD outflow grafts, pump displacement, and a kinked inlet cannula have been described. 1 Because these occurrences are rare and often unexpected, identification of the root cause may not always be readily apparent. We describe a previously unreported presentation of a patient supported with an LVAD for more than 4 years who was found to have a broken and dislodged LVAD outflow cuff floating in an abdominal hematoma without pump failure., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background The presence of a durable left ventricular assist device (LVAD) is associated with increased risk of vasoplegia in the early postoperative period following heart transplantation (HT). However, preoperative predictors of vasoplegia and its impact on survival after HT are unknown. We sought to examine predictors and outcomes of patients who develop vasoplegia after HT following bridging therapy with an LVAD. Methods and Results We identified 94 patients who underwent HT after bridging with continuous-flow LVAD from 2008 to 2018 at a single institution. Vasoplegia was defined as persistent low vascular resistance requiring ≥2 intravenous vasopressors within 48 hours after HT for >24 hours to maintain mean arterial pressure >70 mm Hg. Overall, 44 patients (46.8%) developed vasoplegia after HT. Patients with and without vasoplegia had similar preoperative LVAD, echocardiographic, and hemodynamic parameters. Patients with vasoplegia were significantly older; had longer LVAD support, higher preoperative creatinine, longer cardiopulmonary bypass time, and higher Charlson comorbidity index; and more often underwent combined organ transplantation. In a multivariate logistic regression model, older age (odds ratio: 1.08 per year; P =0.010), longer LVAD support (odds ratio: 1.06 per month; P =0.007), higher creatinine (odds ratio: 3.9 per 1 mg/dL; P =0.039), and longer cardiopulmonary bypass time (odds ratio: 1.83 per hour; P =0.044) were independent predictors of vasoplegia. After mean follow-up of 4.0 years after HT, vasoplegia was associated with increased risk of all-cause mortality (hazard ratio: 5.20; 95% CI, 1.71-19.28; P =0.003). Conclusions Older age, longer LVAD support, impaired renal function, and prolonged intraoperative CPB time are independent predictors of vasoplegia in patients undergoing HT after LVAD bridging. Vasoplegia is associated with worse prognosis; therefore, detailed assessment of these predictors can be clinically important.

Background Diastolic pulmonary gradient (DPG) was proposed as a better marker of pulmonary vascular remodeling compared with pulmonary vascular resistance (PVR) and transpulmonary gradient (TPG). The prognostic significance of DPG in patients requiring a left ventricular assist device (LVAD) remains unclear. We sought to investigate whether pre-LVAD DPG is a predictor of survival or right ventricular (RV) failure post-LVAD. Methods and Results We retrospectively reviewed 268 patients who underwent right heart catheterization before LVAD implantation from 2007 to 2017 and had pulmonary hypertension because of left heart disease. Patients were dichotomized using DPG ≥7 mm Hg, PVR ≥3 mm Hg, or TPG ≥12 mm Hg. The associations between these parameters and all-cause mortality or RV failure post LVAD were assessed with Cox proportional hazards regression and Kaplan-Meier analyses. After a mean follow-up time of 35 months, elevated DPG was associated with increased risk of RV failure (hazard ratio [HR]: 3.30; P=0.004, for DPG ≥7 versus DPG <7), whereas elevated PVR (HR 1.85, P=0.13 for PVR ≥3 versus PVR <3) or TPG (HR 1.47, P=0.35, for TPG ≥12 versus TPG <12) were not associated with the development of RV failure. Elevated DPG was not associated with mortality risk (HR 1.16, P=0.54, for DPG ≥7 versus DPG <7), whereas elevated PVR, but not TPG, was associated with higher mortality risk (HR 1.55; P=0.026, for PVR ≥3 versus PVR <3). Conclusions Among patients with pulmonary hypertension because of left heart disease requiring LVAD support, elevated DPG was associated with RV failure but not survival, while elevated PVR predicted mortality post LVAD implantation.

Objective: To investigate differences in invasive hemodynamic parameters and outcomes in patients with and without heart failure (HF) symptoms after left ventricular assist device (LVAD) implantation., Patients and Methods: We performed a single-center retrospective analysis of 51 symptomatic patients and 50 patients with resolved HF symptoms who underwent right-sided heart catheterization (RHC) after LVAD implantation from March 1, 2007, through June 30, 2016. Patient characteristics and outcomes including all-cause mortality and right ventricular (RV) failure were compared between groups., Results: Fifty-one patients had development of HF symptoms after LVAD implantation and underwent RHC a mean ± SD of 243.7±288 days postoperatively. Fifty asymptomatic LVAD recipients underwent routine RHC 278.6±205 days after implantation. Compared with patients who had resolved HF symptoms, symptomatic patients were older, more likely to be male, and more likely to have ischemic cardiomyopathy. Symptomatic patients had higher right atrial pressure (P<.001), mean pulmonary arterial pressure (P<.001), and pulmonary capillary wedge pressure (P<.001). Improvements in right atrial pressure, mean pulmonary arterial pressure, and pulmonary capillary wedge pressure before and after LVAD implantation were less remarkable in symptomatic patients. The frequency of RV dysfunction was significantly higher among symptomatic patients than patients with resolved HF symptoms (P=.001). Symptomatic patients displayed significantly higher risk of all-cause mortality (hazard ratio, 3.0; 95% CI, 1.3-6.5; P=.007) and RV failure (hazard ratio, 6.2; 95% CI, 1.3-29.7; P=.02) independent of other predictors of outcome., Conclusion: Patients with recurrent HF symptoms after LVAD implantation display more profound hemodynamic derangements, greater burden of RV failure, and increased rates of all-cause mortality compared with LVAD recipients with resolved HF symptoms., (Copyright © 2018 Mayo Foundation for Medical Education and Research. All rights reserved.)

Background: Diabetes mellitus (DM) is a risk factor for morbidity and mortality in patients with heart failure. The effect of DM on post-left ventricular assist device (LVAD) implantation outcomes is unclear. This study sought to investigate whether patients with DM had worse outcomes than patients without DM after LVAD implantation and whether LVAD support resulted in a better control of DM., Methods and Results: We retrospectively reviewed 341 consecutive adults who underwent implantation of LVAD from 2007 to 2016. Patient characteristics and adverse events were studied and compared between patients with and without DM. One hundred thirty-one patients (38%) had DM. Compared with patients without DM, those with DM had higher rates of ischemic cardiomyopathy, LVAD implantation as destination therapy, and increased baseline body mass index. In a proportional hazards (Cox) model with adjustment for relevant covariates and median follow-up of 16.1 months, DM was associated with increased risk of all-cause mortality (hazard ratio, 1.73; 95% confidence interval: 1.18-2.53; P =0.005) and increased risk of nonfatal LVAD-related complications, including a composite of stroke, pump thrombosis, and device infection (hazard ratio, 2.1; 95% confidence interval: 1.35-3.18; P =0.001). Preoperative hemoglobin A1c was not significantly associated with mortality or adverse events among patients with DM. LVAD implantation resulted in a remarkable decrease in hemoglobin A1c levels (7.4±1.9 pre-LVAD versus 6.0±1.5 and 6.3±1.4 after 3 and 12 months post-LVAD, respectively; P <0.0001) and a significant reduction in requirements of DM medications., Conclusions: DM is associated with increased rates of all-cause mortality and major adverse events despite favorable glycemic control after LVAD implantation., (© 2017 American Heart Association, Inc.)

Background: Psychosocial factors impact survival in patients undergoing cardiac transplantation, but it is unclear whether they affect outcomes in patients undergoing left ventricular assist device (LVAD) implantation as destination therapy (DT)., Methods: Patients undergoing DT LVAD at the Mayo Clinic in Rochester, MN, from February 2007 to December 2013 were included. Psychosocial characteristics at the time of LVAD implantation were abstracted from the medical record. Andersen-Gill and Cox models were used to examine the association between psychosocial characteristics and all-cause readmission and death, respectively. Patients were censored at death or last follow-up through September 2014., Results: Among 136 patients (mean age. 64 years; 17% female), most were married/living with a partner (82%), half (55%) had post-high school education, and a history of depression was common (32%). Although most patients were former tobacco users (60%) only a small proportion were current tobacco users (10%) and had a history of alcohol abuse (16%) or illegal drug use (7%). After a mean follow-up of 2.2 ± 1.8 years, 78% of patients had been readmitted (range, 0-14 per person) and 49% had died. There were no statistically significant differences in the risk of death according to psychosocial characteristics. However, current tobacco users had lower risk of readmission (adjusted HR, 0.57; 95% CI, 0.38-0.88), while illegal drug use (HR, 1.55; 95% CI, 1.01-2.35) and depression (HR, 1.77; 95% CI, 1.40-2.22) were associated with higher readmission risk., Conclusions: Psychosocial characteristics are not significant predictors of death but are associated with readmission risk after DT LVAD., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Restrictive cardiomyopathy (RCM) patients have poor prognosis due to progressive heart failure characterized by impaired ventricular filling of either or both ventricles. The goal of this study was to evaluate the outcome of end-stage RCM patients after left ventricular assist device (LVAD) implantation and to determine factors that may be associated with improved survival., Methods: This investigation is a retrospective study of prospectively collected data that include 28 consecutive patients with end-stage RCM who received continuous-flow LVADs at the Mayo Clinic, Rochester, Minnesota. Outcome was assessed by survival with LVAD support until heart transplantation or all-cause mortality., Results: The mean follow-up time post-LVAD implantation was 448 ± 425 days. The mean hospitalization time was 29 ± 19 days and was complicated mainly by post-operative right ventricular (RV) failure requiring short-term medical support. The short-term in-hospital mortality was 14%. Ten patients underwent heart transplantation with 100% survival post-transplant during the follow-up period. One-year survival for patients with LVADs without transplantation was 64%, and was not significantly different between amyloidosis and non-amyloidosis patients. Larger left ventricle (LV) end-diastolic and end-systolic dimensions were significantly associated with improved survival rates (RR = 0.94 and 0.95, p < 0.05, respectively), and left ventricular end-diastolic diameter (LVEDD) ≤46 mm was associated with increased mortality post-LVAD implantation., Conclusions: LVAD is a feasible, life-saving therapy for end-stage heart failure related to RCM, especially as a bridge to transplant and in patients with larger LV dimensions., (Copyright © 2015 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)