Comparative Propensity Matched Outcomes in Severe COVID-19 Respiratory Failure-Extracorporeal Membrane Oxygenation or Maximum Ventilation Alone.

OBJECTIVE: Does extracorporeal membrane oxygenation (ECMO) improve outcomes in ECMO-eligible patients with COVID-19 respiratory failure compared to maximum ventilation alone (MVA)? SUMMARY BACKGROUND DATA: ECMO is beneficial in severe cases of respiratory failure when mechanical ventilation is inadequate. Outcomes for ECMO-eligible COVID-19 patients on MVA have not been reported. Consequently, a direct comparison between COVID-19 patients on ECMO and those on MVA has not been established. METHODS: A total of 3406 COVID-19 patients treated at two major medical centers in Chicago were studied. One hundred ninety-five required maximum ventilatory support, and met ECMO eligibility criteria. Eighty ECMO patients were propensity matched to an equal number of MVA patients using detailed demographic, physiological, and comorbidity data. Primary outcome was survival and disposition at discharge. RESULTS: Seventy-one percent of patients were decannulated from ECMO. Mechanical ventilation was discontinued in 75% ECMO and 16% MVA patients. Twenty-five percent of patients in the ECMO arm expired, 21% while on ECMO, compared with 74% in the MVA cohort. Mortality was significantly lower across all age and BMI groups in the ECMO arm. Sixty-eight percent ECMO and 26% MVA patients were discharged from the hospital. Fewer ECMO patients required long-term rehabilitation. Major complications such as septic shock, ventilator associated pneumonia, inotropic requirements, acute liver and kidney injuries are less frequent among ECMO patients. CONCLUSIONS: ECMO-eligible patients with severe COVID-19 respiratory failure demonstrate a 3-fold improvement in survival with ECMO. They are also in a better physical state at discharge and have lower overall complication rates. As such, strong consideration should be given for ECMO when mechanical ventilatory support alone becomes insufficient in treating COVID-19 respiratory failure.

Intraoperative bronchoscopic visualization of left ventricular assist device thrombus.

Despite advancements in left ventricular assist device (LVAD) design and clinical management, device thrombosis remains a pertinent complication. Limited imaging makes precise visualization of clot location and shape very challenging. We report the usage of videobronchoscopic exploration of explanted LVADs for direct visualization of clot in two patients. This technique is a rapid and inexpensive means of improving our understanding of LVAD clot formation and may be useful in surgical exploration of inflow and outflow tracts during LVAD exchange.

Prospective, multicenter study of ventricular assist device infections.

BACKGROUND: Ventricular assist devices (VADs) improve survival and quality of life in patients with advanced heart failure, but their use is frequently complicated by infection. There are limited data on the microbiology and epidemiology of these infections. METHODS AND RESULTS: One hundred fifty patients scheduled for VAD implantation were enrolled (2006-2008) at 11 US cardiac centers and followed prospectively until transplantation, explantation for recovery, death, or for 1 year. Eighty-six patients (57%) received HeartMate II devices. Data were collected on potential preoperative, intraoperative, and postoperative risk factors for infection. Clinical, laboratory, and microbiological data were collected for suspected infections and evaluated by an infectious diseases specialist. Thirty-three patients (22%) developed 34 VAD-related infections with an incidence rate of 0.10 per 100 person-days (95% confidence interval, 0.073-0.142). The median time to infection was 68 days. The driveline was the most commonly infected site (n=28); 18 (64%) were associated with invasive disease. Staphylococci were the most common pathogen (47%), but pseudomonas or other Gram-negative bacteria caused 32% of infections. A history of depression and elevated baseline serum creatinine were independent predictors of VAD infection (adjusted hazard ratio=2.8 [P=0.007] and 1.7 [P=0.023], respectively). The HeartMate II was not associated with a decreased risk of infection. VAD infection increased 1-year mortality (adjusted hazard ratio=5.6; P<0.0001). CONCLUSIONS: This prospective, multicenter study demonstrates that infection frequently complicates VAD placement and is a continuing problem despite the use of newer, smaller devices. Depression and renal dysfunction may increase the risk of VAD infection. VAD infection is a serious consequence because it adversely affects patient survival. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01471795.

Evaluation and management of emergencies in patients with mechanical circulatory support devices.

Mechanical circulatory support devices such as ventricular assist devices have become the approved and accepted treatment option to improve survival and quality of life in patients with advanced heart failure refractory to medical therapy. Patients as a result are living longer and presenting to emergency medical services, primary care facilities, emergency departments, and critical care units more frequently. Currently, health care providers have limited experience in managing this complex patient population. Thus, we created a standardized method of initial evaluation and algorithmic approach of management to help in the management of emergencies in this unique patient population. We present a comprehensive overview of the types of mechanical assist devices, their complications, and an algorithmic approach to the emergency management in the patients with mechanical circulatory support. A systematic method is crucial in prompt and early recognition of emergencies to ensure appropriate management of these patients.

Staphylococcus epidermidis colonization is highly clonal across US cardiac centers.

BACKGROUND: Little is known about the clonality of Staphylococcus epidermidis in the United States, although it is the predominant pathogen in infections involving prosthetic materials, including ventricular assist devices (VADs). METHODS: Seventy-five VAD recipients at 4 geographically diverse US cardiac centers were prospectively followed up to 1 year of VAD support. The anterior nares, sternum, and (future) driveline exit site were cultured for S. epidermidis before VAD insertion and at 7 times after surgery. Infection isolates were also collected. Isolates were typed by pulsed-field gel electrophoresis. A subset underwent susceptibility testing and staphylococcal chromosomal cassette mec and multilocus sequence typing. RESULTS: A total of 1559 cultures yielded 565 S. epidermidis isolates; 254 of 548 typed isolates (46%) belonged to 1 of 7 clonal types as defined by pulsed-field gel electrophoresis. These clones were identified in up to 27 people distributed across all 4 cardiac centers. They caused 3 of 6 VAD-related infections. Disseminated clones were more antibiotic resistant than were less prevalent isolates (eg, 79% vs 54% methicillin resistant; P = .0021). CONCLUSIONS: This study revealed that healthcare-associated S. epidermidis infection is remarkably clonal. We describe S. epidermidis clones that are highly resistant to antibiotics distributed across US cardiac centers. These clones may have determinants that enhance transmissibility, persistence, or invasiveness. Clinical Trials Registration. NCT01471795.

Management of Pulmonary Mucormycosis After Orthotopic Heart Transplant: A Case Series.

Invasive pulmonary mucormycosis is a potentially fatal infection that can occur in immunosuppressed patients such as those who have undergone orthotopic heart transplant (OHT). High-dose intravenous antifungal agents, including amphotericin B, are generally accepted as the first-line medical treatment, with prompt surgical resection of lesions if feasible. The body of evidence guiding treatment decisions, however, is sparse, particularly regarding adjustment of immunosuppression during acute infection and long-term recovery. We present 2 cases of patients with pulmonary mucormycosis occurring within the first 6 months after OHT, both of whom successfully recovered after appropriate medical and surgical treatment, and we highlight differences in immunosuppression management strategies for this life-threatening condition.

Treatment of HeartMate II Short-to-Shield Patients With an Ungrounded Cable: Indications and Long-Term Outcomes.

Despite modifications and a procedure to externally replace the distal portion of the percutaneous lead, damage to the wiring insulation causing an electrical short to ground, referred to as a short to shield (STS), has become an important factor in the longevity of the HeartMate II left ventricular assist device (LVAD). Device exchange has been the suggested treatment option. The aim of this study was to evaluate the long-term clinical outcomes of patients with an STS supported on an ungrounded cable. A retrospective review of all patients (n = 479) implanted with a HeartMate II at our center between January 2008 and December 2017 was performed. Patients with a documented STS maintained on an ungrounded cable were examined. Patient characteristics, time from device implantation to STS, treatment strategies, and duration of support on an ungrounded cable were summarized. The association between support with an ungrounded cable and clinical outcomes was evaluated. A total of 53 (11% of 479) patients (83% males and 81% destination therapy) with an STS were supported on an ungrounded cable for a median duration of 195 days (range 2 days to 3.3 years). Patients were more active (New York Heart Association [NYHA] p < 0.001, 6 minute walk test [6MWT] p = 0.003) and had a trend toward increased weight gain (p = 0.055) from time of implant to STS. Duration of support before the STS was 1.9 years (range 165 days to 8.6 years). Twenty-two patients were treated directly with an ungrounded cable and 31 patients underwent an external driveline repair and still required an ungrounded cable within 2 days (range 0 days to 1.3 years). During the study period, 38 patients were maintained on an ungrounded cable: 21 patients were ongoing for 299 days (range 114 days to 2.8 years), 11 patients transplanted after 79 days (range 7-295 days), four patients died because of comorbid conditions after 1.6 years (range 141 days to 3.2 years), one patient exchanged for thrombosis after 229 days, and one patient explanted after 279 days. The other 15 patients developed a phase-to-phase electrical short after 51 days (range 2 days to 3.3 years): 14 patients underwent a successful pump exchange and one patient transplanted within 2 days. No patients died because of support with an ungrounded cable or worsening lead damage necessitating device exchange. With extended durations of support, some patients with a HeartMate II LVAD will experience device failure in the form of an STS. Select patients with an STS can be safely supported on an ungrounded cable for several years with close monitoring. This treatment approach should be considered before a device exchange.

Efficacy of nonsteroidal anti-inflammatory medications for prevention of atrial fibrillation following coronary artery bypass graft surgery.

This study was designed to test whether nonsteroidal anti-inflammatory medications could reduce the frequency of atrial fibrillation after coronary artery bypass graft surgery. The study was designed as an open-label, randomized trial. Patients undergoing first-time coronary artery bypass graft surgery were considered eligible. Patients with a history of atrial fibrillation, serum creatinine >2.0 mg/dL, on antiarrhythmic treatment, and those undergoing concomitant valvular surgery were excluded. The study was conducted in a single, university-affiliated community hospital. The researchers' role in the study was restricted to randomizing the patients and collecting data. The primary clinical care team made all decisions regarding patient care. One hundred patients were randomized to two groups: one received 30 mg ketorolac intravenously every 6 hours until able to take oral medications, at which point the patients were switched to 600 mg ibuprofen orally three times a day; the other group received conventional treatment. The primary end point of the study was incidence of atrial fibrillation in the immediate postoperative period. Atrial fibrillation occurred in 14 patients (28.6%) in the conventional treatment group vs. five patients (9.8%) in the ibuprofen group (p<0.017). Nonsteroidal anti-inflammatory medications were relatively safe and effective in significantly reducing the incidence of atrial fibrillation after coronary artery bypass graft surgery.

Percutaneous endoscopic gastrostomy tube in a patient with a left ventricular assist device.

We report a successful PEG tube insertion in a patient with an LVAD. Adequate prolonged nutritional support was provided. PEG placement in patients with an implantable or paracorporeal LVAD may be possible but present additional concerns. We believe that PEG placement should be cpnsidered in patients with an LVAD with swallowing difficulties or who are debilitated are not meeting their caloric requirements.

The development of aortic insufficiency in continuous-flow left ventricular assist device-supported patients.

BACKGROUND: Significant aortic insufficiency (AI) after left ventricular assist device (LVAD) placement affects device performance and end-organ perfusion. This study examined the development and progression of AI after implantation of continuous-flow LVAD. METHODS: Seventy-nine patients undergoing Heart Mate II (Thoratec Corp, Pleasanton, CA) LVAD implantation for predominantly destination therapy (n = 69 [87%]) were examined. Preoperative and postoperative echocardiograms for all patients were reviewed at the intervals of 0 to 3, 3 to 6, 6 to 12, 12 to 18, and 18 to 24 months. AI was graded on an interval scale of 0, none; 0.5, trivial; 1, mild; 1.5, mild to moderate; 2, moderate; 2.5, moderate to severe; and 3, severe. Development and progression of AI were analyzed. RESULTS: The incidence of significant AI (mild or greater) was 52% (n = 41). Median time to AI development was 187 days. The median duration of VAD support was 761 days. Mild AI developed in 41 patients (52%). No severe AI developed. In the Cox regression model (hazard ratio [95% confidence interval]), aortic valve closure (2.51 [1.06 to 5.89]; p = 0.03), and age (1.04 [1.008 to 1.08]; p = 0.01) were independent predictors of AI development. There was no difference in mortality rates in the two groups (p = 0.40 by log-rank test). A mixed-model linear regression analysis showed a significant overall progression of AI over time (ß ± standard error, 0.06 ± 0.02; p = 0.006). CONCLUSIONS: AI develops over time in a significant number of Heart Mate II LVAD patients. AI is more common in patients with closed aortic valves and in the older age group. As more patients require long-term VAD support, the development of AI will need careful attention and monitoring.

Nutrition assessment in advanced heart failure patients evaluated for ventricular assist devices or cardiac transplantation.

BACKGROUND: Malnutrition has been shown to affect clinical outcomes in patients with heart failure. The aim of this study was to analyze the incidence of malnutrition and to assess its prognostic significance in patients with advanced heart failure (AHF) (being evaluated for left ventricular assist device [LVAD] or cardiac transplant) based on nutrition status as assessed by the Mini Nutritional Assessment (MNA). METHODS: A retrospective analysis was conducted on 154 patients. During evaluation, a complete nutrition assessment was performed, and diagnosis of malnutrition and risk of malnutrition was done with the MNA. Its possible independent association with mortality was assessed. RESULTS: The mean (SD) age of the patients was 59.3 (14.1) years, with 76% men. Twenty-two percent were classified as malnourished, 68% at risk of malnutrition, and 10% well nourished. The mortality in the 3 groups was 26.5%, 42.0%, and 6.7%, respectively (P = .02). In the multivariate logistic regression analysis, the undernutrition state (malnourished + at risk) was an independent predictor of mortality (odds ratio, 7.9; confidence interval, 1.01-62.30; P = .04). CONCLUSIONS: The state of undernutrition is an independent predictor of mortality in patients with AHF. Early recognition of undernutrition through use of the MNA may affect the long-term prognosis of these patients by enabling early intervention.

Racial differences in patients with left ventricular assist devices.

We examined clinical outcomes based on ethnicity in patients undergoing left ventricular assist device (LVAD) implantation. We hypothesized that treatment in a specialized, comprehensive heart failure program results in similar survival between African Americans and whites. We retrospectively reviewed patient data implanted with HeartMate II (HM-II) LVAD over 2 years. There were 79 patients: 34 (43%) whites, 33 (42%) African Americans, and 12 (15%) patients belonging to other ethnicities there was no difference in demographics. The etiology of cardiomyopathy was more commonly ischemic in white patients compared to nonischemic in African American patients (p = 0.01). The mean left ventricular ejection fraction was 22.21 ± 10.66% in African American patients and 15.21 ± 5.54% in white patients (p = 0.008). The left ventricular end-diastolic (p = 0.06) and end-systolic (p = 0.03) diameters were greater in white patients compared to African American patients. Hypertension was seen in 79% of African American patients compared to 56% in white patients (p = 0.07). Survival by Kaplan-Meier analysis revealed an unadjusted survival advantage in African American patients (p = 0.04 by log-rank test), but this survival advantage was lost in multivariable Cox regression analysis after adjustment for other covariates. There was no difference in readmissions (p = 0.36). In patients with advanced heart failure undergoing HM-II LVAD implantation, African American patients had a similar survival and no difference in readmissions when compared with white patients despite significant differences in baseline clinical characteristics.

How effective are continuous flow left ventricular assist devices in lowering high pulmonary artery pressures in heart transplant candidates?

BACKGROUND: Pulmonary hypertension (PH) is considered a risk factor for morbidity and mortality in patients undergoing heart transplantation. Medical therapy with oral and pharmacologic agents is not always effective in reducing pulmonary artery (PA) pressures. Left ventricular assist devices (LVADs) have been used to reduce PA pressures in cases of PH unresponsive to medical therapy. METHODS AND RESULTS: Our study sought to evaluate the effectiveness of axial- and centrifugal- continuous flow LVADs in reversing PH in heart transplant candidates. Hemodynamics were assessed pre- and post-operatively in nine patients undergoing HeartMate II and six patients undergoing HeartWare continuous flow LVADs. Mean PA pressures were reduced from 31.9 ± 10.6 mm Hg to 22.1 ± 6.6 mm Hg (p = 0.001), and pulmonary vascular resistance was reduced from 3.08 ± 1.6 mm Hg to 1.8 ± 1.0 mm Hg (p = 0.007). This improvement was seen within seven days of LVAD implantation. Three of 15 patients were successfully transplanted, with 100% survival at an average of 199 days post-transplant. CONCLUSIONS: The results of this study suggest that both axial- and centrifugal-continuous flow LVADs are effective in immediately lowering PA pressures in heart transplant candidates with PH.

Incidence and management of gastrointestinal bleeding with continuous flow assist devices.

BACKGROUND: Continuous flow left ventricular assist devices (CF-LVADs) have emerged as the standard of care for patients in advanced heart failure (HF) requiring long-term mechanical circulatory support. Gastrointestinal (GI) bleeding has been frequently reported within this population. METHODS: A retrospective analysis of 101 patients implanted with the Heart Mate II from January 2005 to August 2011 was performed to identify incidence, etiology, and management of GI bleeding. Univariate and multivariate regression analysis was conducted to identify related risk factors. RESULTS: A significant incidence of GI bleeding (22.8%) occurred in our predominantly destination therapy (DT) (93%) population. Fifty-seven percent of the patients with bleeding episodes bled from the upper GI (UGI) tract (with 54% bleeding from gastric erosions and 37% from ulcers/angiodysplasias), whereas 35% of patients bled from the lower GI (LGI) tract. Previous history of GI bleeding (odds ratio [OR], 22.7; 95% CI, 2.2-228.6; p=0.008), elevated international normalized ratio (INR) (OR, 3.9; CI, 1.2-12.9; p=0.02), and low platelet count (OR, -0.98; CI, 0.98 -0.99; p=0.001) were independent predictors of GI hemorrhage. Recurrent bleeding was more common in older patients (mean, 70 years; p=0.01). The majority of bleeders (60%) rebled from the same site. Management strategies included temporarily withholding anticoagulation, decreasing the speed of LVADs, and using octreotide. Octreotide did not impact the amount of packed red blood cells used, rebleeding rates, length of hospital stay, or all-cause mortality. Only 1 patient died as a direct consequence of GI bleeding. CONCLUSIONS: Multiple factors account for GI bleeding in patients on CF-VADs. A previous history of bleeding increases risk significantly and warrants careful monitoring.

Experience with noncardiac surgery in destination therapy left ventricular assist devices patients.

Continuous flow left ventricular assist devices (CF-LVAD) are increasing the life expectancy of patients with advanced heart failure, with these patients undergoing more noncardiac operations after implantation. The purpose of this study was to determine the safety of noncardiac operations in destination therapy CF-LVAD patients. In a retrospective study of 110 CF-LVAD patients, we reviewed 36 patients who underwent 63 noncardiac operations 315.1 ± 333.5 days after LVAD placement. Fifty-four (84%) operations were elective and 10 were emergent. The mean age of the cohort was 61.4 ± 11.4 years, with the majority (81%) being men. Most patients (n = 24, 38%) underwent total abdominal operation. Of the 36 patients in the study, 23 (63.8%) patients required one surgical procedure, and 13(36.1%) patients underwent more than one procedure. Six critically ill patients (16%) of 37 expired within 30 days after emergent operation. Our study demonstrates overall good clinical outcomes with minimal intraoperative complications in LVAD patients undergoing noncardiac surgeries, except an increased propensity for intra- and postoperative transfusion of blood products because of complex coagulopathies.

Are blood stream infections associated with an increased risk of hemorrhagic stroke in patients with a left ventricular assist device?

Blood stream infections (BSIs) are an important cause of morbidity and mortality in patients with left ventricular assist devices (LVADs). The aim of this study was to examine the correlation between hemorrhagic cerebrovascular accident (CVA) and BSI after implantation of LVAD for advanced heart failure (HF). This was a retrospective descriptive review of 87 patients with end-stage HF, who underwent implantation of HeartMate II continuous-flow LVAD over a 4 year period. Blood stream infections were diagnosed by serial blood cultures, and suspected neurological complications including CVAs were confirmed by neuroimaging. Extensive patient chart review was performed, and descriptive characteristics were analyzed using SPSS statistical software. The mean age of our study population was 62.3 ± 12.8 years, and the majority of our patients were males (n = 75, 86.2%). The baseline characteristics were comparable in the patients with and without CVAs. Patients with BSI had a much greater incidence of CVA compared to patients without BSI (n = 13, 43.3% vs. n = 5, 10.0%; p < 0.0001). There was an increased mortality in patients with BSI than those without (n = 57, 65.5% vs. n = 30, 34.5%; p = 0.003). The risk of all CVAs (hemorrhagic/ischemic) was eightfold (odds ratio [OR] = 7.9; 95% confidence interval [CI] = 2.4-25.5; p = 0.001] in patients with BSI. Patients with BSI had a >20-fold risk of hemorrhagic CVA (OR = 24; 95% CI = 2.8-201.1; p = 0.03). Advanced HF patients with LVAD support who developed BSI need urgent evaluation and close monitoring for suspected neurological complications, particularly hemorrhagic CVA.

Intermittent aortic insufficiency as an aid to diagnosing obstruction in a HeartMate II continuous-flow left ventricular assist device.

This report details two cases of left ventricular assist device (LVAD)-related fungal infection. In both cases, the infection occurred within the device and formed an obstruction resulting in intermittent variation in the output of the LVAD. This was manifested by a change in the pattern of aortic insufficiency (AI) from continuous to intermittent on transesophageal echocardiography. Recognition of this finding may allow for noninvasive diagnosis of LVAD flow obstruction.