Graftmaster savior: Injury to a patent LIMA during pericardiectomy, when a covered stent came to the rescue.

A 71-year-old male with multivessel coronary artery disease who underwent bypass with saphenous vein grafts to a Marginal branch and distal RCA and LIMA to LAD in 1988, DM II, atrial fibrillation on Coumadin, TIA, obstructive sleep apnea and pulmonary hypertension was referred to our institution after extensive dyspnea evaluation with a diagnosis of constrictive pericarditis for pericardiectomy. He had normal left ventricular function, moderate mitral and tricuspid regurgitation. Coronary angiography revealed ostial LAD CTO, patent LIMA to mid LAD, second Marginal branch CTO with left-to-left collaterals and mid RCA CTO with left-to-right collaterals. Vein grafts to the Marginal branch and distal RCA were occluded. The pericardium was heavily calcified on CT of the chest. The LIMA was inadvertently injured leading to acute STEMI and ventricular fibrillation arrest treated with defibrillation once. Surgical repair was unsuccessful. A Graftmaster covered stent was successful deployed with restoration of TIMI III flow to the LAD territory. Pericardiectomy was completed via both the median resternotomy and left thoracotomy. Triple therapy with Aspirin, Clopidogrel, and Coumadin was initiated and maintained for 3 months without hemorrhagic or thrombotic complications. He has continued to do well in follow-up on Clopidogrel and Coumadin.

Non-Cardiac Symptoms of Moderate to Severe Hypokalemia in a Patient with a Syncardia™ Total Artificial Heart.

The Syncardia™ total artificial heart (TAH) is an option for patients as a bridge to transplant in those who are not candidates for left ventricular assist devices (LVAD) due to right ventricular failure. Postoperative course is highly dependent on volume status and aggressive diuresis is often necessary. One complication from aggressive diuresis is hypokalemia; however, in these patients we tolerate a lower potassium level because cardiac arrhythmias are not a concern.  However, in two separate instances non-cardiac symptoms related to severe hypokalemia occurred. These symptoms included nystagmus in one patient and agitation, tremors, and having an "out-of-body" experience in the other patient. Both these patients had resolution of symptoms with potassium replacement.

Neurohormonal regulation and improvement in blood glucose control: reduction of insulin requirement in patients with a nonpulsatile ventricular assist device.

BACKGROUND: Heart failure is associated with prolonged stress and inflammation characterized by elevated levels of cortisol and circulating catecholamines. Persistent sympathetic stimulation secondary to the stress of heart failure causes an induced insulin resistance, which creates a need for higher doses of insulin to adequately manage hyperglycemia in this patient population. We hypothesized that cortisol and catecholamine levels would be elevated in end-stage heart failure patients, however, would be reduced after the implantation of a left ventricular assist device (LVAD). Insulin requirements would therefore be reduced post LVAD implant and control of diabetes improved as compared with pre-implant. METHODS: Pre- and postoperative cortisol, catecholamine, glycated hemoglobin, and blood glucose levels were evaluated retrospectively in 99 LVAD patients at a single center from January 2007 through November 2011. Serum was collected before LVAD implantation and monthly after implantation for 12 months consecutively. Results were evaluated and compared to insulin requirements, if any, before and after implant. Plasma levels were measured by ELISA. RESULTS: There were a total of 99 patients (81 men and 18 women). Two patients were implanted twice due to pump dysfunction. Mean age was 59 years, ± 10, with a median of 63 years. Of those patients, 64 had ischemic cardiomyopathy and 35 had dilated cardiomyopathy. The total patient years of LVAD support were 92.5 years. All patients received a continuous flow left ventricular assist device. Type II diabetes mellitus was diagnosed in 28 patients. Of those patients, 24 required daily insulin with an average dose of 45 units/day. Average preoperative glycated hemoglobin (HbA1c) levels were 6.8% with fasting blood glucose measurements of 136 mg/dL. Mean cortisol levels were measured at 24.3 µg/dL before LVAD implantation, with mean plasma catecholamine levels of 1824 µg/mL. Post operatively, average HbA1c levels were 5.38% with fasting blood glucose measurements of 122 mg/dL. Mean cortisol levels were measured at 10.9 µg/dL with average plasma catecholamine levels were 815 µg/mL. There was a significant decrease in both cortisol levels post LVAD implant (P = 0.012) as well as catecholamine levels (P = 0.044). The average insulin requirements post LVAD implant were significantly reduced to 13 units/day (P = 0.001). Six patients no longer required any insulin after implant. CONCLUSION: Implantation of nonpulsatile LVADs has become a viable option for the treatment of end-stage heart failure, helping to improve patient quality of life by decreasing clinical symptoms associated with poor end-organ perfusion. Frequently, diabetes is a comorbid condition that exists among heart failure patients and with the reduction of the systemic inflammatory and stress response produced by the support of a nonpulsatile LVAD, many patients may benefit from a reduction in their blood glucose levels, as well as insulin requirements.

Comparison of hemolysis between CentriMag and RotaFlow rotary blood pumps during extracorporeal membrane oxygenation.

The purpose of this investigation was to compare the hemolysis levels for patients on extracorporeal membrane oxygenation (ECMO) incorporating two different rotary blood pumps (CentriMag [CMAG] and RotaFlow [RF]) in identical circuits otherwise. The difference between the two pumps is the cost. One is 20-30 times less expensive than the other. A retrospective analysis of all patients placed on ECMO from June 2008 through May 2012 was done to evaluate hemolysis. Daily plasma hemoglobin (pHb), lactate dehydrogenase (LDH), and lactate levels were collected on all patients. Values were compared between those patients who received a CMAG and those who received an RF. Patients had to be on ECMO for more than 2 days to be included in the study. Linear mixed effects models were fit to the data to assess differences over time for each continuous outcome. Forty patients were placed on ECMO incorporating CMAG, whereas 40 patients received an RF. There were no significant statistical differences between CMAG and RF groups when comparing days on support (8.7 ± 5.0; 8.4 ± 5.7), age (44.8 ± 18.3; 46.1 ± 16.0), body surface area (2.03 ± 0.36; 1.96 ± 0.31), gender (male: 58%, female: 42%; male: 55%, female: 45%), etiology, type of support (veno-arterial [VA)]: 78%, veno-venous [VV)]: 22%; VA: 82%, VV: 18%) and pre-ECMO LDH levels (4004.0 ± 3583.2; 3603.7 ± 3354.1). There were also no significant differences between the CMAG and RF groups when comparing the mean values for daily pHb levels (5.7 ± 3.6; 5.7 ± 4.2), lactate levels (2.8 ± 1.9; 3.0 ± 2.1), and LDH levels (2656.3 ± 1606.8; 2688.6 ± 1726.1) or daily lactate, LDH, and pHb levels for the first 10 days of support. From our investigation, there is no difference between the CMAG and the RF blood pumps in regard to the creation of hemolysis during ECMO. The difference in cost of the devices does not correlate with the performance and outcomes.

In Vivo Evaluation of a Physiologic Control System for Rotary Blood Pumps Based on the Left Ventricular Pressure-Volume Loop.

Current generation continuous flow assist devices to operate at a fixed speed, which limits preload response and exercise capacity in left ventricular assist device (LVAD) patients. A feedback control system was developed to automatically adjust pump speed based on direct measurements of ventricular loading using a custom cannula tip with an integrated pressure sensor and volume-sensing conductance electrodes. The input to the control system is the integral of the left ventricular (LV) pressure versus conductance loop (PGA) over each cardiac cycle. The feedback control system adjusts pump speed based on the difference between the measured PGA and the desired PGA. The control system and cannula tip were tested in acute ovine studies (n = 5) using the HeartMate II LVAD. The preload response of the control system was evaluated by partially occluding and releasing the inferior vena cava using a vessel loop snare. The cannula tip was integrated onto a custom centrifugal flow LVAD and tested in a 14-day bovine study. The control system adjusted pump support to maintain constant ventricular loading: pump speed increased (decreased) following an increase (decrease) in preload. This study demonstrated in vivo the Starling-like response of an automatic pump control system based on direct measurements of LV loading.

The new role of the perfusionist in adult extracorporeal life support.

Adult and pediatric extracorporeal life support (ECLS) has been transformed by the European(1) and Australian( 2) experiences with a reduction of the circuit to its most basic form (Figure 1). Many factors have converged at this point in time to allow us to offer this support. The availability in the U.S.A. of an advanced oxygenator (Quadrox(D)) (Maquet Inc., Bridgewater, NJ), long-term centrifugal pumps and circuit coatings offers us the means to provide ECLS. The other equally important factor is the intensivist trained in extracorporeal therapies. Once the intensive care unit registered nurse (ICU RN) is trained to safely and effectively manage both the patient and ECLS circuit, this support may be offered. The perfusionist is in an unique position to educate and mentor the ICU RN in ECLS. There is, perhaps, no one in a better position to explain this equipment and its uses in an interdisciplinary-oriented pediatric and adult ECLS program than a perfusionist.

Cannula Tip With Integrated Volume Sensor for Rotary Blood Pump Control: Early-Stage Development.

The lack of direct measurement of left ventricular unloading is a significant impediment to the development of an automatic speed control system for continuous-flow left ventricular assist devices (cf-LVADs). We have developed an inlet cannula tip for cf-LVADs with integrated electrodes for volume sensing based on conductance. Four platinum-iridium ring electrodes were installed into grooves on a cannula body constructed from polyetheretherketone (PEEK). A sinusoidal current excitation waveform (250 µA pk-pk, 50 kHz) was applied across one pair of electrodes, and the conductance-dependent voltage was sensed across the second pair of electrodes. The conductance catheter was tested in an acute ovine model (n = 3) in conjunction with the HeartMate II rotary blood pump to provide circulatory support and unload the ventricle. Echocardiography was used to measure ventricular size during pump support for verification for the conductance measurements. The conductance measurements correlated linearly with the echocardiography dimension measurements more than the full range of pump support from minimum support to suction. This cannula tip will enable the development of automatic control systems to optimize pump support based on a real-time measurement of ventricular size.

Vasoconstriction seen in coronary bypass grafts during handgrip in humans.

In animal studies, sympathetically mediated coronary vasoconstriction has been demonstrated during exercise. Human studies examining coronary artery dynamics during exercise are technically difficult to perform. Recently, noninvasive transthoracic Duplex ultrasound studies demonstrated that 1) patients with left internal mammary artery (LIMA) grafts to the left anterior descending artery can be imaged and 2) the LIMA blood flow patterns are similar to those seen in normal coronary arteries. Accordingly, subjects with LIMA to the left anterior descending artery were studied during handgrip protocols as blood flow velocity in the LIMA was determined. Beat-by-beat analysis of changes in diastolic coronary blood flow velocity (CBV) was performed in six male clinically stable volunteers (60 +/- 2 yr) during two handgrip protocols. Arterial blood pressure (BP) and heart rate (HR) were also measured, and an index of coronary vascular resistance (CVR) was calculated as diastolic BP/CBV. Fatiguing handgrip performed at [40% of maximal voluntary contraction (MVC)] followed by circulatory arrest did not evoke an increase in CVR (P = not significant). In protocol 2, short bouts of handgrip (15 s) led to increases in CVR (18 +/- 3% at 50% MVC and 20 +/- 8% at 70% MVC). BP was also increased during handgrip. Our results reveal that in conscious humans, coronary vasoconstriction occurs within 15 s of onset of static handgrip at intensities at or greater than 50% MVC. These responses are likely to be due to sympathetic vasoconstriction of the coronary circulation.

Microtextured materials for circulatory support devices: preliminary studies.

Thromboembolic events (TE) associated with circulatory support devices are a major source of mortality and morbidity. Clinically, the lowest TE rates are claimed with devices that incorporate textured blood-contacting materials. The textured materials currently used in circulatory assist devices are composed of small, attached fibers that form the boundaries of connected cavities. These cavities entrap blood components to form a "neointimal" layer, which is believed to minimize thromboembolic events. We believe that the three-dimensional surface topography of blood-contacting materials is a major controlling factor in the formation of a stable neointimal layer upon the material. Particle-cast cavities were used to form geometric features in segmented polyurethane. This microtextured material was incorporated as part of a flexible blood-contacting surface in a blood pump that was implanted as a left ventricular assist device in calves. The structure, thickness, stability, and development of the neointimal layer were then evaluated. These preliminary studies have shown that a stable neointimal layer can be formed upon the particle-cast surfaces. The results also indicate that the cavity size on the particle-cast surfaces has a significant effect on neointimal adhesion. The methods employed can be used in the design of future circulatory support devices.

Clinical Experience With Sternotomy Versus Subcostal Approach for Exchange of HeartMate II Left Ventricular Assist Device.

BACKGROUND: The safety and efficacy of exchanging the HeartMate II (Thoratec Corp, Pleasanton, CA) left ventricular assist device (LVAD) through a less invasive subcostal approach remains unclear. METHODS: We reviewed the records of 17 patients who underwent exchange of their HeartMate II device at our institution since 2007. We divided the cohort into devices exchanged through a subcostal (SC) approach versus a median sternotomy (MS) approach and obtained data pertaining to the short- and long-term outcomes. RESULTS: Nine patients had pump exchange through an MS approach versus 8 patients who underwent an SC approach. The mean duration of support with the first pump was 540 ± 450 days. The reason for exchange was electromechanical failure (7 patients), thrombosis (8 patients), and infection (2 patients). There were no 30-day perioperative deaths with either approach. Compared with sternotomy, patients who underwent an SC approach had significantly shorter operative times (131 vs 222 minutes; p = 0.001) and lower reoperation rates for bleeding (0 vs 44.4%; P = 0.05) and required fewer transfused blood products (packed red cells, 3.5 units vs 7.1 units; p < 0.05; cryoprecipitate, 50.7 mL vs 209.3 mL; p = 0.01; and platelets, 292 mL versus 762 mL; p < 0.05). Additionally, patients who underwent an SC approach had shorter postoperative stays in the intensive care unit (ICU) (5 days vs 13.8 days; p < 0.05) and shorter total hospital stays (16.4 days vs 27.2 days; p < 0.05). Long-term survival after mean follow-up of 260 days for the SC group and 232 days for the sternotomy group was 75% and 33%, respectively. CONCLUSIONS: Exchange of the HeartMate II pump can be accomplished with low morbidity and mortality and good long-term outcomes through a less invasive SC approach.

Severity of end-organ damage as a predictor of outcomes after implantation of left ventricular assist device.

The optimal timing of left ventricular assist device (LVAD) implantation in the management of advanced heart failure remains controversial. We hypothesize that in patients with cardiogenic shock, the severity of end-organ dysfunction as determined by the sequential organ failure assessment (SOFA) score is a determinant of outcomes after LVAD implantation. We determined the preoperative SOFA score and short- and long-term outcomes of 97 consecutive patients who received HeartMate II or HeartWare LVAD at our institution since January 2007. Kaplan-Meier analysis was used to compare long-term survival across SOFA score subgroups. The overall 30 day mortality was 10.1%, with no significant difference among SOFA score subgroups. Patients with scores ≥9 had significantly longer hospital stay (26 ± 6 vs. 18 ± 10 days, p = 0.03). One-year survival for SOFA scores 0-2, 3-5, 6-8, and ≥9 was 94%, 75%, 64%, and 29%, respectively. SOFA score was significantly lower in survivors at 6, 9, 12, 24, and 36 months. SOFA score did not predict adverse outcomes of bleeding, cerebrovascular events, infection, or pump exchange. These results show that preoperative SOFA score is a powerful predictor of outcomes after LVAD implantation. Long-term outcomes can be significantly improved by early intervention before emergence of end-organ dysfunction.

Steroid treatment resolves acute respiratory failure in patient transferred for ECMO.

INTRODUCTION: Space-consuming mediastinal tumors can create respiratory failure. METHODS: We are reporting on a case of mediastinal lymphoma, which created respiratory failure in our patient. IV steroid therapy was used in our patient, who presented with end-stage respiratory failure. RESULTS: Conservative management of our patient was possible without the application of ECMO. CONCLUSIONS: In the right patient population, IV steroid treatment can avoid further deterioration of end-stage respiratory failure.

Preliminary experience with the LionHeart left ventricular assist device in patients with end-stage heart failure.

BACKGROUND: The Arrow LionHeart LVD 2000 left ventricular assist device is the first fully implantable system designed for destination therapy. We report on 2 years of experience with this device, which we implanted for the first time in October 1999. METHODS: Since October 1999, 6 male patients between 55 and 69 years of age (mean 65 +/- 6 years) have received the device at our center; all were in New York Heart Association functional class IV and ineligible for heart transplantation. RESULTS: All surgical procedures were uneventful, with a timely extubation in 5 of 6 patients. Duration of support was 17 to 670 (mean 245 +/- 138) days, with a cumulative experience of 4.5 years. Three patients recovered to be discharged from hospital under support and are long-term survivors. Three patients died 17, 31, and 112 days after implantation from multiple organ failure without being discharged to their homes. The survival rate is 50% after 18 months. There were no major system-related problems or any device-related infections, which are otherwise commonly found among vertricular assist device patients. CONCLUSIONS: Our preliminary experience demonstrates the reliability and efficacy of the different parts of the system. Nevertheless, further sophistication is needed to reduce the size of its components, which so far still constitutes a limiting factor.

Takotsubo's syndrome after mitral valve repair and rescue with extracorporeal membrane oxygenation.

We report a case of Takotsubo's syndrome in a 37-year-old woman after mitral valve repair for severe mitral regurgitation triggered by a severe protamine reaction that was likely associated with immune-mediated coronary hypersensitivity (Kounis' syndrome) and made worse by resuscitation with high doses of catecholamines. The patient recovered fully after a 4-day course of extracorporeal membrane oxygenation therapy (ECMO).

Intracardiac echocardiography for diagnosis and management of left ventricular assist device inlet obstruction.

Left ventricular assist devices (LVADs) have become more important in the management of patients with advanced heart failure. New generation rotary blood pumps demonstrated survival benefits and improved functional status and quality of life in these patients. Although a variety of relevant advances have been achieved in the field of device technology, the risk of severe complications remains. In this report, we describe the application of intracardiac echocardiography in the management of postoperative LVAD complications.

Drive-line infections and sepsis in patients receiving the HVAD system as a left ventricular assist device.

BACKGROUND: Drive-line infections and sepsis lead to significant morbidity and even mortality in patients with ventricular assist devices (VADs). The HeartWare HVAD system is unique compared with other VAD systems in that it has a thin, flexible drive-line and is implanted directly into the pericardial space without the need for a pump pocket. We reviewed 332 patients receiving the HVAD in the pivotal ADVANCE Bridge to Transplant (BTT) trial and Continued Access Protocol (CAP) to determine the incidence of drive-line infections and sepsis. METHODS: Summary statistics of outcomes and Kaplan-Meier freedom-from-event analyses were performed. The Cochran-Mantel-Haenszel test for homogeneity was used to determine whether there was any site effect on rates of either drive-line exit-site or sepsis infections. RESULTS: Drive-line exit-site infections occurred in 16.9% (56 of 332) of patients (0.25 event per patient-year [EPPY]). These infections were primarily treated with antibiotics and most occurred >30 days post-implant (88%, or 66 of 75 drive-line infections). Sepsis occurred in 17.2% (57 of 332) of patients (0.23 EPPY), and sepsis events occurred more frequently >30 days post-implant (86%, or 60 of 70 sepsis events). Of patients with sepsis, 17.5% (10 of 57) died due to sepsis-related neurologic events (7 of 10) and multisystem organ failure (2 of 10) and cardiopulmonary failure (1 of 10), whereas there were no deaths related to drive-line infections. In addition, 17.5% (10 of 57) of patients had a stroke event while under treatment for sepsis (7 hemorrhagic and 3 ischemic strokes), and 3.5% (2 of 57 patients with sepsis) had a device exchange for VAD thrombus (4 days before and 1 day after sepsis diagnosis). Patients with drive-line infections or sepsis had a larger body mass index compared to those without infection (29.4 vs 27.6 kg/m(2), p = 0.015), and were more frequently diabetic (43.7% vs 31.2%, p = 0.034). Although there was no negative impact on survival in patients with drive-line exit-site infections, there was a trend for reduced survival in patients with sepsis events when compared to those patients without sepsis. CONCLUSIONS: The incidence of drive-line infection and sepsis was low in patients receiving the HVAD pump. Despite a trend toward reduced survival in patients with sepsis events, the overall survival of patients with either drive-line infections or sepsis was excellent.

End-organ recovery is key to success for extracorporeal membrane oxygenation as a bridge to implantable left ventricular assist device.

Preexisting organ dysfunctions are known factors of death after placement of implantable mechanical circulatory support (MCS). Extracorporeal membrane oxygenation (ECMO) may able to stabilize organ function in patients with cardiogenic shock before MCS implantation. Between 2008 and 2012, 17 patients with cardiogenic shock were supported with ECMO before implantable MCS placement. Patient's end-organ functions were assessed by metabolic, cardiac, hepatic, renal, and respiratory parameters. Survival data after MCS implantations were analyzed for overall survival to discharge, complications, and breakpoint in days on ECMO to survival. Before MCS implantation, lactate, hepatic, and renal functions were improved and pulmonary edema was resolved. The interval between ECMO initiation and MCS placement was 12.1 ± 7.9 days. Overall survival rate to discharge after left ventricular assist device/total artificial heart placement was 76%. The survival of patients transitioned from ECMO to MCS within 14 days was 92% and was significantly better than the survival of patients from ECMO to MCS supported longer than 14 days, 25%, p < 0.05. ECMO support can immediately stabilize organ dysfunction in patients with cardiogenic shock. After improvement of organ function, MCS implantation should be done without delay, since the patients supported for longer than 14 days with ECMO had inferior survival compared to national data.

Ambulatory extra-aortic counterpulsation in patients with moderate to severe chronic heart failure.

OBJECTIVES: The study sought to assess feasibility, safety, and potential efficacy of a novel implantable extra-aortic counterpulsation system (C-Pulse) in functional class III and ambulatory functional class IV heart failure (HF) patients. BACKGROUND: 30% to 40% of HF patients suffer from poor functional status and quality of life (QoL) but are not in need of end-stage treatments. We undertook a multicenter single-arm study to assess the C-Pulse System in such patients. METHODS: New York Heart Association (NYHA) functional class III or ambulatory functional class IV HF patients were eligible. Safety was assessed continuously through 12 months. Efficacy measurements included changes from baseline to 6 and 12 months in NYHA functional class, Minnesota Living with Heart Failure (MLWHF) and Kansas City Cardiomyopathy Questionnaire (KCCQ) scores, 6-min walk distance (6MWD), and exercise peak oxygen consumption (pVO2; 6 months only). RESULTS: Twelve men and 8 women (56.7 ± 7 years, 34 to 71 years of age) with ischemic (n = 7) or nonischemic (n = 13) cardiomyopathy were implanted. There was no 30-day mortality and no neurological events or myocardial infarctions through 12 months. At 6 months, there were 3 deaths (1 device-related). One-year survival was 85%. At 6 months, C-Pulse produced improvements in NYHA functional class (3.1 ± 0.3 to 1.9 ± 0.7, p = 0.0005), MLWHF (63.6 ± 19.9 to 40.2 ± 23.2, p = 0.0005), and KCCQ scores (43.6 ± 21.1 to 65.6 ± 21.5, p = 0.0002), but not 6MWD (275.5 ± 64.0 to 296.4 ± 104.9, p = NS) or pVO2 (14.5 ± 3.6 to 13.1 ± 4.4, p = NS). Improvements continued at 12 months, with 6MWD change becoming statistically significant (336.5 ± 91.8, p = 0.0425). CONCLUSIONS: Use of C-Pulse in this population is feasible, appears safe, and improves functional status and QoL. A prospective, multicenter, randomized controlled trial is underway. (C-Pulse IDE Feasability Study-A Heart Assist System; NCT00815880).