Circulating c-Met-Expressing Memory T Cells Define Cardiac Autoimmunity.

BACKGROUND: Autoimmunity is increasingly recognized as a key contributing factor in heart muscle diseases. The functional features of cardiac autoimmunity in humans remain undefined because of the challenge of studying immune responses in situ. We previously described a subset of c-mesenchymal epithelial transition factor (c-Met)-expressing (c-Met+) memory T lymphocytes that preferentially migrate to cardiac tissue in mice and humans. METHODS: In-depth phenotyping of peripheral blood T cells, including c-Met+ T cells, was undertaken in groups of patients with inflammatory and noninflammatory cardiomyopathies, patients with noncardiac autoimmunity, and healthy controls. Validation studies were carried out using human cardiac tissue and in an experimental model of cardiac inflammation. RESULTS: We show that c-Met+ T cells are selectively increased in the circulation and in the myocardium of patients with inflammatory cardiomyopathies. The phenotype and function of c-Met+ T cells are distinct from those of c-Met-negative (c-Met-) T cells, including preferential proliferation to cardiac myosin and coproduction of multiple cytokines (interleukin-4, interleukin-17, and interleukin-22). Furthermore, circulating c-Met+ T cell subpopulations in different heart muscle diseases identify distinct and overlapping mechanisms of heart inflammation. In experimental autoimmune myocarditis, elevations in autoantigen-specific c-Met+ T cells in peripheral blood mark the loss of immune tolerance to the heart. Disease development can be halted by pharmacologic c-Met inhibition, indicating a causative role for c-Met+ T cells. CONCLUSIONS: Our study demonstrates that the detection of circulating c-Met+ T cells may have use in the diagnosis and monitoring of adaptive cardiac inflammation and definition of new targets for therapeutic intervention when cardiac autoimmunity causes or contributes to progressive cardiac injury.

Prevalence of 18F-fluorodeoxyglucose positron emission tomography abnormalities in patients with arrhythmogenic right ventricular cardiomyopathy.

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heritable heart muscle disease that causes sudden cardiac death in the young. Inflammatory myocardial infiltrates have been described at autopsy and on biopsy, but there are few data on the presence of myocarditis in living patients with ARVC using non-invasive imaging techniques. FDG-PET is a validated technique for detecting myocardial inflammation in clinically suspected myocarditis. We aimed to determine the prevalence of myocardial inflammation in patients with ARVC using 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). METHODS AND RESULTS: We performed a retrospective analysis of a single centre cohort of patients with ARVC referred for FDG-PET scans between 2012 and 2017 for investigation of symptoms or suspected device infection. Sixteen patients (12 male; age 42 ±â€¯13 years) with a definite diagnosis of ARVC were identified. Seven had positive FDG-PET scans, two of whom had cardiac sarcoidosis on endomyocardial biopsy. Of the remaining five, two carried pathogenic desmoplakin mutations. FDG uptake was found in the left ventricular myocardium in all cases. One patient also had right ventricular uptake. CONCLUSION: In this exploratory study, we show that some patients with ARVC have evidence for myocardial inflammation on FDG-PET, suggesting that myocarditis plays a role in disease pathogenesis.

Ineffective and prolonged apical contraction is associated with chest pain and ischaemia in apical hypertrophic cardiomyopathy.

OBJECTIVES: To investigate the hypothesis that persistence of apical contraction into diastole is linked to reduced myocardial perfusion and chest pain. BACKGROUND: Apical hypertrophic cardiomyopathy (HCM) is defined by left ventricular (LV) hypertrophy predominantly of the apex. Hyperdynamic contractility resulting in obliteration of the apical cavity is often present. Apical HCM can lead to drug-refractory chest pain. METHODS: We retrospectively studied 126 subjects; 76 with apical HCM and 50 controls (31 with asymmetrical septal hypertrophy (ASH) and 19 with non-cardiac chest pain and culprit free angiograms and structurally normal hearts). Perfusion cardiac magnetic resonance imaging (CMR) scans were assessed for myocardial perfusion reserve index (MPRi), late gadolinium enhancement (LGE), LV volumes (muscle and cavity) and regional contractile persistence (apex, mid and basal LV). RESULTS: In apical HCM, apical MPRi was lower than in normal and ASH controls (p<0.05). In apical HCM, duration of contractile persistence was associated with lower MPRi (p<0.01) and chest pain (p<0.05). In multivariate regression, contractile persistence was independently associated with chest pain (p<0.01) and reduced MPRi (p<0.001). CONCLUSION: In apical HCM, regional contractile persistence is associated with impaired myocardial perfusion and chest pain. As apical myocardium makes limited contributions to stroke volume, apical contractility is also largely ineffective. Interventions to reduce apical contraction and/or muscle mass are potential therapies for improving symptoms without reducing cardiac output.

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.

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.

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.

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.

Development of aortic insufficiency in patients supported with continuous flow left ventricular assist devices.

Development of aortic insufficiency (AI) in patients supported with continuous flow left ventricular assist devices (LVAD) can adversely affect pump performance. In this study, we examined the incidence of new AI after LVAD implant at our institution. Pre- and postoperative echocardiograms of 66 patients who received HeartMate II or Heartware LVAD at our institution since June 2008 were reviewed for presence of new AI. Median LVAD support duration was 221 days. New AI developed in 6 patients (9.5%) after a median time of 374.5 days of support. There were no cases of severe or symptomatic AI. There was no significant difference between the AI incidence between HeartMate II and Heartware recipients. For patients who remained on LVAD support at 6 and 12 months, freedom from AI was 100% and 68.4%, respectively. Age, destination therapy status, and duration of support were predictors of new AI after LVAD implant. In conclusion, AI develops frequently during long-term support with continuous flow LVADs, particularly in those supported for longer than 6 months. As we move to the era of long-term LVAD support and destination therapy, further studies with longer follow-ups are required to determine the progression and clinical significance of AI in these patients.

Technique for insertion of HeartMate II left ventricular assist device inflow cannula.

During implantation of the HeartMate II left ventricular assist device, the inflow cannula is typically inserted in such a way that the sewing ring is placed within the ventricular cavity in contact with the endocardium. We describe a novel implantation technique in which the sewing ring is secured to the left ventricular epicardium, thus avoiding the complication of bleeding from the exposed cut surface of apical myocardium. In addition, the shortened intraventricular segment of the inflow cannula protects against inflow occlusion by the interventricular septum.

The intravenous anesthetic propofol inhibits human L-type calcium channels by enhancing voltage-dependent inactivation.

Propofol is commonly used to induce anesthesia but has been associated with some negative cardiovascular side effects, including negative inotropy, hypotension, and bradycardia. This study investigated the effect of propofol on L-type calcium current in acutely isolated human atrial myocytes to better understand the mechanism of these side effects. After informed consent was obtained, the atrial appendage was obtained from patients undergoing open-heart surgery who required cardiopulmonary bypass. Atrial myocytes were isolated using enzymatic digestion, and L-type calcium currents were recorded using the whole-cell patch clamp technique. Propofol enhanced the magnitude and speed of voltage-dependent inactivation of L-current. As a result, the propofol-induced inhibition was increased by protocols that increased inactivation such as longer voltage step duration, holding potential depolarization, and increased pulsing frequency. The preferential enhancement of L-channel inactivation by propofol can explain the associated cardiovascular side effects. The depolarized resting potential of arterial smooth muscle may render the L-channels in these cells particularly sensitive to propofol-induced inhibition, which could explain the hypotension observed in some patients. The enhancement of both inactivation kinetics and steady-state inactivation by propofol can also explain the negative inotropic effect. However, the enhanced voltage-dependent inactivation and use dependence could have beneficial effects for patients prone to certain arrhythmias and tachycardia.

Initial experience with CentriMag extracorporal membrane oxygenation for support of critically ill patients with refractory cardiogenic shock.

BACKGROUND: Cardiogenic shock refractory to conventional therapy has very high mortality and limited support options. New technology with peripherally inserted CentriMag (Levitronix LLC, Waltham, MA) extracorporal membrane oxygenation (ECMO) may have the potential to significantly improve survival in these critically ill patients. Outcomes of the first 10 patients to receive this device at our institutions are presented. METHODS: Patients were identified by their primary physicians and evaluated by our Mechanical Circulatory Support Team. CentriMag ECMO was initiated at the bedside using sterile percutaneous cannulation of femoral vessels. Patients were admitted to the Heart and Vascular Intensive Care Unit, with care managed by regular nursing staff with special training. RESULTS: The patients (5 men, 5 women) were a mean age of 45 +/- 18 years, had a mean left ventricular ejection fraction of 30%, and a mean lactate level of 9 mmol/liter. All patients met criteria for shock refractory to medical therapy, but the etiology varied. Average duration of ECMO support was 5.8 +/- 4 days. Survival was 60%. There were no major complications directly related to the device and no equipment malfunctions. CONCLUSIONS: The peripherally inserted CentriMag ECMO was easy to insert, functioned without mechanical error, and significantly reduced expected mortality in critically ill patients. Further research will be necessary to develop standardized algorithms and gain more experience, but this new technology has promising potential.

Traumatic aortic transection with intraluminal aortic fat: transesophageal echocardiographic characteristics and implications.

Aortic transection can be a catastrophic complication of blunt chest trauma. Transesophageal echocardiography is a useful tool for assessing aortic pathology. Presented is a case of traumatic aortic transection in which periaortic fat was found within the aortic lumen. Transesophageal echocardiographic characteristics are reviewed and clinical implications discussed.

An unexpected surgical complication of ventricular assist device implantation identified by transesophageal echocardiography: a case report.

Ventricular assist devices are used for circulatory support for patients with cardiogenic shock and refractory heart failure. Although early and late complications of left ventricular assist devices have been reported, we report a rare surgical complication of a left ventricular assist device implantation. This unexpected surgical complication was accurately identified by transesophageal echocardiography.