Asghar Khaghani

Multicenter evaluation of an intrapericardial left ventricular assist system

OBJECTIVES The aim of this study was to conduct an initial clinical evaluation of the new HeartWare Ventricular Assist System (HeartWare, Inc., Framingham, Massachusetts) in a multicenter, prospective, nonrandomized single-arm clinical trial. BACKGROUND Heart failure is a worldwide epidemic. The effectiveness of heart transplantation and medical therapy is limited, resulting in the emergence of mechanical circulatory support as a primary treatment for end-stage heart disease. Left ventricular assist devices that use rotary pumps are small and durable, which might reduce morbidity and mortality during support. METHODS Fifty heart transplant candidates with New York Heart Association functional class IV symptoms were supported at 5 international centers by the HeartWare System for 180 days, until heart transplant, myocardial recovery and device explant, or death. Patients who continue to be supported have been followed for a minimum of 2 years. RESULTS Of the 50 patients, 20 (40%) received transplants, 4 (8%) had the pump explanted after myocardial recovery, and 17 (34%) continue support at 2 years. Nine (18%) patients died during support from sepsis (n = 3), multiple organ failure (n = 3), or hemorrhagic stroke (n = 3). The actual survival at 6, 12, and 24 months was 90%, 84%, and 79%, respectively. In the survivors, measures of quality of life showed a significant improvement over baseline values. Significant improvements were found for recognition memory at 3 months after implant (p = 0.006). The most frequent adverse events were infection and bleeding. CONCLUSIONS Patients with end-stage heart failure can be safely and effectively supported by the HeartWare Ventricular Assist System with improved quality of life and neurocognitive function.

Cardiopulmonary bypass impairs small intestinal transport and increases cut permeability

Gastrointestinal damage occurs in 0.6% to 2% of patients after cardiopulmonary bypass (CPB), and carries a mortality of 12% to 67%. The incidence of subclinical gastrointestinal damage may be much greater. We examined the effects of nonpulsatile, hypothermic CPB on intestinal absorption and permeability in 41 patients. Bowel mucosal saccharide transport and permeation were evaluated using 100 mL of an oral solution containing 3-O-methyl-D-glucose (0.2 g), D-xylose (0.5 g), L-rhamnose (1.0 g), and lactulose (5.0 g) to assess active carrier-mediated, passive carrier-mediated, transcellular, and paracellular transport, respectively, with a 5-hour urine analysis. Patients were studied before, immediately after, and 5 days after CPB. Immediately after CPB there was a decrease in urinary excretion of 3-O-methyl-D-glucose (from 34% +/- 2.2% to 5.2% +/- 0.7%; p < 0.0001), D-xylose (from 25.4% +/- 1.4% to 4.1% +/- 0.8%; p < 0.0001), and L-rhamnose (from 8.3% +/- 0.6% to 2.6% +/- 0.4%; p < 0.0001). The permeation of 3-O-methyl-D-glucose and D-xylose returned to normal levels 5 days after CPB, but that of L-rhamnose remained significantly below pre-CPB values at 6.6% +/- 0.5% (p = 0.004). However, the permeation of lactulose increased after CPB (from 0.35% +/- 0.04% to 0.59% +/- 0.1%; p = 0.018), and the lactulose/L-rhamnose gut permeability ratio increased markedly (from 0.045 +/- 0.04 to 0.36 +/- 0.08; normal = 0.06 to 0.08; p = 0.004). Patients who had a CPB time of 100 minutes or more had a greater increase in gut permeability (p = 0.049).(ABSTRACT TRUNCATED AT 250 WORDS)

Initial clinical experience with a novel left ventricular assist device with a magnetically levitated rotor in a multi-institutional trial

BACKGROUND Third-generation rotary blood pumps have magnetically levitated rotors that eliminate mechanical wear over the years. Together with their potential for miniaturization, these pumps seem suitable for long-term support of patients with a wide range of body surface areas (BSA). Recently, the novel HVAD pump (HeartWare Inc, Framingham, MA), a miniaturized centrifugal pump with a hydrodynamic, magnetically levitated rotor, became ready for clinical application. METHODS In a multi-institutional trial in Europe and Australia, 23 patients (mean age, 47.9 ± 12 years) in end-stage heart failure were enrolled in 5 centers. The primary end point of the bridge-to-transplant study was survival to heart transplant or survival to 180 days on the device, whichever occurred first. Follow-up data at 1 year are presented. The small size of the device allows for intrapericardial placement of the pump. RESULTS Implant procedures were generally fast and uneventful. Mean duration of support was 167 ± 143 days (range, 13-425 days), and mean blood flow provided by the pump was 6.1 ± 1.1 liters/min. At the 180-day end point, 2 patients had undergone successful transplant at 157 and 175 days, 2 patients died while on the device, and 19 patients continued pump support for more than 180 days. Actuarial survival after 6 months was 91% and was 86% at the 1-year follow-up. CONCLUSIONS The design of the HVAD pump enables a quick and less invasive implantation. The results to date demonstrate satisfactory long-term survival with excellent quality of life in this cohort of 23 patients of the initial multi-institutional Conformité Européene (CE) mark trial.

Clinical Recovery From End-Stage Heart Failure Using Left-Ventricular Assist Device and Pharmacological Therapy Correlates With Increased Sarcoplasmic Reticulum Calcium Content but Not With Regression of Cellular Hypertrophy

Background—Left ventricular assist device (LVAD) treatment is known to lead to structural and functional cellular modifications in the heart. The relevance of these changes for clinical recovery is unknown. Methods and Results—We compared properties of cardiomyocytes obtained from tissue taken at explantation of the LVAD in patients with clinical recovery with those obtained from hearts of patients who did not show clinical recovery, thus requiring transplantation. Compared with myocytes taken at implantation, both the recovery and nonrecovery groups showed ≈50% reduction in cell capacitance, an index of cell size. However, action potential duration shortened, L-type Ca2+ current fast inactivation was more rapid, and sarcoplasmic reticulum Ca2+ content was increased in the recovery compared with the nonrecovery group. Conclusions—These results show that specific changes in excitation-contraction coupling, and not regression of cellular hypertrophy, are specifically associated with clinical recovery after LVAD and further identify sarcoplasmic reticulum Ca2+ handling as a key functional determinant in patients with heart failure.

European results with a continuous-flow ventricular assist device for advanced heart-failure patients §

OBJECTIVE The HeartMate II (HM II) LVAD is a small, quiet, continuous-flow, left ventricular assist device (LVAD) for circulatory support in advanced heart-failure patients, with over 2000 implants worldwide. This article reports on the European experience with this device. METHODS The HM II was implanted in 571 patients at 64 European institutions. In 72% of cases (411 patients), implantation has taken place at least 6 months before the closing date of the study (1 August 2008). Patients (19% female, 70% ischaemic aetiology) were on maximum medical therapy, including inotropic support. Body surface area ranged from 1.30 to 2.50 m(2) and age from 14 to 75 years (mean: 51+/-14 years; n=115, 28% over age 60 years). The intention of support was to provide a bridge to transplantation (73%), destination therapy (21%) and a bridge to recovery (6%). Adverse events were documented in the first 53 patients - for obtaining the Conformité Européenne (CE) Mark (group A) - from a European multicentric study (Strüber et al. [Strüber M, Sander K, Lahpor J, Ahn H, Litzler P-Y, Drakos SG, Musumeci F, Schlensak C, Friedrich I, Gustafsson R, Oertel F, Leprince P. HeartMate II left ventricular assist device; early European experience. Eur J Cardiovasc Surg 2008;34(2):289-94.]: 101 patients) and from a single-centre study (UMCU, The Netherlands: 30 patients). RESULTS The mean support duration ranged from 0 to 1019 days with a mean of 236+/-214 days (249 patients: >6 months, 119: 1 year, 12: >2 years; total support time: 293 years). The overall survival to transplantation, recovery or ongoing device support at the end of the study was 69% (284) with an early mortality of 17.5% and late mortality of 13.5%. Of the surviving patients, 23% have been transplanted, 4% had their device removed after recovery of the left ventricle and 42% are still ongoing. Adverse events included bleeding (ranging from 42% in group C to 59% in group A), percutaneous lead infections (A: 0.19, B: 0.61 and C: 0.18 events per patient year), pocket infections (A: 0.08, B: 0.07 and C: 0.09 events per patient year), ischaemic stroke (A: 0.06, B: 0.09 and C: 0.04 events per patient year), haemorrhagic stroke (B: 0.07, C: 0.04 events per patient year) and transient ischaemic attacks (TIAs; A: 0.08, B: 0.02 and C: 0.13 events per patient year). CONCLUSIONS These results support the use of the HM II continuous-flow LVAD for long-term support as a bridge to transplantation and possibly for destination therapy. Future emphasis should focus on minimising adverse events such as infections, bleeding and neurological events.

Pulmonary Retransplantation: Predictors of Graft Function and Survival in 230 Patients

BACKGROUND Despite improving results in lung transplantation, a significant number of grafts fail early or late postoperatively. The pulmonary retransplant registry was founded in 1991 to determine the predictors of outcome after retransplantation. We hypothesized that ambulatory status of the recipient and center retransplant volume, which had been previously shown to predict survival after retransplantation, would also be associated with improved graft function postoperatively. METHODS Two hundred thirty patients underwent retransplantation in 47 centers from 1985 to 1996. Logistic regression methods were used to determine variables associated with, and predictive of, survival and lung function after retransplantation. RESULTS Kaplan-Meier survival was 47% +/- 3%, 40% +/- 3%, and 33% +/- 4% at 1, 2, and 3 years, respectively. On multivariable analysis, the predictors of survival included ambulatory status or lack of ventilator support preoperatively (p = 0.005; odds ratio, 1.62; 95% confidence interval, 1.15 to 2.27), followed by retransplantation after 1991 (p = 0.048; odds ratio, 1.41; 95% confidence interval, 1.003 to 1.99). Ambulatory, nonventilated patients undergoing retransplantation after 1991 had a 1-year survival of 64% +/- 5% versus 33% +/- 4% for nonambulatory, ventilated recipients. Eighty-one percent, 70%, 62%, and 56% of survivors were free of bronchiolitis obliterans syndrome at 1, 2, 3, and 4 years after retransplantation, respectively. Factors associated with freedom from stage 3 (severe) bronchiolitis obliterans syndrome at 2 years after retransplantation included an interval between transplants greater than 2 years (p = 0.01), the lack of ventilatory support before retransplantation (p = 0.03), increasing retransplant experience within each center (fifth and higher retransplant patient, p = 0.04), and total center volume of five or more retransplant operations (p = 0.05). CONCLUSIONS Nonambulatory, ventilated patients should not be considered for retransplantation with the same priority as other candidates. The best intermediate-term functional results occurred in more experienced centers, in nonventilated patients, and in patients undergoing retransplantation more than 2 years after their first transplant. In view of the scarcity of lung donors, patient selection for retransplantation should remain strict and should be guided by the outcome data reviewed in this article.

Tumor Necrosis Factor-α Is Expressed in Donor Heart and Predicts Right Ventricular Failure After Human Heart Transplantation

BACKGROUND-Myocardial failure is an important problem after heart transplantation. Right ventricular (RV) failure is most common, although its mechanisms remain poorly understood. Inflammatory cytokines play an important role in heart failure. We studied the expression of tumor necrosis factor (TNF)-alpha and other cytokines in donor myocardium and their relationship to the subsequent development of RV failure early after transplantation. METHODS AND RESULTS-Clinical details were obtained, and ventricular function was assessed by transesophageal echocardiography in 26 donors before heart retrieval. A donor RV biopsy was obtained immediately before transplantation, and each recipient was followed for the development of RV failure. Reverse transcriptase-polymerase chain reaction was performed to detect TNF-alpha, interleukin-2, interferon-gamma, and inducible nitric oxide synthase expression. Eight of 26 recipients (30.8%) developed RV failure. Seven of these 8 (87.5%) expressed TNF-alpha, but only 4 of the 18 (22.2%) who did not develop RV failure expressed TNF-alpha (P<0.005). As a predictor of RV failure, TNF-alpha mRNA had a sensitivity of 87.5%, a specificity of 83.3%, a positive predictive value of 70%, and a negative predictive value of 93.7%. Western blotting demonstrated more TNF-alpha protein in the myocardium of donor hearts that developed RV failure (658+/-60 versus 470+/-57 optical density units, P<0.05). Immunocytochemistry localized TNF-alpha expression to cardiac myocytes. Reverse transcriptase-polymerase chain reaction detected interferon-gamma in 2 (7.7%), interleukin-2 in 1 (3.8%), and inducible nitric oxide synthase mRNA in 1 (3.8%) of the 26 donor hearts, none of which developed RV failure. CONCLUSIONS-TNF-alpha expression in donor heart cardiac myocytes seems to predict the development of RV failure in patients early after heart transplantation.

Gene Profiling Changes in Cytoskeletal Proteins During Clinical Recovery After Left Ventricular–Assist Device Support

Background—After left ventricular–assist device (LVAD) support, a proportion of patients recover sufficient ventricular function to enable explantation of the device. The exact molecular mechanisms involved in myocardial recovery remain unknown. Cytoskeletal proteins are essential for the structure and function of the cardiac myocyte and might play a major role. Methods and Results—A total of 15 patients with nonischemic cardiomyopathy who required LVAD implantation were studied; 6 recovered sufficiently to allow explantation of the device compared with 9 who did not recover and required transplantation. LV myocardial samples were collected at implantation and explantation/transplantation. Affymetrix microarray analysis was performed on the paired samples and analyzed with reference to sarcomeric and nonsarcomeric cytoskeletal proteins. In the recovery group, of the nonsarcomeric proteins, lamin A/C increased 1.5-fold (P<0.05) and spectrin 1.6-fold (P<0.05) between the times of implantation and explantation. Integrins β1, β6, and α7 decreased 1.7-fold (P<0.05), 2.4-fold (P<0.05), and 1.5-fold (P<0.05), respectively, but integrins α5 and β5 increased 2.3-fold (P<0.01) and 1.2-fold (P<0.01) at explantation. The following sarcomeric proteins changed in the recovered group only: β-actin increased 1.4-fold (P<0.05); α-tropomyosin, 1.3-fold (P<0.05); α1-actinin, 1.8-fold (P<0.01); and α-filamin A, 1.6-fold (P<0.05). Both troponin T3 and α2-actinin decreased by 1.6-fold at the time of explantation (P<0.05). Vinculin decreased 1.7-fold (P=0.001) in the recovered group but increased by 1.7-fold (P<0.05) in the nonrecovered group. Vinculin protein levels decreased 4.1-fold in the recovered group. Conclusions—Myocardial recovery was associated with a specific pattern of changes in sarcomeric, nonsarcomeric, and membrane-associated proteins, which could have important implications in understanding the mechanisms involved.

Energetics and function of the failing human heart with dilated or hypertrophic cardiomyopathy

Impaired energy metabolism in the failing human heart could be an important mechanism of functional deterioration. The purpose of this study was to assess the changes of myocardial energy metabolism in the human heart at end‐stage heart failure.

The role of bridge to transplantation: should LVAD patients be transplanted?

Purpose of review The decrease in useable donor organs means an increasing number of patients are requiring support with a left ventricular assist device (LVAD) for survival when their clinical status deteriorates before transplantation. We address whether these patients should be transplanted, if so, with what priority, and when and if they are not transplanted, what are the alternatives? Recent findings The perioperative mortality and morbidity of LVAD insertion remains high. Infection and device failure still limit the safety of long periods of bridging and might necessitate earlier transplantation. Early results suggest that the smaller impeller pumps may be associated with a lower incidence of device failure and infection, but with more thromboembolic and hemorrhagic complications. Transplantation of LVAD patients results in survival rates as good as those with conventional transplantation, and the survival benefit is better than for non-LVAD-supported patients. A small number of LVAD patients have shown a significant improvement in myocardial function, sufficient enough to allow explantation of the device. The proportion of these patients has previously been reported to be as low as 5%, but a strategy to maximize recovery has allowed pump removal in approximately two thirds of dilated cardiomyopathy patients. In a recent destination therapy trial, survival in LVAD patients was superior to those on medical therapy, but the frequency of infection, bleeding, and malfunction of the device was higher. Summary LVAD technology is continuing to evolve quickly, while transplantation is here to stay. The interaction between these two powerful modalities requires continued thoughtful evaluation for maximal benefit to patients.