No abstract

Background Right ventricular (RV) failure after left ventricular assist device (LVAD) placement is a serious complication and is difficult to predict. In the era of destination therapy and the total artificial heart, predicting post-LVAD RV failure requiring mechanical support is extremely important. Methods We reviewed patient characteristics, laboratory values, and hemodynamic data from 266 patients who underwent LVAD placement at the University of Pennsylvania from April 1995 to June 2007. Results Of 266 LVAD recipients, 99 required RV assist device (BiVAD) placement (37%). We compared 36 parameters between LVAD (n=167) and BiVAD patients (n=99) to determine preoperative risk factors for RV assist device (RVAD) need. By univariate analysis, 23 variables showed statistically significant differences between the two groups (P ≤ 0.05). By multivariate logistic regression, cardiac index ≤ 2.2 L/min·m2 (odds ratio [OR] 5.7), RV stroke work index ≤ 0.25 mmHg·mL/m2 (OR 5.1), severe preoperative RV dysfunction (OR 5.0), preoperative creatinine ≥ 1.9 mg/dL (OR 4.8), previous cardiac surgery (OR 4.5), and systolic blood pressure ≤ 96 mmHg (OR 2.9) were the best predictors of RVAD need. Conclusions The most significant predictors for RVAD need were cardiac index, RV stroke work index, severe preoperative RV dysfunction, creatinine, previous cardiac surgery, and systolic blood pressure. Using these, we constructed an algorithm which can predict which LVAD patients will require RVAD with greater than 80% sensitivity and specificity.

Objective It is generally accepted that patients who require biventricular mechanical support (BiVAD) have poorer outcomes than those requiring isolated left ventricular support (LVAD). However, it is unknown how the timing of BiVAD insertion affects outcomes. We hypothesized that planned BiVAD insertion improves survival compared to delayed conversion of LVAD to BiVAD. Methods We reviewed and compared outcomes of 266 patients undergoing LVAD or BiVAD placement at the University of Pennsylvania from April 1995 to June 2007. We subdivided BiVAD patients into planned BiVAD (P-BiVAD) and delayed BiVAD (D-BiVAD) groups, based on the timing of RVAD insertion. We defined D-BiVAD as any failure of isolated LVAD support. Results Of 266 LVAD patients, 99 required BiVAD (37%). We compared preoperative characteristics, successful bridging to transplant, survival to hospital discharge, and Kaplan-Meier one-year survival between P-BiVAD (n=71) and D-BiVAD (n=28) groups. Preoperative comparison showed that patients who ultimately require biventricular support have similar preoperative status. LVAD (n=167) outcomes in all categories exceeded both P-BiVAD and D-BiVAD outcomes. Further, P-BiVAD patients had superior survival to discharge than D-BiVAD patients (51% v 29% p<0.05). One-year and long-term Kaplan-Meier survival distribution confirmed this finding. There was also a trend towards improved bridging to transplant in P-BiVAD (n=55) vs. D-BiVAD (n=22) patients (65% v 45% p=0.10). Conclusion When patients at risk for isolated LVAD support failure are identified, proceeding directly to BiVAD implantation is advised, as early institution of biventricular support results in dramatic improvement in survival.

Background In the era of destination continuous flow left ventricular assist devices (LVAD), the decision of whether a patient will tolerate isolated LVAD support or will need biventricular support (BIVAD) can be challenging. Incorrect decision making with delayed right ventricular (RV) assist device implantation results in increased morbidity and mortality. Continuous flow LVADs have been shown to decrease pulmonary hyper-tension and improve RV function. We undertook this study to determine predictors in the continuous flow LVAD era that identify patients who are candidates for isolated LVAD therapy as opposed to biventricular support. Methods We reviewed demographic, hemodynamic, laboratory, and echocardiographic variables for 218 patients who underwent VAD implant from 2003 through 2011 (LVAD = 167, BIVAD = 51), during the era of continuous flow LVADs. Results Fifty preoperative risk factors were compared between patients who were successfully managed with an LVAD and those who required a BIVAD. Seventeen variables demonstrated statistical significance by univariate analysis. Multivariable logistic regression analysis identified central venous pressure >15 mmHg (OR 2.0, “C”), severe RV dysfunction (OR 3.7, “R”), preoperative intubation (OR 4.3, “I”), severe tricuspid regurgitation (OR 4.1, “T”), heart rate >100 (OR 2.0, Tachycardia - “T”) -CRITT as the major criteria predictive of the need for biventricular support. Utilizing these data, a highly sensitive and easy to use risk score for determining RV failure was generated that outperformed other established risk stratification tools. Conclusions We present a preoperative risk calculator to determine suitability of a patient for isolated LVAD support in the current continuous flow ventricular assist device era.

Solar-powered heart? Harnessing light to create myocardial renewable energy.

Background Exogenously delivered chemokines have enabled neovasculogenic myocardial repair in models of ischemic cardiomyopathy; however, these molecules have short half-lives in vivo. In this study, we hypothesized that the sustained delivery of a synthetic analog of stromal cell–derived factor 1-α (engineered stromal cell–derived factor analog [ESA]) induces continuous homing of endothelial progenitor cells and improves left ventricular function in a rat model of myocardial infarction. Methods and Results Our previously designed ESA peptide was synthesized by the addition of a fluorophore tag for tracking. Hyaluronic acid was chemically modified with hydroxyethyl methacrylate to form hydrolytically degradable hydrogels through free-radical–initiated crosslinking. ESA was encapsulated in hyaluronic acid hydrogels during gel formation, and then ESA release, along with gel degradation, was monitored for more than 4 weeks in vitro. Chemotactic properties of the eluted ESA were assessed at multiple time points using rat endothelial progenitor cells in a transwell migration assay. Finally, adult male Wistar rats (n=33) underwent permanent ligation of the left anterior descending (LAD) coronary artery, and 100 μL of saline, hydrogel alone, or hydrogel+25 μg ESA was injected into the borderzone. ESA fluorescence was monitored in animals for more than 4 weeks, after which vasculogenic, geometric, and functional parameters were assessed to determine the therapeutic benefit of each treatment group. ESA release was sustained for 4 weeks in vitro, remained active, and enhanced endothelial progenitor cell chemotaxis. In addition, ESA was detected in the rat heart >3 weeks when delivered within the hydrogels and significantly improved vascularity, ventricular geometry, ejection fraction, cardiac output, and contractility compared with controls. Conclusions We have developed a hydrogel delivery system that sustains the release of a bioactive endothelial progenitor cell chemokine during a 4-week period that preserves ventricular function in a rat model of myocardial infarction.

No abstract

No abstract