Risk of conventional cardiac surgery among patients with severe left ventricular dysfunction in the era of mechanical circulatory support

Programmatic approach to patients with advanced ischemic cardiomyopathy: Integrating microaxial support into strategies for the modern era

Patients with advanced ischemic cardiomyopathy manifesting as left ventricular dysfunction exist along a spectrum of severity and risk, and thus decision-making surrounding optimal management is challenging. Treatment pathways can include medical therapy as well as revascularization through percutaneous coronary intervention or coronary artery bypass grafting. Additionally, temporary and durable mechanical circulatory support, as well as heart transplantation, may be optimal for select patients. Given this spectrum of risk and the complexity of treatment pathways, patients may not receive appropriate therapy given their perceived risk, which can lead to sub-satisfactory outcomes. In this review, we discuss the identification of high-risk ischemic cardiomyopathy patients, along with our programmatic approach to patient evaluation and perioperative optimization. We also discuss our strategies for therapeutic decision-making designed to optimize both short- and long-term patient outcomes.

Temporary Mechanical Circulatory Support: Left, Right, and Biventricular Devices

Temporary mechanical circulatory support (MCS) encompasses a wide array of invasive devices, which provide short-term hemodynamic support for multiple clinical indications. Although initially developed for the management of cardiogenic shock, indications for MCS have expanded to include prophylactic insertion prior to high-risk percutaneous coronary intervention, treatment of acute circulatory failure following cardiac surgery, and bridging of end-stage heart failure patients to more definitive therapies, such as left ventricular assist devices and cardiac transplantation. A wide variety of devices are available to provide left ventricular, right ventricular, or biventricular support. The choice of a temporary MCS device requires consideration of the clinical scenario, patient characteristics, institution protocols, and provider familiarity and training. In this review, the most common forms of left, right, and biventricular temporary MCS are discussed, along with their indications, contraindications, complications, cannulations, hemodynamic effects, and available clinical data.

Use of 90-day mortality does not change assessment of hospital quality after coronary artery bypass grafting in New York State

OBJECTIVES

Publicly reported postoperative 30-day mortality rates are commonly used to compare hospital quality after coronary artery bypass grafting. We sought to determine whether 90-day mortality rates, which are not publicly reported but better capture postdischarge mortality, are a better determinant of hospital performance.

METHODS

We performed a retrospective cohort analysis of 30- versus 90-day risk-standardized mortality rates at adult cardiac surgical centers in New York State from 2008 to 2014. Hospitals were classified as good or poor performing outliers at each time point based on the bounds of the 95% confidence interval around each hospital's predicted risk-standardized mortality rates determined via hierarchical models. The primary outcome was change in institutional performance via outlier classification from 30 to 90 days.

RESULTS

During the study period, 72,398 adults underwent a coronary artery bypass grafting procedure at 1 of 42 institutions. The risk-standardized mortality rates increased from 30 to 90 days at all institutions, with a median 30-day risk-standardized mortality rate of 2.16% (interquartile range, 0.69%) and median 90-day risk-standardized mortality rate of 3.69% (interquartile range, 1.00%). In using a 90-day instead of a 30-day metric, 3 hospitals changed outlier status. One hospital improved to a good from as expected performer, and 2 worsened to as expected from good performers.

CONCLUSIONS

In a cohort of patients who underwent coronary artery bypass grafting surgery from 2008 to 2014 in New York State, use of a 90-day mortality metric resulted in a change in hospital quality assessment for a minority of hospitals. The use of 90-day mortality may not provide additional value when evaluating institutional performance for this population.

Improved anti-cancer effect of epidermal growth factor-gold nanoparticle conjugates by protein orientation through site-specific mutagenesis

Epidermal growth factor (EGF)-nanoparticle conjugates have the potential for cancer therapeutics due to the unique cytotoxic activity in cancer cells with EGF receptor (EGFR) overexpression. To gain its maximum activity, the EGF molecule should be immobilized on the nanoparticle surface in a defined orientation so as the bulky nanoparticle will not interfere EGF-EGFR interaction. Herein, we demonstrate successful enhancement of the anti-cancer activity of EGF-gold nanoparticle conjugates (EGF-GNPs) by controlling the EGF orientation on the surface of the nanoparticle through site-specific mutagenesis. Three lysine-free EGF variants (RR, RS, and SR) were designed, where two endogenous lysine residues were replaced with either arginine (R) or serine (S). The EGF mutants can be conjugated to the GNPs in a controlled orientation through the single amino group at the N-terminus. The ability of the mutants to induce extracellular signal-regulated kinase (ERK) phosphorylation was no different from wild type EGF (WT) in soluble form, rather lowered for one mutant (RR). However, after conjugated to GNPs, the SR mutants exhibited an enhanced biological activity than WT, in terms of ERK phosphorylation and growth inhibition of cancer cells. Further analysis of the binding constant of each mutant indicated the emergent enhanced activity of the GNP conjugates of the SR mutant was not solely contributed to the orientation, but to its higher binding activity to EGFR. These results validate the present genetic recombination strategy to improve the anticancer efficiency of EGF-GNPs.