Differences in Inpatient Outcomes After Surgical Aortic Valve Replacement at Transcatheter Aortic Valve Replacement (TAVR) and Non-TAVR Centers.

Background Transcatheter aortic valve replacement (TAVR) has solidified the importance of a heart team and revolutionized patient selection for surgical aortic valve replacement (SAVR). It is unknown if hospital ability to offer TAVR impacts SAVR outcomes. We investigated outcomes after SAVR between TAVR and non-TAVR centers. Methods and Results Hospitalizations of patients aged ≥50 years, undergoing elective SAVR between January 2012 and September 2015, in the National Readmission Database (NRD) were included. Multivariable logistic, linear, and generalized logistic regression models were used to adjust for patient and hospital characteristics and estimate association between undergoing SAVR at a TAVR center, compared with a non-TAVR center. The association between TAVR volumes and these outcomes were also assessed. SAVR hospitalizations (n = 32 198) were identified; 22 066 (69%) at TAVR and 10 132 (31%) at non-TAVR centers. SAVRs at TAVR centers had lower odds of inpatient mortality (odds ratio 0.67, 95% CI 0.55-0.82) and discharge to skilled nursing facility (odds ratio 0.92, 95% CI 0.85-0.99), compared with non-TAVR centers. There was no difference in LOS (change in estimate -0.09, 95% CI -0.26 to 0.08) or 30-day re-admission (odds ratio 0.95, 95% CI 0.88-1.03). SAVRs performed at the highest TAVR volume centers had the lowest inpatient mortality, compared with non-TAVR centers (odds ratio 0.43 95% CI 0.29-0.63). Conclusions Patients undergoing SAVR at TAVR centers are more likely to survive and have better discharge disposition than patients undergoing SAVR at non-TAVR centers. Whether this represents benefits of a heart-team approach to care or differences in patient selection for SAVR when TAVR is unavailable requires further study.

Length of Stay and Discharge Disposition After Transcatheter Versus Surgical Aortic Valve Replacement in the United States.

BACKGROUND: As transcatheter aortic valve replacement (TAVR) extends its reach to lower surgical risk patients, the differences between resource utilization for TAVR and surgical AVR (SAVR) will become increasingly important. METHODS AND RESULTS: AVR procedures between January 2012 and September 2015 at hospitals performing TAVR were identified using the National Inpatient Sample databases. Adults aged ≥50 years with aortic stenosis who underwent isolated TAVR or SAVR were eligible for inclusion. Standardized morbidity ratio weights were calculated using patient demographics, comorbidities, and hospital characteristics. Weighted linear and generalized logistic regression models were used to estimate the effect of undergoing TAVR, compared with undergoing SAVR, on length of stay (LOS) and discharge disposition. In TAVR-performing hospitals, 7266 (40%) patients underwent TAVR (6107 endovascular approach and 1159 transapical approach), while 10 833 (60%) underwent isolated SAVR. Patients undergoing TAVR were older, more likely to be female, and had more comorbidities. From 2012 to 2015, average LOS declined for both TAVR (6.3 days to 4.6 days; P<0.0001) and SAVR (7.5 days to 6.8 days; P<0.0001), with greater reduction in the TAVR group ( P<0.0001). An increase in home/home health discharge was noted with TAVR (67.7%-77.4%; P<0.0001) but not with SAVR (76.8%-79.5%; P=0.25). After standardizing, patients undergoing TAVR had significantly shorter LOS (change in estimate, -2.93, 95% CI, -3.26 to -2.60) and lower incidence of transfer to skilled nursing facility (odds ratio, 0.45; 95% CI, 0.40-0.51) but no difference in in-hospital mortality (odds ratio, 0.85; 95% CI, 0.61-1.20) compared with if they had undergone SAVR. As compared with SAVR, patients who had TAVR performed via an endovascular approach had shorter LOS and lower rates of skilled nursing facility transfer, whereas in the transapical cohort, LOS, and skilled nursing facility transfer were similar to SAVR. CONCLUSIONS: As compared with if they undergo SAVR, patients undergoing TAVR (by a nontransapical approach) had a shorter LOS and higher likelihood of home discharge, as opposed to skilled nursing facility. From 2012 to 2015, there was a greater trend towards a reduction of LOS and more home discharges among TAVR, as opposed to SAVR. These data have important implications in the era of constrained resources with a growing emphasis on reducing health care costs.

Cardiac Progenitor Cells Enhance Neonatal Right Ventricular Function After Pulmonary Artery Banding.

BACKGROUND: C-kit+ cardiac progenitor cells (CPCs) have been shown to be safe and effective in large-animal models and in an early-phase clinical trial for adult patients with ischemic heart disease. However, CPCs have not yet been evaluated in a preclinical model of right ventricular (RV) dysfunction, which is a salient feature of many forms of congenital heart disease. METHODS: Human c-kit+ CPCs were generated from right atrial appendage biopsy specimens obtained during routine congenital cardiac operations. Immunosuppressed Yorkshire swine (6 to 9 kg) underwent pulmonary artery banding to induce RV dysfunction. Thirty minutes after banding, pigs received intramyocardial injection into the RV free wall with c-kit+ CPCs (1 million cells, n = 5) or control (phosphate-buffered saline, n = 5). Pigs were euthanized at 30 days postbanding. RESULTS: Banding was calibrated to a consistent rise in the RV-to-systemic pressure ratio across both groups (postbanding: CPCs = 0.76 ± 0.06, control = 0.75 ± 0.03). At 30 days postbanding, the CPCs group demonstrated less RV dilatation and a significantly greater RV fractional area of change than the control group (p = 0.002). In addition, measures of RV myocardial strain, including global longitudinal strain and strain rate, were significantly greater in the CPCs group at 4 weeks relative to control (p = 0.004 and p = 0.01, respectively). The RV free wall in the CPCs group demonstrated increased arteriole formation (p < 0.0001) and less myocardial fibrosis compared with the control group (p = 0.02). CONCLUSIONS: Intramyocardial injection of c-kit+ CPCs results in enhanced RV performance relative to control at 30 days postbanding in neonatal pigs. This model is important for further evaluation of c-kit+ CPCs, including long-term efficacy.

Intracoronary Stem Cell Delivery to the Right Ventricle: A Preclinical Study.

Clinical protocols for stem cell-based therapies are currently under development for patients with hypoplastic left heart syndrome. An ideal cell delivery method should have minimal safety risks and provide a wide distribution of cells to the nonischemic right ventricle (RV). However, the optimal strategy for stem cell delivery to the RV has yet to be explored in a preclinical model, necessary for a hypoplastic left heart syndrome trial. Human c-kit+ cardiac stem cells (CSCs) were delivered to healthy Yorkshire swine through the proximal right coronary artery with a stop and reflow technique. The effect of premedication with antiarrhythmic (AA) medications in this model was retrospectively reviewed, with the primary outcome of survival 2 hours after infusion. A group underwent CSC delivery to the RV without prophylactic AA medication (no AA, n = 7), whereas the second group was premedicated with a loading dose and intravenous infusion of amiodarone and lidocaine (AA, n = 13). Cardiac biopsies were obtained from each chamber to ascertain the biodistribution of CSCs. Survival was significantly greater in the prophylactic AA group compared with the group without AA (13/13 [100%] vs 1/7 [14.3%], P < 0.0001). Cardiac arrest during balloon inflation was the cause of death in each of the nonmedicated animals. In the premedicated group, 9 (69.2%) pigs experienced transient ST segment changes in the precordial leads during CSC delivery, which resolved spontaneously. Most c-kit+ CSCs were distributed to lateral segments of the RV free wall, consistent with the anatomical course of the right coronary artery (lateral RV, 19.2 ± 1.5 CSCs/field of view vs medial RV, 10.4 ± 1.3 CSCs/field of view, P < 0.0001). Few c-kit+ CSCs were identified in the right atrium, septum, or left ventricle. Prophylactic infusion of AA enhances survival in swine undergoing intracoronary delivery of human c-kit+ CSCs to the RV. Additionally, intracoronary delivery results in a limited biodistribution of c-kit+ CSCs within the RV. Human clinical protocols can be optimized by requiring infusion of AA medications before cell delivery.