Magnetic and Biocompatible Polyurethane Nanofiber Biomaterial for Tissue Engineering

Recruitment of endothelial cells to cardiovascular device surfaces could solve issues of thrombosis, neointimal hyperplasia, and restenosis. Since current targeting strategies are often nonspecific, new technologies to allow for site-specific cell localization and capture in vivo are needed. The development of cytocompatible superparamagnetic iron oxide nanoparticles has allowed for the use of magnetism for cell targeting. In this study, a magnetic polyurethane (PU)-2205 stainless steel (2205-SS) nanofibrous composite biomaterial was developed through analysis of composite sheets and application to stent-grafts. The PU nanofibers provide strength and elasticity while the 2205-SS microparticles provide ferromagnetic properties. Sheets were electrospun at mass ratios of 0-4:1 (2205-SS:PU) and stent-grafts with magnetic or nonmagnetic stents were coated at the optimal ratio of 2:1. These composite materials were characterized by microscopy, mechanical testing, a sessile drop test, magnetic field measurement, magnetic cell capture assays, and cytocompatibility after 14 days of culturing with endothelial cells. Results of this study show that an optimal ratio of 2:1 2205-SS:PU results in a hydrophobic material that balanced mechanical and magnetic properties and was cytocompatible up to 14 days. Significant cell capture required a thicker material of 0.5 mm thickness. Stent-grafts fabricated from a magnetic coating and a magnetic stent demonstrated uniform cell capture throughout the device surface. This novel biomaterial exhibits a combination of mechanical and magnetic properties that enables magnetic capture of cells and other therapeutic agents for vascular and other tissue engineering applications.

The Interaction of FEV1 and NT-Pro-BNP with Outcomes after Transcatheter Aortic Valve Replacement

OBJECTIVES

Low forced expiratory volume in 1 second (FEV1) and elevated N-terminal Pro form B-type natriuretic peptide (NT-Pro-BNP) have been individually associated with poor outcomes after transcatheter aortic valve replacement (TAVR). We hypothesized a combination of the two would provide prognostic indication after TAVR.

METHODS

We categorized 871 patients who received TAVR from 2008 to 2018 into 4 groups according to baseline FEV1 (< or ≥ 60% predicted) and NT-Pro-BNP (< or ≥ 1601 pg/ml): group A (n = 312, high FEV1, low NT-Pro-BNP), group B (n = 275, high FEV1, high NT-Pro-BNP), group C (n = 123 low FEV1, low NT-Pro-BNP), and group D (n = 161, low FEV1, high NT-Pro-BNP). The primary endpoint was survival at 1 and 5 years.

RESULTS

Patients in group A had more severe aortic stenosis and achieved the best long-term survival at 1- (93% (95% CI: 90-96) and 5- years (45.3% (95% CI: 35.4-58). Low FEV1 and high NT-Pro-BNP (group D) patients had more severe symptoms, higher Society of Thoracic Surgeons predicted risk of operative mortality, lower ejection fraction and aortic valve gradient at baseline. They had the worst survival at 1- (76% (95% CI: 69-83) and at 5-years (13.1% (95% CI: 7-25), Hazard Ratio compared to group A: 2.29 (95% CI: 1.6-3.2, p < 0.001) with 25.7% of patients in NYHA class III-IV. Patients in groups B and C had intermediate outcomes.

CONCLUSIONS

The combination of FEV1 and NT-Pro-BNP stratify patients into 4 groups with distinct risk profiles and clinical outcomes. Patients with low FEV1 and high NT-Pro-BNP have increased comorbidities, poor functional outcomes, and decreased long term survival after TAVR.

Cell-intrinsic differences between human airway epithelial cells from children and adults

The airway epithelium is a protective barrier that is maintained by the self-renewal and differentiation of basal stem cells. Increasing age is a principle risk factor for chronic lung diseases, but few studies have explored age-related molecular or functional changes in the airway epithelium. We retrieved epithelial biopsies from histologically normal tracheobronchial sites from pediatric and adult donors and compared their cellular composition and gene expression profile (in laser capture-microdissected whole epithelium, fluorescence-activated cell-sorted basal cells, and basal cells in cell culture). Histologically, pediatric and adult tracheobronchial epithelium was similar in composition. We observed age-associated changes in RNA sequencing studies, including higher interferon-associated gene expression in pediatric epithelium. In cell culture, pediatric cells had higher colony formation ability, sustained in vitro growth, and outcompeted adult cells in a direct competitive proliferation assay. Our results demonstrate cell-intrinsic differences between airway epithelial cells from children and adults in both homeostatic and proliferative states.

Temporal Trends in Use of Complementary Therapies Among Patients With Cardiovascular Disorders

This study aimed to evaluate the use and frequency of complementary and integrative medicine (CIM) therapies in an outpatient cohort with cardiovascular disease (CVD) and compare trends over time. This cross-sectional point-of-care prospective study assessed patients attending a cardiology outpatient clinic. As in our 2009 cohort, data were collected with a 17-question survey on demographic characteristics, CVD history, current use and future interest in CIM. In total, 964 patients completed the survey. CIM use continues to be high (2009 vs 2018, 83.4% vs 81.8%) (p = 0.34), with dietary supplements the most common therapy (75% in both studies). We observed increased use of mind-body therapies (28.5% vs 23.9%, p = 0.02), especially meditation, yoga, and tai chi. Of the patients receiving CIM therapies, 41.9% reported using CIM for heart-related symptoms. Relaxation, stress management, and meditation were the top three mind-body therapies for CVD-related symptoms in both cohorts. Reporting of CIM use to clinicians is low (15%) and interest on future use is high (47%). In conclusion, CIM is highly used in cardiology patients-4 of 10 patients use CIM for CVD-related symptoms. Most take dietary supplements, with an increased use of mind-body therapies. Our data highlight the importance of documenting CIM use in practice and the need for research to document efficacy.

Cardiogenic shock complicating non-ST-segment elevation myocardial infarction: An 18-year study

OBJECTIVE

To evaluate the epidemiology and outcomes of non-ST-segment-elevation myocardial infarction-cardiogenic shock (NSTEMI-CS) in the United States.

METHODS

Adult (>18 years) NSTEMI-CS admissions were identified using the National Inpatient Sample (2000-2017) and classified by tertiles of admission year (2000-2005, 2006-2011 and 2012-2017). Outcomes of interest included temporal trends of prevalence and in-hospital mortality, use of cardiac procedures, in-hospital mortality, hospitalization costs, and length of stay.

RESULTS

In over 7.3 million NSTEMI admissions, CS was noted in 189,155 (2.6%). NSTEMI-CS increased from 1.5% in 2000 to 3.6% in 2017 (adjusted odds ratio 2.03 [95% confidence interval 1.97-2.09]; P < .001). Rates of non-cardiac organ failure and cardiac arrest increased during the study period. Between 2000 and 2017, coronary angiography (43.9%-63.9%), early coronary angiography (13.6%-25.6%), percutaneous coronary intervention (14.8%-31.6%), and coronary artery bypass grafting use (19.0%-25.8%) increased (P < .001). Over the study period, the use of intra-aortic balloon pump remained stable (28.6%-28.8%), and both percutaneous left ventricular assist devices (0%-9.1%) and extra-corporeal membrane oxygenation (0.1%-1.6%) increased (all P < .001). In hospital mortality decreased from 50.2% in 2000 to 32.3% in 2017 (adjusted odds ratio 0.27 [95% confidence interval 0.25-0.29]; P < .001). During the 18-year period, hospital lengths of stay decreased, and hospitalization costs increased.

CONCLUSIONS

In the United States, prevalence of CS in NSTEMI has increased 2-fold between 2000 and 2017, while in-hospital mortality has decreased during the study period. Use of coronary angiography and percutaneous coronary intervention increased during the study period.

Characterization of Blood Outgrowth Endothelial Cells (BOEC) from Porcine Peripheral Blood

The endothelium is a dynamic integrated structure that plays an important role in many physiological functions such as angiogenesis, hemostasis, inflammation, and homeostasis. The endothelium also plays an important role in pathophysiologies such as atherosclerosis, hypertension, and diabetes. Endothelial cells form the inner lining of blood and lymphatic vessels and display heterogeneity in structure and function. Various groups have evaluated the functionality of endothelial cells derived from human peripheral blood with a focus on endothelial progenitor cells derived from hematopoietic stem cells or mature blood outgrowth endothelial cells (or endothelial colony-forming cells). These cells provide an autologous resource for therapeutics and disease modeling. Xenogeneic cells may provide an alternative source of therapeutics due to their availability and homogeneity achieved by using genetically similar animals raised in similar conditions. Hence, a robust protocol for the isolation and expansion of highly proliferative blood outgrowth endothelial cells from porcine peripheral blood has been presented. These cells can be used for numerous applications such as cardiovascular tissue engineering, cell therapy, disease modeling, drug screening, studying endothelial cell biology, and in vitro co-cultures to investigate inflammatory and coagulation responses in xenotransplantation.

Safe Triage of STEMI Patients to General Telemetry Units After Successful Primary Percutaneous Coronary Intervention

Objective

To analyze outcomes of patients with ST-segment elevation myocardial infarction (STEMI) after successful primary percutaneous coronary intervention (PCI) triaged to the cardiac intensive care unit (CICU) vs a general telemetry unit by a Zwolle risk score–based algorithm.

Methods

We introduced a quality improvement protocol in 2014 encouraging admission of STEMI patients with Zwolle score of 3 or less to general telemetry units unless they were hemodynamically unstable. We subsequently conducted a retrospective single-center cohort study of consecutive STEMI patients who had undergone primary PCI from January 1, 2014, to December 31, 2018. Outcomes studied include immediate complications, need for urgent unplanned intervention, need for CICU care, length of hospitalization, and survival.

Results

We identified 547 patients, 406 with a Zwolle score of 3 or less. Of these, 192 (47.3%) were admitted to general telemetry and 214 (52.7%) to the CICU. Reasons for CICU admission included persistent chest pain, late presentation, and procedural complications. The average hospital length of stay was 2.1±1.4 days for non-CICU patients and 3.3±2.8 days for low-risk CICU patients (P<.001). Two patients initially admitted to general telemetry required transfer to the CICU. There were 26 patients who required unplanned cardiovascular intervention within 30 days, 5 from the general telemetry unit; 540 patients survived to discharge. One in-hospital death occurred among those initially triaged to the general telemetry unit, and this was due to a noncardiac cause.

Conclusion

A Zwolle score–based algorithm can be used to safely triage post-PCI STEMI patients to a general telemetry unit.

Doppler Mean Gradient Is Discordant to Aortic Valve Calcium Scores in Patients with Atrial Fibrillation Undergoing Transcatheter Aortic Valve Replacement

BACKGROUND

Doppler mean gradient (MG) may underestimate aortic stenosis (AS) severity when obtained during atrial fibrillation (AF) because of lower forward flow compared with sinus rhythm (SR). Whether AS is more advanced at the time of referral for aortic valve intervention in AF compared with SR is unknown. The aim of this study was to examine flow-independent computed tomographic aortic valve calcium scores (AVCS) and their concordance to MG in AF versus SR in patients undergoing transcatheter aortic valve replacement (TAVR).

METHODS

Patients who underwent TAVR from 2016 to 2020 for native valve severe AS with left ventricular ejection fraction ≥ 50% were identified from an institutional TAVR database. MGs during AF and SR in high-gradient AS (HGAS) and low-gradient AS (LGAS) were compared with AVCS (AVCS/MG ratio). AVCS were obtained within 90 days of pre-TAVR echocardiography.

RESULTS

Six hundred thirty-three patients were included; median age was 82 years (interquartile range [IQR], 76-86 years), and 46% were women. AF was present in 109 (17%) and SR in 524 (83%) patients during echocardiography. Aortic valve area index was slightly smaller in AF versus SR (0.43 cm²/m² [IQR, 0.39-0.47 cm²/m²] vs 0.46 cm²/m² [IQR, 0.41-0.51 cm²/m²], P = .0003). Stroke volume index, transaortic flow rate, and MG were lower in AF (P < .0001 for all). AVCS were higher in men with AF compared with SR (3,510 Agatston units [AU] [IQR, 2,803-4,030 AU] vs 2,722 AU [IQR, 2,180-3,467 AU], P < .0001) in HGAS but not in LGAS. AVCS were not different in women with AF versus SR. Overall AVCS/MG ratios were higher in AF versus SR in HGAS and LGAS (P < .03 for all), except in women with LGAS.

CONCLUSIONS

AVCS were higher than expected by MG in AF compared with SR. The very high AVCS in men with AF and HGAS at the time of TAVR suggests late diagnosis of severe AS because of underestimated AS severity during progressive AS and/or late referral to TAVR. Additional studies are needed to examine the extent to which echocardiography may be underestimating AS severity in AF.

Temporal Incidence and Predictors of High-Grade Atrioventricular Block After Transcatheter Aortic Valve Replacement

Background

The temporal incidence of high‐grade atrioventricular block (HAVB) after transcatheter aortic valve replacement (TAVR) is uncertain. As a result, periprocedural monitoring and pacing strategies remain controversial. This study aimed to describe the temporal incidence of initial episode of HAVB stratified by pre‐ and post‐TAVR conduction and identify predictors of delayed events.

Methods and Results

Consecutive patients undergoing TAVR at a single center between February 2012 and June 2019 were retrospectively assessed for HAVB within 30 days. Patients with prior aortic valve replacement, permanent pacemaker (PPM), or conversion to surgical replacement were excluded. Multivariable logistic regression was performed to assess predictors of delayed HAVB (initial event >24 hours post‐TAVR). A total of 953 patients were included in this study. HAVB occurred in 153 (16.1%). After exclusion of those with prophylactic PPM placed post‐TAVR, the incidence of delayed HAVB was 33/882 (3.7%). Variables independently associated with delayed HAVB included baseline first‐degree atrioventricular block or right bundle‐branch block, self‐expanding valve, and new left bundle‐branch block. Forty patients had intraprocedural transient HAVB, including 16 who developed HAVB recurrence and 6 who had PPM implantation without recurrence. PPM was placed for HAVB in 130 (13.6%) (self‐expanding valve, 23.7% versus balloon‐expandable valve, 11.9%; P<0.001). Eight (0.8%) patients died by 30 days, including 1 unexplained without PPM present.

Conclusions

Delayed HAVB occurs with higher frequency in patients with baseline first‐degree atrioventricular block or right bundle‐branch block, new left bundle‐branch block, and self‐expanding valve. These findings provide insight into optimal monitoring and pacing strategies based on periprocedural ECG findings.

Fibrinolysis vs. primary percutaneous coronary intervention for ST-segment elevation myocardial infarction cardiogenic shock

AIMS

There are limited contemporary data on the use of initial fibrinolysis in ST-segment elevation myocardial infarction cardiogenic shock (STEMI-CS). This study sought to compare the outcomes of STEMI-CS receiving initial fibrinolysis vs. primary percutaneous coronary intervention (PPCI).

METHODS

Using the National (Nationwide) Inpatient Sample from 2009 to 2017, a comparative effectiveness study of adult (>18 years) STEMI-CS admissions receiving pre-hospital/in-hospital fibrinolysis were compared with those receiving PPCI. Admissions with alternate indications for fibrinolysis and STEMI-CS managed medically or with surgical revascularization (without fibrinolysis) were excluded. Outcomes of interest included in-hospital mortality, development of non-cardiac organ failure, complications, hospital length of stay, hospitalization costs, use of palliative care, and do-not-resuscitate status.

RESULTS

During 2009-2017, 5297 and 110 452 admissions received initial fibrinolysis and PPCI, respectively. Compared with those receiving PPCI, the fibrinolysis group was more often non-White, with lower co-morbidity, and admitted on weekends and to small rural hospitals (all P < 0.001). In the fibrinolysis group, 95.3%, 77.4%, and 15.7% received angiography, PCI, and coronary artery bypass grafting, respectively. The fibrinolysis group had higher rates of haemorrhagic complications (13.5% vs. 9.9%; P < 0.001). The fibrinolysis group had comparable all-cause in-hospital mortality [logistic regression analysis: 28.8% vs. 28.5%; propensity-matched analysis: 30.8% vs. 30.3%; adjusted odds ratio 0.97 (95% confidence interval 0.90-1.05); P = 0.50]. The fibrinolysis group had comparable rates of acute organ failure, hospital length of stay, rates of palliative care referrals, do-not-resuscitate status use, and lesser hospitalization costs.

CONCLUSIONS

The use of initial fibrinolysis had comparable in-hospital mortality than those receiving PPCI in STEMI-CS in the contemporary era in this large national observational study.

An Algorithm for Pairing Interventionalists and Surgeons for the TAVR Procedure

The Transcatheter Aortic Valve Replacement (TAVR) procedure requires an initial consultation and a subsequent procedure by an interventionalist (IC) and surgeon. The IC-surgeon pair coordination is extremely challenging, especially at Mayo Clinic due to provider time commitments distributed across practice, research, and education activities. Current practice aims to establish the coordination manually, resulting in a scheduling process that is cumbersome and time consuming for the schedulers. We develop an algorithm for pairing ICs and surgeons that minimizes the lead time (days elapsed between the clinic consult and procedure). As compared to current practice, this algorithm is able to reduce average lead time by 59% and increase possible IC-surgeon pairs by 7%. The proposed algorithm is shown to be flexible enough to incorporate practice variations such as lead time upper bound and two procedure days for a single consult day. Algorithm alternatives are also presented for practices who may find the proposed algorithm infeasible for their practice.

Do Right Heart Hemodynamic Improvements Persist After Pulmonary Thromboendarterectomy?

The survival benefits of pulmonary thromboendarterectomy (PTE) for the treatment of chronic thromboembolic pulmonary hypertension have been well described. However, the significance of right heart hemodynamic changes and their impact on survival remains poorly understood. We sought to characterize the effects of these changes. We conducted a single center, retrospective review of 159 patients who underwent PTE between 1993 and 2015. Echocardiographic and right heart catheterization data were compared longitudinally before and after PTE in order to establish the extent of hemodynamic response to surgery. Kaplan Meier estimates were used to characterize patient survival over time. Univariable and multivariable Cox proportional hazards regression models were used to assess factors associated with long-term mortality. Among the 159 patients studied, 74 (46.5%) were male with a median age of 55 (IQR: 42-66). One-, 5-, 10-, and 15-year survival was 91.0% (95% CI: 86.6-95.6), 79.6% (73.5-86.3), 66.5% (59.2-74.7), and 56.2% (48.1-65.8). Of the 9 candidate risk factors that were evaluated, only advanced age and increased cardiopulmonary bypass time were found to be significantly associated with increased risk of mortality. Pre- and postsurgical echocardiographic imaging data, when available, revealed a median reduction in right ventricular systolic pressure of 29.0 mm Hg (P < 0.0001) and improvement of tricuspid regurgitation (P < 0.0001), both of which appeared to be sustained across long-term follow-up. Improvements in right heart hemodynamics and tricuspid valvular regurgitation persist on long term surveillance following PTE. While patient selection is often driven by the distribution of disease, close postoperative follow up may improve outcomes.

Remote robotic percutaneous coronary intervention: An animal feasibility study

OBJECTIVES

The purpose of this study was to explore the feasibility and safety of robotic PCI performed using an off-siteremote-control system in an animal model.

BACKGROUND

Access to primary percutaneous coronary intervention (PCI) remains a challenge in acute myocardial infarction management. The combination of telemedicine and robotic PCI allow the potential delivery of primary PCI to remote locations without the delay of transfer.

METHODS

This single-center prospective pilot preclinical feasibility study compared robotic PCI with remote PCI on swine across three stages (adjacent room, different floor of the same building, two different buildings). Latency up to 1,000 ms was introduced into the operating environment to simulate decreased network quality (blinded to operator). The primary outcome measures were technical success and acute safety. The secondary outcome measures included lesion wiring time, procedural time and qualitative scoring of the PCI experience by the operator.

RESULTS

Across 52 experiments in 15 animals, technical success was 100%. No procedural complications occurred during the study. No significant difference in lesion treatment time was detected between stages (p = .11) and between time per target vessel when latency up to 1,000 ms was introduced (p = .58). Injected delay >250 ms had the greatest impact on procedure perceived lag. Longer procedure time was associated with lower procedure impact score, regardless of injected latency.

CONCLUSIONS

Remote robotic PCI was feasible and safe in an animal model. Procedural duration was acceptable and unaffected by network latency. Future studies are needed to determine the safety and feasibility of remote PCI in humans.

Analysis of the Changing Economics of US Hospital Transcatheter Aortic Valve Replacement Programs

New technologies in medicine, even if they are promising medically, are often expensive and logistically difficult to implement at the hospital level. Transcatheter aortic valve replacement (TAVR) is a model technology that is revolutionary in treating aortic stenosis, but has been plagued with significant challenges with financial sustainability. In this article, a margin analysis at the hospital level was performed using literature data. A TAVR industry analysis was performed using Porter's Five Forces framework. The data indicate that TAVR is more expensive than surgical aortic valve replacement, although the cost of TAVR is declining with the use of an optimized minimalist protocol. The overall industry is growing as its clinical indications expand, and it will likely undergo significant reduction of costs when new valves enter the US market. As such, TAVR is a growing industry, with financial sustainability currently dependent on operational efficiency. A concluding list of specific program interventions is provided to help TAVR programs improve operational efficiency and clinical outcomes, as well as help decide whether to create, expand, or redirect funding for TAVR programs. Importantly, the frameworks used to analyze this rapidly evolving technology can be applied to other new technologies to determine financial sustainability.

Characteristics and Long-Term Outcomes of Patients With Prior Coronary Artery Bypass Grafting Undergoing Primary Percutaneous Coronary Intervention for ST-Segment Elevation Myocardial Infarction

Limited data are available on characteristics and long-term outcomes of patients with coronary artery bypass grafts (CABG) undergoing primary percutaneous coronary intervention for ST-elevation myocardial infarction (STEMI). Between January 2000 to December 2014, we identified STEMI patients with prior CABG undergoing primary percutaneous coronary intervention from 3 sites. Kaplan-Meier methods to estimate survival and major adverse cardiac events (MACE) were employed and compared to a propensity matched cohort of non-CABG STEMI patients. Independent predictors of outcomes were analyzed with Cox modeling. Of the 3,212 STEMI patients identified, there were 296 (9.2%) CABG STEMI patients, having nearly similar frequencies of culprit graft (47.6%) versus culprit native (52.4%) as the infarct-related artery (IRA). At 10 years, the adjusted survival was 44% in CABG STEMI versus 55% in non-CABG STEMI (HR 1.26; 95%CI 0.86 to 1.87; p = 0.72). Survival free of MACE was lower for CABG STEMI (graft IRA, 37%; native IRA, 46%) as compared to non-CABG STEMI controls (63%) (p = 0.02). Neither CABG history nor IRA (native vs graft) was independently associated with death or MACE in multivariable analysis. Temporal trends showed no significant change in death or MACE rates of CABG STEMI patients over time. In conclusion, long term survival of CABG STEMI patients is not significantly different than matched STEMI patients without prior CABG; however, CABG STEMI patients were at significantly higher risk for MACE events.

Effect of Transcatheter Aortic Valve Replacement on Right Ventricular-Pulmonary Artery Coupling

OBJECTIVES

The aim of this study was to test the hypothesis that the acute left ventricular (LV) unloading effect of transcatheter aortic valve replacement (TAVR) would improve right ventricular (RV) function and RV-pulmonary artery (PA) coupling in patients with severe aortic stenosis (AS).

BACKGROUND

RV dysfunction is an ominous prognostic marker in patients undergoing TAVR, suggesting that relief of obstruction might be less beneficial in this cohort. However, the left ventricle and right ventricle influence each other through ventricular interaction, which could lead to improved RV function through LV unloading.

METHODS

Prospective invasive hemodynamic measurements with simultaneous echocardiography were performed in symptomatic patients with severe AS before and immediately after TAVR.

RESULTS

Forty-four patients (mean age 81 ± 8 years, 27% women) with severe AS underwent TAVR. At baseline, right atrial, PA mean (27 ± 7 mm Hg), and pulmonary capillary wedge (16 ± 4 mm Hg) pressures were mildly elevated, with a low normal cardiac index (2.3 l/min/m²). Pulmonary vascular resistance was mildly elevated (222 ± 133 dynes · s/cm⁵) and PA compliance mildly reduced (3.4 ± 01.4 ml/mm Hg). Following TAVR, aortic valve area increased (from 0.8 ± 0.3 to 2.7 ± 1.1 cm²; p < 0.001) with a reduction in mean aortic gradient (from 37 ± 11 to 7 ± 4 mm Hg; p < 0.001) and an increase in cardiac index (from 2.3 ± 0.5 to 2.5 ± 0.6 l/min/m²; p = 0.03). LV stroke work, end-systolic wall stress, and systolic ejection period decreased by 23% to 27% (p < 0.001 for all), indicating substantial LV unloading. RV stroke work (from 16 ± 7 to 18 ± 7 mm Hg · ml; p = 0.04) and tricuspid annular systolic velocities (from 9.5 ± 2.0 to 10.4 ± 3.5 cm/s; p = 0.01) increased, along with a decrease in PVR (194 ± 113 dynes · s/cm⁵; p = 0.03), indicating improvement in RV-PA coupling. Increased RV stroke work following TAVR directly correlated with the magnitude of increase in aortic valve area (r = 0.58; p < 0.001).

CONCLUSIONS

Acute relief in obstruction to LV ejection with TAVR is associated with improvements in RV function and RV-PA coupling. These findings provide new insights into the potential benefits of LV unloading with TAVR on RV dysfunction in patients with severe AS.

Outcomes of Patients With Severe Symptomatic Aortic Valve Stenosis After Chest Radiation: Transcatheter Versus Surgical Aortic Valve Replacement

Background Patients with symptomatic severe aortic stenosis and a history of chest radiation therapy represent a complex and challenging cohort. It is unknown how transcatheter aortic valve replacement ( TAVR ) compares with surgical aortic valve replacement in this group of patients, which was the objective of this study. Methods and Results We retrospectively reviewed all patients with severe aortic stenosis who underwent either TAVR or surgical aortic valve replacement at our institution with a history of mediastinal radiation (n=55 per group). End points were echocardiographic and clinical outcomes in-hospital, at 30 days, and at 1 year. Inverse propensity weighting analysis was used to account for intergroup baseline differences. TAVR patients had a higher STS score than surgical aortic valve replacement patients (5.1% [3.2, 7.7] versus 1.6% [0.8, 2.6], P<0.001) and more often ( P<0.01 for all) a history of atrial fibrillation (45.5% versus 12.7%), chronic lung disease (47.3% versus 7.3%), peripheral arterial disease (38.2% versus 7.3%), heart failure (58.2% versus 18.2%), and pacemaker therapy (23.6% versus 1.8%). Postoperative atrial fibrillation was less frequent (1.8% versus 27.3%; P<0.001) and hospital stay was shorter in TAVR patients (4.0 [2.0, 5.0] versus 6.0 [5.0, 8.0] days; P<0.001). The ratio of observed-to-expected 30-day mortality was lower after TAVR as was 30-day mortality in inverse propensity weighting-adjusted Kaplan-Meier analyses. Conclusions In patients with severe aortic stenosis and a history of chest radiation therapy, TAVR performs better than predicted along with less adjusted 30-day all-cause mortality, postoperative atrial fibrillation, and shorter hospitalization compared with surgical aortic valve replacement. These data support further studies on the preferred role of TAVR in this unique patient population.

Artificial Intelligence in Cardiology: Present and Future

Artificial intelligence (AI) is a nontechnical, popular term that refers to machine learning of various types but most often to deep neural networks. Cardiology is at the forefront of AI in medicine. For this review, we searched PubMed and MEDLINE databases with no date restriction using search terms related to AI and cardiology. Articles were selected for inclusion on the basis of relevance. We highlight the major achievements in recent years in nearly all areas of cardiology and underscore the mounting evidence suggesting how AI will take center stage in the field. Artificial intelligence requires a close collaboration among computer scientists, clinical investigators, clinicians, and other users in order to identify the most relevant problems to be solved. Best practices in the generation and implementation of AI include the selection of ideal data sources, taking into account common challenges during the interpretation, validation, and generalizability of findings, and addressing safety and ethical concerns before final implementation. The future of AI in cardiology and in medicine in general is bright as the collaboration between investigators and clinicians continues to excel.

Acute Myocardial Infarction Due to Fixed Coronary Artery Stenosis From Myocardial Bridging

Myocardial bridging is a common coronary abnormality often associated with left ventricular hypertrophy. It can be noted incidentally on coronary angiography by findings of systolic narrowing of the involved coronary artery. We present the case of a 59-year-old woman that presented with a non-ST elevation myocardial infarction. She had a history of angina and workup 9-months prior with CT coronary angiography that revealed an intra-myocardial course of the left anterior descending coronary artery (LAD) with minimal stenosis and no concomitant coronary artery disease. Invasive coronary angiography now demonstrated apparent myocardial bridging associated with a severe fixed stenosis of the LAD without change in diameter with nitroglycerin injection. Due to persistent symptoms, surgical myotomy was attempted and then aborted because of difficulty unroofing the LAD due to surrounding fibrosis. Coronary artery bypass grafting (CABG) was then successfully performed using a left internal mammary artery graft. The patient had complete resolution of her chest pain and was without functional limitation at 3-month follow-up. This case highlights possible sequelae of myocardial bridging and suggests that, in rare cases, fixed obstruction of the involved coronary artery may occur in the setting of fibrosis of the bridged segment. In such cases, surgical myotomy may not be feasible and CABG may be required.

Transcatheter Aortic Valve Replacement Programs: Clinical Outcomes and Developments

Transcatheter aortic valve replacement is a relatively recent revolutionary treatment that has now become a standard procedure for treating severe aortic stenosis. In this article, the authors review the clinical history of transcatheter aortic valve replacement, summarize the major clinical trials, and describe the evolution of the technique over time. In doing so, the authors hope to provide a clear and concise review of the history and clinical evidence behind transcatheter aortic valve replacement.

Incidence, Mechanisms, and Predictors of Mean Systolic Gradients ≥20 mm Hg after Transcatheter Aortic Valve Implantation

There is a significant increase in transvalvular gradients after transcatheter aortic valve implantation (TAVI) in some patients; however, mechanisms underlying the greater than expected gradients are unknown. We sought to determine the incidence and mechanisms of greater than expected gradients post-TAVI. A total of 424 patients who underwent TAVI at our institution between November 2008 and August 2015 and had at least 1 follow-up echocardiogram were included in the study. Greater than expected gradients were defined as mean systolic Doppler gradients ≥20 mm Hg. The primary end-point was incidence and mechanisms of mean systolic Doppler gradients ≥20 mm Hg. A total of 36 (8%) patients had mean systolic Doppler gradients ≥20 mm Hg. The mechanisms of mean systolic Doppler gradients ≥20 mm Hg were: patient prosthesis mismatch in 15 (42%) patients, high cardiac output in 13 (36%), prosthetic and periprosthetic regurgitation in 11 (31%), stenosis in 5 (14%), and multiple mechanisms in 8 (22%). Patients with mean systolic Doppler gradients ≥20 mm Hg had higher cardiac re-hospitalization rate, but no difference in mortality or major cardiovascular events when compared with the normal gradient group. Smaller prosthetic valve size (p <0.0001) and larger body mass index (p = 0.02) were associated with mean systolic Doppler gradients ≥20 mm Hg; warfarin therapy at discharge had no effect on gradients. In conclusion, about 8% patients had mean systolic Doppler gradients ≥20 mm Hg following TAVI, and patient-prosthesis mismatch was the most common mechanism. The mean systolic Doppler gradients ≥20 mm Hg after TAVI are not benign and warrant careful surveillance.

A Metabolic Intravascular Platform to Study FDG Uptake in Vascular Injury

PURPOSE

Metabolic alterations underlie many pathophysiological conditions, and their understanding is critical for the development of novel therapies. Although the assessment of metabolic changes in vivo has been historically challenging, recent developments in molecular imaging have allowed us to study novel metabolic research concepts directly in the living subject, bringing us closer to patients. However, in many instances, there is need for sensors that are in close proximity to the organ under investigation, for example to study vascular metabolism.

METHODS

In this study, we developed and validated a metabolic detection platform directly in the living subject under an inflammatory condition. The signal collected by a scintillating fiber is amplified using a photomultiplier tube and decodified by an in-house tunable analysis platform. For in vivo testing, we based our experiments on the metabolic characteristics of macrophages, cells closely linked to inflammation and avid for glucose and its analog ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG). The sensor was validated in New Zealand rabbits, in which inflammation was induced by either a) high cholesterol (HC) diet for 16 weeks or b) vascular balloon endothelial denudation followed by HC diet.

RESULTS

There was no difference in weight, hemodynamics, blood pressure, or heart rate between the groups. Vascular inflammation was detected by the metabolic sensor (Inflammation: 0.60 ± 0.03 AU vs. control: 0.48 ± 0.03 AU, p = 0.01), even though no significant inflammation/atherosclerosis was detected by intravascular ultrasound, underscoring the high sensitivity of the system. These findings were confirmed by the presence of macrophages on ex vivo aortic tissue staining.

CONCLUSION

In this study, we validated a tunable very sensitive metabolic sensor platform that can be used for the detection of vascular metabolism, such as inflammation. This sensor can be used not only for the detection of macrophage activity but, with alternative probes, it could allow the detection of other pathophysiological processes.

Computed Tomography Evaluation of Brain in Chronic Alcoholics

Background  Chronic alcoholism causes brain damage. Published data from rural India is scant. Our aim is to determine computed tomography (CT) changes in the brain of rural chronic alcoholics.

Methods  This prospective cross-sectional study was done in our tertiary care hospital on chronic alcoholic patients referred from deaddiction center over a period of 2 years. Age- and sex-matched nonalcoholic controls were included and Student’s t -test and chi-square test comparison was done. Correlation coefficient was obtained by Pearson’s correlation coefficient. Patients and the controls were studied in two age groups: 30 to 45 and 46 to 60 years. Noncontrast CT scan of head was done in each case and CT indices of brain damage were measured.

Results  The study included 106 alcoholics out of which 55 were in the younger age group (30–45 years) and 51 in the older age group (46–60 years). Seven hundred age-matched, nonalcoholic controls were included. Mean values of ethanol were higher in the older age group than in the younger age group. As compared with controls, various CT scan indices of ventricular changes, cortical changes, and subcortical changes were significantly higher in both age groups. In both age groups, there was a significant decrease in the mean values of hemoglobin and a significant increase in the mean values of indices of brain damage with increase in the grade of alcoholism.

Conclusion  The results of this prospective epidemiological study showed marked alterations in all CT indices of brain atrophy and were correlated to the duration and amount of ethanol consumption. This study highlights that chronic alcoholism is a significant risk factor for brain atrophy.

Extracorporeal Membrane Oxygenation Use in Acute Myocardial Infarction in the United States, 2000 to 2014

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is increasingly used in acute myocardial infarction (AMI); however, there are limited large-scale national data.

METHODS

Using the National Inpatient Sample database from 2000 to 2014, a retrospective cohort of AMI utilizing ECMO was identified. Use of percutaneous coronary intervention, intra-aortic balloon pump, and percutaneous left ventricular assist device (LVAD) was also identified in this population. Outcomes of interest included temporal trends in utilization of ECMO alone and with concomitant procedures (percutaneous coronary intervention, intra-aortic balloon pump, and percutaneous LVAD), in-hospital mortality, and resource utilization.

RESULTS

In ≈9 million AMI admissions, ECMO was used in 2962 (<0.01%) and implanted a median of 1 day after admission. ECMO was used in 0.5% and 0.3% AMI admissions complicated by cardiogenic shock and cardiac arrest, respectively. ECMO was used more commonly in admissions that were younger, nonwhite, and with less comorbidity. ECMO use was 11× higher in 2014 as compared with 2000 (odds ratio, 11.37 [95% CI, 7.20-17.97]). Same-day percutaneous coronary intervention was performed in 23.1%; intra-aortic balloon pump/percutaneous LVAD was used in 57.9%, of which 30.3% were placed concomitantly. In-hospital mortality with ECMO was 59.2% overall but decreased from 100% (2000) to 45.1% (2014). Durable LVAD and cardiac transplantation were performed in 11.7% as an exit strategy. Of the hospital survivors, 40.8% were discharged to skilled nursing facilities. Older age, male sex, nonwhite race, and lower socioeconomic status were independently associated with higher in-hospital mortality with ECMO use.

CONCLUSIONS

In AMI admissions, a steady increase was noted in the utilization of ECMO alone and with concomitant procedures (percutaneous coronary intervention, intra-aortic balloon pump, and percutaneous LVAD). In-hospital mortality remained high in AMI admissions treated with ECMO.

Utility of 30-Day Continuous Ambulatory Monitoring to Identify Patients With Delayed Occurrence of Atrioventricular Block After Transcatheter Aortic Valve Replacement

Background:

Mechanical injury in the conduction system requiring permanent pacemaker (PPM) associated with transcatheter aortic valve replacement (TAVR) procedure is a common complication. The objective of this study was to use ambulatory monitor BodyGuardian to assess late occurrence of atrioventricular block (AVB) after TAVR.

Methods:

This prospective study evaluated 365 patients who underwent TAVR at Mayo Clinic, Rochester, Minnesota between June 2016 and August 2017. Patients who received PPM for bradycardia after TAVR before discharge were considered as the PPM group. Those not requiring PPM received a BodyGuardian system (BodyGuardian group) for 30 days of continuous monitoring. Primary end point was Mobitz II or third-degree atrioventricular block (II/III AVB) at 30-day follow-up.

Results:

Of 365 patients, 74 who had a PPM or an implantable cardioverter-defibrillator before TAVR and 94 who were enrolled in other studies were excluded. Of 197 patients enrolled in the study, 70 (35.5%) received PPM and 127 had BodyGuardian before the hospital dismissal. Eleven of 127 (8.6%) BodyGuardian group required PPM within 30 days after TAVR for late occurrence of symptomatic bradycardia. In total, 33 of 197 (16.7%) patients developed II/III AVB (24 before and 9 after discharge). Thirty-four patients had preexisting right bundle branch block. Of them, 16 (47%) developed II/III AVB. Of 53 patients who developed new left bundle branch block after TAVR, 14% progressed to II/III AVB within 30 days.

Conclusions:

In patients without a standard post-TAVR pacing indication, yet a potential risk to develop AVB, a strategy of 30-day monitoring identifies additional patients who require permanent pacing.

Balloon Pulmonary Angioplasty for Chronic Thromboembolic Pulmonary Hypertension: Initial Single-Center Experience

Objective

To evaluate the safety and efficacy of balloon pulmonary angioplasty (BPA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) seen at a US medical center.

Patients and Methods

Patients with inoperable or residual postendarterectomy CTEPH who underwent BPA at Mayo Clinic in Rochester, Minnesota, between August 11, 2014, and May 17, 2018, were included. Invasive hemodynamic, clinical, laboratory, and echocardiographic data were collected and analyzed retrospectively.

Results

We identified 31 patients (26 with inoperable CTEPH and 5 with residual postendarterectomy CTEPH) who underwent 75 BPA procedures performed in a staged manner to reduce complications. The median number of sessions was 2 (interquartile range [IQR], 1-3) per patient, and the number of vessels treated per session was 3 (IQR, 2-3). Of the 31 patients, 24 (77.4%) were taking pulmonary vasodilators and 22 (71.0%) were taking riociguat. The mean pulmonary arterial pressure decreased from 40 mm Hg (IQR, 29-48 mm Hg) to 29 mm Hg (IQR, 25-37 mm Hg; P<.001); pulmonary vascular resistance decreased from 5.5 Wood units (WU) (IQR, 3.0-7.6 WU) to 3.3 WU (2.2-5.2 WU; P<.001). The follow-up 6-minute walk test was performed in 13 patients and improved from 402 m (IQR, 311-439 m) to 439 m (366-510 m; P=.001). Of the 31 patients, 19 (61.3%) had improvement in New York Heart Association functional class. The mean ± SD nadir of minute ventilation/carbon dioxide production decreased by 3.4±5.5 (P=.03), reflecting improved ventilatory efficiency. Complications included hemoptysis requiring overnight intensive care unit observation (n=1) and cardiac tamponade requiring pericardiocentesis (n=1). One patient had reperfusion injury requiring intubation, recovered, and was dismissed to home but died unexpectedly within less than 30 days of the procedure. Serious complications occurred in 3 of the 75 BPA procedures (4.0%).

Conclusion

Our experience with BPA revealed that this procedure has acceptable risk and improves hemodynamics, functional class, and exercise tolerance in patients with inoperable or residual CTEPH.

Outcomes of Percutaneous Coronary Interventions in Patients With Anemia Presenting With Acute Coronary Syndrome

OBJECTIVE

To study the influence of anemia on long-term outcomes of patients with acute coronary syndrome undergoing percutaneous coronary intervention (PCI).

PATIENTS AND METHODS

The study included 5668 consecutive unique patients with acute coronary syndrome who underwent PCI at Mayo Clinic from January 1, 2004, through December 31, 2014. The patients were stratified on the basis of the presence (hemoglobin [Hgb] level, <13 g/dL in men and <12 g/dL in women) and severity (moderate to severe Hgb level, <11 g/dL in men and women) of pre-PCI anemia and compared with patients without anemia. The primary outcomes were in-hospital and long-term all-cause mortality after balancing baseline comorbidities using the inverse propensity weighting method.

RESULTS

Unadjusted all-cause in-hospital mortality (4.6% [84 of 1831] vs 2.0% [75 of 3837]) and 5-year follow-up mortality (44.4% [509] vs 15.4% [323]) were higher in patients with anemia than in those without anemia (P<.001 for both). After applying inverse propensity weighting analysis, the all-cause in-hospital mortality (2.0% [37] vs 2.0% [75]; P=.85) and 5-year mortality (17.8% [203] vs 15.4% [323]; P=.05) were not significantly different between patients with and without anemia; however, there were higher rates of all-cause 5-year mortality in patients with moderate to severe anemia (22.3% [113] vs 15.4% [323]; P<.001) compared with patients without anemia. The trend in 5-year mortality was driven by increased noncardiac mortality in patients with anemia (10.2% [91] vs 7.1% [148]; P=.04) and moderate to severe anemia (10.4% [52] vs 7.1% [148]; P=.006) when compared with nonanemic patients.

CONCLUSION

After accounting for differences in risk profiles of anemic and nonanemic patients, anemia appeared to be an independent risk factor for increased long-term all-cause and noncardiac mortality.

Characteristics and long term outcomes of patients with acute coronary syndromes due to culprit left main coronary artery disease treated with percutaneous coronary intervention

BACKGROUND

Patients with acute coronary syndrome (ACS) due to unprotected culprit left main coronary artery disease (LMCAD) treated with percutaneous coronary intervention (PCI) are rare, high-risk, and not represented in trials. Data regarding long term outcome after PCI are limited.

METHODS

Between January 2000 and December 2014, there were 8,794 patients hospitalized with unstable angina/non-ST elevation myocardial infarction (UA/NSTEMI) or ST-elevation myocardial infarction (STEMI) treated with PCI at our institution; of these, 83 (0.94%) patients were identified as having culprit LMCAD ACS.

RESULTS

Of the 83 patients with unprotected LMCAD ACS, 40 patients presented with STEMI and 43 patients presented with UA/NSTEMI. As compared to LM UA/NSTEMI, LM STEMI patients were younger and had less hypertension, with a trend towards greater frequency of cardiogenic shock. Distal LM involvement was common in both groups and did not differ by ACS type. In-hospital mortality was 33% in LM STEMI and 9% in LM UA/NSTEMI (P = .009). Over median follow up of 6.3 years, long term survival rates in both groups were similar (46% for STEMI vs 51% for UA/NSTEMI; P = .50 by log-rank).

CONCLUSIONS

Unprotected culprit LMCAD ACS necessitating PCI is uncommon, occurring in <1% of cases, but is associated with reduced survival, with long term follow-up noting continued and similar risk of death regardless of index ACS type.

Nanoparticle-Mediated Cell Capture Enables Rapid Endothelialization of a Novel Bare Metal Stent

Incomplete endothelialization of intracoronary stents has been associated with stent thrombosis and recurrent symptoms, whereas prolonged use of dual antiplatelet therapy increases bleeding-related adverse events. Facilitated endothelialization has the potential to improve clinical outcomes in patients who are unable to tolerate dual antiplatelet therapy. The objective of this study was to demonstrate the feasibility of magnetic cell capture to rapidly endothelialize intracoronary stents in a large animal model. A novel stent was developed from a magnetizable duplex stainless steel (2205 SS). Polylactic-co-glycolic acid and magnetite (Fe₃O₄) were used to synthesize biodegradable superparamagnetic iron oxide nanoparticles, and these were used to label autologous blood outgrowth endothelial cells. Magnetic 2205 SS and nonmagnetic 316L SS control stents were implanted in the coronary arteries of pigs (n = 11), followed by intracoronary delivery of magnetically labeled cells to 2205 SS stents. In this study, we show extensive endothelialization of magnetic 2205 SS stents (median 98.4% cell coverage) within 3 days, whereas the control 316L SS stents exhibited significantly less coverage (median 48.9% cell coverage, p < 0.0001). This demonstrates the ability of intracoronary delivery of magnetic nanoparticle labeled autologous endothelial cells to improve endothelialization of magnetized coronary stents within 3 days of implantation.

Coronary artery bypass grafting in patients treated with thoracic radiation: a case-control study

Background and aim

Thoracic radiation therapy (XRT) for cancer is associated with the development of significant coronary artery disease that may require coronary artery bypass grafting surgery (CABG). Contemporary acute surgical outcomes and long-term postoperative survival of patients with prior XRT have not been well characterised.

Methods

This was a retrospective, single-centre study of patients with a history of thoracic XRT who required CABG and who were propensity matched against 141 controls who underwent CABG over the same time period. The objectives were to assess early CABG outcomes and long-term survival in patients with prior XRT.

Results

Thirty-eight patients with a history of previous thoracic XRT underwent CABG from 1994 to 2013. The median time from XRT exposure to surgery was 7.9 years (IQR: 2.5–18.4 years). Perioperative adverse events were similar in the XRT group and controls; however, there was a trends lower utilisation of internal mammary artery (IMA) grafts in the XRT group (89%vs98%, P=0.13). After a median postoperative follow-up of 5.4 years (IQR 0.9–9.4 years), no difference in long-term all-cause mortality was observed.

Conclusion

Patients with prior thoracic XRT who undergo CABG have similar long-term all-cause mortality compared with controls. Isolated CABG after thoracic XRT is not associated with higher perioperative complications, but IMA graft use may be limited by prior XRT.

Morbidity and Mortality Associated With Balloon Aortic Valvuloplasty

Background—

The introduction of transcatheter aortic valve replacement (TAVR) led to renewed interest in balloon aortic valvuloplasty (BAV). We sought to assess contemporary trends in BAV utilization and their outcomes.

Methods and Results—

The Nationwide Inpatient Sample was used to identify patients who underwent BAV between 2004 and 2013. In-hospital morbidity and mortality, and predictors of death after BAV were assessed. Outcomes of propensity-matched groups of patients undergoing elective BAV or TAVR were evaluated. BAV utilization increased from 707 cases in 2004 to 3715 cases in 2013 (national estimates). Procedural and in-hospital mortality were 1.4% and 8.5%, respectively. Vascular complications occurred in 7.0% of cases, blood transfusion in 17.5%, clinical stroke in 1.8%, and pacemaker implantation in 3.0%. The strongest predictors of in-hospital death were cardiogenic shock (odds ratio, 6.01; 95% confidence interval, 4.19–8.61; P <0.001), need for left ventricular assist device (odds ratio, 3.48; 95% confidence interval, 2.25–5.36; P <0.001), coagulopathy (odds ratio, 2.19; 95% confidence interval, 1.51–3.18; P <0.001), and low institutional volume of BAV (odds ratio, 1.58; 95% confidence interval, 1.06–2.37; P =0.03). In propensity-matched patients undergoing elective BAV or TAVR, rates of in-hospital mortality (2.9% versus 3.5%; P =0.60), clinical stroke (1.6% versus 3.1%; P =0.10), and vascular complications (8.2% versus 10.9%; P =0.14) were similar. However, BAV was associated with lower rates of pacemaker implantation (2.9% versus 8.0%; P <0.001) and blood transfusion (12.8% versus 22.9%; P <0.001).

Conclusions—

In a contemporary national registry, BAV is associated with significant morbidity and mortality that are similar to TAVR. With the substantial increase in BAV utilization and the continuous improvement in TAVR outcomes, these data have important implications to aid clinicians in the selection of appropriate BAV candidates.

Percutaneous revascularization in patients treated with thoracic radiation for cancer

OBJECTIVES

To assess coronary revascularization outcomes in patients with previous thoracic radiation therapy (XRT).

BACKGROUND

Previous chest radiation has been reported to adversely affect long term survival in patients with coronary disease treated with percutaneous coronary interventions (PCI).

METHODS

Retrospective, single center cohort study of patients previously treated with thoracic radiation and PCI. Patients were propensity matched against control patients without radiation undergoing revascularization during the same time period.

RESULTS

We identified 116 patients with radiation followed by PCI (XRT-PCI group) and 408 controls. Acute procedural complications were similar between groups. There were no differences in all-cause and cardiac mortality between groups (all-cause mortality HR 1.31, P=.078; cardiac mortality 0.78, P=.49).

CONCLUSION

Patients with prior thoracic radiation and coronary disease treated with PCI have similar procedural complications and long term mortality when compared to control subjects.

Magnetizable stent-grafts enable endothelial cell capture

Emerging nanotechnologies have enabled the use of magnetic forces to guide the movement of magnetically-labeled cells, drugs, and other therapeutic agents. Endothelial cells labeled with superparamagnetic iron oxide nanoparticles (SPION) have previously been captured on the surface of magnetizable 2205 duplex stainless steel stents in a porcine coronary implantation model. Recently, we have coated these stents with electrospun polyurethane nanofibers to fabricate prototype stent-grafts. Facilitated endothelialization may help improve the healing of arteries treated with stent-grafts, reduce the risk of thrombosis and restenosis, and enable small-caliber applications. When placed in a SPION-labeled endothelial cell suspension in the presence of an external magnetic field, magnetized stent-grafts successfully captured cells to the surface regions adjacent to the stent struts. Implantation within the coronary circulation of pigs (n=13) followed immediately by SPION-labeled autologous endothelial cell delivery resulted in widely patent devices with a thin, uniform neointima and no signs of thrombosis or inflammation at 7 days. Furthermore, the magnetized stent-grafts successfully captured and retained SPION-labeled endothelial cells to select regions adjacent to stent struts and between stent struts, whereas the non-magnetized control stent-grafts did not. Early results with these prototype devices are encouraging and further refinements will be necessary in order to achieve more uniform cell capture and complete endothelialization. Once optimized, this approach may lead to more rapid and complete healing of vascular stent-grafts with a concomitant improvement in long-term device performance.

Cancer History Portends Worse Acute and Long-term Noncardiac (but Not Cardiac) Mortality After Primary Percutaneous Coronary Intervention for Acute ST-Segment Elevation Myocardial Infarction

OBJECTIVE

To define the effect of a history of cancer on in-hospital and long-term mortality after primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI).

PATIENTS AND METHODS

In this retrospective cohort study of 2346 patients with STEMI enrolled in the Mayo Clinic PCI registry from November 1, 2000, through October 31, 2010, we identified 261 patients (11.1%) with a history of cancer. The in-hospital and long-term outcomes (median follow-up, 6.2 years; interquartile range=4.3-8.5 years), including cardiac and noncardiac death and heart failure hospitalization, of these patients were compared with those of 1313 cancer-negative patients matched on age, sex, family history of coronary artery disease, and date of STEMI.

RESULTS

Patients with cancer had higher in-hospital noncardiac (1.9% vs 0.4%; P=.03) but similar cardiac (5.8% vs 4.6%; P=.37) mortality as matched controls. The group at highest acute mortality risk were those diagnosed as having cancer within 6 months before STEMI (hazard ratio [HR]=7.0; 95% CI, 1.4-34.4; P=.02). At 5 years, patients with cancer had similar cardiac mortality (4.2% vs 5.8%; HR=1.27; 95% CI, 0.77-2.10; P=.35) despite more heart failure hospitalizations (15% vs 10%; HR=1.72; 95% CI, 1.18-2.50; P=.01) but faced higher noncardiac mortality (30.0% vs 11.0%; HR=3.01; 95% CI, 2.33-3.88; P<.001) than controls, attributable solely to cancer-related deaths.

CONCLUSION

One in 10 patients in this contemporary registry of patients undergoing primary PCI for STEMI has a history of cancer. These patients have more than a 3 times higher acute in-hospital and long-term noncardiac mortality risk but no increased acute or long-term cardiac mortality risk with guideline-recommended cardiac care.

Low Body Mass Index, Serum Creatinine, and Cause of Death in Patients Undergoing Percutaneous Coronary Intervention

BACKGROUND

Low body mass index (BMI) and serum creatinine are surrogate markers of frailty and sarcopenia. Their relationship with cause-specific mortality in elderly patients undergoing percutaneous coronary intervention is not well studied.

METHODS AND RESULTS

We determined long-term cardiovascular and noncardiovascular mortality in 9394 consecutive patients aged ≥65 years who underwent percutaneous coronary intervention from 2000 to 2011. BMI and serum creatinine were divided into 4 categories. During a median follow-up of 4.2 years (interquartile range 1.8-7.3 years), 3243 patients (33.4%) died. In the multivariable model, compared with patients with normal BMI, patients with low BMI had significantly increased all-cause mortality (hazard ratio [HR] 1.4, 95% CI 1.1-1.7), which was related to both cardiovascular causes (HR 1.4, 95% CI 1.0-1.8) and noncardiovascular causes (HR 1.4, 95% CI 1.06-1.9). Compared with normal BMI, significant reduction was noted in patients who were overweight and obese in terms of cardiovascular mortality (overweight: HR 0.77, 95% CI 0.67-0.88; obese: HR 0.80, 95% CI 0.70-0.93) and noncardiovascular mortality (overweight: HR 0.85, 95% CI 0.74-0.97; obese: HR 0.82, 95% CI 0.72-0.95). In a multivariable model, in patients with normal BMI, low creatinine (≤0.70 mg/dL) was significantly associated with increased all-cause mortality (HR 1.8, 95% CI 1.3-2.5) and cardiovascular mortality (HR 2.3, 95% CI 1.4-3.8) compared with patients with normal creatinine (0.71-1.0 mg/dL); however, this was not observed in other BMI categories.

CONCLUSIONS

We identified a new subgroup of patients with low serum creatinine and normal BMI that was associated with increased all-cause mortality and cardiovascular mortality in elderly patients undergoing percutaneous coronary intervention. Low BMI was associated with increased cardiovascular and noncardiovascular mortality. Nutritional support, resistance training, and weight-gain strategies may have potential roles for these patients undergoing percutaneous coronary intervention.

Fabrication of Small Caliber Stent-grafts Using Electrospinning and Balloon Expandable Bare Metal Stents

Stent-grafts are widely used for the treatment of various conditions such as aortic lesions, aneurysms, emboli due to coronary intervention procedures and perforations in vasculature. Such stent-grafts are manufactured by covering a stent with a polymer membrane. An ideal stent-graft should have a biocompatible stent covered by a porous, thromboresistant, and biocompatible polymer membrane which mimics the extracellular matrix thereby promoting injury site healing. The goal of this protocol is to manufacture a small caliber stent-graft by encapsulating a balloon expandable stent within two layers of electrospun polyurethane nanofibers. Electrospinning of polyurethane has been shown to assist in healing by mimicking native extracellular matrix, thereby promoting endothelialization. Electrospinning polyurethane nanofibers on a slowly rotating mandrel enabled us to precisely control the thickness of the nanofibrous membrane, which is essential to achieve a small caliber balloon expandable stent-graft. Mechanical validation by crimping and expansion of the stent-graft has shown that the nanofibrous polyurethane membrane is sufficiently flexible to crimp and expand while staying patent without showing any signs of tearing or delamination. Furthermore, stent-grafts fabricated using the methods described here are capable of being implanted using a coronary intervention procedure using standard size guide catheters.

Economic and clinical impact of routine weekend catheterization services

OBJECTIVES

To assess the impact of weekend cardiac catheterization (cath) services for nonemergent inpatients.

STUDY DESIGN

Retrospective cohort study of patients undergoing cath before and after Saturday cath service availability (CSA).

METHODS

Cohorts included Friday and Saturday admissions with cath (with or without revascularization) on the subsequent Monday from January 1, 2007, to December 31, 2008 (pre-CSA events), and Friday or Saturday admissions undergoing cath the subsequent or same Saturday from January 1, 2009, to December 31, 2010 (post-CSA events). Administrative and registry data provided demographics, comorbidities, percutaneous coronary intervention (PCI) details, adverse events, hospital length of stay (LOS), and inpatient expenditures. We used generalized linear modeling to predict LOS and costs, and logistic regression to estimate the likelihood of adverse events during follow-up.

RESULTS

We identified 331 pre-CSA cases (327 patients) and 244 post-CSA cases (243 patients). Cohorts were similar in age (66 years), sex (59% male), and level of comorbidity. PCI use was higher following CSA (42% vs 26%; P <.001), with procedural success accomplished in 95% and 94% of pre- and post-CSA patients, respectively. Adjusted clinical outcomes were similar (odds ratio [OR] for in-hospital mortality, 0.67 post-CSA vs pre-CSA; P = .55; OR for 30-day revascularization, 1.14; P = .68). Models predict an average LOS reduction of 1.7 days following CSA (5.7 vs 4.0 days; P <.001) yet inpatient costs were similar ($24,817 vs $24,753; 95% CI of difference, -$3611 to $3576).

CONCLUSIONS

Weekend CSA for routine inpatients was clinically safe and effective, and reduced hospital LOS. Similar inpatient costs likely reflect a shift in case mix in this nonrandomized study.