Citations

Introduction: The COVID-19 pandemic has had major impacts on all healthcare services, including cardiac imaging. In this study, we investigate annual changes in cardiac imaging procedural volume and reimbursement among Medicare Beneficiaries (MB) from 2018 to 2020. Methods: We used the Center of Medicare and Medicaid Services database to identify a 100% sample of MB who underwent cardiac imaging procedures from 2018 to 2020. Using the Current Procedural Terminology (CPT) codes, we identified transthoracic echocardiogram (TTE), transesophageal echocardiogram (TEE), stress echocardiogram, and nuclear stress test procedures. We examined each procedure’s total, inpatient (facility), and outpatient (non-facility) annual volumes per 1,000 MB. We also examined the total annual Medicare reimbursement per imaging type during that period. We compared annual changes in volumes and total reimbursement between two-time intervals: 2018-2019 and 2019-2020. Results: All annual cardiac imaging procedural volumes decreased significantly in 2020 compared to 2019 ( P<0.001 ). The biggest change was observed in TEE, which decreased by 29.20%, followed by stress echocardiography (26.01%), nuclear stress test (22.96%), and TTE (10.68%). The decrease was more evident in the inpatient setting. Inpatient stress echocardiography decreased by 27.04% (vs 23.82% in the outpatient setting), nuclear stress test decreased by 24.82% (vs 20.66%), and TTE decreased by 11.03% (vs 9.58%). There was also a significant reduction in total annual reimbursement for all procedures in 2020 compared to 2019 ( P=0.0015 ). Stress echocardiogram, nuclear stress test, TEE, and TTE reimbursement decreased by 28.08%, 24.00%, 21.11%, and 15.79%, respectively. Conclusions: The COVID-19 pandemic was associated with a significant and abrupt reduction in annual cardiac imaging procedural volumes and total reimbursement among MB in both inpatient and outpatient settings.

Introduction: High-sensitivity cardiac troponin (hs-cTn) assays were first approved for use in the U.S. in 2017. They are the guideline preferred biomarker to evaluate patients with acute chest pain. Few data exist regarding implementation of hs-cTn assays in the U.S. Hypothesis: We hypothesize that use of hs-cTn assays has increased over time and that patients assessed with hs-cTn have a shorter length of stay (LOS) and similar use of cardiac testing. Methods: We examined trends in implementation of hs-cTn assays among participating hospitals in the NCDR Chest Pain MI Registry from 1/1/2019 through 9/30/2021. Excluding STEMI patients, associations between hs-cTn use, in-hospital diagnostic imaging, and patient outcomes were assessed using logistic or negative binomial regression models. Results: Among 550 participating hospitals with 251,000 patients in the registry, implementation of hs-cTn assays increased from 3.3% in Q1, 2019 to 32.6% in Q3, 2021 (P trend <0.0001; Figure ). Implementation was similar by hospital size, type, and geographic location. hs-cTn use was associated with more echocardiography among patients with NSTE-ACS (82% vs. 75%; aOR: 1.43, 95% CI, 1.19-1.73) but not in low-risk chest pain. hs-cTn use was associated with decreased odds of invasive coronary angiography in low-risk patients (3.7% vs. 4.5%; aOR: 0.73, 95% CI, 0.58-0.92) but similar use in NSTE-ACS. There was no association between hs-cTn use and non-invasive stress/CTCA testing. Among NSTE-ACS patients, hs-cTn use was not associated with PCI, CABG, or in-hospital mortality. Use of hs-cTn was associated with shorter LOS (47.6 hours vs. 48 hours; IRR: 0.96, 95% CI, 0.93-0.98). Conclusions: Although implementation of hs-cTn among U.S. hospitals is increasing, most U.S hospitals continue to use less-sensitive troponin assays. hs-cTn use was associated with shorter LOS overall, greater use of echocardiography in NSTE-ACS, and lower use of invasive angiograms in low-risk patients.

Introduction: Leadless pacing(LP) technology has been expanding in recent practice as an alternative to traditional pacing This technology is associated with reduce complications such as infection, dislodgment, and hardware burden. There has been recent reports on effusions with its implantation .Historically the manufacturer has recommend bolus of heparin or infusions We present the results and operative outcomes of patients who received a LP without initial heparinization or infusion from 2016 to 2021 at a single center. Objective We sought to describe the outcomes of LP implantation without the need of heparin administration. Methods: We report the clinical outcomes and operative findings of 200 patients who underwent LP implantation without initial heparin loading or infusions . An aggressive flushing strategy of the sheaths before and during the procedures was performed Data recorded include indication, ejection fraction (EF) R waves, capture thresholds, ventricular ectopy on deployment,recaptures, procedure times, and complications. Patients on chronic anticoagulation were excluded Results: A total of 200 patients were included , average age was 77 years and 20 (10%) had a reduced EF (<40%) pre-procedure. The most common indications included complete AV block (97, 48.5%) and atrial fibrillation with slow ventricular response (76, 38%). All patients (100%) had successful establishment of ventricular pacing with no short-term complications postoperatively. Average R waves after deployment were 9.7 with average capture thresholds of 0.84 @ 0.24 Ventricular ectopy was seen for 134 (67%) of patients upon deployment with 62 (31%) patients requiring recaptures, and 29 (14.5%) requiring more than one recapture. There was no evidence of thrombus in the sheaths or implanting instruments . There were no embolic or thrombotic complications. Conclusions: LP implantation is highly effective and efficacious in establishing single-chamber ventricular pacing for a variety of conduction pathologies with minimal complications postoperatively. It appears that an aggressive flushing strategy of the implanting equipment & sheaths is safe & effective without the need of heparinization. Further studies will be require to validate this strategy

Introduction: Renin-Angiotensin System (RAS) regulates the cardiovascular system and has been implicated in the development of abdominal aortic aneurysm (AAA). RAS modulates function via balancing the ACE/Chymase/AngII-AT1 receptor and ACE-2/Ang(1-7)-Mas receptor axis. Preferential activation of the ACE/Chymase/AngII-AT1 receptor pathway of the RAS contributes to dysregulation of cardiovascular system and disease while the Ang(1-7)-MasR axis contributes to anti-inflammatory pathways. Therefore, identifying the RAS axis mechanism involved in growth, progression, or the risk of rupture in AAA humans could bring a novel treatment perspective. Hypothesis: We hypothesize that in the AAA, the local RAS is altered such as it favours the ACE/AngII/AT1R axis while decreasing the ACE-2/Ang(1-7)/MasR pathway, with consequent AAA development. Objective: We sought to investigate the expression of RAS components in the AAA human aorta. Methods: Aorta tissue from AAA patients (n=21) was collected during the AAA conventional repair surgery, and aorta control aortas were obtained from organ donors (Control, n=11). Protein expression of renin, chymase, ACE, ACE-2 AT1, AT2, and MAS receptors was analyzed by Western Blotting. Results: Our AAA cohort consisted mostly males (76.6% AAA vs. 63.6% Control, p=0.68), smokers or ex-smokers (90.4% AAA vs. 36.3% Control, p=0.002) and most of them had hypertension(71.4% AAA vs. 36.3% Control, p=0.07). Analysis of protein expression in the AAA group showed that ACE and AT1 receptors were upregulated compared with Control (p=0.05; p=0.02, respectively,), while chymase expression was decreased in AAA compared to the control (p=0.03). Additionally, the AAA group showed downregulation in ACE-2 and AT2 compared with Control (respectively, p=0.01, p=0.03). There was no significant difference in the expression of renin and MAS receptors between groups (p=0.52, p=0.41, respectively,). Conclusions: Our data show that the ACE/AT1R axis was upregulated while ACE-2 and AT2 receptors were downregulated in the AAA aorta. Our results implicate local RAS in AAA development and warrant further studies.

Background: Drug-induced QT prolongation (DI-QTP) is a clinical entity in which administration of a HERG/I Kr blocker such as dofetilide prolongs the cardiac action potential duration (APD) at the cellular level and the QT interval clinically, and increases the risk for a potentially lethal, QT-triggered ventricular arrhythmia. There may be a role for inhibition of I NaL to counter DI-QTP. Recently, we have shown that inhibition of serum and glucocorticoid regulated kinase-1 (SGK1) reduces the APD90 in induced pluripotent stem cell derived cardiomyocytes (iPSC-CM) from patients with LQT3 and ameliorates increases in I NaL . Objective: To test the efficacy of novel SGK1 inhibitors (SGK-I) in re-engineered cardiomyocyte models of dofetilide-induced APD prolongation. Methods: Normal iPSC-CMs were treated with dofetilide [5 nM] to produce a DI-QTP iPSC-CM model. The SGK1-I’s therapeutic efficacy for shortening the dofetilide-induced APD90 prolongation was compared to mexiletine. The APD90 values were recorded 4 hours after treatment using FluoVolt, a voltage-sensitive fluorescent dye. Results: The APD90 was significantly prolonged in normal iPSC-CMs treated with dofetilide (673 ± 8 ms with dofetilide vs 436 ± 4 ms with DMSO, p<0.0001). While 10 μM mexiletine shortened the average APD90 of dofetilide-treated normal iPSC-CMs from 673 ± 4 ms to 563 ± 8 ms (46% attenuation, p<0.0001), 30 nM of SGK-I shortened the APD90 from 673 ± 4 ms to 478 ± 10 ms (82% attenuation, p<0.0001). Conclusions: Therapeutically inhibiting SGK1 effectively shortens the cardiomyocyte APD in a human heart cell model of DI-QTP. The novel SGK1 inhibitor normalized the pathological APD prolongation almost fully (> 80%) in the iPSC-CM model treated with dofetilide. This pre-clinical data supports further development of this therapeutic strategy to counter and neutralize the threat of DI-QTP.

Introduction: Coronary disease is the most common cause of heart failure (HF). HF is classified as ischemic (IHF) or non-ischemic (NIHF) based on this etiology. IHF and NIHF have distinct mechanisms not accounted for by ejection fraction (EF) and an improved understanding of the differences could drive the discovery of novel therapeutic targets. We therefore sought to identify proteomic signatures between IHF and NIHF. Methods: Proteomic profiling using the SomaScan®1.7K was performed using plasma samples from HF patients in a community cohort (Rochester Epidemiology Project, 2003-2012). IHF was defined by prior myocardial infarction, percutaneous coronary intervention or coronary artery bypass graft, or obstructive disease in at least 1 vessel on coronary angiography. We compared the protein expression levels between IHF and NIHF using t-test and applied the Benjamini-Hochberg false-discovery rate (FDR) procedure for multiple comparisons. We explored pathway analysis for functional annotations using the biological process component of the Gene Ontology Resource (Panther 17v). Results: Among 1,388 patients, there were 518 IHF patients (age: 75±12years, 39.4% female, NYHA Class III/IV: 72.5%, EF:45±15%), and 870 NIHF patients (age: 75±14years, 53.6% female, NYHA Class III/IV: 66.9%, EF:49±17%). Among 7335 plasma proteins quantified, 63 unique proteins (FDR < 0.05) were differentially expressed between IHF and NIHF. Thirty-seven proteins including Troponin-I and T, and Myoglobin showed increased expression in IHF compared to NIHF and 26 including IGFBP-3 showed decreased expression. Pathophysiologic pathways including angiogenesis, coagulation, and lipid metabolism were represented in IHF, while inflammation and remodeling signaling pathways were dominant in relation to NIHF. Conclusions: High-throughput proteomic techniques are able to delineate IHF versus NIHF patients based on distinct biomarkers and pathophysiologic processes.

Background: Long QT syndrome (LQTS) often stems from pathogenic variants in KCNQ1 (LQT1), KCNH2 (LQT2), or SCN5A (LQT3) and is characterized cellularly by prolongation of the cardiac action potential duration (APD). We have shown that inhibition of serum and glucocorticoid regulated kinase-1 (SGK1) reduces I NaL and is proposed as a novel therapeutic strategy for LQT3. Objective: To test the efficacy of a potent and selective SGK1 inhibitor (SGK1-I) in human cardiomyocyte models of LQT1, LQT2, and LQT3. Methods: Induced pluripotent stem cell derived cardiomyocytes (iPSC-CMs) were generated from patients with either LQT1, LQT2, or LQT3. The mexiletine (MEX)-sensitive SCN5A-P1332L iPSC-CMs were tested initially. A CRISPR/Cas9 P1332L variant-corrected isogenic control (IC) was used as a control. The SGK1-I’s therapeutic efficacy was compared to MEX and to a commercially available SGK1 inhibitor (EMD638683). The novel SGK-I was then tested for APD shortening in SCN5A-R1623Q, KCNH2-G604S and KCNQ1-V254M iPSC-CMs. The APD90 values were recorded 4 hours after treatment using FluoVolt. Results: The APD90 was significantly prolonged in SCN5A-P1332L iPSC-CMs compared to its IC (646 ± 7 ms vs 482 ± 23 ms, p<0.0001). MEX shortened the average APD90 to 560 ± 7 ms (52% attenuation). Interestingly, SGK1-I significantly shortened the APD to 518 ± 5 ms (78% attenuation) but did not further shorten the APD in the IC. SGK1-I also shortened the APD90 of the SCN5A-R1623Q iPSC-CMs from 753 ± 8 ms to 475 ± 19 ms compared to 558 ± 19 ms with MEX. The SGK1-I shortened the APD90 in KCNH2-G604S (666 ± 10ms to 574 ± 18ms for SGK1-I versus 538 ± 15 ms after MEX). EMD had limited APD shortening effects in SCN5A and KCNH2 iPSC-CMs. Interestingly, while neither MEX nor EMD reduced the APD90 in the KCNQ1-V254M iPSC-CMs, the novel SGK1-I reduced the APD90 from 544 ± 10 ms to 475 ± 11ms (p=0.0004). Conclusions: Therapeutically inhibiting SGK1 effectively shortens the cardiomyocyte APD in human heart cell models of the 3 major LQTS genotypes. The novel SGK1-I normalized the pathological APD prolongation almost fully (> 70%) in the patient-derived SCN5A-P1332L iPSC-CM model. These pre-clinical data support further development of SGK1-I as a novel, first-in-class therapy for patients with congenital LQTS.

Introduction: patients exposed to chest, breast or mediastinal RT, may present with accelerated atherosclerosis and CAD due to diffuse micro and macrovascular fibrosis. However, CAD risk has not been well established in a community-based study. Aims: Describe CAD risk in patients treated with chemotherapy with and without RT and evaluate the cumulative incidence of CAD (coronary revascularization, MI and abnormal stress test and coronary angiogram). Methods: From 1985-2010, we identified 744 patients with a new diagnosis of breast cancer or lymphoma, using the Rochester Epidemiology Project (REP) who received chemotherapy with or without RT. CAD risk was assessed by a proportional hazards model for time to event. RT was treated as a time dependent co-variable, with index date being chemotherapy start date, significance was considered as a p<.05. Characteristics were evaluated by a multivariable Cox model to consider RT and time censoring. Results: 744 patients treated with chemotherapy were identified, of these 488 (65.6%) had breast cancer, 256 (34.4%) lymphoma, and 367 (49%) also received RT. The mean total RT dose was 5.5 ± 1.2 (Gy) for those that had CAD and 5.4 (Gy) ± 1.1 for non-CAD patients, p=0.4. The cumulative incidence of CAD events (accounting for death as a competing risk) at 5 and 10 years of follow-up was 1.9% (CI 1.14-3.2) and 3.06% (CI 2.01-4.7), respectively p<.05 figure1. Baseline differences between those receiving RT or not, were not significant for DM and HTN; however, males and ages 70-79 were less likely to receive RT, table1. In a multivariable model, there was no difference in the CAD outcomes between those with and without RT, HR= 1.21 [0.48-3.06] p=.69, after adjusting for age, gender, DM, and HTN and those <49 y/o had a lower risk of CAD. Table2 Conclusion: In this REP retrospective cohort study, the risk of developing a CAD event was similar between chemotherapy plus RT and chemotherapy only regimens, even after considering gender, age, HTN and DM.

Background: Recognition of the causes of early mortality after atrial fibrillation (AF) catheter ablation is essential for the improvement of patient safety. Objective: This study sought to determine the causes of early mortality (≤90-days) after AF ablation and to further understand the circumstances surrounding death after the procedure. Methods: We performed a retrospective analysis of AF ablation from January 1, 2013, to December 1, 2021 at the Mayo Clinic (Rochester, Phoenix, and Jacksonville). Causes of death were identified through a comprehensive chart review of the electronic health record from within the Mayo Clinic system and outside records when available. Results: A total of 6,723 patients were included in the study. The 30-day and 90-day all-cause mortality rates were 0.09% and 0.22%, respectively. Among all 90-day deaths, majority of the deaths (73.3%) did not have a direct relationship with the procedure. Sudden death was the most common cause of early death (20%), followed by peri-procedural stroke (13%), respiratory failure (13%), atrioesophageal fistula (13%), infection (7%), heart failure (7%), and traumatic brain injury (7%). The 90-day mortality rate directly due to AF ablation procedural complications was 0.06%. Most of the early deaths (93.3%) occurred after discharge from index hospitalization, among which 64.3% were readmitted before their death, 14% died at home, and 7% were discharged on comfort care and died in hospice. The main reason for readmission leading to death was respiratory failure (33%). Conclusion: Atrial fibrillation ablation procedure has a 90-day mortality of 0.22% and the most common cause of early mortality was sudden death. The majority (73.3%) of early mortality was not directly associated with a procedural complication, and the mortality rate due to complications associated with the AF ablation procedure was 0.06%.

Introduction: Peripheral artery disease (PAD) is a risk factor for adverse limb events (LE) and cardiovascular events (CVE) that often coexists with type 1 (T1) and type 2 (T2) diabetes mellitus (DM), which differ mechanistically. There is a paucity of data on comparative risk of LE and CVE in T1DM and T2DM patients with PAD. Methods: We queried our database of 40,144 patients ≥18y old who underwent ankle brachial index (ABI) measurement from 01/1996-02/2020. We isolated patients with T1DM or T2DM and with PAD diagnosed by ABI (low [<1.0] or elevated [>1.4]). We retrieved demographics including hemoglobin A1c (A1c). Primary outcomes were LE (critical limb ischemia or vascular amputation) and CVE (myocardial infarction or ischemic stroke). All-cause mortality was a secondary outcome. Multivariable Cox proportional regression yielded hazard ratios (HR) with 95% confidence intervals (CI) after adjusting for age, sex, A1c, hypertension, hyperlipidemia, coronary artery disease (CAD), chronic kidney disease (CKD), and tobacco use. Results: Our study found 9,271 patients with PAD and DM (36% T1DM, 64% T2DM) with median follow-up time 34 mo (interquartile range [IQR] 85 mo). T1DM patients were younger than T2DM (mean age 67 vs 70y), with higher median A1c (7.7 [IQR 1.9] vs 6.7% [IQR 1.6]), and higher prevalence of hypertension, hyperlipidemia, CAD, and CKD. Antiplatelet and statin use did not differ. Elevated ABI was more common in T1DM (47 vs 27%). LE occurred in 23% and CVE in 12% of patients. LE risk was higher in T1DM patients than T2DM (HR 1.59[95% CI 1.45,1.74], p<0.0001), but CVE and all-cause mortality did not differ significantly. Conclusions: PAD patients with T1DM had a higher LE risk than those with T2DM, even after adjustment for A1c and pertinent risk factors, but CVE risk and all-cause mortality were equivocal. These data suggest a potential role for more intensive LE risk modification in PAD patients with T1DM, but further investigation is needed to minimize limb morbidity.