Citations

e15543 Background: In the last two decades, colorectal cancer (CRC) mortality has been decreasing in the United States (US). However, the mortality trends for the different subtypes of CRC, including different sides of colon, rectosigmoid, and rectal cancer remain unclear. Methods: We analyzed death certificate data from CDC WONDER from 1999 to 2020. We calculated age-adjusted mortality rates (AAMR) per 100,000 individuals of CRC and its different subtypes and examined the trends over time by estimating the average annual percent change (AAPC) using the Joinpoint Regression Program. Results: From 1999 to 2020, 1,166,099 deaths were attributed to CRC, of which 957,182 deaths (82.08%) were due to colon cancer, 148,862 deaths (12.77%) from rectal cancer, and 60,055 deaths (5.15%) from rectosigmoid cancer. The overall CRC rates decreased significantly from 26.42 (95% CI, 26.20-26.64) to 15.98 (95% CI, 15.84-16.12) per 100,000 individuals, with AAPC of -2.41 (95% CI, -2.55, -2.27). However, the AAMR of rectosigmoid cancer increased significantly from 0.82 (95% CI, 0.78 -0.86) to 1.08 (95% CI, 1.04-1.11) per 100,000 individuals and the AAMR of right-sided colon cancer increased from 0.57 (95% CI, 0.54-0.60) to 0.70 (95% CI, 0.67-0.73) per 100,000 individuals, with AAPC of +1.10 (95%, 0.21-2.00) and +2.06 (95% CI, 0.85 - 3.27) respectively. Men had higher AAMR of CRC than women (23.90 [95% CI, 23.84-23.96] vs. 17.03 [95% CI, 16.99-17.08] per 100,000 individuals). African Americans had the highest AAMR of CRC (26.93 [95% CI, 26.79-27.07]), followed by Whites (19.60 [95%, 19.56-19.64] per 100,000 individuals), American Indians (14.53 [95%, 14.15-14.92] per 100,000 individuals), and Asians (13.04 [95%, 12.89-13.19] per 100,000 individuals). The overall AAMR of CRC decreased for those aged ≥ 50 years but increased significantly from 1.02 to 1.58 per 100,000 individuals for those aged 15-49 years, with an AAPC of +0.75. The AAMR from CRC was the highest in the Midwest (21.04 [95% CI, 20.96-21.12] per 100,000 individuals), followed by the South (20.51 [95% CI, 20.44-20.57]), the Northeast (20.30 [95% CI, 20.22-20.38] per 100,000 individuals), and the West (18.03 [95% CI, 17.95-18.10] per 100,000 individuals). Rural populations had higher AAMR than urban populations (22.40 [95% CI, 22.30-22.49] vs. 19.60 [95%, 19.56-19.64] per 100,000 individuals). Conclusions: Although overall CRC mortality declined, there were rising trends in young-onset CRC, rectosigmoid cancer, and right-sided colon cancer. Disparities persist in terms of sex, race, geographic region, and urbanization level, emphasizing the need for targeted public health measures.

e15138 Background: Neuroendocrine carcinomas (NECs) are poorly characterized due to their innate heterogeneity, thus limiting treatment and clinical trial options for patients. Here, we used whole exome sequencing (WES) and RNA sequencing (RNA-seq) to explore the genetic and microenvironmental landscape of NECs in order to understand the unique features of different NEC types, with the aim of improving treatment modalities. Methods: We analyzed 51 NEC clinical samples morphologically verified by a pathologist: lung NEC (20 small cell NEC and 1 large cell NEC cases), gastroenteropancreatic NEC (GEP, 12 cases), cancer of unknown primary (7 cases), Merkel cell carcinoma (MCC, 5 cases), genitourinary tract NEC (3 cases), and breast NEC (3 cases). Findings on tumor mutational burden (TMB, mut/Mb), microsatellite instability (MSI), gene expression signatures, and tumor microenvironment (TME) profiling were reported. Small cell lung cancer (SCLC) subtyping was performed as reported by Gay et al. on the entire NEC cohort. Results: Half of the patients with lung NEC and 84% of those with extrapulmonary NEC satisfied the molecular inclusion criteria for clinical trials, with the most frequent criterion being KRAS G12X or G13X mutations. Among the extrapulmonary NEC samples, 13.7% were deemed eligible for targeted therapy, specifically for cases with BRAF V600E mutation and/or high TMB (> 10 mut/Mb). We detected varying TMB and distinct gene expression features across the entire cohort. Specifically, we found 2 MCC cases to be Merkel cell polyomavirus-positive with low TMB and devoid of UV-associated mutations. One GEP-NEC case exhibited a high MSI (MSI-high) status. We detected 6 SCLC cases (3 non-smokers, 3 former smokers) with surprisingly low levels of tobacco-associated mutations (<10% of all mutations). Two GEP-NEC cases had high levels of mutations associated with tobacco smoking. While TME profiling showed no significant difference in cell population makeup across all samples, transcriptional SCLC subtyping revealed significant differences among the cases. Inflammatory SCLC (SCLC-I) samples showed statistically significant enrichment of all subpopulations of the immune microenvironment (i.e., B cells, T cells, NK cells), supporting the use of immune checkpoint blockade for treatment. The POU2F3+ SCLC (SCLC-P) samples showed low expression of all neuroendocrine diagnostic markers (i.e., INSM1, NCAM1, SYP, CHGA). Conclusions: Given the heterogeneous molecular features across diverse NEC tumors, a uniform treatment strategy is unlikely to benefit all NEC patients. Hence, our ability to detect these unique molecular features is crucial for matching individual NEC patients with specific clinical trials and targeted therapies that may improve their outcomes. Thus, a concerted effort using in-depth genomic, transcriptomic, and TME profiling for NEC tumors is warranted.

Abstract Background: Stroke remains a major health concern globally, with oral anticoagulants widely prescribed for stroke prevention. The efficacy and safety of mechanical thrombectomy (MT) in anticoagulated patients with distal medium vessel occlusions (DMVO) are not well understood. Methods: This retrospective analysis involved 1282 acute ischemic stroke (AIS) patients who underwent MT in 37 centers across North America, Asia, and Europe from September 2017 to July 2023. Data on demographics, clinical presentation, treatment specifics, and outcomes were collected. The primary outcomes were functional outcomes at 90 days post-MT, measured by modified Rankin Scale (mRS) scores. Secondary outcomes included reperfusion rates, mortality, and hemorrhagic complications. Results: Of the patients, 223 (34%) were on anticoagulation therapy. Anticoagulated patients were older (median age 78 vs 74 years; p &lt; 0.001) and had a higher prevalence of atrial fibrillation (77% vs 26%; p &lt; 0.001). Their baseline National Institutes of Health Stroke Scale (NIHSS) scores were also higher (median 12 vs 9; p = 0.002). Before propensity score matching (PSM), anticoagulated patients had similar rates of favorable 90-day outcomes (mRS 0–1: 30% vs 37%, p = 0.1; mRS 0–2: 47% vs 50%, p = 0.41) but higher mortality (26% vs 17%, p = 0.008). After PSM, there were no significant differences in outcomes between the two groups. Conclusion: Anticoagulated patients undergoing MT for AIS due to DMVO did not show significant differences in 90-day mRS outcomes, reperfusion, or hemorrhage compared to non-anticoagulated patients after adjustment for covariates.

Introduction: Carcinoid heart disease (CHD) is a rare sequelae of hormonally active neuroendocrine tumors that often requires cardiac surgical intervention. Little is reported on cardiac implantable electronic device (CIED) implantation in the CHD patient population. Hypothesis: We sought to establish the safety and efficacy of CIED implantation in patients with CHD. Methods: We retrospectively reviewed patients with a diagnosis of CHD who underwent CIED implantation at our institution (Mayo Clinic) and evaluated indications for implant, perioperative complications, and mortality. Results: A total of 27 patients with a cumulative follow up of 75 patient-years were identified during the study period. The most common indication for device implant was high grade atrioventricular block (n=18, 66.7%). 14 (51.8%) had baseline conduction disease and 26 (96.2%) underwent cardiac surgery prior to CIED implant. The majority of devices implanted were dual chamber permanent pacemakers (PPM) (n=17, 63.0%), while other devices included single chamber PPM, epicardial PPM, chronic resynchronization devices, and intracardiac defibrillators. Peri-operative complication occurred in 6 patients (22.2%), with 2 patients requiring ICU level care. No patient suffered carcinoid crisis during implantation and there was no peri-implant mortality. Long term, 3 patients required device extraction: 1 for infection, 1 for lead related pain, and 1 for generator migration. The median time to death from implant was 2.5 years, with one-year mortality at 15%. Conclusions: In this unique cohort of patients with CHD, CIED can be performed safely. CIED most often occurred in the post cardiac surgical period and carcinoid crisis was uncommon.

Introduction: Surgically implanted epicardial left ventricular (eLV) lead has been used as an alternative approach when implantation of transvenous LV (tLV) lead in patients requiring cardiac resynchronization therapy (CRT) has failed. Recent literatures noted similarities in clinical response between tLV and eLV-CRT patients. However, comparison between CRT patients with ischemic (ICM) and dilated cardiomyopathy (DCM) is currently lacking in eLV-CRT patients. Hypothesis: We hypothesize that DCM patients respond better to eLV-CRT than ICM patients. Methods: Of 1038 patients who underwent tLV-CRT implantation at UCSD and Mayo Clinics between 2002 and 2013, 44 (Age 63±15, 28M) had failed tLV lead placement and received eLV-CRT. Electronic Medical Records of these patients were reviewed. NYHA class and echocardiograph were assessed before and after successful CRT implantation. Results: Following eLV-CRT implantation, improvements were noted in LVEF (26% vs. 31%, p < 0.01), NYHA class (2.9 vs. 2.3, p < 0.01) and LVESD (57mm vs. 52mm, p = 0.03) in the study cohort. In patients with DCM (n=19), the NYHA class (3.0 vs. 2.3, p = 0.01), LVEF (24% vs. 30%, p = 0.02) and LVESD (57mm vs. 52mm, p = 0.04) had significantly improved following CRT implantation compared to baseline (figures). No statistically significant changes in NYHA class, LVEF and LVESD were observed in patients with ICM (all p > 0.05). Conclusion: In this two-center study, eLV-CRT patients with DCM benefited significantly after CRT, as compared to ICM patients. Although larger scaled studies are needed, eLV-CRT may be considered a viable alternative to tLV-CRT, especially in patients with DCM.

Introduction: Surgically implanted epicardial left ventricular (eLV) lead is an alternative approach when transvenous LV (tLV) lead implantation in CRT patients has failed. With advancement in surgical technique and free from limitations of cardiac venous anatomy, operators have the freedom to choose the most optimal LV pacing site. Recent literatures noted differential clinical response in tLV-CRT patients with different LV lead locations. However, to the best of the authors’ knowledge, no such analysis has been published for eLV-CRT patients. Hypothesis: We hypothesize that optimal LV lead location in eLV-CRT is similar to tLV-CRT and similar clinical response is expected. Methods: After unsuccessful attempt(s) of tLV-CRT implantation, 44 (Age 63±15, 28M) patients received eLV-CRT from UCSD and Mayo Clinics between 2002 and 2013. Two-view (PA, lateral) chest radiographs were used to determine lead location by blinded independent observers. 9 patients were partially excluded from lead location analysis due to congenital cardiac anomaly or unavailable lateral chest radiograph. eLV lead locations were classified as basal, mid, or apical on the PA view; and anterior, anterolateral, lateral, posterolateral, or posterior on the lateral view. Survival data were collected from the national death and location database. Results: During an average follow up of 65 months, 15 patients have died following eLV-CRT implant. No death was attributed to acute surgical complication to eLV-CRT implantation. Kaplan-Meyer survival estimate showed anterior and apical eLV lead positions had lower survival rate as compared to non-anterior (p<0.01, figure A) and non-apical location (p=0.07, figure B). Conclusion: In this two-center study, apical and anterior eLV lead locations were associated with significantly lower survival rate. The study implies apical and/or anterior locations should be avoided, if possible, during eLV-CRT implantation.

Introduction: The treatment options for high and extreme-risk patients with severe symptomatic aortic stenosis have changed significantly over the past decade because of advances in transcatheter aortic valve replacement (TAVR). However new permanent pacemaker implant (PPI) remains an impending concern after TAVR. Hypothesis: We sought to determine the frequency, predictors and outcomes of patients requiring PPI after TAVR. Methods: We queried the National Inpatient Sample (NIS) database using the ICD-9-CM procedure code of 35.05 for transfemoral/transaortic and 35.06 for transapical replacement of aortic valve .We identified TAVR procedures associated with new permanent pacemaker implants using appropriate validated ICD-9-CM codes. Using multivariate analysis we further identified predictors of PPM implants Results: An estimated 8828 TAVR procedures were performed in United States between 2011-2012. 773 (8.7%) TAVR procedures were associated with PPIs. PPI were higher in older (age>80 years), White race, diabetics, left bundle branch block (LBBB), right bundle branch block (RBBB), transfemoral approach. The inhospital mortality ( 5.2% vs.4.6% ) , mean length of stay ( 9.8 vs. 8.3 days ) disposition to short term nursing facility was higher (38.2% vs. 32.1%) and mean total costs (82217$ vs. 52283$) was higher in TAVR + PPI group . On multivariate analysis, Age in 5 year increment [Odds ratio (OR) 1.11; Confidence interval (CI) 1.05-1.17, p<0.001], diabetes [OR 1.26; CI 1.07-1.49, p<0.001], LBBB [OR 1.99; CI 1.55-2.56, p<0.001], RBBB [OR 5.36; CI 3.80-7.55, p<0.001] were independent predictors of PPI. Transfemoral approach was associated with more PPI implants [OR 1.41; CI 1.12 -1.78, p<0.001] Conclusion: Age, baseline conduction system disturbances, diabetes, transfemoral approach emerged as independent predictors of PPI after TAVR. This study provides useful tools to identify high-risk patients for PPI after TAVR.

Background Little is known about the effects of permanent transvenous device leads on bioprosthetic tricuspid valve (BTV) function. Hypothesis The goal of this study was to test the hypothesis that transvalvular device leads promote clinically significant BTV regurgitation. Methods A retrospective review of 58 patients who underwent BTV implantation and subsequently required endocardial pacemaker (n=52) or defibrillator (n=6) lead implantation through the BTV was conducted. Patient and prosthesis characteristics, lead type, and clinical events were collected. The incidence and severity of prosthetic tricuspid regurgitation (TR), determined by Doppler echocardiography, was compared to 265 patients who underwent BTV implantation without undergoing subsequent transvalvular device lead implantation. Results Over a mean follow up of 25 months, 5 patients (9%) with a transvalvular lead developed ≥ moderate prosthetic TR compared to 12 patients (5%) in the control group (P = 0.20). Kaplan Meier survival analysis revealed no significant difference in the incidence of TR in BTV patients with and without transvalvular leads (p = 0.45). Clinically significant prosthetic TR in patients with and without a transvalvular lead more commonly occurred 2 years or later after lead implantation or BTV implantation (4/5, 80% and 10/12, 83%). Conclusions Compared to BTV controls, there was no significant difference in the incidence of ≥ moderate prosthetic TR in patients with a transvalvular pacemaker or defibrillator lead (p = 0.45). Transvalvular lead implantation appears to be an acceptable approach for patients with a BTV who require permanent pacemaker or defibrillator placement.