Citations

Introduction: Abdominal aortic aneurysms (AAA) are common among individuals over age 65 with a prevalence of 9%. Most AAAs are small and require surveillance imaging to monitor size and growth rates. Tools capable of predicting growth rates would be clinically useful. Hypothesis: We investigated how computational hemodynamics derived from CT angiography (CTA) differentiated slow and rapid-growing AAAs. Methods: Using readily available computing power in the clinical workflow, 3D models were generated for 25 subjects with AAA from available 3D CTA data. AAA growth rates were categorized as slow ( less than 5 mm/year) or rapid (greater than 5 mm/year) based on serial imaging. A geometrical analysis was performed using 7 indices (Volume, Surface Area, Length, Max/Min radius, Expansion Ratio [Mean radius/vessel radius], Proximal vessel area, Voronoi diagram-based metrics) for each AAA. Computational hemodynamics were performed using commercial software (ANSYS-Fluent). Computational hemodynamics were completed for all cases (see Fig. 1). In-house software assessed wall shear stress-(WSS) and vortex-based hemodynamics. Support vector machine (SVM) was run with cross-validation (50 iterations) to assess predictive strength using these 16 parameters. Results: Among 25 AAAs studied, 7 were rapid and 18 were slow-growing. The combination of proximal vessel area, spatiotemporally averaged WSS, and spatially averaged OSI provided the best accuracy for growth differentiation. The area under receiving operating curve (AUROC) and total accuracy are 0.770 and 0.765, respectively, with 48% and 86% of rapid and slow-growing AAAs correctly identified, respectively. Conclusions: Computational hemodynamics appears feasible with reasonable growth rate prediction. With optimization, this tool may enable resource utilization refinement for imaging surveillance strategies by distinguishing rapid from slow-growing AAAs.

Introduction: We aim to elucidate the incidence of major complications related to right heart catheterization (RHC) and ascertain if there are unique risks with right ventricular biopsy. Methods: Diagnostic RHC procedures from 1/1/2002 through 12/31/2013 were identified using the clinical scheduling system at Mayo Clinic, Rochester. Major complications were identified through electronic records using International Classification of Diseases, Ninth Revision billing codes. All events were recorded and adjudicated. Analysis was performed on four separate patient categories (RHC/RV angiography alone, RV biopsy alone, multiple RHC procedures, and concurrent RHC/LHC procedures) and the overall group. Primary outcomes are described in Table 1. Outcomes were measured within 7 days of the procedure, except for death (same day events) and tricuspid regurgitation (variable time endpoints). Results: There were 17,696 RHC procedures (5,556 RHC/RV angiography, 3,846 RV biopsy alone, 776 multiple RHC procedures, and 7,518 combined RHC/LHC). Patient population had a mean age of 56.5 years (15.3) and was predominantly male (58.5%). Same-day death related to RHC procedure occurred in 1 procedure or 0.6 of 10,000 RHCs. There was no significant difference in the risk of complications across RHC procedure categories except for worsening tricuspid regurgitation, which was significantly (p<0.001) more prevalent with RV biopsy (392 cases, 6.0%) than without (136 cases, 1.2%). Conclusion: The incidence of major complications related to right heart catheterization is rare. Worsening tricuspid regurgitation is the most frequently identified change with a significantly higher prevalence with biopsies.

Introduction: The role of seasons in the outcomes and management of acute myocardial infarction (AMI) patients with cardiac arrest (CA) remains understudied. Methods: We used the National Inpatient Sample (2000-2017) to identify adults AMI admissions with concomitant CA. Admission month was used to classify them into- Spring (March-May), Summer (June-August), Fall (September-November) and Winter (December-February) admissions. We evaluated seasonal variation in the prevalence of CA among AMI admissions and associated in-hospital mortality. Use of cardiac and non-cardiac procedures, hospital length of stay, hospitalization costs and discharge disposition were also analyzed. Results: Between 2000-2017, of the 10,880,856 AMI admissions with information on admission month available, CA was identified in 546,334 (5.0%). Incidence of CA was 4.9% in spring, 5.0% in summer, 5.1% in fall, and 5.1% in winter AMI admissions. Adjusted trends identified a steady increase in STEMI-CA admissions with a relatively stable or declining trend for NSTEMI-CA admissions across all seasons. AMI-CA admissions admitted in summer were less often female, had lower comorbidity, more often presented with STEMI and had higher rates of cardiogenic shock and shockable rhythms compared to AMI-CA admissions in spring, fall and winter. Compared to AMI-CA admissions in other seasons, those admitted in winter had slightly lower rates of coronary angiography (61.4% vs. 63.3%-64.3%) and PCI (45.6% vs. 47.2-48.4%) (p<0.001). Compared to those admitted in the spring, adjusted in-hospital mortality was higher for winter (OR 1.08 [95% CI 1.06-1.10]; p<0.001), lower for summer (OR 0.96 [95% CI 0.94-0.98]; p<0.001) and comparable for fall (OR 1.00 [95% CI 0.98-1.02]; p=0.91) AMI-CA admissions. Length of hospital stay, total hospitalization charges, and discharge dispositions for AMI-CA admissions were comparable across the seasons. Conclusions: Lower use of guideline directed therapies and higher in-hospital mortality was identified in winter AMI-CA hospitalizations. The role of pathobiology and/or impact of environmental conditions across seasons in AMI-CA remains to be evaluated.

Introduction: Spontaneous coronary artery dissection (SCAD) is a nonatherosclerotic cause of acute coronary syndrome. While most patients are managed conservatively, some patients may require percutaneous or surgical revascularization. Limited data exist on SCAD patients referred for coronary artery bypass graft (CABG) surgery. Hypothesis: Examine the clinical characteristics, management, and outcomes of SCAD patients referred for CABG. Methods: Retrospective study of patients enrolled in the Mayo Clinic SCAD Registry between 2010-2020 who underwent CABG during the initial management of acute SCAD episode. Results: Among the 81 patients with SCAD referred for CABG, 3 (4%) were men, mean age was 40.6 +/- 8.4 years; the majority were white (91%), and 24 (30%) had pregnancy-associated SCAD (P-SCAD). The most common presenting symptom was chest pain 80 (99%); 57 (70%) presented with ST elevation myocardial infarction (STEMI), and 21 (26%) presented with non-ST elevation MI. Multivessel dissection occurred in 40 (49%), left anterior descending artery (LAD) involvement occurred in 66 (81%) and left main (LM) in 32 (40%). Left ventricular ejection fraction was <50% in 40 patients (49%) at time of initial SCAD. The most common reasons for CABG were the presence of high-risk anatomy (56%), hemodynamic instability/active ischemia (7%), failed PCI (9%), and other/unknown (12%). Most patients received venous plus arterial bypass grafts 42 (52%), saphenous vein grafts in 20 (25%), and left internal mammary artery in 17 (21%). Screening for underlying arteriopathy was performed in 50 (62%) of whom 29 (36%) had fibromuscular dysplasia. Recurrent SCAD occurred in 10 (12%) after an average of 6.2 +/- 5 years after initial SCAD. Of those with recurrent SCAD, none required repeat surgical revascularization and 6 required percutaneous intervention (PCI). There were no deaths. Conclusions: Patients undergoing CABG for SCAD commonly present with STEMI, LM, or multivessel dissection, and failed percutaneous intervention attempts. In addition, CABG for P-SCAD was more frequent than expected and may relate to the increased prevalence of multivessel dissection. CABG was associated with low mortality, but recurrent SCAD may still occur.

Introduction: We investigated the predictive power of a machine learning (ML) algorithm for 5-year mortality in patients with atherosclerotic cardiovascular disease (ASCVD). Candidate features included clinical variables from the electronic health record (EHR) as well as self-reported health and lifestyle data. Methods: The study cohort included 4,689 patients (66±11 years, 62% male) with ASCVD enrolled in the Vascular Disease Biorepository, which recruits patients referred to noninvasive vascular evaluation at Mayo Clinic, Rochester, MN. Clinical variables including comorbidities, lab measurements, and medication use were obtained from the EHR using validated electronic phenotyping algorithms. Information regarding social habits, physical activity levels, and personal health was obtained from a survey filled by the participants. Mortality was ascertained from the national death index. Clinical variables (n=52) and self-reported variables related to health and lifestyle habits (n=48) were added as individual features to reinforcement learning trees (RLT), a sparse decision tree algorithm, to construct the prediction model. We assessed the impact of each feature on prediction accuracy by applying feature selection and computing variable importance (VI). Results: Features with trivial VI that made no contribution to prediction were excluded. A model with 15 features had an area under the ROC curve (AUC) of 0.82 [95% CI 0.79 - 0.83] in the test set. Among the top 10 predictors of 5-year mortality, 6 were self-reported health variables (Table) , including outlook on personal health, limitations on routine daily activities, and physical activity levels. Conclusions: A ML approach had robust discrimination (AUC 0.82) in predicting 5-year mortality in patients with ASCVD. Self-reported health variables were among the top predictive features in the final model.

Introduction: Pectus excavatum (PE) is the most common anterior chest wall deformity with dorsal deviation into the thoracic cavity. Depending on the severity, PE can cause minor cosmetic problem to significant cardiac compression in severe cases. This compression most frequently affects right heart chambers causing symptoms such as dyspnea, palpitations, fatigue, exercise intolerance, and difficulty with keeping up with peers. Previously, we reported the change in these symptoms with positon associated with change in right heart hemodynamics. Further, we are comparing the changes in right heart hemodynamics with position in pectus patients to normal healthy adults. Methods: A prospective cohort of 40 pectus excavatum patients (mean Haller index: 5.4±2) undergoing evaluation at Mayo clinic underwent 2-D transthoracic echo (TTE) with Doppler assessment of Right Ventricular Outflow Tract (RVOT) Velocity Time Integral (VTI). A cohort of 8 healthy adults without chest wall abnormality who had clinically indicated echocardiogram was used as control (Table). Additional assessment of the RVOT VTI was performed in sitting position in either group. A two-sample t-test was performed to assess significance between cohorts. Results: There is a significant difference in RVOT VTI between case and control cohorts in both supine and sitting positions (p=0.03 & p=0.001 respectively). Also, there is a significant decrease in RVOT VTI from supine to sitting position in PE patients compared to healthy adults (Table). Conclusion: This is the 1 st prospective cohort study in PE patients vs healthy adults showing the feasibility and utility of dynamic echocardiography in assessing the right ventricular hemodynamics. This study demonstrates a significant decrease in right sided hemodynamic changes with change in position in patients with PE which might explain their symptoms.

Introduction: Severe hypertriglyceridemia (SHTG), defined as plasma triglyceride (TG) level ≥ 500 mg/dl, is a risk factor for cardiovascular disease. In the NHANES dataset (2001 - 2006), the prevalence of SHTG was 1.7%. However, the prevalence of primary SHTG in the community is unknown. We conducted a community-based study to estimate the prevalence of primary SHTG, in Olmsted County, Minnesota. Methods: We used the Rochester Epidemiology Project (REP) records linkage system to identify individuals with TG ≥ 500 mg/dl between 1998-2015. Index date was defined as the first documentation of TG ≥500 mg/dl during the study period. We excluded individuals with mixed hyperlipidemia (TG ≥500 mg/dl and non-high density lipoprotein (HDL) cholesterol ≥190 mg/dl). HTG was defined as secondary in the presence of hypothyroidism, biliary obstruction, nephrotic syndrome, uncontrolled diabetes, pregnancy, liver disease, renal failure, BMI ≥35 and medication use (isotretinoin, tetracyclines, anti-retrovirals). Primary HTG was defined as absence of an identifiable secondary etiology. Characteristics of the primary SHTG individuals were ascertained from the electronic health record. Results: SHTG was identified in 3802 individuals of whom 2511 had mixed hyperlipidemia, 743 had a secondary cause for SHTG and the remaining 548 had primary SHTG. Using the 2015 population census of 151,436 for Olmsted County, the prevalence of SHTG was 2.5%, of secondary SHTG was 0.49% and of primary SHTG was 0.36%. Only half of the primary SHTG group had a diagnosis of dyslipidemia in the electronic health record and 44.3% were on lipid-lowering therapy on index date. Characteristics of individuals with primary SHTG are summarized in Table 1. Conclusions: These data highlight that primary SHTG is relatively common (≈1 in 300, similar to the prevalence of familial hypercholesterolemia), underdiagnosed and undertreated.

Introduction: Prior reports of the genetic etiology of hypercholesterolemia are affected by referral bias, inclusion of individuals with secondary hypercholesterolemia and variability in identifying pathogenic variants. We sought to assess the prevalence of monogenic and polygenic etiologies in a community based cohort of adults with primary hypercholesterolemia (LDL-C ≥155 mg/dL after excluding secondary causes). Methods: We identified 1719 individuals aged 18-70 years with primary hypercholesterolemia from SE Minnesota. The Dutch Lipid Clinic Network (DLCN) score was ascertained by an electronic health record (EHR) based algorithm followed by manual review. Familial hypercholesterolemia (FH) was considered present with a DLCN score ≥6 whereas a DLCN score of 3-5 was considered possible FH. Participants underwent sequencing of FH genes ( LDLR, APOB, PCSK9 ) and genotyping of 12 SNPs known to be associated with LDL-C. Rare (frequency <0.1%) and putatively functional variants were identified and pathogenicity was assigned based on the ACMG guidelines using relevant database, literature and EHR review. A polygenic score (PGS) for LDL-C (derived from 12 SNPs) >90 th percentile was considered an indicator of polygenic etiology. Results: A pathogenic/likely pathogenic variant (16 in LDLR , 1in APOB and 2 in PCSK9 ) was present in 24 (1.3%) individuals, a PGS >90 th percentile was present in 265 (15.4%) and 4 (0.2%) had both a monogenic and polygenic etiology. The overall prevalence of an identifiable genetic etiology was 17%. Based on clinical criteria the overall prevalence of FH (DLCN ≥6) was 7.0% (6.1% probable and 0.9% definite) and that of possible FH was 30.0%. In the possible, probable and definite FH categories, a monogenic etiology was present in 2.4%, 9.5% and 26.7% and a polygenic etiology in 19.1%, 21.0% and 13.3% respectively. 52.0% of those with a monogenic etiology and 9.7% of those with a polygenic etiology met the DLCN criteria for FH. Conclusions: This study provides for the first time estimates of monogenic and polygenic etiology of hypercholesterolemia in adults from the community, excluding cases of secondary hypercholesterolemia and using standardized methods of variant annotation.

Introduction: Gastrointestinal bleeding (GIB) after continuous-flow left ventricular assist device (CF-LVAD) implantation is common, with an incidence estimated at 18-40% per year. While the pathophysiology of GIB in these patients is unclear, physiologic changes related to the absence of pulsatility may account for the high rates of GIB seen in these patients. Hypothesis: Improved left ventricular (LV) function (increased myocardial pulsatility) after LVAD implantation may be associated with decreased rates of GIB. Methods: We studied 119 consecutive patients with CF-LVADs implanted between March 2006-November 2016 who received serial transthoracic echocardiograms (TTE), including at least one pre-implant and one post-implant TTE. Left ventricular ejection fraction (LVEF) was assessed by experienced readers, with a kappa statistic between readers >0.90. Improved LV function was defined as an improvement of at least 7% between the pre-implant LVEF and the best post-implant LVEF obtained with 9 months of the implantation date. Similarly, worsening LV function was defined as a decrease of at least 7%. Primary GIB was defined using INTERMACS adverse event criteria. Patients were followed until transplantation, device complication requiring explantation, or death. Results: The study sample was 58±12 years old, 72% male, and 63% Caucasian. Hemoglobin at implantation was 11±2 g/dL. Maximum LV recovery was seen a median of 103 (IQR 49-158) days after LVAD implantation. Improved LV function occurred in 25 (21%) patients, while LVEF remained stable or worsened in 94 (79%) of patients. When compared with patients whose LVEF remained stable or worsened, patients with improved LV function were more likely to be female (p=0.05). GIB occurred in 29 patients (24%). Improved LV function was associated with a significantly decreased risk of GIB (Figure; p=0.05). Conclusions: Improved LV function is seen in one-fourth of patients and is associated with a significantly decreased risk of GIB following CF-LVAD implantation.

Introduction: Survivorship needs to be comprehensively evaluated amongst older adults. We examined follow-up mortality in patients referred to cardiac catheterization laboratory by prospectively examining frailty. Methods: Frailty in 923 patients ≥55 years was determined using Rockwood’s deficit index. The frailty deficit was based on symptoms, signs, disabilities, diseases, and laboratory measurements. The number of deficits was expressed as a proportion of the total measured deficits. Frailty index was grouped into <0.10 (control), 0.10-<0.20, 0.20-<0.30, 0.30+ and age- and gender-adjusted follow-up mortality was determined using a Cox proportional hazards model. Results: There were 180 (20%) with frailty index <0.10, 348 (38%) in 0.10-<0.20, 215 (23%) in 0.20-<0.30 and 177 (19%) with an index of 0.30 or higher. Patients with a frailty index of 0.30+ were significantly older than those with an index <0.10 (75 ± 10 vs 67 ± 8 years; p<0.001) and more likely to be women (50% vs 20%; p<0.001). Patients with frailty index ≥0.20 and ≥0.30 had a significantly higher mortality risk (HR 3.95, 95% CI 1.51-10.3 and HR: 10.3, 95% CI 4.11-25.7, respectively) on follow-up which remained significant following adjustment for age and gender (HR 3.20, 95% CI 1.21-8.45 and HR: 7.99, 95% CI 3.13-20.4). Conclusions: Among older adults refereed to catheterization laboratory, frailty deficit index predicts follow-up mortality.