Geske, Jeffrey B.

Introduction: Safety of vigorous exercise for individuals with appropriately-treated HCM remains debated. Physical activity practices in this population have not been described. The objective of this report is to describe physical activity pattern in HCM patients. Long term follow up which is ongoing will determine safety of vigorous exercise. Methods: The NIH-funded LIVE-HCM study prospectively enrolled individuals age 8-60 years with clinically overt HCM or patients with a positive genetic test for sarcomeric HCM. Participants (or parents, for children) answered surveys describing activity patterns. Vigorous exercise was defined as > 6 METS for > 60 hours per year. Clinical and demographic data were derived from medical record review. Results: Among 1798 participants, 745 (41%) reported exercising vigorously, including 296 competitive athletes, with 59 at high-school or college varsity level, 770 (43%) were exercising at moderate, and 283 (16%) at low levels. Of those working, 6% described jobs more active than walking, including 16 in protective services, and 11 in sports/coaching. Clinical/demographic data including imaging characteristics and treatments, are shown in Table, and were mostly similar amongst the exercise-groups. Conclusions: Many patients with HCM are engaged in vigorous exercise including competitive athletics. Prospective follow-up of this cohort is ongoing. Comparison of arrhythmic outcomes outcomes in vigorous exercisers vs moderate/low level exercisers will help determine the safety of exercise in HCM patients.

Introduction: Patients with hypertrophic cardiomyopathy (HCM) have lower peak oxygen uptake (VO2) than healthy peers. The mechanism of peak VO2 limitation in HCM has not been fully elucidated. Hypothesis: We assessed the hypothesis that resting echocardiographic parameters are predictive of peak VO2 in HCM. Methods: A retrospective review of adult HCM patients seen at a tertiary referral center from 2006-2012 was performed. Patients who underwent a comprehensive echocardiogram and cardiopulmonary treadmill exercise test within 1 week were included. Multivariate modeling was used to identify predictors of peak VO2 adjusting for age, sex, body mass index, beta blocker use, diabetes, smoking, systolic blood pressure, and obstructive HCM. Results: Five hundred and forty one patients met the inclusion criteria. The average age was 52 +/- 0.65 years, 62% were male, 78% had obstructive HCM, and 42% were NYHA class III or IV. Independent predictors of peak VO2 included averaged left ventricular (LV) longitudinal peak systolic strain (p<0.01) and right ventricular systolic pressure (RVSP) (p<0.01) (Figure 1). Obstructive versus non-obstructive HCM, grade of diastolic dysfunction, LV mass and wall thickness, left atrial volume index, right ventricular dysfunction and moderate or greater mitral or tricuspid regurgitation were not independent predictors of peak VO2. Conclusions: In conclusion, higher RVSP and less negative LV longitudinal peak systolic strain were moderate independent predictors of lower peak VO2. These findings confirm the hypothesis that resting echocardiographic parameters are predictive of peak VO2 in HCM. Further study of the relationship between echocardiographic findings and outcomes on cardiopulmonary exercise testing may help elucidate the mechanisms of exercise limitation in HCM.

Introduction: Aortic dilatation has been associated with various cardiac conditions, although its prevalence and clinical correlates in hypertrophic cardiomyopathy (HCM) remains unclear. Hypothesis: We hypothesized that tubular ascending aorta dilatation would be common in a large referral population of patients with HCM. Furthermore, we hypothesized that aortic size would correlate with age and presence of left ventricular outflow tract obstruction. Methods: 1704 patients with HCM underwent echocardiographic measurement of the tubular ascending aorta during index evaluation at a tertiary HCM referral center. End-diastolic ascending aorta dimension was indexed to body surface area, with dilatation defined as two standard deviations above normal (>19 mm/m2). Aortic size and presence of aortic enlargement were correlated with clinical and echocardiographic parameters. Results: Aortic dilatation was present in 304 patients with HCM (18%). Indexed ascending thoracic aorta dimension was 16.5 (IQR 17.8-18.2) mm/m2 (Figure 1). Indexed dimension increased linearly with age (R=0.53, p<0.0001). Women and patients with a history of systemic hypertension were more likely to have aortic enlargement (29.8% vs 9.9% and 24.1% vs 10.6%, p<0.0001 for both). There was a correlation between resting left ventricular outflow tract gradient and indexed aortic dimension (R=0.12, p<0.0001) and patients with either resting (≥30 mmHg) or provocable obstruction (≥50 mmHg) were more likely to have aortic enlargement (19.6% vs 14.3%, p=0.006). Conclusions: In this large cohort of patients with HCM, aortic dilatation was common. Key correlates of aortic enlargement included age, female sex, history of hypertension and left ventricular outflow tract obstruction. Given an increased prevalence of aortic dilatation in HCM, further study is needed on the clinical impact of aortic dilatation.

Background: Transthoracic echocardiography is the mainstay of cardiac imaging and is highly dependent upon cardiac sonographers for whom image acquisition can be physically demanding and associated with musculoskeletal pain. Prior studies are limited by the absence of adequate control groups and a lack of adjustment for potential confounders. Objectives: The purpose of this study was to determine the prevalence and impact of work-related musculoskeletal pain in cardiac sonographers as compared to a large control group of non-invasive healthcare professionals with similar demographics. Methods: An electronic survey was administered to Mayo Clinic employees identified by human resources at six major patient care facilities in four different states. Results: There were 2682 employees within the departments of cardiology and radiology who were contacted and 1532 (57%) completed the survey. After exclusion of those who wear protective lead aprons, 517 employees comprised the control group and 66 cardiac sonographers made up the study group. Cardiac sonographers and the control group were similar in age, sex, BMI, length of employment and history of prior musculoskeletal pain. Cardiac sonographers reported work-related musculoskeletal pain more frequently than the control group (88% vs 40%; p<0.001). This association persisted after multivariable adjustment for age, sex, body mass index, length of current employment and history of pre-existing musculoskeletal pain (OR 11.6; (95% CI 5.32, 25.5); p<0.001). Cardiac sonographers were more likely to seek medical care for their work-related pain (55% vs 21%; p<0.001) and to have missed work due to pain (35% vs 12%, p<0.001). Conclusions: In this multi-site case control study, cardiac sonographers experienced significantly more work-related pain and missed more work due to pain than a large control group of non-invasive healthcare professionals with similar demographics.

Introduction: Impaired peak VO2 and obesity are known predictors of morbidity and mortality in Hypertrophic Cardiomyopathy (HCM). The purpose of this study is to determine the degree of exercise impairment due to excess weight in patients with HCM. Methods: Adult HCM patients who underwent cardiopulmonary treadmill testing at our tertiary referral center from 2006 - 2012 and had consented to research participation were identified retrospectively. Percent predicted peak VO2 was calculated by the Astrand formula for men and the Jones formula for women which adjust for age and gender. Baseline echocardiographic features obtained within 1 week of exercise testing and % predicted peak VO2 were compared among four groups of patients stratified by body mass index (BMI). Results: 510 patients were identified, with a mean age at diagnosis of 44.3 ± 16.1 years, 186 (36.5%) female. Mean BMI at the time of cardiopulmonary exercise testing was 29.7 ± 5.3 and 227 (44.6%) patients had a BMI ≥ 30. Overweight and obese patients were older and were more likely to be male than their normal weight peers. However, there was no significant difference in ejection fraction (EF), resting left ventricular outflow tract gradient, right ventricular systolic pressure (RVSP), or septal thickness among the groups. HCM patients show impaired peak VO2 across all BMI groups. While peak VO2 increased progressively across BMI groups consistent with greater O2 demand generated by higher body weight, the adjusted peak VO2 in mL/kg/min fell progressively, indicating progressively greater performance impairment with increasing BMI despite similar degrees of cardiac impairment (p <0.0001) (Table 1). Conclusion: Increased BMI is associated with reduced exercise performance in a graded manner in HCM patients independent of cardiac impairment identified on echocardiography.

Objective The goal of this study was to determine the effectiveness of a video presentation to first‐year medical students in clarifying their professional roles in the anatomy laboratory. Methods At the Mayo Clinic in 2005, we created a 10‐minute video interview of a woman whose parents donated their bodies to the anatomy program. In the interview, she discussed the lives of her parents, their message for medical students, and medical students’ roles in professionalism and confidentiality. First‐year anatomy students viewed the video during the first week of their anatomy course and were surveyed using an 11‐point Likert scale to assess the impact of the video (0=strongly disagree, 10=strongly agree). Results Students generally agreed that the video helped them understand professionalism and, especially, confidentiality in the context of the gross anatomy laboratory. Students tended to agree, although slightly less strongly, that they gained a deeper respect for donors after watching the video. Many believed that potential donors would benefit from viewing the video presentation. Finally, most students strongly agreed that future medical students would benefit from watching the video interview. Conclusions The results support the hypothesis that the video presentation clarifies medical students’ professional roles in protecting the confidentiality and humanity of the donors. Students generally agreed that it is worth showing to future classes of medical students. Furthermore, the video may benefit those contemplating body donation.

Abstract Hypertrophic cardiomyopathy (HCM) is a heritable, phenotypically diverse, and often asymptomatic heart muscle disease which is a major cause of sudden cardiac death (SCD) in young adults. The gold-standard for the diagnosis of HCM is echocardiography (echo), which is an ultrasound-based cardiac imaging modality. Across all sites of the Mayo Clinic enterprise, echo images and measurement data are reviewed, interpreted, and reported via the Echo Information Management System (EIMS). The objective of this paper is to develop a machine learning model for the identification of HCM from cardiac measurements obtained by the echo. We developed a novel machine learning model on patient demographic information and echo measurements that were retrieved from the EIMS digital data registry and selected by cardiologists. Random forest (RF) was utilized to investigate the predictive performance of these features on the identification of HCM patients. The HCM cohort consists of 3,548 patients with at least one HCM diagnostic billing code (ICD-9 or ICD-10), from 2014 to 2019. The class labels “HCM yes” and “HCM no” were assigned by manual review of medical records as well as the outcomes of the gold standard imaging tests for HCM diagnosis. The developed model performed well in finding HCM patients with an accuracy of 95%, recall of 99%, and precision of 97%. The F1 score was 98 %, while 4% of patients were misclassified. This model will be translated into clinical practice for a clinical decision support system in EIMS to assist providers in the accurate diagnosis of HCM from echo data automatically while ensuring high-quality echo interpretation.

Background: Left ventricular outflow tract (LVOT) obstruction is an important determinant in management of hypertrophic cardiomyopathy (HCM). Valsalva maneuver and amyl nitrite are used in clinical practice during resting echocardiography to induce latent obstruction (LVOT gradient <30 mmHg at rest, ≥30 mmHg with maneuver). With a nationwide shortage of amyl nitrite in 2019, we implemented a “repetitive squat-to-stand” maneuver to provoke LVOT obstruction during echocardiography. Methods: Patients with known or suspected HCM without resting obstruction who underwent repetitive squat-to-stand maneuver during echocardiography between February and September 2019 were included. Maximal instantaneous gradients were recorded. Provocable gradients were compared utilizing a two-sided t-test. Amyl nitrite was not available during the study period. Results: Squat-to-stand assessments were available in 125 patients without resting obstruction (age 58 ± 15 years, 67% male); 114 also performed Valsalva maneuver. 47 of 125 patients (37.6%) demonstrated provocable obstruction. 46 (36.8%) demonstrated latent obstruction provoked by squat-to-stand, which was severe (gradient ≥50 mmHg) in 29 (23.2%). Of the 46 patients, 19 demonstrated latent obstruction only with squat-to-stand but not with Valsalva, 13 of which demonstrated severe obstruction. Among patients with latent obstruction who performed both Valsalva and squat-to-stand maneuver (n=41), squat-to-stand resulted in a higher gradient than Valsalva maneuver (p<0.0001, Figure). Conclusion: Repetitive squat-to-stand maneuver is a clinically useful adjunct to the traditional echocardiographic exam in HCM. This maneuver appears to be more sensitive than the Valsalva maneuver for identifying severe dynamic LVOT obstruction. Use of repetitive squat-to-stand warrants further study in comparison to amyl nitrite, particularly regarding cost savings and diagnostic performance.