Ommen, Steve R.

ImportanceThere was a shift in patient volume from in-person to video telemedicine visits during the COVID-19 pandemic.ObjectiveTo determine the concordance of provisional diagnoses established at a video telemedicine visit with diagnoses established at an in-person visit for patients presenting with a new clinical problem.Design, Setting, and ParticipantsThis is a diagnostic study of patients who underwent a video telemedicine consultation followed by an in-person outpatient visit for the same clinical problem in the same specialty within a 90-day window. The provisional diagnosis made during the video telemedicine visit was compared with the reference standard diagnosis by 2 blinded, independent medical reviewers. A multivariate logistic regression model was used to determine factors significantly related to diagnostic concordance. The study was conducted at a large academic integrated multispecialty health care institution (Mayo Clinic locations in Rochester, Minnesota; Scottsdale and Phoenix, Arizona; and Jacksonville, Florida; and Mayo Clinic Health System locations in Iowa, Wisconsin, and Minnesota) between March 24 and June 24, 2020. Participants included Mayo Clinic patients residing in the US without age restriction. Data analysis was performed from December 2020 to June 2021.ExposuresNew clinical problem assessed via video telemedicine visit to home using Zoom Care Anyplace integrated into Epic.Main Outcomes and MeasuresConcordance of provisional diagnoses established over video telemedicine visits compared against a reference standard diagnosis.ResultsThere were 2393 participants in the analysis. The median (IQR) age of patients was 53 (37-64) years; 1381 (57.7%) identified as female, and 1012 (42.3%) identified as male. Overall, the provisional diagnosis established over video telemedicine visit was concordant with the in-person reference standard diagnosis in 2080 of 2393 cases (86.9%; 95% CI, 85.6%-88.3%). Diagnostic concordance by International Statistical Classification of Diseases and Related Health Problems, Tenth Revision chapter ranged from 64.7% (95% CI, 42.0%-87.4%) for diseases of the ear and mastoid process to 96.8% (95% CI, 94.7%-98.8%) for neoplasms. Diagnostic concordance by medical specialty ranged from 77.3% (95% CI, 64.9%-89.7%) for otorhinolaryngology to 96.0% (92.1%-99.8%) for psychiatry. Specialty care was found to be significantly more likely than primary care to result in video telemedicine diagnoses concordant with a subsequent in-person visit (odds ratio, 1.69; 95% CI, 1.24-2.30; P < .001).Conclusions and RelevanceThis diagnostic study of video telemedicine visits yielded a high degree of diagnostic concordance compared with in-person visits for most new clinical concerns. Some specific clinical circumstances over video telemedicine were associated with a lower diagnostic concordance, and these patients may benefit from timely in-person follow-up.

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: Mutations in sarcomeric/myofilament proteins are commonly implicated in hypertrophic cardiomyopathy (HCM). However, the mechanisms underlying disease pathogenesis are not completely understood. Utilizing flash-frozen surgically resected left ventricular (LV) tissue from patients with obstructive HCM, we investigated the effect of sarcomeric HCM on tissue expression of various myofilament proteins. Methods: Frozen surgical specimens from 47 patients with HCM who underwent septal myectomy at the Mayo Clinic between 1999 and 2003 were examined. Using PCR, DHPLC, and direct DNA sequencing, all were genotyped for mutations involving the 8 myofilament-encoding genes that currently comprise the clinically available genetic test for sarcomeric HCM. Whole protein lysate was extracted from the frozen myectomy tissues and levels of myosin binding protein C, myosin heavy chain, alpha actin and alpha actinin were analyzed by Western Blot; GAPDH was used as a loading control. Frozen LV tissue derived from normal hearts of accidental death victims served as a reference group. Results: Overall, 25/47 (53%) patients had sarcomeric HCM including 13 patients with myosin binding protein C (MYBPC3) mutations and 10 with mutations in the beta myosin heavy chain (MYH7). Compared to normal heart tissue, the expression of myosin heavy chain was up-regulated significantly regardless of the underlying disease-causing genotype (genotype positive = genotype negative). However, there was gene-specific upregulation of myosin binding protein C with marked increases detected in patients with MYH7-HCM. In contrast, normal levels of myosin binding protein C were seen in patients with either MYBPC3-HCM or genotype-negative HCM. Conclusions: This is the first study to examine the expression pattern of sarcomeric proteins in a large collection of flash frozen human HCM myectomy tissue. Up-regulated, genotype-specific cardiac tissue expression of myosin binding protein C among patients with MYH7 (beta myosin heavy chain)-HCM suggests a novel compensatory pathway underlying the development of cardiac hypertrophy for one of most common genetic subtypes of HCM.

Background: Apical hypertrophic cardiomyopathy (apical HCM) is a less common subtype of HCM characterized by a focal thickening in the left ventricular apex. “Classic” ECG features have been described, however, apical HCM can persist for many years without detection. We investigated the relationship between ECG findings and echocardiographic morphometry in a large referral series of patients with apical HCM. Methods: We enumerated all patients diagnosed with apical HCM prior to Sept. 30, 2006 using the Mayo Clinic HCM database. We compared echocardiographic measures separately for patients with positive status for two ECG indices of left ventricular hypertrophy (LVH); the Sokolow-Lyon index and the Romhilt-Estes (RE) point-score. We also compared echocardiographic measurements in patients with and without negative T-waves in the precordial leads. Results: Apical HCM was detected in 177 patients (111 men and 68 women). Only 51% had positive Sokolow criteria and 51% had positive RE criteria. The agreement between Sokolow and RE status was high (agreement = 75.0%; kappa = 0.50; 95% CI = 0.38 – 0.62). In particular, Sokolow positive patients had increased LV ejection fraction (P = 0.02), and decreased LV end-systolic diameter (P = 0.03) compared with Sokolow negative patients. The prevalence of right atrial enlargement (47 vs. 28%; P = 0.02) and intracavity obstruction (22 vs. 8%; P = 0.01) were more common in Sokolow positive patients. Positive RE criteria was associated with a greater thickness of the basal septal and basal posterior walls (P = 0.001 and 0.02, respectively), and with a higher frequency of intracavity obstruction (21 vs. 9%; P = 0.04). Most patients (89%) exhibited at least one negative T-wave in the precordial leads; however, only 10% of patients had a negative T-wave of greater than 1.0 mV. We found that patients with an inverted T-wave larger than 0.4 mV (median) had a significantly increased LV ejection fraction (P = 0.03) compared with patients who had smaller or no negative T-waves. Conclusions: Among patients with apical HCM, nearly half do not have ECG evidence of LVH based on classic criteria and most do not have marked T-wave inversions. However, the majority did have at least a mild expression of negative T-waves.

Background: Although dynamic left ventricular outflow tract (LVOT) obstruction is a hallmark for hypertrophic obstructive cardiomyopathy (HOCM), it can occur in other conditions. The aim of this study was to determine underlying conditions and clinical importance of LVOT obstruction in patients without HOCM. Methods: We reviewed the echocardiographic and clinical data of patients who underwent transthoracic echocardiography in Mayo Clinic Rochester from October 2001 to August 2006, and had LVOT peak pressure gradient (PG) > 25mmHg at rest. Results: Of 719 patients identified, 159 (22 %) patients had dynamic LVOT obstruction without HOCM (77 men; mean age, 66.6 ± 12.9 years). Main presenting symptoms were chest pains in 95 (59.7 %), and dyspnea in 46 (28.9 %). LVOT PG was 51 ± 24 mmHg at rest and 68 ± 27 mmHg after provocation. In 114 (71.7 %) patients, early diastolic transmitral inflow velocity (E) and early diastolic mitral annular tissue velocity (Ea) were obtained. Mean E, Ea, and E/Ea were 105 ± 47 cm/s, 6.4 ± 5.7 cm/s, and 18.3 ± 11.0, respectively. Systolic anterior motion of mitral apparatus was observed in 100 (62.9 %) patients. Concentric increase in LV wall thickness or LVH was most common condition present in 57 patients (36%). The cause of LVH was hypertension in 40 (70.1%), aortic stenosis in 8 (14.0%), and chronic renal failure in 4 (7.0%). In these patients, major precipitating factors were hyperdynamic LV systolic function in 54 (94.7%), use of vasodilator in 34 (59.6%) and small LV cavity in 30 (52.6%). Other prominent associated conditions were basal septal hypertrophy, mitral valve repair, cardiac amyloid, and apical ballooning. There were 28 (17.6%) all-cause mortalities during follow up (25 ± 17 months) including malignancy in 6 (21.4 %), sudden cardiac deaths in 4 (14.3 %), congestive heart failure in 3 (10.7 %). Conclusions: Dynamic LVOT obstruction can be found in patients without HOCM. The most common condition to develop dynamic LVOT obstruction without HOCM, is concentric increase in LV wall thickness in the setting of hyperdynamic motion, small LV cavity, and use of vasodilator. Other conditions which predispose patients for dynamic LVOT obstruction are hypovolemia, cardiac amyloidosis, apical ballooning syndrome, and mitral valve repair.

Introduction: Papillary fibroelastomas (PFEs) are the 3rd most common primary cardiac tumors with a prevalence of around 0.01% in patients with echocardiograms. The pathogenesis is controversial but endocardial trauma has been implicated. We hypothesized that increased turbulence in hypertrophic cardiomyopathy (HCM) would be a risk factor for PFE development and characterized PFEs in HCM. Around 5% of HCM patients had neurologic events. We postulated that patients with both PFE and HCM had a higher risk of neurologic events. Methods: We reviewed pathology records from 1990 –2006 and identified 129 subjects with PFEs and 2479 patients with HCM. We then identified the subjects who had both HCM and PFE (n = 19). All subjects signed release for use of their medical records for research. Results: 19 subjects (68.4% female) had both HCM and PFE. Mean age at diagnosis of HCM was 49 (range 21– 81) years. All had outflow tract obstruction with resting gradient >/=30 mm Hg except 2 who had resting gradients <30 mm Hg but elevated gradients on provocation. PFE diagnosis was after a mean of 9.7 years (SD 8.3) following HCM diagnosis. 5 subjects were diagnosed pre-operatively by transthoracic echocardiography, 2 subjects by transesophageal echocardiography and 12 subjects at surgery only. Most subjects had only 1 PFE (57.9%) but 1 subject had as many as 40 tumors. Most PFEs were on the aortic valve (47.4%) and the left ventricular side of the septum and left ventricular outflow tract (42.1%). Only 2 patients had right heart lesions that were presumably unrelated to HCM. 3 patients had previous septal myectomies and all 3 had PFEs near the previous resection. 5 of 19 subjects (26.3%) with PFE and HCM had neurologic events (either strokes or transient ischemic attacks) compared to 199 of 2261 subjects (8.8%) with HCM alone (OR = 4.1; 95% CI 1.4 –11.4, p < 0.05). Conclusion: Nearly 90% of PFEs in HCM are located in the septum, left ventricular outflow tract and aortic valve. This may be supportive of endocardial trauma as a risk factor for PFE development in HCM. About a quarter of patients with PFEs and HCM had neurologic events. This may indicate that these lesions are not innocuous and should perhaps be actively searched for in patients with HCM and unexplained neurologic events.

Introduction Multi-detector computed tomography (MDCT) is commonly used to identify pulmonary vein and left atrial anatomy prior to catheter ablation for atrial fibrillation (CAAF). Additionally, transesophageal echocardiography (TEE) is utilized to exclude left atrial/left atrial appendage thrombus (ICT). Whether MDCT alone can be used to exclude thrombus obviating the need for TEE is unknown. Methods All Pts referred for CAAF at Mayo Clinic between March 2004 and October 2006 were included. Clinical data (including CHADS score), 64 slice MDCT (non-ECG gated), TEE and intra-cardiac echocardiograph (ICE) were all performed and recorded. Image data was reviewed independently and blinded. The left atrial appendage (LAA) was defined as fully opacified or underfilled. An underfilled LAA was further interrogated using a region of interest over the filling defect and mean attenuation in Hounsfield Units (HU) were recorded. Results In total 400 Pts (mean age 56 ± 10 yrs; 76% male; EF 56 ± 10 % ) were included. 362 had no ICT by TEE nor filling defect by MDCT. 38 patients had an underfilled LAA in whom ICT was confirmed by TEE in 7. Sensitivity and specificity of MDCT for ICT was 100% and 92% respectively with a NPV of 100%. In 19 Pts with underfilled LAA’s, a mean LAA emptying velocity was found to be significantly reduced at 26 cm/s (6 – 61 cm/s). Those with a thrombus had a mean attenuation value below 70 HU. CHADS2 score was higher (2.0 versus 1.0) in Pts with LAA filling defect versus those without LAA filling defect. All Pts with confirmed thrombus were taking Warfarin. ICT was not seen in any Pts aged <52 yrs with CHADS score ≤1. Conclusions Sensitivity and specificity of MDCT for detection of LAA thrombus is high. LAA filling defects on MDCT correlate with low emptying velocities by TEE and low attenuation value in HU. These data would suggest that in the absence of MDCT filling defect, no further imaging is required. TEE should be utilized prior to CAAF to investigate MDCT filling defects. Multidetector Computed Tomography for the Detection of LAA Thrombus

Background Recently, genetic testing for sarcomeric hypertrophic cardiomyopathy (HCM) became a commercially available diagnostic test involving analysis of 8 HCM-associated myofilament genes, four of which encode thin filament proteins - TNNT2- encoded cardiac troponin T, TPM1 -encoded alpha tropomyosin, TNNI3- encoded cardiac troponin I, and ACTC- encoded cardiac actin. Compared to the two most common subtypes of sarcomeric HCM, much less is known about the prevalence and spectrum of thin filament HCM. Methods Comprehensive open reading frame/splice site mutational analysis of these 4 thin filament-encoding genes was performed, using polymerase chain reaction, denaturing high performance liquid chromatography, and direct DNA sequencing, on the largest assembled cohort of unrelated patients (N = 1025, 61% male, 49 ± 18 years at diagnosis, maximal left ventricular wall thickness, LVWT, 22.3 ± 7 mm) with clinically diagnosed HCM that were seen at the Mayo Clinic. Results Nineteen distinct missense mutations, involving conserved residues and absent in 600 reference alleles, were identified in 36 of 1025 patients (3.5%) including TNNT2 (16 patients), TNNI3 (12), TPM1 (7) and ACTC (1). Among these 36 patients with thin filament-HCM, their average age at diagnosis was 33.2 ± 16 years and the average LVWT was 21 ± 8 mm. Eighteen patients (50%) had evidence for familial HCM and 13% had a positive history for sudden cardiac death. Only 13 patients (36%) had a reverse septal curvature by echocardiography. Instead, 12 patients (34%) had either sigmoidal or neutral septal contours and 9 patients (25%) had apical variant-HCM. Conclusion Here, we present the largest cohort analysis of thin filament HCM to date and detail the prevalence and spectrum of HCM-associated mutations in these 4 genes. Compared to the strong association between reverse septal curvature and thick filament HCM, the septal morphology associated with thin filament HCM was quite varied. Contrary to published estimates of the frequency of troponin T-HCM (5 – 10%) and the other subtypes of thin filament HCM, the prevalence of thin filament HCM was very low in this cohort. If confirmed in other cohorts, a revised cascade for HCM genetic testing should be considered.

Background. Apical hypertrophic cardiomyopathy (AHCM) has been considered a ``benign” form of HCM in Asian and non-Asian patients (pt). However, data on long-term outcome of pt with AHCM are limited. The purpose of this study was to determine the natural history of pt with AHCM followed at a tertiary referral center in North America. Methods. Between July 1976 and September 2006, 193 pt with the diagnosis of AHCM were seen at the Hypertrophic Cardiomyopathy Clinic. The last echocardiographic exam was reviewed in all pt. Follow-up data were obtained where possible (clinic visit). Results. Mean age at diagnosis 56±17 years, mean age at first presentation at our center was 58±17 years. Symptoms included chest pain in 69 pt (36 %), and exertional dyspnea ≥NYHA II in 97 pt (50 %). A family history of either HCM and/or sudden cardiac death was reported by 36 pt (19 %). Coronary artery disease was proven in 40 pt (21 %). Median follow up was 50 months (1–318) and obtained in 124 pt (64 %). The following events were reported at the last clinic visit: heart failure in =5 pt, syncope in =0 pt, ventricular tachycardia in =7 pt, ICD implantation in 22 pt, and stroke in 22 pt. Death from all causes occurred in 51 of 193 pt (26 %) at a mean age of 72 years (14–78). Kaplan-Meier survival analysis was used to examine survival from all causes of death since first presentation. Observed survival in patients with AHCM was significantly less than expected in an age- and gender matched Minnesota white population (p=0.009). The observed survival at 5, 10 and 15 years was 87 %, 82 %, and 57 % respectively, while the expected survival for these time points was 91 %, 81 %, and 72 %. Conclusions. AHCM in this predominantly North American patient population is associated with an increased mortality. Patients with AHCM have a high incidence of significant cardiovascular symptoms and ventricular arrhythmias. As the disease is less benign than previously suspected, careful longitudinal care by a cardiologist is warranted.