Diagnostic Yield Research Articles

Diagnostic yield and characteristics of germline-positive genetic testing ordered by obstetricians and gynecologists in female patients with a personal history of cancer

Diagnostic yield and characteristics of germline-positive genetic testing ordered by obstetricians and gynecologists in female patients with a personal history of cancer

From sampling to cellblock: The fully automated journey of cytological specimens.

In recent years, technological innovation have emerged to standardize pathology laboratory processes and reduce the handling of diagnostic samples. Among them is an automatic tissue embedding system that eliminates the need for manual activity in tissue paraffin embedding, thereby improving sample preservation. Unfortunately, this system cannot be used for cytological specimens due to the lack of an effective holder to support the procedure steps. In this study, we evaluated the performance of a commercial polymer matrix to enable and standardize the automatic paraffin embedding of cytological material from different organs and sources. Cytological samples from 40 patients were collected on the matrices and submitted for fully automatic workflow preparation, from formalin fixation until paraffin block, using the Sakura embedding system. Our results demonstrated the feasibility of the automated procedure, from loading cytological sample onto the matrix to obtaining the paraffin cellblock, thereby avoiding manual manipulation of cellular material. All samples resulted adequately processed and paraffin-embedded showing satisfactory tissue permeation by processing reagents, optimal preservation of cytoplasmic and nuclear details, and good quality of staining results on paraffin sections. Automated embedding of cytological samples eliminates the risk of lost specimens, reduces laboratory burden, standardizes procedures, increases diagnostic yield, and ultimately improves patients' management.

Additional Diagnostic Yield of the Rapid Drink Challenge in Chicago Classification Version 4.0 Compared With Version 3.0.

Chicago classification version 4.0 enhances the diagnosis of esophageal motility disorders using position change and provocative tests such as multiple rapid swallows and a rapid drink challenge. This study investigates the diagnostic role of the rapid drink challenge based on Chicago classification 4.0 using a functional luminal imaging probe to estimate the cutoff value. This study included 570 patients who underwent esophageal manometry with a rapid drink challenge between January 2019 and October 2022. The diagnostic flow was analyzed according to Chicago classification 4.0. Ninety-nine patients (38, achalasia; 11, esophagogastric junction outflow obstruction; 7, ineffective esophageal motility; 1, hypercontractile esophagus; and 42, normal esophageal function) failed the rapid drink challenge. Among the 453 participants, 50 and 86 were diagnosed with achalasia and esophagogastric junction outflow obstruction, respectively, using Chicago classification 4.0. In 249/453 (55.0%) patients initially diagnosed with esophagogastric junction outflow obstruction using Chicago classification 3.0, the diagnosis was changed to achalasia (n = 28), hypercontractile esophagus (n = 7), ineffective esophageal motility (n = 7), or normal esophageal function (n = 121) using Chicago classification 4.0. Rapid drink challenge-integrated relaxation pressure's diagnostic cutoff value was 19 mmHg. Nine patients had diagnoses changed after the rapid drink challenge, including 3 with panesophageal pressurization. Chicago classification 4.0 increased the diagnostic yield of the rapid drink challenge by 2.0% (9/453 patients). However, the rapid drink challenge had a failure rate of 17.9% (99/552 patients). Given the relatively low diagnostic yield and high failure rate of the rapid drink challenge, we recommend adopting an individualized approach to manometry.

Implications of age and sex on the diagnostic yield of sudden arrhythmic death syndrome

Abstract Introduction Sudden arrhythmic death syndrome (SADS) refers to an unexplained sudden death with a negative autopsy. An inherited cardiac condition (ICC) may be diagnosed through familial clinical evaluation (FE) or post-mortem genetic testing (molecular autopsy [MA]) or both. We aimed to investigate the impact of age and sex of SADS decedents on the diagnostic yield and aetiology to facilitate a targeted approach to management. Methods Consecutive referrals to a single centre for FE only, MA only or both, following a SADS death were included. First-degree family members underwent comprehensive FE. A panel of 36 cardiac genes was sequenced for MA. A post-mortem diagnosis could be obtained by either FE, MA or both. A Bayesian framework for analysis was performed to identify associations. Results Seven-hundred-and-sixty SADS decedents (66% male; mean age 31±12 years) were investigated. The overall diagnostic yield for an ICC was 37% (32-42%) and 9% (6-12%) for FE and MA cohorts, respectively. In a subset where both MA and FE were performed the diagnostic yield was 45% (38-61%). For each year increase in age, the relative risk of an FE diagnosis of long QT syndrome (LQTS) or Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) versus remaining unexplained declined by 5.6% (RR 0.94 [0.91-0.98]) and by 11% (RR 0.89 [0.81-0.97]), respectively. Females were more likely to have a diagnosis compared with males by both FE (40% [34-45%] vs 36% [31-41%]) and MA (15% [10-21%] vs 6% [3-8%]). Females (8.1% [4.1-13.4%)], were more likely to be diagnosed with LQTS than males (1.2% [0.2-2.7%]) in the MA cohort. Conclusions After a SADS death, the diagnostic yield of comprehensive FE, MA or both in an expert setting can be up to 45%. Younger age of death is associated with greater likelihood of LQTS and CPVT diagnosis with the highest yield in children and adolescents. Female sex in SADS decedents is associated with a higher yield of LQTS in MA. These data highlight the relative utility of FE and MA depending on age and sex for determining underlying diagnoses following SADS deaths.

Diagnostic yield of clinical cardiac screening in first-degree relatives of SADS and unexplained cardiac arrest probands: a systematic review of the literature

Abstract Background First-degree relatives of SADS victims (defined as a sudden death of a previously healthy individual where no cause can be found despite post-mortem examination) or individuals suffering an Unexplained Cardiac Arrest (defined as a sudden cardiac arrest with successful resuscitation where no cause can be found despite thorough investigation) are recommended to undergo clinical cardiac evaluation for potential inherited cardiac conditions (ICC). However, data on the yield of family screening in these populations remains scarce. Aim This study aimed to perform the first systematic review of the diagnostic yield of clinical screening of first-degree relatives of SADS or UCA probands. A secondary aim was to compare the diagnostic yield of adult-aged and paediatric-aged relatives. Methods The systematic review was prospectively registered on PROSPERO and was undertaken utilising PRISMA guidelines. The online databases Embase, Medline and Web of Science were searched for original articles published in English from 1946 to June 2023. Included studies described the clinical cardiac screening and diagnostic yield of first-degree relatives of SADS and UCA probands. Quality of selected studies were assessed using a modified Joanna Briggs Institute (JBI) checklist. Results 14 studies met the inclusion criteria, which together included 1646 first-degree relatives of SADS probands and 656 first-degree relatives of UCA probands. 11 out of the 14 studies were retrospective cohort studies and cohort size varied from 56 – 398 (median 108, IQR 82-215). Of those studies that reported follow up length (n=8), screening ranged from one-off clinical evaluation to serial clinical screening. Overall diagnostic yield described by included studies ranged from 0 – 25%. The combined mean diagnostic yield of SADS relatives was 11.7% ± 7.5. This did not differ significantly from that of relatives of UCA probands (6.9% ± 7.4) [p=0.246]. Three studies described outcomes of clinical screening in 235 paediatric relatives, with an overall reported yield of 9.4% ± 3.4, which is not significantly different to adult populations (10.4% ± 8.4 [p=0.849]). The most common diagnosis in relatives was Long QT Syndrome followed by Brugada Syndrome. Despite probands having no heart muscle phenotype on post-mortem or clinical evaluation, 22 relatives were diagnosed with a cardiomyopathy (9.3% of all diagnoses). Conclusion Whilst there is a clear indication for clinical screening of first-degree relatives for ICCs following a SADS death or an Unexplained Cardiac Arrest, a lack of well-designed large population-based studies means that the evidence base supporting when or how relatives should be screened is not robust. The diagnostic yield in reported literature varies considerably with no difference between SADS and UCA cohorts and a similar yield in paediatric and adult relatives. This supports systematic screening for all first-degree relatives regardless of age.PRISMA Flow Diagram

Selective use of implatable loop recorders improves diagnostic potential for unexplained syncope

Abstract Background Syncope remains a common medical problem with significant socio-economic consequences. Recently, the role of dedicated Syncope Units (SU) and implantable loop recorders (ILR) has emerged, in the investigation of unexplained syncope. Purpose To investigate the possibilities for a more rational and targeted use of various diagnostic tools. Methods In this retrospective study, 196 patients with Unexplained Syncope admitted in a single SU, between March 2019 and February 2023 were included. Various diagnostic tools were utilised during the investigational process, according to clinical judgement. Patients were retrospectively allocated into Group A including those who, among other tests, underwent ILR insertion and Group B including patients investigated without ILR implantation. Data were also compared with Group C, including patients assessed prior to SU establishment. Results There was no difference between Group A (n=133) and Group B (n=63) in the diagnostic yield (74% vs. 76%, p=0.22). There was significant difference between Group A and B regarding age (67.3 ± 16.9 years vs. 48.3 ± 19.1 years, p<0.001) and regarding cause of syncope (cardiogenic in 69% of group A and reflex syncope in 77% of group B, p<0.001). The diagnosis was based on electrocardiography (ECG) in 55% of group A and in 19% of group B (p<0.001). Time to diagnosis was 4.2 ± 2.7 months in patients with ILR implantation and 7.5 ± 5.6 months in Group B, p<0.001. In Group C, the diagnostic yield was 57.9% and the ECG-based diagnostic yield was 18.3%. Conclusions A selective use of ILR according to the clinical and electrocardiographic characteristics represents an acceptable diagnostic pathway that increases the effectiveness of the structured SU-approach by further preserving financial resources

Diagnostic yield of actionable arrhythmias in patients referred with syncope and collapse using ePatch extended holter

Abstract Background/Introduction Cardiac syncope commonly points to a potentially lethal disease process and carries one-year mortality up to 30%. Current guidelines on management of syncope suggest choosing ambulatory monitoring modality based upon the likelihood of symptoms during the monitoring period and is frequently undertaken with short duration (0-2 days) or extended wear Holter (EWH) monitoring (3-14 days). Purpose Determine the diagnostic yield (DY) of actionable arrhythmias (AA) in patients referred for syncope and collapse prescribed short or extended ambulatory monitoring. Methods A retrospective analysis was conducted for patients wearing the Philips ePatch between July 1st, 2022, and June 30th, 2023, with ICD-10 referral code R55 (Syncope and Collapse). Monitoring duration was grouped by 0-2, 3-7, and 8-14 days of wear time. Wear time was defined as number of hours with analysable ECG data. Arrhythmia detection was defined as either non-AA (did not meet urgent or emergent criteria) or AA (met urgent and/or emergent criteria). Urgent criteria were defined as Atrial Fibrillation/Flutter (>10 seconds), Ventricular Tachycardia (>100 BPM for >3 beats), Severe Tachycardia (>170 BPM for ≥30 seconds), Pause/Asystole (≥3 seconds), Severe Bradycardia (<35 BPM), and 2nd Degree or Higher AV Block. Emergent criteria were defined as VT (>100 BPM for ≥30 beats), Severe Tachycardia (≥220 BPM for ≥30 seconds), Pause/Asystole (≥10 seconds), and Severe Bradycardia (<20 BPM). Results The DY for any urgent and/or emergent AA was 6.8%, 11.0%, and 20.4% at 0-2, 3-7 and 8-14 days of wear time, respectively (p<0.00001 for all). For urgent AA, DY increased 1.6X at 3-7 vs 0-2 days, 1.9X at 8-14 vs 3-7 days and 3X at 8-14 vs 0-2 days of wear time (p<0.05 for all); for emergent AA, the DY increased 5X at 3-7 vs 0-2 days, 1.6X at 8-14 vs 3-7 days, and 8.2X at 8-14 vs 0-2 days of wear time (p<0.05 for all) (Graph 1). When examining tachyarrhythmias vs bradyarrhythmias, similar multiplicative yields in AA were noted between short, intermediate, and extended duration monitoring; statistical significance was noted for all arrhythmia subtypes (p<0.01), except for Severe Tachycardia and Bradycardia which were not significant between 0-2 and 3-7 days of wear time (Graph 2). Conclusion(s) In patients referred for ambulatory monitoring with syncope and collapse, urgent and emergent actionable arrhythmias increase significantly when extending from short to intermediate to long duration monitoring, with both tachyarrhythmias and bradyarrhythmias demonstrating similar increases in occurrence. Accordingly, EWH monitoring in patients referred with syncope and collapse has greater potential to identify arrhythmic aetiologies than use of standard duration Holter.

Enhancement of the Mayo Clinic Genotype Predictor Score using Cardiac MRI

Abstract Introduction Hypertrophic cardiomyopathy (HCM) is the most prevalent heritable cardiomyopathy typically transmitted in an autosomal dominant fashion. There is growing importance in identifying genetic test positive patients given its prognostic value. The Mayo HCM Genotype Predictor Score has been extensively validated for assessment of patient’s pre-test probability for genotype positive HCM and helps guide clinical decision-making based on clinical and echocardiographic variables. Herein, we evaluated the role of cardiac magnetic resonance (CMR) to enhance the genotype predictor score. Purpose Evaluate performance of the Mayo Clinic HCM Genotype Predictor Score using CMR variables, and develop an updated, CMR incorporated score. Methods Retrospective analysis was conducted on 175 unrelated HCM patients with at least 1 MRI and a HCM genetic testing seen at the Mayo Clinic between April 2004 and April 2018. Phenotyping information was obtained through review of electronic medical records. The original Mayo HCM Genotype Predictor Score was calculated using both echocardiography and clinical variables. An updated score was created incorporating CMR-specific variables. Diagnostic accuracy of the models was assessed thought Receiver Operating Characteristic (ROC) curves. Results Overall, 108 (62%) were males with a mean age at CMR of 51 ± 18 years. The yield of positive genetic test for the echocardiogram-derived Mayo HCM Genotype Predictor Score ranged from 38% for patients with -1 point to 100% for patients with 4 or 5 points. There was a significant incremental increase in diagnostic yield between score subgroups (p < 0.01) with an AUC of 0.659 (Figure 1A). Similar findings were observed using CMR variables (AUC of 0.697; Figure 1B). Univariate and multivariate analysis identified late gadolinium enhancement (LGE) as a strong predictor of a positive genetic test (OR 3.72; p=0.002), and it was added to the original score to create a new version. The Updated Mayo HCM Genotype Predictor Score predicted a positive genetic test ranging from 25% for patients with -1 point to 100% for patients with 5 or 6 points (p < 0.01). There was a significant increase in diagnostic accuracy when compared to the original score (AUC 0.724 vs 0.679; p=0.03; Figure 1C). Conclusion Using LGE, the updated CMR-based Mayo HCM Genotype Predictor score provides a simple and improved tool to aid in genetic counseling for HCM patients.

Clinical impact of performing esophagogastroduodenoscopy before percutaneous coronary intervention in patients with acute coronary syndrome patients and anaemia

Abstract Background In patients presenting with acute coronary syndrome (ACS) and anaemia, esophagogastroduodenoscopy (EGD) is commonly performed to exclude an upper gastrointestinal source of bleeding prior to perform percutaneous coronary intervention (PCI). However, the diagnostic yield and clinical impact of EGD in this setting is uncertain. Purpose We aimed to investigate the clinical yield and impacts of EGD on the 1-year clinical outcomes in ACS patients with concomitant anaemia who underwent PCI. Methods We retrospectively analysed electronic health records of ACS patients who underwent PCI at 16 public hospitals from 2014-2018. Patients with anaemia (defined as haemoglobin (Hb) <11dl/L) and EGD before PCI during the same admission were identified. The primary outcomes were bleeding events including clinical GIB (as diagnosed by EGD), need for urgent EGD, need for transfusion, Hb drop of >3 dl/L and Hb <8 dl/L. Secondary outcomes were 12-month 4-point MACE including myocardial infarction (MI), stroke, subsequent PCI or CABG, or cardiovascular-related death. Propensity-score models with inverse probability of treatment weighting (IPTW) against EGD were developed for the comparisons. A weighted Cox Proportional Hazard Model was performed to estimate adjusted hazards ratio (aHR) with corresponding 95% confidence intervals (CI). Results Of 13,793 patients, 3625 (25%) had anaemia on admission and 12.8% (n=466/3625) underwent EGD. Most EGD findings were not accountable for overt GIB, with gastritis, gastric polyps and gastric erosion being the 3 most common EGD diagnoses. After IPTW, clinical outcomes of 466 patients with EGD were compared with 3159 patients without EGD. 12-month bleeding event rates were higher among EGD patients compared to non-EGD patients (59.7% vs. 27.6%, p< 0.01; aHR = 3.01, 95% CI 2.58-3.52, p<0.005). Overall, 12-month GIB rate was low 1.0%, with 4.1% in EGD patients and 0.57% in non-EGD patients (aHR=7.99, 95% CI 4.13-15.45, p<0.005). The 12-month cumulative MACE rate overall was 39.9% and no significant difference between EGD and non-EGD patients. Conclusion Our real-world data demonstrated that the presence of anaemia is common among ACS patients. The yield of EGD in identifying sources of upper GI bleeding was low and there was no difference in 12-month clinical outcome among EGD patients. Although EGD was associated with higher rates of 12-month bleeding events, the cause was unclear with very low incidence of upper GI bleeding events. Therefore, the benefits of routine EGD prior to PCI in ACS patients with anaemic is unclear.

The effectiveness and barrier of reverse cascade screening for paediatric familial hypercholesterolaemia

Abstract Background Familial Hypercholesterolaemia (FH) is an autosomal dominant genetic disorder that is prevalent in one out of every 300 individuals in the general population. Recognized as an actionable condition, early diagnosis of FH in children is crucial to prevent the onset of atherosclerosis, and equally important is the identification of parents before the development of coronary artery disease events. Therefore, the significance of universal FH screening during childhood combined with reverse cascade screening has been increasingly acknowledged. To achieve these objectives, in our region, universal lipid screening is conducted in elementary schools for children aged 9 or 10 years, annually screening approximately 8,000 individuals, with those identified being referred through a three-step process to four major healthcare facilities within the prefecture. However, the effectiveness of reverse-cascade screening remains unclear. Purpose Our study aimed to assess the effectiveness of and identify barriers to implementing reverse cascade screening in conjunction with universal lipid screening. Methods We conducted a single-center, retrospective observational study from January 2018 to July 2023 and evaluated the utility of reverse cascade screening for children genetically diagnosed with FH following universal screening. This study analysed prevalent barriers and identified families with suspected FH through reverse cascade screening, counting those with Potential FH among second-degree relatives. Beyond successful identification, we categorized the frequently encountered barriers into five distinct categories: bereavement, prior cardiovascular events, dyslipidaemia with unspecified LDL-C levels, incomplete family history information, and inadequate disease awareness of FH. Reverse FH diagnosis adhered to current guidelines. Results and Discussion Of 151 paediatric patients referred to our facility, 67 were genotypically confirmed to have FH. Excluding 8 cases of divorce and 4 cases of tracking challenges, 55 patients were finally analysed. 62 patients were diagnosed with reverse FH, and appropriate treatment was initiated. Notably, 158 cases of Potential FH were identified. (25 first-degree and 133 second-degree relatives). While a higher number of reverse FH diagnoses were observed in first-degree relatives (55 cases), the diagnostic yield was lower among second-degree relatives (seven cases). Common barriers for second-degree relatives included dyslipidaemia with unspecified LDL-C levels (42 cases) and incomplete family history information (66 cases). Conclusion Integrating universal screening with reverse cascade screening facilitates the identification of new FH cases. A comprehensive strategy for diagnosing reverse FH is paramount, raising disease awareness, genetic testing, the development of a family-based care plan, and enhancing access to information and communication technologies.

Exploring the diagnostic yield of family screening and genetic testing in adolescent individuals with pre-clinical phenotypes

Abstract Introduction Family screening and genetic testing are key components in the management strategy of individuals diagnosed with an inherited cardiac condition (ICC). Disease penetrance for most ICCs, notably cardiomyopathies is age dependent, which is why a more permissive approach towards family screening is adopted in young individuals with a pre-clinical phenotype. Study Objectives The main objective of this study was to explore the role of family screening and genetic testing in adolescent subjects with a pre-clinical phenotype has not been formally explored. Methodology Adolescent probands with a pre-clinical phenotype following a national cardiac screening program (BEAT-IT) were offered genetic testing and family screening. Probands with anterior TWI were rescreened at 16 years. Only those with persistent changes were enrolled in the study. Genetic counselling was also offered to probands and relatives. Testing was initially offered to first degree relatives. Cascade testing (clinical and genetic) was also offered to other generations if a screened relative satisfied one or more of these conditions i) phenotype positive, ii) pre-clinical phenotype, iii) clinically relevant genotype. Results 16 probands (mean age 15 years) were identified with a pre-clinical phenotype. All had an abnormal ECG (9=inferior/lateral TWI, 6=anterior TWI, 1=ST depression). A comprehensive evaluation was otherwise normal. Half were gene positive (G+), 4 had clinically relevant genotypes (n=4 inferior/lateral TWI). These were classified as likely pathogenic according to ACMG criteria (n=2 MYH7, n=1 ACTC1, n=1 MYBPC3). 71 family members were subsequently screened (59.2% female, median 43Y [IQR 27] at evaluation, 11.3% <18Y at evaluation, 67.6% first degree relatives). A substantial proportion (n=13, 18.3%) were referred for further evaluation. Two (2/8, 25.0%) were <18Y. An abnormal ECG was the commonest reason for referral (n=9, 12.7%). Three (4.2%) were given a diagnosis (n=2 HCM [both MYH7}, n=1 DCM [ACTC1]). Seven (9.9%) were referred because of an abnormal ECG (n=3 inferolateral TWI, n=2 ventricular ectopics, n=1 anterolateral TWI, n=1 ST depression). Four were G+ and were offered surveillance. Fourteen (19.7%) were offered family screening because of incorporating genetic testing into the study protocol. Genetics altered the evaluation strategy in 16.9% of screened relatives. More in-depth cascade testing identified 6 (8.5%) individuals who needed follow-up (n=1 diagnosis [DCM], n=1 abnormal ECG, n=4 G+). Gene negative individuals (6, 8.5%) were safely reassured and discharged. Conclusion Family screening in adolescent probands with pre-clinical phenotypes offers a reasonable diagnostic yield (4.2% diagnosis, 14.1% surveillance). Incorporating genetic testing into the evaluation protocol offers a more personalized strategy, altering management in a significant proportion of screened relatives (16.9%).

Whole-exome sequencing to identify causative variants in cases of sudden cardiac death below 50 years

Abstract Background Sudden cardiac death (SCD) in individuals under 50 frequently remains unexplained, especially when no structural cardiac abnormalities are present, a condition known as sudden arrhythmic death (SAD). This study assesses the utility of whole exome sequencing (WES) with a comprehensive gene panel in elucidating the genetic foundations of SCD. Methods SCD autopsy cases from a university hospital (1995-2023) were analysed both retrospectively and prospectively. WES was conducted on 32 cases, employing a virtual panel of 1,304 genes. Variant prioritization was based on pathogenicity according to American College of Medical Genetics and Genomics guidelines. Results WES unveiled causative variants in 22 out of 32 cases (68% diagnostic yield). Of these, 12 cases (38%) possessed pathogenic or likely pathogenic variants, and 17 highly suspicious variants of uncertain significance (VUS/LP) were identified in 10 patients (31%). The diagnostic yield of our comprehensive panel (69%) surpassed that of major susceptibility gene panels, with 22% for primary susceptibility genes and 56% for the TruSight Cardio Panel. Half of the cases had multiple variants, underscoring the genetic complexity of SCD. Of the genes analysed, 18 were associated with cardiac disease on OMIM or ClinGen, while 9, unique to our panel, were linked to cardiac function but had disputed or limited disease associations. Conclusions WES with a specific gene panel, a scheme for variant prioritization, and a comprehensive, multidisciplinary approach to variant interpretation is an effective approach to genetic testing in SCD cases ≤50 years.Added value of WES

Enhancing the selection of heart failure patients for invasive procedures: how machine learning can predict the diagnostic yield of endomyocardial biopsy

Abstract Background Determining the etiology of heart failure (HF) is crucial for appropriate treatment. Endomyocardial biopsy (EMB) is an invasive procedure that complements clinical assessment and imaging in diagnosing various cardiac disorders. The diagnostic value of EBM depends upon the anticipated yield of the procedure. Whether results from non-invasive examinations may predict the diagnostic yield from EMB is unclear. Purpose We aimed to investigate the relative importance of clinical and instrumental features in predicting a diagnostic EMB result, using a machine learning (ML) approach. Methods We retrospectively examined 665 consecutive adult patients with HF symptoms who underwent right EBM as part of their diagnostic work-up. The primary outcome was a positive biopsy result with a clear diagnosis. The ML algorithm consisted of Gradient Boosting Machines (GBM), with computation of relative variable importance using conditional importance. We calculated the conditional variable importance for 53 clinical or instrumental variables. Model performance was evaluated using a receiver operating characteristic curve, which was compared to a logistic regression model using the same variables. Validation was performed using a 10-fold cross-validation model. Results Among the 665 patients (50±14 years, 67% male), the EMB provided a diagnosis in 138 cases (20.8%). Patients attaining diagnosis were more often older, had a shorter disease duration, presented with ventricular arrhythmia or cardiac arrest, had a pacemaker or defibrillator, displayed higher creatinine, NT-proBNP and high-sensitive troponin T levels, and had smaller ventricular volumes with higher ejection fraction at CMR. All patients with a diagnostic EMB showed late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) in the right ventricle, the right atrium or in the left atrium. The relative importance of different variables predicting outcomes is presented in Figure 1. The top six included four distinct CMR features and two circulating biomarkers (NT-proBNP and high-sensitive troponin T). LGE in the right ventricle and the presence of left ventricular hypertrophy were stronger predictors compared to the remaining variables. The GBM model performed significantly better than the logistic regression model (AUC GBM 0.98, AUC logistic regression 0.93, DeLong’s test p<0.001) (Figure 2). Conclusion Using a ML algorithm, CMR LGE, left ventricular hypertrophy, and elevated cardiac biomarkers, stand out as strong overall predictors of an endomyocardial biopsy with a high diagnostic yield.Figure 1Figure 2

Clinical genome sequencing in patients with suspected rare genetic disease in Peru

There is limited access to molecular genetic testing in most low- and middle-income countries. The iHope program provides clinical genome sequencing (cGS) to underserved individuals with signs or symptoms of rare genetic diseases and limited or no access to molecular genetic testing. Here we describe the performance and impact of cGS in 247 patients from three clinics in Peru. Although most patients had at least one genetic test prior to cGS (70.9%), the most frequent was karyotyping (53.4%). The diagnostic yield of cGS was 54.3%, with candidate variants reported in an additional 22.3% of patients. Clinical GS results impacted clinician diagnostic evaluation in 85.0% and genetic counseling in 72.1% of cases. Changes in management were reported in 71.3%, inclusive of referrals (64.7%), therapeutics (26.3%), laboratory or physiological testing (25.5%), imaging (19%), and palliative care (17.4%), suggesting that increased availability of genomic testing in Peru would enable improved patient management.

Autosomal recessive VWA1-related disorder: comprehensive analysis of phenotypic variability and genetic mutations

Abstract A newly identified subtype of hereditary axonal motor neuropathy, characterized by early proximal limb involvement, has been discovered in a cohort of 34 individuals with biallelic variants in von Willebrand factor A domain containing 1 (VWA1). This study further delineates the disease characteristics in a cohort of 20 individuals diagnosed through genome or exome sequencing, incorporating neurophysiological, laboratory, and imaging data, along with data from previously reported cases across three different studies. Newly reported clinical features include hypermobility/hyperlaxity, axial weakness, dysmorphic signs, asymmetric presentation, dystonic features, and, notably, upper motor neuron signs. Foot drop, foot deformities, and distal leg weakness followed by early proximal leg weakness are confirmed to be initial manifestations. Additionally, this study identified 11 novel VWA1 variants, reaffirming the 10bp insertion-induced p.Gly25ArgfsTer74 as the most prevalent disease-causing allele, with a carrier frequency of ∼1 in 441 in the UK and Western European population. Importantly, VWA1-related pathology may mimic various neuromuscular conditions, advocating for its inclusion in diverse gene panels spanning hereditary neuropathies to muscular dystrophies. The study highlights the potential of lower quality control filters in exome analysis to enhance diagnostic yield of VWA1-disease that may account for up to 1% of unexplained hereditary neuropathies.

Prevalence and implications of cardiomyopathy-associated genetic variants in early-onset atrial fibrillation

Abstract Background Atrial fibrillation (AF) is a common and morbid arrhythmia. Despite a substantial heritable component, genetics does not currently play a role in personalized medicine for AF. Rare genetic variants in genes associated with inherited cardiomyopathies (CMP) are enriched in AF patients. However, prior studies on rare variants in AF mainly relied on hospital-based populations, and knowledge on clinical outcomes remains limited. Purpose We aimed to evaluate the potential diagnostic yield and prognostic implication of pathogenic or likely pathogenic (PLP) genetic variants for CMP in persons with AF, using large population-based cohorts. Methods This study utilized sequencing data and electronic health records (EHR) from the All of Us Researh Program (AllofUs) and UK Biobank (UKB). Using ClinVar, we curated a set of PLP variants in 36 CMP-associated genes and assessed the carrier prevalence overall, in participants with AF, and in participants with early-onset AF (below 65, 55 and 45 years). Next, we used Cox proportional hazards models to evaluate the association between variant carrier status and incident risk of heart failure or CMP, after AF diagnosis. In all time-to-event analyses, individuals with prevalent heart failure or CMP at AF diagnosis were excluded and models were adjusted for age, sex, and principal components of ancestry. Sensitivity analyses were performed requiring a minimum period from AF to HF or CMP, of 1, 3 and 6 months. Results After excluding related individuals, we identified 32,281 (8.19%) and 9,666 (6.06%) AF cases in UKB and AllofUs, respectively. Compared to the overall populations (UKB: 1.15%; AllofUs: 1.36%), PLP variants for CMP were about ~5 times more prevalent in AF with onset before 45 (UKB: 4.98%; AllofUs: 5.26%), ~3 times more prevalent in AF with onset before 55 (UKB: 3.41%; AllofUs: 4.34%) and ~2 times more prevalent in all AF patients (UKB: 2.03%; AllofUs: 2.67%). In turn, AF patients carrying PLP variants had increased risk of developing heart failure or CMP, after AF diagnosis (AllofUs HR 1.81, 1.44-2.29, p<1e10-6, UKB:HR=1.39 1.08-1.78, p<0.01), which remained present when requiring a minimum of 6 months after AF diagnosis (AllofUs:HR 1.70, 1.29-2.25, p<0.001; UKB:HR=1.59, 1.21-2.07, p<0.001). Effect sizes were greater when limiting analysis to AF patients with onset before 65 (cases=1021, HR 1.91, 1.35-2.68, p<0.0001) and before 55 years (cases=384, HR 2.53, 1.55-4.1, p <0.001) in AllofUs. UK Biobank did not reflect this increase (cases<65=513, HR<65=1.27, 0.63-2.39, p<65>0.05). Considering only HF events in AllofUs, the effect remained present (HR 1.70, 1.32-2.19, p<0.0001). Conclusion The yield of CMP-associated PLP variants is substantial among persons with early-onset AF, even when considering a 55 year cutoff. AF patients with PLP variants have an increased risk of future heart failure or CMP. Our results further support the clinical relevance of genetic testing in early-onset AF.Prevalence of CMP variants in AF by age

CCTA and CTP imaging for detecting clinically suspected in-stent restenosis: a meta-analysis

Abstract Background The evaluation of coronary artery stents via Coronary Computed Tomography Angiography (CCTA) can be compromised by artefacts, potentially undermining its diagnostic accuracy. The integration of CT Perfusion (CTP) with CCTA (CCTA+CTP) has been proposed to enhance the diagnostic yield in detecting in-stent restenosis (ISR). Purpose This meta-analysis aims to assess the diagnostic performance of CCTA and combined CCTA+CTP in detecting ISR. Methods A comprehensive literature search of studies from 2005 to 2022 identified 13,747 articles. Inclusion criteria comprised the utilization of multidetector CT scanners with ≥64 slices and invasive coronary angiography as the reference standard. Studies that systematically evaluated stent patency in asymptomatic patients as part of their protocol were excluded. Results After removing duplicates, screening titles and abstracts, and conducting full-text reviews, 20 studies met the inclusion criteria (17 CCTA, 3 CCTA+CTP). Data on 2,674 CCTA-assessed stents and 752 CCTA+CTP-assessed stents were analyzed. The meta-analysis revealed that CCTA alone achieved a sensitivity of 90% (95% CI; 84-94%) and a specificity of 89% (95% CI; 86-92%)(Figure 1). CCTA+CTP exhibited comparable diagnostic performance, with a per-stent sensitivity of 88% (95% CI; 80-94%) and a specificity of 88% (95% CI; 84-93%) (Figure 2). The summary Receiver Operating Characteristic (sROC) Area Under the Curve (AUC) was 0.96 (95% CI; 0.94-0.97) for CCTA and 0.96 (95% CI; 0.89-1.00) for CCTA+CTP, indicating a high overall performance for both diagnostic modalities. Conclusion Utilizing contemporary imaging hardware, both CCTA and CCTA+CTP demonstrate high diagnostic performance in evaluating ISR. The findings suggest that the presence of coronary artery stents should not preclude the use of these non-invasive diagnostic tests in clinical practice.Figure 1Figure 2

High prevalence of cardiotropic viruses in endomyocardial biopsies from patients with inflammatory cardiomyopathy demonstrated by a novel targeted NGS approach

Abstract Background Viral infection of the heart muscle is a common cause of myocarditis and viral persistence can lead to chronic inflammatory cardiomyopathies (DCMi). A number of viruses including parvovirus B19 (B19V), adenovirus (AdV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes virus 6 (HHV-6) and enteroviruses (EV) are known to infect the myocardium, but their prevalence and role in persisting DCMi are not well understood. Virological etiologies can only be determined via endomyocardial biopsy (EMB), but the low tissue amount limits the number of conventional viral nucleic acid tests (virus-specific PCR) that can be performed in parallel. This study aimed to detect known and novel cardiotropic viruses in EMB of DCMi patients using a targeted next generation sequencing (NGS) approach. Methods A cohort of 33 patients with inflammatory cardiomyopathy (DCMi) (LVEF=29±12%) were retrospectively analyzed and compared to previous results of virus-specific PCR. DNA and RNA extracted from EMB were used for sequencing library preparation, and viral nucleic acids were enriched via a custom myBaits hybridization capture approach. Enriched libraries were sequenced on an Illumina MiSeq-platform in paired-end mode (500.000 reads/sample), and reads were taxonomically classified via Kraken2 and mapped against viral reference genomes using BWA-MEM2 or HiSat2, and subsequently deduplicated. Viral reads detected via both Kraken2 and mapping were classified as valid. Results Targeted NGS confirmed 19 out of 22 (86%) of the previous PCR-based viral detections. However, NGS was able to detect B19V DNA and RNA in an additional 11 and 15 patient samples respectively; CMV DNA/RNA in additional 5 and 4 samples respectively; EBV DNA/RNA in additional 5 and 1 samples respectively; and HHV-6 DNA/RNA in additional 3 and 1 samples respectively. Furthermore, viral reads of adenovirus type 2, adenovirus-associated virus type 2 (AAV-2), herpes viruses 7 and 8, and human parvovirus 4 were also found among the cohort. Thus, targeted NGS was able to identify 82 viral infections in a cohort of 33 DCMi patients, while only 22 were found using routine PCR tests. For routinely tested B19V, the use of the new NGS diagnostic approach improved sensitivity by 42% and specificity by 72%. Conclusions The presented NGS method represents a powerful new tool for the diagnosis of viral and inflammatory heart disease. The sensitivity is significantly higher than with conventional PCR approaches and the taxonomic classification is more specific. This enables the detection of previously false-negative routine viruses as well as potentially new cardiotropic pathogens from limited bioptic patient material – thus significantly increasing the diagnostic yield of EMB. In addition, our study demonstrates a high prevalence of non-enteroviral cardiotropic viruses in DCMi patients, shedding new light on the etiology of this heterogenous diseases and paving the way for more specific future treatments.

Myocarditis in the modern era: analysing the impact of high-sensitivity troponin & C-reactive protein in predicting the extent of myocarditis and LV systolic dysfunction on cardiac magnetic resonance

Abstract Background The diagnostic yield of acute myocarditis has improved considerably since the advent of high-sensitivity troponin (hs-Tn) assays and adoption of the 2018 Lake Louise criteria for cardiac magnetic resonance (CMR)-based imaging for myocardial oedema and injury (1). Yet, a seminal 1997 study, predating these technological advances, remains widely cited for highlighting an absence of troponin rise in two-thirds of myocarditis cases (2). We hypothesize that all cases of myocarditis exhibit hs-Tn rise. However, whether such elevations in hs-Tn or inflammatory markers correlate with the extent of myocardial injury and left ventricular systolic dysfunction (LVSD) on CMR remain unclear. To provide insight into this, we examined a contemporary cohort of cases between 2019-2023. Methods Two authors independently conducted case-notes reviews to verify the diagnosis of myocarditis. CMR findings were stratified into regional (e.g. inferolateral) and global myocarditis (e.g. subepicardial LGE in all segments). This classification aimed to explore potential correlations with LVSD severity, peak hs-Tn and other inflammatory markers. Receiver operating characteristics (ROC) curves was calculated to determine any cut-off value for predicting CMR findings and adverse patient outcomes. Results 103 inpatients were clinically coded as ‘myocarditis’ upon discharge, but subsequent CMR (within 4 weeks) reclassified 23 patients into other causes (Figure 1). Analysis of the myocarditis cohort revealed a predominantly male population (76%) with median age 53, commonly presenting with chest pain without a viral prodrome (Figure 2A-D). Elevated hs-Tn levels were observed universally, with a median peak hs-TnT of 610ng/L (IQR 1081.5ng/L) and hs-TnI of 3820ng/L (IQR 12416ng/L). In contrast, peak CRP ranged between 2mg/L (normal) and 600mg/L. Global myocarditis was detected in 11/80 patients (13.8%); however, this finding did not correlate with adverse patient outcomes which included all-cause mortality (9.6%) and cardiac re-admissions within 12 months (9.6%, namely for chest pains). No arrhythmic deaths were noted. COVID was present in 4% on admission. CRP cut-off of 140mg/L predicted the occurrence of global myocarditis with a sensitivity of 72.7% and specificity of 87.0% (AUC 0.74, 95% CI 0.52-0.96, p=0.014) (Figure 2E). However, neither hs-Tn or CRP levels correlated with the degree of LVSD (Figure 2F) or adverse outcomes. This is likely limited by the small sample. Conclusion Although all cases of myocarditis exhibited raised hs-Tn, this did not correlate with the degree of LV systolic impairment on CMR. Myocarditis with regional LV involvement can have normal CRP levels, while a CRP cut-off >140mg/L may predict the occurrence of global myocarditis. However, CMR stratification into regional and global was not associated with adverse patient outcome within 12 months. A larger sample size is required to verify this finding, including longer term follow-ups.Flowchart of patients included in studyMain findings

Rates of therapeutic interventions in a large real-world cohort with insertable cardiac monitors

Abstract Background Insertable cardiac monitors (ICMs) provide up to several years of continuous monitoring and have demonstrated high diagnostic yields for arrhythmia detection. However, the rates of arrhythmia-related therapeutic interventions following ICM implant have not been comprehensively characterized across indicated patient populations. Purpose To quantify rates of arrhythmia therapies in a large, real-world U.S. cohort of ICM patients. Methods De-identified patients receiving a Reveal LINQ ICM between Oct 1, 2016 – Sept 30, 2020 with no prior cardiac implantable electronic devices (CIEDs) and ≥1 year of follow-up in the Optum Clinformatics® Data Mart claims database were identified (N=17,037). Patients were stratified by indication for ICM placement: N=431 (2.5%) of patients were indicated for AF ablation monitoring, 2,193 (12.9%) for AF management, N=4,852 (28.5%) Cryptogenic stroke, N=1,252 (7.3%) Palpitations, 1,346 (7.9%) Suspected AF, 6,716 (39.4%) Unexplained syncope, and 247 (1.4%) Ventricular tachycardia (VT). Each patient was followed in the claims database after ICM insertion until end of continuous claims enrollment, end of database, or death. Therapeutic interventions for arrhythmias were characterized during follow-up, including procedures (CIED implants, cardioversion, and ablation) and arrhythmia medication initiation (antiarrhythmics, rate-control medications, and oral anticoagulants). Results Mean(SD) follow-up in the claims database post ICM placement was 3.4(1.3) years; 52.4% of patients were female, and mean age was 70.8(11.9) years. Overall, 54.5% of patients received a therapeutic intervention during follow-up, with 25.0% of patients receiving a therapeutic procedure and 44.0% initiating an arrhythmia-related medication (table). The highest procedure rates included implantable pulse generator (IPG) implants in the Unexplained syncope population (21.4% of patients) and cardiac ablations in the populations receiving ICM for known AF (27.8% of AF ablation monitoring patients and 23.5% of AF management patients). Medication initiation rates were highest for oral anticoagulants in the Cryptogenic stroke population (31.0% of patients). The mean time from ICM insertion to therapeutic action was 13(13) months for procedures and 7(11) months for medication initiation. Conclusions In a large sample of real-world ICM patients, more than half received a therapeutic intervention after ICM placement. Time to intervention was lengthy and showed substantial variability amongst patients, underscoring the importance of long-term continuous monitoring to uncover clinically-relevant arrhythmia findings.