Sex-Based Differences in the Epidemiology, Clinical Characteristics, and Outcomes Associated with Worsening Heart Failure Events in a Learning Health System.

BACKGROUND: Differences in demographics, risk factors, and clinical characteristics may contribute to variations in men and women in terms of the prevalence, clinical setting, and outcomes associated with worsening heart failure (WHF) events. We sought to describe sex-based differences in the epidemiology, clinical characteristics, and outcomes associated with WHF events across clinical settings. METHODS AND RESULTS: We examined adults diagnosed with HF from 2010 to 2019 within a large, integrated health care delivery system. Electronic health record data were accessed for hospitalizations, emergency department (ED) visits and observation stays, and outpatient encounters. WHF was identified using validated natural language processing algorithms and defined as ≥1 symptom, ≥2 objective findings (including ≥1 sign), and ≥1 change in HF-related therapy. Incidence rates and associated outcomes for WHF were compared across care setting by sex. We identified 1,122,368 unique clinical encounters with a diagnosis code for HF, with 124,479 meeting WHF criteria. These WHF encounters existed among 102,116 patients, of whom 48,543 (47.5%) were women and 53,573 (52.5%) were men. Women experiencing WHF were older and more likely to have HF with preserved ejection fraction compared with men. The clinical settings of WHF were similar among women and men: hospitalizations (36.8% vs 37.7%), ED visits or observation stays (11.8% vs 13.4%), and outpatient encounters (4.4% vs 4.9%). Women had lower odds of 30-day mortality after an index hospitalization (adjusted odds ratio 0.88, 95% confidence interval 0.83-0.93) or ED visit or observation stay (adjusted odds ratio 0.86, 95% confidence interval 0.75-0.98) for WHF. CONCLUSIONS: Women and men contribute similarly to WHF events across diverse clinical settings despite marked differences in age and left ventricular ejection fraction.

Haplotype analysis of the internationally distributed BRCA1 c.3331_3334delCAAG founder mutation reveals a common ancestral origin in Iberia.

BACKGROUND: The BRCA1 c.3331_3334delCAAG founder mutation has been reported in hereditary breast and ovarian cancer families from multiple Hispanic groups. We aimed to evaluate BRCA1 c.3331_3334delCAAG haplotype diversity in cases of European, African, and Latin American ancestry. METHODS: BC mutation carrier cases from Colombia (n = 32), Spain (n = 13), Portugal (n = 2), Chile (n = 10), Africa (n = 1), and Brazil (n = 2) were genotyped with the genome-wide single nucleotide polymorphism (SNP) arrays to evaluate haplotype diversity around BRCA1 c.3331_3334delCAAG. Additional Portuguese (n = 13) and Brazilian (n = 18) BC mutation carriers were genotyped for 15 informative SNPs surrounding BRCA1. Data were phased using SHAPEIT2, and identical by descent regions were determined using BEAGLE and GERMLINE. DMLE+ was used to date the mutation in Colombia and Iberia. RESULTS: The haplotype reconstruction revealed a shared 264.4-kb region among carriers from all six countries. The estimated mutation age was ~ 100 generations in Iberia and that it was introduced to South America early during the European colonization period. CONCLUSIONS: Our results suggest that this mutation originated in Iberia and later introduced to Colombia and South America at the time of Spanish colonization during the early 1500s. We also found that the Colombian mutation carriers had higher European ancestry, at the BRCA1 gene harboring chromosome 17, than controls, which further supported the European origin of the mutation. Understanding founder mutations in diverse populations has implications in implementing cost-effective, ancestry-informed screening.

Identification of recurrent atrial fibrillation using natural language processing applied to electronic health records.

AIMS: This study aimed to develop and apply natural language processing (NLP) algorithms to identify recurrent atrial fibrillation (AF) episodes following rhythm control therapy initiation using electronic health records (EHRs). METHODS AND RESULTS: We included adults with new-onset AF who initiated rhythm control therapies (ablation, cardioversion, or antiarrhythmic medication) within two US integrated healthcare delivery systems. A code-based algorithm identified potential AF recurrence using diagnosis and procedure codes. An automated NLP algorithm was developed and validated to capture AF recurrence from electrocardiograms, cardiac monitor reports, and clinical notes. Compared with the reference standard cases confirmed by physicians' adjudication, the F-scores, sensitivity, and specificity were all above 0.90 for the NLP algorithms at both sites. We applied the NLP and code-based algorithms to patients with incident AF (n = 22 970) during the 12 months after initiating rhythm control therapy. Applying the NLP algorithms, the percentages of patients with AF recurrence for sites 1 and 2 were 60.7% and 69.9% (ablation), 64.5% and 73.7% (cardioversion), and 49.6% and 55.5% (antiarrhythmic medication), respectively. In comparison, the percentages of patients with code-identified AF recurrence for sites 1 and 2 were 20.2% and 23.7% for ablation, 25.6% and 28.4% for cardioversion, and 20.0% and 27.5% for antiarrhythmic medication, respectively. CONCLUSION: When compared with a code-based approach alone, this study's high-performing automated NLP method identified significantly more patients with recurrent AF. The NLP algorithms could enable efficient evaluation of treatment effectiveness of AF therapies in large populations and help develop tailored interventions.

Eligibility and Potential Benefit of Transcatheter Edge-to-Edge Repair in a Contemporary Cohort With Heart Failure: Evidence From a Large Integrated Health Care Delivery System.

Background: The eligibility and potential benefit of transcatheter edge-to-edge repair (TEER) in addition to guideline-directed medical therapy to treat moderate-severe or severe secondary mitral regurgitation (MR) has not been reported in a contemporary heart failure (HF) population. Methods: Eligibility for TEER based on Food and Drug Administration (FDA) labeling: (1) HF symptoms, (2) moderate-severe or severe MR, (3) left ventricular ejection fraction (LVEF) 20% to 50%, (4) left ventricular end-systolic dimension 7.0 cm, and (5) receiving GDMT (blocker + angiotensin-converting enzyme inhibitor/angiotensin receptor blocker). The proportion (%) of patients eligible for TEER. The hypothetical number needed to treat to prevent or postpone adverse outcomes was estimated using relative risk reductions from published hazard ratios in the registration trial and the observed event rates. Results: We identified 50,841 adults with HF and known LVEF. After applying FDA criteria, 2461 patients (4.8%) were considered eligible for transcatheter mitral valve replacement (FDA+), with the vast majority of patients excluded (FDA-) based on a lack of clinically significant MR (N = 47,279). FDA+ patients had higher natriuretic peptide levels and were more likely to have a prior HF hospitalization compared to FDA- patients. Although FDA+ patients had a more dilated left ventricle and lower LVEF, median (25th-75th) left ventricular end-systolic dimension (cm) was low at 4.4 (3.7-5.1) and only 30.8% had severely reduced LVEF. FDA+ patients were at higher risk of HF-related morbidity and mortality. The estimated number needed to treat to potentially prevent or postpone all-cause hospitalization was 4.4, 8.8 for HF hospitalization, and 5.3 for all-cause death at 24 months in FDA+ patients. Conclusions: There is a low prevalence of TEER eligibility based on FDA criteria primarily due to absence of moderate-severe or severe MR. FDA+ patients are a high acuity population and may potentially derive a robust clinical benefit from TEER based on pivotal studies. Additional research is necessary to validate the scope of eligibility and comparative effectiveness of TEER in real-world populations.

Clinical Outcomes of Direct Oral Anticoagulants vs Warfarin for Extended Treatment of Venous Thromboembolism.

Importance: Extending the duration of oral anticoagulation for venous thromboembolism (VTE) beyond the initial 3 to 6 months of treatment is often recommended, but it is not clear whether clinical outcomes differ when using direct oral anticoagulants (DOACs) or warfarin. Objective: To compare rates of recurrent VTE, hospitalizations for hemorrhage, and all-cause death among adults prescribed DOACs or warfarin whose anticoagulant treatment was extended beyond 6 months after acute VTE. Design, Setting, and Participants: This cohort study was conducted in 2 integrated health care delivery systems in California with adults aged 18 years or older who received a diagnosis of incident VTE between 2010 and 2018 and completed at least 6 months of oral anticoagulant treatment with DOACs or warfarin. Patients were followed from the end of the initial 6-month treatment period until discontinuation of anticoagulation, occurrence of an outcome event, health plan disenrollment, or end of the study follow-up period (December 31, 2019). Data were obtained from the Kaiser Permanente Virtual Data Warehouse and electronic health records. Data analysis was conducted from March 2022 to January 2023. Exposure: Dispensed prescriptions of DOACs or warfarin after a 6-month initial treatment for VTE. Main Outcomes and Measures: The primary outcomes were rates per 100 person-years of recurrent VTE, hospitalizations for hemorrhage, and all-cause death. Comparison of DOAC and warfarin outcomes were performed using multivariable Cox proportional hazards regression. Results: A total of 18 495 patients (5477 [29.6%] aged ≥75 years; 8973 women [48.5%]) with VTE who were treated with at least 6 months of anticoagulation were identified, of whom 2134 (11.5%) were receiving DOAC therapy and 16 361 (88.5%) were receiving warfarin therapy. Unadjusted event rates were lower for patients receiving DOAC therapy than warfarin therapy for recurrent VTE (event rate per 100 person-years, 2.92 [95% CI, 2.29-3.54] vs 4.14 [95% CI, 3.90-4.38]), hospitalizations for hemorrhage (event rate per 100 person-years, 1.02 [95% CI, 0.66-1.39] vs 1.81 [95% CI, 1.66-1.97]), and all-cause death (event rate per 100 person-years, 3.79 [95% CI, 3.09-4.49] vs 5.40 [95% CI, 5.13-5.66]). After multivariable adjustment, DOAC treatment was associated with a lower risk of recurrent VTE (adjusted hazard ratio [aHR], 0.66; 95% CI, 0.52-0.82). For patients prescribed DOAC treatment, the risks of hospitalization for hemorrhage (aHR, 0.79; 95% CI, 0.54-1.17) and all-cause death (aHR, 0.96; 95% CI, 0.78-1.19) were not significantly different than those for patients prescribed warfarin treatment. Conclusions and Relevance: In this cohort study of patients with VTE who continued warfarin or DOAC anticoagulation beyond 6 months, DOAC treatment was associated with a lower risk of recurrent VTE, supporting the use of DOACs for the extended treatment of VTE in terms of clinical outcomes.

Assessment of the Risk of Venous Thromboembolism in Nonhospitalized Patients With COVID-19.

Importance: Patients hospitalized with COVID-19 have higher rates of venous thromboembolism (VTE), but the risk and predictors of VTE among individuals with less severe COVID-19 managed in outpatient settings are less well understood. Objectives: To assess the risk of VTE among outpatients with COVID-19 and identify independent predictors of VTE. Design, Setting, and Participants: A retrospective cohort study was conducted at 2 integrated health care delivery systems in Northern and Southern California. Data for this study were obtained from the Kaiser Permanente Virtual Data Warehouse and electronic health records. Participants included nonhospitalized adults aged 18 years or older with COVID-19 diagnosed between January 1, 2020, and January 31, 2021, with follow-up through February 28, 2021. Exposures: Patient demographic and clinical characteristics identified from integrated electronic health records. Main Outcomes and Measures: The primary outcome was the rate per 100 person-years of diagnosed VTE, which was identified using an algorithm based on encounter diagnosis codes and natural language processing. Multivariable regression using a Fine-Gray subdistribution hazard model was used to identify variables independently associated with VTE risk. Multiple imputation was used to address missing data. Results: A total of 398 530 outpatients with COVID-19 were identified. The mean (SD) age was 43.8 (15.8) years, 53.7% were women, and 54.3% were of self-reported Hispanic ethnicity. There were 292 (0.1%) VTE events identified over the follow-up period, for an overall rate of 0.26 (95% CI, 0.24-0.30) per 100 person-years. The sharpest increase in VTE risk was observed during the first 30 days after COVID-19 diagnosis (unadjusted rate, 0.58; 95% CI, 0.51-0.67 per 100 person-years vs 0.09; 95% CI, 0.08-0.11 per 100 person-years after 30 days). In multivariable models, the following variables were associated with a higher risk for VTE in the setting of nonhospitalized COVID-19: age 55 to 64 years (HR 1.85 [95% CI, 1.26-2.72]), 65 to 74 years (3.43 [95% CI, 2.18-5.39]), 75 to 84 years (5.46 [95% CI, 3.20-9.34]), greater than or equal to 85 years (6.51 [95% CI, 3.05-13.86]), male gender (1.49 [95% CI, 1.15-1.96]), prior VTE (7.49 [95% CI, 4.29-13.07]), thrombophilia (2.52 [95% CI, 1.04-6.14]), inflammatory bowel disease (2.43 [95% CI, 1.02-5.80]), body mass index 30.0-39.9 (1.57 [95% CI, 1.06-2.34]), and body mass index greater than or equal to 40.0 (3.07 [1.95-4.83]). Conclusions and Relevance: In this cohort study of outpatients with COVID-19, the absolute risk of VTE was low. Several patient-level factors were associated with higher VTE risk; these findings may help identify subsets of patients with COVID-19 who may benefit from more intensive surveillance or VTE preventive strategies.

Outcomes of Adults with Severe Aortic Stenosis Undergoing Urgent or Emergent vs. Elective Transcatheter Aortic Valve Replacement Within an Integrated Health Care Delivery System.

Background: Transcatheter aortic valve replacement (TAVR) may be used to urgently or emergently treat severe aortic stenosis, but outcomes for this high-risk population have not been well-characterized. We sought to describe the incidence, clinical characteristics, and outcomes of patients undergoing urgent or emergent vs. elective TAVR. Methods: We identified all adults who received TAVR for primary aortic stenosis between 2013 and 2019 within an integrated health care delivery system in Northern California. Elective or urgent/emergent procedure status was based on standard Society of Thoracic Surgeons definitions. Data were obtained from electronic health records, the Society of Thoracic Surgeons-American College of Cardiology Transcatheter Valve Therapy Registry, and state/national reporting databases. Logistic regression and Cox proportional hazard models were performed. Results: Among 1564 eligible adults that underwent TAVR, 81 (5.2%) were classified as urgent/emergent. These patients were more likely to have heart failure (63.0% vs. 47.4%), reduced left ventricular ejection fraction (21.0% vs. 11.8%), or a prior aortic valve balloon valvuloplasty (13.6% vs. 5.0%) and experienced higher unadjusted rates of 30-day and 1-year morbidity and mortality. Urgent/emergent TAVR status was independently associated with non-improved quality of life at 30-days (hazard ratio, 4.87; p < 0.01) and acute kidney injury within 1-year post-TAVR (hazard ratio, 2.11; p = 0.01). There was not a significant difference in adjusted 1-year mortality with urgent/emergent TAVR. Conclusions: Urgent/emergent TAVR status was uncommon and associated with high-risk clinical features and higher unadjusted rates of short- and long-term morbidity and mortality. Procedure status may be useful to identify patients less likely to experience significant short term improvement in health-related quality of life post-TAVR.

Temporal trends in the prevalence and severity of aortic stenosis within a contemporary and diverse community-based cohort.

BACKGROUND: Data on the epidemiology of aortic stenosis (AS) are primarily derived from single center experiences and administrative claims data that do not delineate by degree of disease severity. METHODS: An observational cohort study of adults with echocardiographic AS was conducted January 1st, 2013-December 31st, 2019 at an integrated health system. The presence/grade of AS was based on physician interpretation of echocardiograms. RESULTS: A total of 66,992 echocardiogram reports for 37,228 individuals were identified. The mean ± standard deviation (SD) age was 77.5 ± 10.5, 50.5% (N = 18,816) were women, and 67.2% (N = 25,016) were non-Hispanic whites. The age-standardized AS prevalence increased from 589 (95% Confidence Interval [CI] 580-598) to 754 (95% CI 744-764) cases per 100,000 during the study period. The age-standardized AS prevalences were similar in magnitude among non-Hispanic whites (820, 95% CI 806-834), non-Hispanic blacks (728, 95% CI 687-769), and Hispanics (789, 95% CI 759-819) and substantially lower for Asian/Pacific Islanders (511, 95% CI 489-533). Finally, the distribution of AS by degree of severity remained relatively unchanged over time. CONCLUSIONS AND RELEVANCE: The population prevalence of AS has grown considerably over a short timeframe although the distribution of AS severity has remained stable.

Diagnostic Yield, Outcomes, and Resource Utilization With Different Ambulatory Electrocardiographic Monitoring Strategies.

Accurate diagnosis of arrhythmias is improved with longer monitoring duration but can risk delayed diagnosis. We compared diagnostic yield, outcomes, and resource utilization by arrhythmia monitoring strategy in 330 matched adults (mean age 64 years, 40% women, and 30% non-White) without previously documented atrial fibrillation or atrial flutter (AF/AFL) who received ambulatory electrocardiographic monitoring by 14-day Zio XT (patch-based continuous monitor), 24-hour Holter, or 30-day event monitor (external loop recorder) between October 2011 and May 2014. Patients were matched by age, gender, site, likelihood of receiving Zio XT patch, and indication for monitoring, and subsequently followed for monitoring results, management changes, clinical outcomes, and resource utilization. AF/AFL ≥30 seconds was noted in 6% receiving Zio XT versus 0% by Holter (p = 0.04) and 3% by event monitor (p = 0.07). Nonsustained ventricular tachycardia was noted in 24% for Zio XT patch versus 8% (p <0.001) for Holter and 4% (p <0.001) for event monitor. No significant differences between monitoring strategies in outcomes or resource utilization were observed. Prolonged monitoring with 14-day Zio XT patch or 30-day event monitor was superior to 24-hour Holter in detecting new AF/AFL but not different from each other. Documented nonsustained ventricular tachycardia was more frequent with Zio XT than 24-hour Holter and 30-day event monitor without apparent increased risk of adverse outcomes or excess utilization. In conclusion, additional efforts are needed to further personalize electrocardiographic monitoring strategies that optimize clinical management and outcomes.

Adverse Events After Initiating Angiotensin-Converting Enzyme Inhibitor/Angiotensin II Receptor Blocker Therapy in Individuals with Heart Failure and Multimorbidity.

BACKGROUND: Current clinical practice guidelines recommend routine kidney function and serum potassium testing within 30 days of initiating angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker (ARB) therapy. However, evidence is lacking on whether routine follow-up testing reduces therapy-related adverse events in adults with heart failure and if multimorbidity influences the association between laboratory testing and these adverse events. METHODS: We conducted a retrospective cohort study among adults with heart failure from 4 US integrated health care delivery systems. Multimorbidity was defined using counts of chronic conditions. Patients with outpatient serum creatinine and potassium tests in the 30 days after starting ACEI or ARB therapy were matched 1:1 to patients without follow-up tests. We evaluated the association of follow-up testing with 30-day all-cause mortality and hospitalization with acute kidney injury or hyperkalemia using Cox regression. RESULTS: We identified 3629 matched adults with heart failure initiating ACEI or ARB therapy between January 1, 2005, and December 31, 2012. Follow-up testing was not significantly associated with 30-day all-cause mortality (adjusted hazard ratio [aHR] 0.45, 95% confidence interval [CI] 0.14; 1.39) and hospitalization with hyperkalemia (aHR 0.73, 95% CI, 0.33; 1.61). However, follow-up testing was significantly associated with hospitalization with acute kidney injury (aHR, 1.40, 95% CI, 1.01; 1.94). Interaction between multimorbidity burden and follow-up testing was not statistically significant in any of the outcome models examined. CONCLUSIONS: Routine laboratory monitoring after ACEI or ARB therapy initiation was not associated with risk of 30-day all-cause mortality or hospitalization with hyperkalemia across the spectrum of multimorbidity burden in a cohort of patients with heart failure.

The anticoagulation length of therapy and risk of new adverse events in venous thromboembolism (ALTERNATIVE) study: Design and survey results.

The Anticoagulation Length of Therapy and Risk of New Adverse Events In Venous Thromboembolism (ALTERNATIVE) study was designed to compare the benefits and harms of different treatment options for extended treatment of venous thromboembolism (VTE). In this paper, we describe the study cohort, survey data collection, and preliminary results. We identified 39,605 adult patients (age ≥ 18 years) from two large integrated health care delivery systems who were diagnosed with incident VTE and received initial anticoagulation therapy of 3 months or longer. A subset of the cohort (12,737) was invited to participate in a survey. Surveys were completed in English, Spanish or Mandarin via a mailed questionnaire, an online secure web link, or telephone. The survey domains included demographics, personal medical history, anticoagulant treatment history, anticoagulant treatment satisfaction, health-related quality of life and health literacy. A total of 5,017 patients participated in the survey for an overall response rate of 39.4%. The mean (SD) age of the survey respondents was 63.0 (14.5) years and self-reported race was 76.0% White/European, 11.1% Black/African American, and 3.8% Asian/Pacific Islander and 14.0% reported Hispanic ethnicity. Sixty percent of respondents completed the web survey, while 29.0% completed the mail-in paper survey, and 11.0% completed the survey via telephone. The ALTERNATIVE Study will address knowledge gaps by comparing several treatment alternatives for the extended management of VTE so that this information could be used by patients and clinicians to make more informed, patient-centered treatment choices.

COVID-19 and Risk of VTE in Ethnically Diverse Populations.

BACKGROUND: Limited existing data suggest that the novel COVID-19 may increase risk of VTE, but information from large, ethnically diverse populations with appropriate control participants is lacking. RESEARCH QUESTION: Does the rate of VTE among adults hospitalized with COVID-19 differ from matched hospitalized control participants without COVID-19? STUDY DESIGN AND METHODS: We conducted a retrospective study among hospitalized adults with laboratory-confirmed COVID-19 and hospitalized adults without evidence of COVID-19 matched for age, sex, race or ethnicity, acute illness severity, and month of hospitalization between January 2020 and August 2020 from two integrated health care delivery systems with 36 hospitals. Outcomes included VTE (DVT or pulmonary embolism ascertained using diagnosis codes combined with validated natural language processing algorithms applied to electronic health records) and death resulting from any cause at 30 days. Fine and Gray hazards regression was performed to evaluate the association of COVID-19 with VTE after accounting for competing risk of death and residual differences between groups, as well as to identify predictors of VTE in patients with COVID-19. RESULTS: We identified 6,319 adults with COVID-19 and 6,319 matched adults without COVID-19, with mean ± SD age of 60.0 ± 17.2 years, 46% women, 53.1% Hispanic, 14.6% Asian/Pacific Islander, and 10.3% Black. During 30-day follow-up, 313 validated cases of VTE (160 COVID-19, 153 control participants) and 1,172 deaths (817 in patients with COVID-19, 355 in control participants) occurred. Adults with COVID-19 showed a more than threefold adjusted risk of VTE (adjusted hazard ratio, 3.48; 95% CI, 2.03-5.98) compared with matched control participants. Predictors of VTE in patients with COVID-19 included age ≥ 55 years, Black race, prior VTE, diagnosed sepsis, prior moderate or severe liver disease, BMI ≥ 40 kg/m2, and platelet count > 217 k/µL. INTERPRETATION: Among ethnically diverse hospitalized adults, COVID-19 infection increased the risk of VTE, and selected patient characteristics were associated with higher thromboembolic risk in the setting of COVID-19.

Contemporary Burden and Correlates of Symptomatic Paroxysmal Supraventricular Tachycardia.

BACKGROUND: Contemporary data about symptomatic paroxysmal supraventricular tachycardia (PSVT) epidemiology are limited. We characterized prevalence and correlates of symptomatic PSVT within a large healthcare delivery system and estimated national PSVT burden. METHODS AND RESULTS: We identified adults with an encounter for potential PSVT between 2010 and 2015 in Kaiser Permanente Northern California, excluding those with prior known atrial fibrillation or atrial flutter. We adjudicated medical records, ECGs, and other monitoring data to estimate positive predictive values for targeted International Classification of Diseases (ICD), 9th and 10th Revisions codes in inpatient, emergency department, and outpatient settings. Combinations of diagnosis codes and settings were used to calculate PSVT prevalence, and PSVT correlates were identified using multivariable regression. We estimated national rates by applying prevalence estimates in Kaiser Permanente to 2010 US Census data. The highest positive predictive values included codes for "PSVT" in the emergency department (82%), "unspecified cardiac dysrhythmia" in the emergency department (27%), "anomalous atrioventricular excitation" as a primary inpatient diagnosis (33%), and "unspecified paroxysmal tachycardia" as a primary inpatient diagnosis (23%). Prevalence of symptomatic PSVT was 140 per 100 000 (95% confidence interval, 100-179) and was higher for individuals who were older, women, white or black, or who had valvular heart disease, heart failure, diabetes mellitus, lung disease, or prior bleeding. We estimate the national prevalence of symptomatic PSVT to be 168 per 100 000 (95% confidence interval, 120-215). CONCLUSIONS: Selected diagnostic codes in inpatient and emergency department settings may be useful to identify symptomatic PSVT episodes. We project that at least 0.168% of US adults experience symptomatic PSVT, and certain characteristics can identify people at higher risk.