Back to Authors

Saadatagah, Seyedmohammad

https://orcid.org/0000-0003-4950-8334

Mayo Clinic

Mayo Clinic

Citations 20

Abstract 12798: Somatic Mosaicism in Blood Cells is a Risk Factor for Incident Heart Failure in 200,628 UK Biobank Participants
Kullo, Iftikhar, Satterfield, Benjamin A. , Saadatagah, Seyedmohammad , Dikilitas, Ozan

Circulation | April 23, 2024 | Volume: 144 | Issue: Suppl_1 | Pages: No page available

10.1161/circ.144.suppl_1.12798 Get It

Introduction: Somatic mutations accrue in hematopoietic stem cells with age and can lead to selective clonal expansion, a process termed Clonal Hematopoiesis of Indeterminate Potential (CHIP). CHIP has been associated with increased risk of coronary heart disease (CHD) and myocardial infarction (MI). Whether CHIP is a risk factor for incident heart failure is unclear. Methods: The presence of CHIP was assessed in exome sequence data from 200,628 UKB participants using the Genome Analysis Toolkit pipeline and filtering somatic mutations from a pre-specified list within DNMT3A , TET2 , and ASXL1 . CHIP was defined as somatic mutations in these 3 genes with variant allele fraction (VAF) >10%. We ascertained incident heart failure (overall, ischemic, and non-ischemic), death, cardiovascular death, and coronary heart disease (CHD defined as of MI and/or coronary revascularization) as determined by UKB algorithms, self-report, and diagnosis/procedure codes. Cox proportional hazard models adjusted for age, sex, self-reported race/ethnicity, diabetes, hypertension, smoking, and BMI were used to assess whether CHIP was associated with incident adverse events. Results: We identified 3,885 participants with CHIP in DNMT3A , TET2 , and ASXL1 at a VAF of >10%. Over a median follow-up of 9 years, 2,055 participants developed incident heart failure. CHIP was associated with both ischemic and non-ischemic heart failure. We replicated previously reported associations of CHIP with death and incident CHD ( Table ). Conclusions: CHIP was associated with increased risk of both ischemic and non-ischemic heart failure. The association with ischemic subtype is likely mediated by the increased risk of CHD. The basis for the increased hazard of non-ischemic heart failure is unclear but may be due to an inflammatory milieu in CHIP carriers.
Atrial Fibrillation and Clonal Hematopoiesis in TET2 and ASXL1
Selvin, Elizabeth , Matsushita, Kunihiro , Nambi, Vijay , Yu, Bing , Bick, Alexander G. , Li, Na , Shah, Amil M. , Natarajan, Pradeep , Selvin, Elizabeth , Selvin, Elizabeth , Natarajan, Pradeep , Bick, Alexander G , Shah, Amil , Saadatagah, Seyedmohammad , Naderian, Mohammadreza , Uddin, Md Mesbah , Dikilitas, Ozan , Niroula, Abhishek , Schuermans, Art , Hoogeveen, Ron Cornelis , Chen, Lin Y. , Ebert, Benjamin L. , Honigberg, Michael C. , Kullo, Iftikhar J. , Ballantyne, Christie M.

JAMA Cardiology | April 10, 2024 | Volume: 9 | Issue: 6 | Pages: 497

10.1001/jamacardio.2024.0459 Get It

ImportanceClonal hematopoiesis of indeterminate potential (CHIP) may contribute to the risk of atrial fibrillation (AF) through its association with inflammation and cardiac remodeling.ObjectiveTo determine whether CHIP was associated with AF, inflammatory and cardiac biomarkers, and cardiac structural changes.Design, Setting, and ParticipantsThis was a population-based, prospective cohort study in participants of the Atherosclerosis Risk in Communities (ARIC) study and UK Biobank (UKB) cohort. Samples were collected and echocardiography was performed from 2011 to 2013 in the ARIC cohort, and samples were collected from 2006 to 2010 in the UKB cohort. Included in this study were adults without hematologic malignancies, mitral valve stenosis, or previous mitral valve procedure from both the ARIC and UKB cohorts; additionally, participants without hypertrophic cardiomyopathy and congenital heart disease from the UKB cohort were also included. Data analysis was completed in 2023.ExposuresCHIP (variant allele frequency [VAF] ≥2%), common gene-specific CHIP subtypes (DNMT3A, TET2, ASXL1), large CHIP (VAF ≥10%), inflammatory and cardiac biomarkers (high-sensitivity C-reactive protein, interleukin 6 [IL-6], IL-18, high-sensitivity troponin T [hs-TnT] and hs-TnI, N-terminal pro–B-type natriuretic peptide), and echocardiographic indices.Main Outcome MeasureIncident AF.ResultsA total of 199 982 adults were included in this study. In ARIC participants (4131 [2.1%]; mean [SD] age, 76 [5] years; 2449 female [59%]; 1682 male [41%]; 935 Black [23%] and 3196 White [77%]), 1019 had any CHIP (24.7%), and 478 had large CHIP (11.6%). In UKB participants (195 851 [97.9%]; mean [SD] age, 56 [8] years; 108 370 female [55%]; 87 481 male [45%]; 3154 Black [2%], 183 747 White [94%], and 7971 other race [4%]), 11 328 had any CHIP (5.8%), and 5189 had large CHIP (2.6%). ARIC participants were followed up for a median (IQR) period of 7.0 (5.3-7.7) years, and UKB participants were followed up for a median (IQR) period of 12.2 (11.3-13.0) years. Meta-analyzed hazard ratios for AF were 1.12 (95% CI, 1.01-1.25; P = .04) for participants with vs without large CHIP, 1.29 (95% CI, 1.05-1.59; P = .02) for those with vs without large TET2 CHIP (seen in 1340 of 197 209 [0.67%]), and 1.45 (95% CI, 1.02-2.07; P = .04) for those with vs without large ASXL1 CHIP (seen in 314 of 197 209 [0.16%]). Large TET2 CHIP was associated with higher IL-6 levels. Additionally, large ASXL1 was associated with higher hs-TnT level and increased left ventricular mass index.Conclusions and RelevanceLarge TET2 and ASXL1, but not DNMT3A, CHIP was associated with higher IL-6 level, indices of cardiac remodeling, and increased risk for AF. Future research is needed to elaborate on the mechanisms driving the associations and to investigate potential interventions to reduce the risk.
Abstract 17155: Lipoprotein (a) Testing in an Academic Medical System
Hamed, Marwan , Alhalabi, Lubna, Teymourzadeh, Azin , Nur, Yakub, Sherafati, Alborz , Naderian, Mohammadreza , Saadatagah, Seyedmohammad , Kullo, Iftikhar J.

Circulation | December 19, 2023 | Volume: 148 | Issue: Suppl_1 | Pages: No page available

10.1161/circ.148.suppl_1.17155 Get It

Introduction: Lp(a) is a causal risk factor for ASCVD that is often elevated in patients with personal or family history (FHx) of ASCVD. The 2019 ESC guidelines recommend universal Lp(a) testing, while the 2019 AHA/ACC guidelines include Lp(a) as a ‘risk enhancer’. We used electronic health records (EHR) to assess utilization of Lp(a) testing in patients with ASCVD, premature ASCVD, and FHx of ASCVD at Mayo Clinic sites in Rochester MN, Phoenix AZ and Jacksonville FL and the Mayo Clinic Health System (MCHS) from 1999-2021. Methods: We ascertained Lp(a) testing using LOINC codes and ASCVD status using validated ICD/CPT-based algorithms. ASCVD included coronary heart disease (CHD), cerebrovascular disease (CVD) (ischemic stroke and/or carotid artery stenosis), peripheral artery disease, and abdominal aortic aneurysm. Premature ASCVD was defined as occurring in males < 55 years and females < 65 years. We ascertained FHx using EHR survey data from 2017-2021. We estimated the proportion of patients with ASCVD, premature ASCVD, or FHx of ASCVD who underwent Lp(a) testing. Results: Between 1999-2021, we identified 310,760 patients with at least 1 ASCVD subtype of whom 66,710 had premature disease. FHx data was available starting 2017. For the timeframe 2017-2021, we identified 267,177 patients with FHx of ASCVD and 90,269 ASCVD patients. As summarized in Table 1, Lp(a) was tested only in a small proportion of patients; 7% of ASCVD patients, 11% of premature ASCVD patients, and 6% of patients with FHx of ASCVD. Premature CHD patients had the highest testing proportion (17%). Conclusions: Our results demonstrate underutilization of Lp(a) testing in patients with personal or FHx of ASCVD. Lp(a) is one of the mediators of “ASCVD residual risk” in patients on statins, and with new Lp(a)-lowering medications in phase III clinical trials, patient and provider education will be needed to increase awareness of Lp(a) as a modulator of ASCVD risk.
Abstract 15853: Long-Term Outcomes of Young Patients With Chest Pain and Normal Epicardial Coronary Arteries: A 10-Year Prospective Study
Ramandi, Alireza , Alipasandi, Kian , Pourhosseini, Hamidreza, sadeghian, saeed, Naderian, Mohammadreza , Saadatagah, Seyedmohammad , Sadeghian, Saeed

Circulation | December 19, 2023 | Volume: 148 | Issue: Suppl_1 | Pages: No page available

10.1161/circ.148.suppl_1.15853 Get It

Introduction: Long-term outcomes of young patients with chest pain and normal epicardial coronary arteries (NECA) in angiography remain understudied. Methods: We conducted a prospective study in a tertiary heart hospital between 2004-2020, enrolling men<45 and women<55 years presenting with symptoms or objective findings of coronary artery disease (CAD) and confirmed NECA in angiography. Patients with cardiomyopathy, coronary anomaly, and significant valvular, renal, pulmonary, or liver diseases were excluded. The primary outcome was MACCE, defined as the composite of death, CCU admission (for MI or unstable angina), stroke, and revascularization. Follow-ups were done every 5 years using a standardized questionnaire and a committee of experts reviewed all the events. Expected age and sex-adjusted mortality rates were estimated using national data. The association between exposures and MACCE was studied using multivariable Cox-proportional hazard models. Results: 1257 patients, 340 (27.05%) men (38.34±5.46 years), and 917 (72.95%) women (48.41±4.94 years) were included. 698 (55.53%) had acute and 559 (44.47%) had chronic symptoms. Over the median 9.4 (8.5-11.0) years of follow-up, 134 (10.66%) events happened. CCU admission (6.33%) was the most common event (Figure). The 10-year mortality rate (per 100,000-person-years) was 265 for men and 174 for women, which were 1.6 and 2.5 times higher than the age-sex-matched rate of the normal population, respectively. Diabetes, hypertension, and presenting with acute symptoms were associated with higher MACCE with the hazard ratios (95% CI) of 1.87 (1.05-3.31, P:0.03), 1.72 (1.13-2.61, P:0.01), and 1.56 (1.03-2.36, P:0.04), respectively. During follow-up, 192 (15.27%) repeated angiographies were done and 19.8% developed obstructive CAD. Conclusions: In young patients with chest pain and NECA, approximately 10% experienced MACCE during a 10-year follow-up, and the mortality is higher than expected.
Abstract 15784: Clonal Hematopoiesis of Indeterminate Potential is Associated With Increased Risk of Incident Hypertension
Naderian, Mohammadreza , Saadatagah, Seyedmohammad , Dikilitas, Ozan , Kullo, Iftikhar J.

Circulation | December 19, 2023 | Volume: 148 | Issue: Suppl_1 | Pages: No page available

10.1161/circ.148.suppl_1.15784 Get It

Introduction: Clonal hematopoiesis of indeterminate potential (CHIP) is associated with an increased risk of heart failure (HF) and stroke, particularly HF with preserved ejection fraction and hemorrhagic stroke (HS). Hypothesis: We hypothesized that CHIP is associated with incident hypertension and this association mediates the effect of CHIP on HF and HS. Methods: In 200K UK-Biobank participants with exome sequencing, we ascertained CHIP as variant allele fraction (VAF) ≥2% and large CHIP as VAF ≥10%. Hypertension, HF, and HS diagnosis were determined based on the ICD-9 and ICD-10 codes. Cox proportional hazards models were used to test the association of both CHIP and the CHIP subtypes based on the most implicated driver genes (i.e., DNMT3A , TET2 , and ASXL1 ) with incident hypertension. Logistic regression models were used for mediation analyses, quantifying the extent to which hypertension mediates the effects of CHIP. Results: After excluding those with hematological malignancy (n=1,025) and pre-existing hypertension (n=14,754), 184,760 participants (56.14±8.12 years, 44.25% male, and 95.33% white ethnicity) were included. During a median follow-up of 12.2 years, 42,049 (22.76%) participants developed hypertension. CHIP mutations were significantly associated with incident hypertension (Table). Mutations in DNMT3A and TET2 but not ASXL1 drove this association. Mediation analysis revealed 17.9% (9.4% - 38.2%, P<0.001) of the effect of CHIP on HF and 5.7% (2.4% - 22.4%, P<0.001) of the effect on HS were mediated through the increased risk of hypertension. Conclusion: CHIP is associated with an increased risk of hypertension. The association of CHIP with HF and HS is partially mediated by hypertension. These findings suggest a new mechanistic pathway for the association of CHIP with cardiovascular diseases.
Abstract 13711: Clonal Hematopoiesis Driven by TET2 and ASXL1 but Not DNMT3A is Associated With Interleukin 6 Levels, Cardiac Biomarkers, Cardiac Remodeling, and R
Matsushita, Kuni, Nambi, Vijay , Yu, Bing , Saadatagah, Seyedmohammad , Naderian, Mohammadreza , Uddin, Md Mesbah , Dikilitas, Ozan , Schuermans, Art , Niroula, Abhishek , Selvin, Elizabeth , Hoogeveen, Ron Cornelis , Matsushita, Kunihiro , Chen, Lin Y. , Bick, Alexander G. , Ebert, Benjamin L. , Honigberg, Michael C. , Li, Na , Shah, Amil M. , Natarajan, Pradeep , Kullo, Iftikhar J. , Ballantyne, Christie M.

Circulation | December 19, 2023 | Volume: 148 | Issue: Suppl_1 | Pages: No page available

10.1161/circ.148.suppl_1.13711 Get It

Introduction: Aging and inflammation are associated with risk of atrial fibrillation (AF), to which clonal hematopoiesis of indeterminate potential (CHIP) may contribute. We investigated whether CHIP was associated with AF, inflammatory and cardiac biomarkers and cardiac structural changes. Methods: We ascertained CHIP (variant allele frequency, VAF ≥2%) in the Atherosclerosis Risk in Community Study (ARIC visit-5, n = 4,131) and the UK Biobank (UKBB, n = 195,851) participants. Using multivariable Cox regression models, we studied the association of CHIP and the top three implicated genes (i.e., DNMT3A , TET2 , ASXL1 ) with incident AF and conducted a meta-analysis on both cohorts. We also ascertained high-sensitivity C-reactive protein (hs-CRP), interleukin 6 (IL6), IL18, high-sensitivity troponin T and I (hs-TnT and hs-TnI), NT-proBNP, and echocardiography indices in ARIC. We first standardized the natural log of all markers (st-ln) and used the adjusted quantile regression to compare the median in those with and without CHIP. Results: In ARIC, the mean ± SD age was 75.8 ± 5.2 years, 41% were men, 23% were Black, 25% had CHIP, and 11.6% had large CHIP (VAF ≥10%). These measures in UKBB were 56.4 ± 8.1 years, 45%, 2%, 5.8%, and 2.6%, respectively. In the meta-analysis, compared to those without CHIP, the hazard ratios (95% confidence interval) for AF were 1.12 (1.01 - 1.25, P =0.035), 1.31 (1.07 - 1.60, P =0.009), and 1.48 (1.05 - 2.08, P =0.026) for Large-CHIP, Large- TET2, and Large- ASXL1 , respectively. hs-CRP and IL18 levels were similar in those with and without CHIP as well as gene-specific subgroups. Large- TET2 and ASXL1 were associated with higher IL6, which was separately associated with AF. Additionally, Large- ASXL1 was associated with increased left ventricle mass index and NT-proBNP (coefficients in Figure 1 ). Conclusion: Large TET2 and ASXL1 but not DNMT3A CHIP is associated with higher IL6 levels, indices of cardiac remodeling, and an increased risk of AF.
Abstract 10822: Familial Hypercholesterolemia in the EMERGE Network: 1-Year Outcomes After Return of Results
Kochan, David C., Perez, Emma , Anderson, Katherine , Salvati, Zachary , Hebbring, Scott J. , Gibbs, Richard A. , Linder, Jodell E. , Roden, Dan M. , Manolio, Teri A. , Sherafati, Alborz , Dikilitas, Ozan , Saadatagah, Seyedmohammad , Satterfield, Benjamin A. , Jones, Laney K , Sharp, Richard R. , Sturm, Amy C. , Zouk, Hana , Venner, Eric , Chung, Wendy K. , Peterson, Josh F. , Jarvik, Gail P. , Rehm, Heidi L. , Roden, Dan M. , Williams, Marc S , Kullo, Iftikhar J.

Circulation | June 15, 2023 | Volume: 146 | Issue: Suppl_1 | Pages: No page available

10.1161/circ.146.suppl_1.10822 Get It

Introduction: Relatively little is known about outcomes following return of secondary findings detected in large scale sequencing projects. We assessed 1-year outcomes following return of pathogenic/likely pathogenic (P/LP) variants associated with familial hypercholesterolemia (FH) in phase III of the eMERGE network (2015-2019). Methods: Adult participants (n=18,544) at 7 sites were enrolled in a prospective cohort study to study the clinical impact of returning results from targeted sequencing of 68 actionable genes, including LDLR , APOB , and PCSK9 . Process, intermediate, and/or clinical outcomes within 1-year after return of results (RoR) were ascertained by electronic health record (EHR) review. A process outcome was defined as referral to a specialist or ordering new tests, including lipid profile and screening tests for coronary heart disease. An intermediate outcome was defined as new diagnosis of FH or atherosclerotic cardiovascular disease. A clinical outcome was defined as initiation or change in lipid-lowering medication. The primary outcomes were a new diagnosis of FH and modification of lipid lowering therapy. Results: Results were returned to 134 individuals, and data for 119 participants were available for the outcomes analysis. Process (86%), intermediate (49%), and/or clinical (26%) outcomes occurred in 92% of participants. Process outcomes included 72% with new tests ordered and 61% referred to a specialist. Before RoR, 86.5% of individuals with FH associated P/LP variants had a diagnosis of hypercholesterolemia but only 17.6% had a diagnosis of FH; 89% were on a statin but only 58% were on a high intensity statin. Following RoR, 44% (52/119) received a new diagnosis of FH. Lipid lowering treatment was modified in 26% (31/119), including initiation of a statin in 5%, increasing statin dose in 13%, and adding ezetimibe or a PCSK9 inhibitor in 12.6%. Conclusions: In a multisite cohort of EHR-linked biobanks, monogenic FH was underdiagnosed (only 17.6% had a specific diagnosis) and undertreated (only 58% were on a high intensity statin); 44% of participants received a new diagnosis of FH and 26% had lipid lowering treatment modified after RoR. These results highlight the clinical utility of returning FH variants in EHR-linked biobanks.
Abstract 10360: Polygenic Risk Score, Rare Monogenic Variants, and Family History Have Independent and Additive Effects on the Risk of Coronary Heart Disease
Hamed, Marwan , Miller, Alexandra , Bangash, Hana , Nigbur, Scott, Kamzabek, Arailym, Norland, Kristján , Kosel, Matt, Schaid, Daniel J. , Saadatagah, Seyedmohammad , Nigbur, Scott, Kamzabek, Arailym, Kosel, Matthew , Kullo, Iftikhar J.

Circulation | June 15, 2023 | Volume: 146 | Issue: Suppl_1 | Pages: No page available

10.1161/circ.146.suppl_1.10360 Get It

Introduction. We assessed the effects of a polygenic risk score (PRS), monogenic variants (Mono + ), and family history (FamHx) on the risk of coronary heart disease (CHD) and whether incorporating a PRS into the Pooled Cohort Equations (PCE) improves risk prediction. Method. In 199,997 UK Biobank participants, we calculated a PRS CHD (metaGRS, based on ~1.6 million single nucleotide variants), identified individuals with monogenic etiology (presence of a pathogenic variant in LDLR , APOB , or PCSK9 ), and ascertained family history of CHD (CHD in a first-degree relative). Odds of CHD (myocardial infarction/ coronary revascularization/ cardiovascular death) associated with PRS CHD , Mono + , and FamHx at age 55 were computed using logistic regression analyses adjusted for age, sex, and first 4 principal components of ancestry. We combined PRS CHD and PCE into an integrated score (IS) and assessed net reclassification using an actionable risk threshold of 7.5%. Results. The odds ratio (OR) for CHD in the top 5 th percentile of PRS CHD (PRS P95 ), Mono + , and FamHx were 3.37 (2.98 - 3.81), 2.68 (1.67 - 4.07), and 1.61 (1.47 - 1.76), respectively (all p<0.001). These effects were independent and similar in different subgroups. ( Figure 1-A ) Compared to PRS Q2-4 Mono - (3 middle quintiles of PRS CHD and no monogenic variants), the OR for CHD ranged from 1.73 (0.28 - 5.48, p = 0.446) in PRS Q1 Mono + to 5.10 (2.14 - 10.24, p <0.001) in PRS Q5 Mono + . A similar pattern was seen for other combinations, indicating additive effects ( Figure 1-B ). Incorporating PRS CHD into PCE resulted in a net reclassification improvement of 4.56%. Compared to those with high PCE and low IS, the hazard ratio for CHD in those with low PCE and high IS was 1.48 (1.34 - 1.64, p <0.001). Conclusion. The CHD risk associated with PRS CHD , monogenic variants, and family history is independent and additive. Combining PRS CHD and PCE improved risk prediction, that could improve further by adding monogenic variants and family history.
Clinician Perspectives on Clinical Decision Support for Familial Hypercholesterolemia
Bangash, Hana , Elsekaily, Omar, Saadatagah, Seyedmohammad , Sutton, Joseph , Johnsen, Paul J., Gundelach, Justin H. , Kamzabek, Arailym, Johnsen, Paul, Freimuth, Robert, Freimuth, Robert R. , Caraballo, Pedro J. , Kullo, Iftikhar J.

Journal of Personalized Medicine | May 31, 2023 | Volume: 13 | Issue: 6 | Pages: 929

10.3390/jpm13060929 Get It

Familial Hypercholesterolemia (FH) is underdiagnosed in the United States. Clinical decision support (CDS) could increase FH detection once implemented in clinical workflows. We deployed CDS for FH at an academic medical center and sought clinician insights using an implementation survey. In November 2020, the FH CDS was deployed in the electronic health record at all Mayo Clinic sites in two formats: a best practice advisory (BPA) and an in-basket alert. Over three months, 104 clinicians participated in the survey (response rate 11.1%). Most clinicians (81%) agreed that CDS implementation was a good option for identifying FH patients; 78% recognized the importance of implementing the tool in practice, and 72% agreed it would improve early diagnosis of FH. In comparing the two alert formats, clinicians found the in-basket alert more acceptable (p = 0.036) and more feasible (p = 0.042) than the BPA. Overall, clinicians favored implementing the FH CDS in clinical practice and provided feedback that led to iterative refinement of the tool. Such a tool can potentially increase FH detection and optimize patient management.
Familial Hypercholesterolemia in the Electronic Medical Records and Genomics Network: Prevalence, Penetrance, Cardiovascular Risk, and Outcomes After Return of Results
Dikilitas, Ozan , Sherafati, Alborz , Saadatagah, Seyedmohammad , Kochan, David C., Anderson, Katherine , Chung, Wendy K. , Hebbring, Scott J. , Salvati, Zachary , Sharp, Richard R. , Sturm, Amy C. , Gibbs, Richard A. , Rowley, Robb , Linder, Jodell E. , Perez, Emma , Peterson, Josh F. , Jarvik, Gail P. , Roden, Dan M. , Manolio, Teri A. , Satterfield, Benjamin A , Anderson, Katherine C , Chung, Wendy K. , Salvati, Zachary M , Sharp, Richard R , Sturm, Amy C , Rowley, Robb , Venner, Eric , Linder, Jodell E , Jones, Laney K , Peterson, Josh F , Jarvik, Gail P , Rehm, Heidi L , Zouk, Hana , Roden, Dan M. , Williams, Marc S , Manolio, Teri A , Kullo, Iftikhar J , Dikilitas, Ozan , Satterfield, Benjamin A. , Venner, Eric , Rehm, Heidi L. , Kullo, Iftikhar J.

Circulation: Genomic and Precision Medicine | February 22, 2023 | Volume: 16 | Issue: 2 | Pages: No page available

10.1161/circgen.122.003816 Get It

Background: The implications of secondary findings detected in large-scale sequencing projects remain uncertain. We assessed prevalence and penetrance of pathogenic familial hypercholesterolemia (FH) variants, their association with coronary heart disease (CHD), and 1-year outcomes following return of results in phase III of the electronic medical records and genomics network. Methods: Adult participants (n=18 544) at 7 sites were enrolled in a prospective cohort study to assess the clinical impact of returning results from targeted sequencing of 68 actionable genes, including LDLR , APOB , and PCSK9 . FH variant prevalence and penetrance (defined as low-density lipoprotein cholesterol >155 mg/dL) were estimated after excluding participants enrolled on the basis of hypercholesterolemia. Multivariable logistic regression was used to estimate the odds of CHD compared to age- and sex-matched controls without FH-associated variants. Process (eg, referral to a specialist or ordering new tests), intermediate (eg, new diagnosis of FH), and clinical (eg, treatment modification) outcomes within 1 year after return of results were ascertained by electronic health record review. Results: The prevalence of FH-associated pathogenic variants was 1 in 188 (69 of 13,019 unselected participants). Penetrance was 87.5%. The presence of an FH variant was associated with CHD (odds ratio, 3.02 [2.00–4.53]) and premature CHD (odds ratio, 3.68 [2.34–5.78]). At least 1 outcome occurred in 92% of participants; 44% received a new diagnosis of FH and 26% had treatment modified following return of results. Conclusions: In a multisite cohort of electronic health record–linked biobanks, monogenic FH was prevalent, penetrant, and associated with presence of CHD. Nearly half of participants with an FH-associated variant received a new diagnosis of FH and a quarter had treatment modified after return of results. These results highlight the potential utility of sequencing electronic health record–linked biobanks to detect FH.