Maternal Nativity and Preterm Birth.

Importance: Preterm birth is a major contributor to neonatal morbidity and mortality, and considerable differences exist in rates of preterm birth among maternal racial and ethnic groups. Emerging evidence suggests pregnant individuals born outside the US have fewer obstetric complications than those born in the US, but the intersection of maternal nativity with race and ethnicity for preterm birth is not well studied. Objective: To determine if there is an association between maternal nativity and preterm birth rates among nulliparous individuals, and whether that association differs by self-reported race and ethnicity of the pregnant individual. Design, Setting, and Participants: This was a nationwide, cross-sectional study conducted using National Center for Health Statistics birth registration records for 8 590 988 nulliparous individuals aged 15 to 44 years with singleton live births in the US from 2014 to 2019. Data were analyzed from March to May 2022. Exposures: Maternal nativity (non-US-born compared with US-born individuals as the reference, wherein US-born was defined as born within 1 of the 50 US states or Washington, DC) in the overall sample and stratified by self-reported ethnicity and race, including non-Hispanic Asian and disaggregated Asian subgroups (Asian Indian, Chinese, Filipino, Japanese, Korean, Pacific Islander, Vietnamese, and other Asian), non-Hispanic Black, Hispanic and disaggregated Hispanic subgroups (Cuban, Mexican, Puerto Rican, and other Hispanic), and non-Hispanic White. Main Outcomes and Measures: The primary outcome was preterm birth (<37 weeks of gestation) and the secondary outcome was very preterm birth (<32 weeks of gestation). Results: Of 8 590 988 pregnant individuals included (mean [SD] age at delivery, 28.3 [5.8] years in non-US-born individuals and 26.2 [5.7] years in US-born individuals; 159 497 [2.3%] US-born and 552 938 [31.2%] non-US-born individuals self-identified as Asian or Pacific Islander, 1 050 367 [15.4%] US-born and 178 898 [10.1%] non-US-born individuals were non-Hispanic Black, 1 100 337 [16.1%] US-born and 711 699 [40.2%] non-US-born individuals were of Hispanic origin, and 4 512 294 [66.1%] US-born and 328 205 [18.5%] non-US-born individuals were non-Hispanic White), age-standardized rates of preterm birth were lower among non-US-born individuals compared with US-born individuals (10.2%; 95% CI, 10.2-10.3 vs 10.9%; 95% CI, 10.9-11.0) with an adjusted odds ratio (aOR) of 0.90 (95% CI, 0.89-0.90). The greatest relative difference was observed among Japanese individuals (aOR, 0.69; 95% CI, 0.60-0.79) and non-Hispanic Black individuals (aOR, 0.74; 0.73-0.76) individuals. Non-US-born Pacific Islander individuals experienced higher preterm birth rates compared with US-born Pacific Islander individuals (aOR, 1.15; 95% CI, 1.04-1.27). Puerto Rican individuals born in Puerto Rico compared with those born in US states or Washington, DC, also had higher preterm birth rates (aOR, 1.07; 95% CI, 1.03-1.12). Conclusions and Relevance: Overall preterm birth rates were lower among non-US-born individuals compared with US-born individuals. However, there was substantial heterogeneity in preterm birth rates across maternal racial and ethnic groups, particularly among disaggregated Asian and Hispanic subgroups.

The 2017 American College of Cardiology/American Heart Association Hypertension Guideline and Blood Pressure in Older Adults.

INTRODUCTION: The 2017 American College of Cardiology/American Heart Association blood pressure guideline redefined hypertension and lowered the blood pressure treatment target. Empirical data on the guideline's impact are needed. METHODS: Data were analyzed from Atherosclerosis Risk in Communities study participants who attended baseline pre-guideline (2016-2017) and post-guideline (2018-2019) visits with baseline systolic blood pressure between 120 and 159 mmHg. Participants were grouped according to baseline systolic blood pressure by change in classification under the new guideline as follows: not reclassified (120-129 mmHg), reclassified to Stage 1 hypertension (130-139 mmHg), and reclassified to Stage 2 hypertension (140-159 mmHg). Means and 95% CIs for systolic blood pressure changes between baseline and follow-up, changes in antihypertensive use, and percentages that achieved the post-guideline recommendation (systolic blood pressure <130 mmHg) were calculated. Analyses were performed in 2021-2022. RESULTS: Among 2,193 community-dwelling Atherosclerosis Risk in Communities participants aged 71-95 years at baseline, systolic blood pressure changes between baseline and follow-up visits differed among participants not reclassified (+4.1 mmHg, 95% CI=3.0, 5.3 mmHg), reclassified to Stage 1 hypertension (-1.1 mmHg, 95% CI= -2.2, 0.1 mmHg), and reclassified to Stage 2 hypertension (-5.7 mmHg, 95% CI= -6.8, -4.7 mmHg). Antihypertensive use changed from 77.3% to 78.4% (p=0.25) among participants reclassified to Stage 1 hypertension and from 78.3% to 81.4% (p<0.01) among participants reclassified to Stage 2 hypertension. At follow-up, 41.8% of the Stage 1 and 22.4% of the Stage 2 hypertension groups reached the systolic blood pressure <130 mmHg goal. CONCLUSIONS: There were small decreases in systolic blood pressure and increases in antihypertensive therapy among older adults reclassified to Stage 2 hypertension but not among those reclassified to Stage 1 hypertension by the 2017 American College of Cardiology/American Heart Association guideline.

Temporal Trends in Adverse Pregnancy Outcomes in Birthing Individuals Aged 15 to 44 Years in the United States, 2007 to 2019.

Background Adverse pregnancy outcomes (APOs) (hypertensive disorders of pregnancy [HDP], preterm delivery [PTD], or low birth weight [LBW]) are associated adverse maternal and offspring cardiovascular outcomes. Therefore, we sought to describe nationwide temporal trends in the burden of each APO (HDP, PTD, LBW) from 2007 to 2019 to inform strategies to optimize maternal and offspring health outcomes. Methods and Results We performed a serial cross-sectional analysis of APO subtypes (HDP, PTD, LBW) from 2007 to 2019. We included maternal data from all live births that occurred in the United States using the National Center for Health Statistics Natality Files. We quantified age-standardized and age-specific rates of APOs per 1000 live births and their respective mean annual percentage change. All analyses were stratified by self-report of maternal race and ethnicity. Among 51 685 525 live births included, 15% were to non-Hispanic Black individuals, 24% Hispanic individuals, and 6% Asian individuals. Between 2007 and 2019, age standardized HDP rates approximately doubled, from 38.4 (38.2-38.6) to 77.8 (77.5-78.1) per 1000 live births. A significant inflection point was observed in 2014, with an acceleration in the rate of increase of HDP from 2007 to 2014 (+4.1% per year [3.6-4.7]) to 2014 to 2019 (+9.1% per year [8.1-10.1]). Rates of PTD and LBW increased significantly when co-occurring in the same pregnancy with HDP. Absolute rates of APOs were higher in non-Hispanic Black individuals and in older age groups. However, similar relative increases were seen across all age,racial and ethnic groups. Conclusions In aggregate, APOs now complicate nearly 1 in 5 live births. Incidence of HDP has increased significantly between 2007 and 2019 and contributed to the reversal of favorable trends in PTD and LBW. Similar patterns were observed in all age groups, suggesting that increasing maternal age at pregnancy does not account for these trends. Black-White disparities persisted throughout the study period.

Corrigendum: Rationale and Design of a Pharmacist-led Intervention for the Risk-Based Prevention of Heart Failure: The FIT-HF Pilot Study.

[This corrects the article DOI: 10.3389/fcvm.2021.785109.].

Association of State Medicaid Expansion Status With Hypertensive Disorders of Pregnancy in a Singleton First Live Birth.

BACKGROUND: Incidence of hypertensive disorders of pregnancy is increasing in the United States. Early detection is important to prevent adverse maternal and offspring outcomes. This ecological study evaluated changes in rates of hypertensive disorders of pregnancy among states that expanded Medicaid compared with states that did not expand Medicaid. METHODS: A quasi-experimental analysis using difference-in-differences models compared changes in rates of hypertensive disorders of pregnancy in Medicaid expansion states relative to non-Medicaid expansion states from 2012 to 2019. Maternal data from singleton first live births to individuals aged 20 to 39 years were obtained from the National Center for Health Statistics. Outcomes of interest included age-adjusted rates of de novo hypertension in pregnancy (gestational hypertension or preeclampsia) and prepregnancy hypertension. RESULTS: Data from 7 764 965 individuals with a singleton first live birth were analyzed from 17 states and Washington, DC that expanded Medicaid and 15 states that did not. Rates of de novo hypertension in pregnancy increased over the study period in both expansion (54.34 [95% CI, 48.25-60.43] to 74.87 [95% CI, 71.20-78.55] per 1000 births) and nonexpansion states (68.32 [95% CI, 61.02-75.62] to 84.79 [95% CI, 80.67-88.91] per 1000 births). In adjusted difference-in-differences analyses, expansion status was associated with a greater increase in rates of de novo hypertension in pregnancy (difference-in-differences coefficient, +8.18 [95% CI, 4.00-12.36] per 1000 live births) but a decline in rates of de novo hypertension in pregnancy complicated by low birth weight (-7.20 [95% CI, -13.71 to -0.70] per 1000 births with hypertensive disorders of pregnancy). In adjusted difference-in-differences analyses, there were no significant changes in rates of prepregnancy hypertension in expansion relative to nonexpansion states (+1.13 [95% CI, -0.09 to +2.35] per 1000 live births). CONCLUSIONS: Between 2012 and 2019, states that expanded Medicaid had a significantly greater increase in rates of de novo hypertension, with some evidence of better outcomes among those with de novo hypertension diagnosed in pregnancy.

Gestational Diabetes and Hypertensive Disorders of Pregnancy by Maternal Birthplace.

INTRODUCTION: Gestational diabetes mellitus and hypertensive disorders of pregnancy increase the risk for future adverse health outcomes in the pregnant woman and baby, and disparities exist in the rates of gestational diabetes mellitus and hypertensive disorders of pregnancy by race/ethnicity. The objective of this study is to identify the differences in gestational diabetes mellitus and hypertensive disorders of pregnancy rates by maternal place of birth within race/ethnicity groups. METHODS: In women aged 15-44 years at first live singleton birth in U.S. surveillance data between 2014 and 2019, age-standardized rates of gestational diabetes mellitus and hypertensive disorders of pregnancy and the rate ratios of gestational diabetes mellitus and hypertensive disorders of pregnancy in women born outside versus those born in the U.S. were evaluated, stratified by race/ethnicity. Analyses were conducted in 2021. RESULTS: Of 8,574,264 included women, 6,827,198 were born in the U.S. (mean age=26.2 [SD 5.7] years), and 1,747,066 were born outside the U.S. (mean age=28.2 [SD=5.8] years). Overall, the gestational diabetes mellitus rate was higher in women born outside than in those born in the U.S. (70.3, 95% CI=69.9, 70.7 vs 53.2, 95% CI=53.0, 53.4 per 1,000 live births; rate ratio=1.32, 95% CI=1.31, 1.33), a pattern observed in most race/ethnic groups. By contrast, the overall hypertensive disorders of pregnancy rate was lower in those born outside than in those born in the U.S. (52.5, 95% CI=52.2, 52.9 vs 90.1, 95% CI=89.9, 90.3 per 1,000 live births; rate ratio=0.58, 95% CI=0.58, 0.59), a pattern observed in most race/ethnic groups. CONCLUSIONS: In the U.S., gestational diabetes mellitus rates were higher and hypertensive disorders of pregnancy rates were lower in women born outside the U.S. than in those born in the U.S. in most race/ethnicity groups.

Rationale and Design of a Pharmacist-led Intervention for the Risk-Based Prevention of Heart Failure: The FIT-HF Pilot Study.

Background: Given rising morbidity, mortality, and costs due to heart failure (HF), new approaches for prevention are needed. A quantitative risk-based strategy, in line with established guidelines for atherosclerotic cardiovascular disease prevention, may efficiently select patients most likely to benefit from intensification of preventive care, but a risk-based strategy has not yet been applied to HF prevention. Methods and Results: The Feasibility of the Implementation of Tools for Heart Failure Risk Prediction (FIT-HF) pilot study will enroll 100 participants free of cardiovascular disease who receive primary care at a single integrated health system and have a 10-year predicted risk of HF of ≥5% based on the previously validated Pooled Cohort equations to Prevent Heart Failure. All participants will complete a health and lifestyle questionnaire and undergo cardiac biomarker (B-type natriuretic peptide [BNP] and high-sensitivity cardiac troponin I [hs-cTn]) and echocardiography screening at baseline and 1-year follow-up. Participants will be randomized 1:1 to either a pharmacist-led intervention or usual care for 1 year. Participants in the intervention arm will undergo consultation with a pharmacist operating under a collaborative practice agreement with a supervising cardiologist. The pharmacist will perform lifestyle counseling and recommend initiation or intensification of therapies to optimize risk factor (hypertension, diabetes, and cholesterol) management according to the most recent clinical practice guidelines. The primary outcome is change in BNP at 1-year, and secondary and exploratory outcomes include changes in hs-cTn, risk factor levels, and cardiac mechanics at follow-up. Feasibility will be examined by monitoring retention rates. Conclusions: The FIT-HF pilot study will offer insight into the feasibility of a strategy of quantitative risk-based enrollment into a pharmacist-led prevention program to reduce heart failure risk. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT04684264.

Risk-Based Intensive Blood Pressure Lowering and Prevention of Heart Failure: A SPRINT Post Hoc Analysis.

[Figure: see text].

Gestational Diabetes and Overweight/Obesity: Analysis of Nulliparous Women in the U.S., 2011-2019.

INTRODUCTION: The rates of gestational diabetes mellitus are increasing in parallel with the rates of overweight and obesity. This analysis examines nationwide trends in the population-attributable fraction for gestational diabetes mellitus associated with prepregnancy overweight and obesity. METHODS: A serial, cross-sectional study was performed using U.S. population-based birth data files maintained by the National Center for Health Statistics between 2011 and 2019. Live singleton births to nulliparous women aged 15-44 years were included, and all analyses were stratified by race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic, non-Hispanic Asian). Prevalences of prepregnancy overweight (25.0-29.9 kg/m2 and 23.0-27.4 kg/m2) and obesity (≥30.0 kg/m2 and ≥27.5 kg/m2) based on standard and Asian-specific BMI categories, respectively, were quantified. Logistic regression estimated the adjusted associations between prepregnancy overweight and obesity and gestational diabetes mellitus, with normal weight (18.0-24.9 kg/m2and 18.0-22.9 kg/m2) as the ref. Annual population-attributable fractions for gestational diabetes mellitus associated with prepregnancy overweight and obesity were calculated, which account for both the prevalence of the risk factor and the associated risk of gestational diabetes mellitus. RESULTS: Among 11,950,881 included women, the mean maternal age was 26.3 years. From 2011 to 2019, the population-attributable fractions for gestational diabetes mellitus associated with overweight were stable (Hispanic: 12.0%-11.3%, non-Hispanic Asian: 12.1%-11.6%, p≥0.20) or decreased (non-Hispanic White: 10.8%-9.4%, non-Hispanic Black: 12.3%-9.2%, p<0.002); the population-attributable fractions for gestational diabetes mellitus associated with obesity were stable (non-Hispanic Black: 36.3%-37.9%, p=0.11) or increased (non-Hispanic White: 30.9%-33.3%, Hispanic: 27.2%-33.3%, non-Hispanic Asian 12.2%-15.4%, p<0.001). CONCLUSIONS: The population-attributable fractions for gestational diabetes mellitus associated with obesity largely increased in the past decade, underscoring the importance of optimizing weight before pregnancy.

Trends in prepregnancy cardiovascular health in the United States, 2011-2019.

OBJECTIVE: To evaluate contemporary patterns in prepregnancy cardiovascular health (CVH) in the United States (US). METHODS: We conducted a serial, cross-sectional study of National Center for Health Statistics Natality Data representing all live births in the US from 2011 to 2019. We assigned 1 point for each of four ideal prepregnancy metrics (nonsmoking and ideal body mass index [18.5-24.9 kg/m2] provided by maternal self-report, and absence of hypertension and diabetes ascertained by the healthcare professional at delivery) to construct a prepregnancy clinical CVH score ranging from 0 to 4. We described the distribution of prepregnancy CVH, overall and stratified by self-reported race/ethnicity, age, insurance status, and receipt of the Women, Infants, and Children program (WIC) for supplemental nutrition. We examined trends by calculating average annual percent changes (AAPCs) in optimal prepregnancy CVH (score of 4). RESULTS: Of 31,643,982 live births analyzed between 2011 and 2019, 53.6% were to non-Hispanic White, 14.5% non-Hispanic Black, 23.3% Hispanic, and 6.6% non-Hispanic Asian women. The mean age (SD) was 28.5 (5.8) years. The prevalence (per 100 live births) of optimal prepregnancy CVH score of 4 declined from 42.1 to 37.7 from 2011 to 2019, with an AAPC (95% CI) of -1.4% per year (-1.3,-1.5). While the relative decline was observed across all race/ethnicity, insurance, and WIC subgroups, significant disparities persisted by race, insurance status, and receipt of WIC. In 2019, non-Hispanic Black women (28.7 per 100 live births), those on Medicaid (30.4), and those receiving WIC (29.1) had the lowest prevalence of optimal CVH. CONCLUSIONS: Overall, less than half of pregnant women had optimal prepregnancy CVH, and optimal prepregnancy CVH declined in each race/ethnicity, age, insurance, and WIC subgroup between 2011-2019 in the US. However, there were persistent disparities by race/ethnicity and socioeconomic status.

Trends in Gestational Diabetes at First Live Birth by Race and Ethnicity in the US, 2011-2019.

Importance: Gestational diabetes is associated with adverse maternal and offspring outcomes. Objective: To determine whether rates of gestational diabetes among individuals at first live birth changed from 2011 to 2019 and how these rates differ by race and ethnicity in the US. Design, Setting, and Participants: Serial cross-sectional analysis using National Center for Health Statistics data for 12 610 235 individuals aged 15 to 44 years with singleton first live births from 2011 to 2019 in the US. Exposures: Gestational diabetes data stratified by the following race and ethnicity groups: Hispanic/Latina (including Central and South American, Cuban, Mexican, and Puerto Rican); non-Hispanic Asian/Pacific Islander (including Asian Indian, Chinese, Filipina, Japanese, Korean, and Vietnamese); non-Hispanic Black; and non-Hispanic White. Main Outcomes and Measures: The primary outcomes were age-standardized rates of gestational diabetes (per 1000 live births) and respective mean annual percent change and rate ratios (RRs) of gestational diabetes in non-Hispanic Asian/Pacific Islander (overall and in subgroups), non-Hispanic Black, and Hispanic/Latina (overall and in subgroups) individuals relative to non-Hispanic White individuals (referent group). Results: Among the 12 610 235 included individuals (mean [SD] age, 26.3 [5.8] years), the overall age-standardized gestational diabetes rate significantly increased from 47.6 (95% CI, 47.1-48.0) to 63.5 (95% CI, 63.1-64.0) per 1000 live births from 2011 to 2019, a mean annual percent change of 3.7% (95% CI, 2.8%-4.6%) per year. Of the 12 610 235 participants, 21% were Hispanic/Latina (2019 gestational diabetes rate, 66.6 [95% CI, 65.6-67.7]; RR, 1.15 [95% CI, 1.13-1.18]), 8% were non-Hispanic Asian/Pacific Islander (2019 gestational diabetes rate, 102.7 [95% CI, 100.7-104.7]; RR, 1.78 [95% CI, 1.74-1.82]), 14% were non-Hispanic Black (2019 gestational diabetes rate, 55.7 [95% CI, 54.5-57.0]; RR, 0.97 [95% CI, 0.94-0.99]), and 56% were non-Hispanic White (2019 gestational diabetes rate, 57.7 [95% CI, 57.2-58.3]; referent group). Gestational diabetes rates were highest in Asian Indian participants (2019 gestational diabetes rate, 129.1 [95% CI, 100.7-104.7]; RR, 2.24 [95% CI, 2.15-2.33]). Among Hispanic/Latina participants, gestational diabetes rates were highest among Puerto Rican individuals (2019 gestational diabetes rate, 75.8 [95% CI, 71.8-79.9]; RR, 1.31 [95% CI, 1.24-1.39]). Gestational diabetes rates increased among all race and ethnicity subgroups and across all age groups. Conclusions and Relevance: Among individuals with a singleton first live birth in the US from 2011 to 2019, rates of gestational diabetes increased across all racial and ethnic subgroups. Differences in absolute gestational diabetes rates were observed across race and ethnicity subgroups.

Trends in Prepregnancy Obesity and Association With Adverse Pregnancy Outcomes in the United States, 2013 to 2018.

Background The prevalence of obesity in the population has increased in parallel with increasing rates of adverse pregnancy outcomes (APOs). Quantifying contemporary trends in prepregnancy obesity and associations with interrelated APOs (preterm birth, low birth weight, and pregnancy-associated hypertension) together and individually can inform prevention strategies to optimize cardiometabolic health in women and offspring. Methods and Results We performed a serial, cross-sectional study using National Center for Health Statistics birth certificate data including women aged 15 to 44 years with live singleton births between 2013 and 2018, stratified by race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic, and non-Hispanic Asian). We quantified the annual prevalence of prepregnancy obesity (body mass index ≥30.0 kg/m2; body mass index ≥27.5 kg/m2 if non-Hispanic Asian). We then estimated adjusted associations using multivariable logistic regression (odds ratios and population attributable fractions) for obesity-related APOs compared with normal body mass index (18.5-24.9 kg/m2; 18.5-22.9 kg/m2 if non-Hispanic Asian). Among 20 139 891 women, the prevalence of prepregnancy obesity increased between 2013 and 2018: non-Hispanic White (21.6%-24.8%), non-Hispanic Black (32.5%-36.2%), Hispanic (26.0%-30.5%), and non-Hispanic Asian (15.3%-18.6%) women (P-trend < 0.001 for all). Adjusted odds ratios (95% CI) for APOs associated with obesity increased between 2013 and 2018, and by 2018, ranged from 1.27 (1.25-1.29) in non-Hispanic Black to 1.94 (1.92-1.96) in non-Hispanic White women. Obesity was most strongly associated with pregnancy-associated hypertension and inconsistently associated with preterm birth and low birth weight. Population attributable fractions of obesity-related APOs increased over the study period: non-Hispanic White (10.6%-14.7%), non-Hispanic Black (3.7%-6.9%), Hispanic (7.0%-10.4%), and non-Hispanic Asian (7.4%-9.7%) women (P-trend < 0.01 for all). Conclusions The prevalence of prepregnancy obesity and burden of obesity-related APOs have increased, driven primarily by pregnancy-associated hypertension, and vary across racial/ethnic subgroups.

Cardiovascular Risk Assessment in Hypertensive Patients.

Hypertension is a highly prevalent and causal risk factor for cardiovascular disease (CVD). Quantitative cardiovascular (CV) risk assessment is a new paradigm for stratifying hypertensive patients into actionable groups for clinical management and prevention of CVD. The large heterogeneity in hypertensive patients makes this evaluation complex, but recent advances have made CV risk assessment more feasible. In this review, we first describe the prognostic significance of various levels and temporal patterns of blood pressure (BP). We then discuss CV risk prediction equations and the rationale of taking global risk into account in hypertensive patients. Finally, we review several adjunctive biomarkers that may refine risk assessment in certain patients. We observe that, beyond individual cross-sectional measurements, both short-term and long-term BP patterns are associated with incident CVD; that current CV risk prediction performs well, and its incorporation into hypertension management is associated with potential population benefit; and that adjunctive biomarkers of target organ damage show the most promise in sequential screening strategies that target biomarker measurement to patients in whom the results are most likely to change clinical management. Implementation of quantitative risk assessment for CVD has been facilitated by tools and direct electronic health record integrations that make risk estimates accessible for counseling and shared decision making for CVD prevention. However, it should be noted that treatment does not return an individual to the risk of someone who never develops hypertension, underscoring the need for primordial prevention in addition to continued innovation in risk assessment.

Optimization of S. aureus dCas9 and CRISPRi Elements for a Single Adeno-Associated Virus that Targets an Endogenous Gene.

The power of CRISPRi to decrease targeted gene expression for clinical applications has been inhibited by delivery challenges. Existing constructs are too large to fit within the ∼4.7 kb packaging size limitation of adeno-associated virus (AAV), the only FDA approved viral vector for clinical use. Therefore, we optimized CRISPRi components to generate a single AAV vector that contains all functional elements and effectively knocks down expression of an endogenous gene in vivo. First, we increased nuclear targeting of Staphylococcus aureus deactivated Cas9 (SadCas9) 4-fold by using a helical linker and the c-Myc nuclear localization signal. Second, we identified an amino-terminal Krüppel associated box (KRAB) construct as the most effective in decreasing expression of target genes in vitro. Third, we optimized promoters for guide RNA and evaluated mini-promoters for expression of KRAB-SadCas9 in liver cells. Our final construct decreased protein convertase subtilisin/kexin type 9 (Pcsk9) mRNA and secreted protein 5-fold in vitro. The corresponding AAV2/8 vector was localized in nuclei of liver cells and decreased Pcsk9 mRNA and serum protein levels by 30% in vivo. This single AAV approach provides a potential clinically translatable method for decreasing targeted gene transcription by CRISPRi in vivo.