Transcriptional Dysregulation Underlies Both Monogenic Arrhythmia Syndrome and Common Modifiers of Cardiac Repolarization.

BACKGROUND: Brugada syndrome (BrS) is an inherited arrhythmia syndrome caused by loss-of-function variants in the cardiac sodium channel gene SCN5A (sodium voltage-gated channel alpha subunit 5) in ≈20% of subjects. We identified a family with 4 individuals diagnosed with BrS harboring the rare G145R missense variant in the cardiac transcription factor TBX5 (T-box transcription factor 5) and no SCN5A variant. METHODS: We generated induced pluripotent stem cells (iPSCs) from 2 members of a family carrying TBX5-G145R and diagnosed with Brugada syndrome. After differentiation to iPSC-derived cardiomyocytes (iPSC-CMs), electrophysiologic characteristics were assessed by voltage- and current-clamp experiments (n=9 to 21 cells per group) and transcriptional differences by RNA sequencing (n=3 samples per group), and compared with iPSC-CMs in which G145R was corrected by CRISPR/Cas9 approaches. The role of platelet-derived growth factor (PDGF)/phosphoinositide 3-kinase (PI3K) pathway was elucidated by small molecule perturbation. The rate-corrected QT (QTc) interval association with serum PDGF was tested in the Framingham Heart Study cohort (n=1893 individuals). RESULTS: TBX5-G145R reduced transcriptional activity and caused multiple electrophysiologic abnormalities, including decreased peak and enhanced "late" cardiac sodium current (INa), which were entirely corrected by editing G145R to wild-type. Transcriptional profiling and functional assays in genome-unedited and -edited iPSC-CMs showed direct SCN5A down-regulation caused decreased peak INa, and that reduced PDGF receptor (PDGFRA [platelet-derived growth factor receptor α]) expression and blunted signal transduction to PI3K was implicated in enhanced late INa. Tbx5 regulation of the PDGF axis increased arrhythmia risk due to disruption of PDGF signaling and was conserved in murine model systems. PDGF receptor blockade markedly prolonged normal iPSC-CM action potentials and plasma levels of PDGF in the Framingham Heart Study were inversely correlated with the QTc interval (P<0.001). CONCLUSIONS: These results not only establish decreased SCN5A transcription by the TBX5 variant as a cause of BrS, but also reveal a new general transcriptional mechanism of arrhythmogenesis of enhanced late sodium current caused by reduced PDGF receptor-mediated PI3K signaling.

Sex Differences in the Development of Anthracycline-Associated Heart Failure.

BACKGROUND: Female sex is frequently cited as a risk factor for anthracycline cardiotoxicity based on pediatric data, but the role of sex in the development of cardiotoxicity has not been clearly established in adults. OBJECTIVES: To assess the effect of female sex on the development of incident heart failure (HF) in adult patients treated with anthracyclines. METHODS: This was a retrospective cohort study of 1525 adult patients with no prior history of HF or cardiomyopathy who were treated with anthracyclines between 1992 and 2019. The primary outcome was new HF within 5 years of the first dose of anthracyclines. The effect of sex was assessed using Cox proportional hazards and competing risk models. RESULTS: Over a median (IQR) follow-up of 1.02 (0.30-3.01) years, 4.78% of patients developed HF (44 men and 29 women). Female sex was not associated with the primary outcome in a multivariable Cox proportional hazards model (HR 0.87; 95% CI 0.53-1.43; P = 0.58). Similar results were observed in a multivariable model accounting for the competing risk of death (HR 0.94; 95% CI 0.39-2.25; P = 0.88). Age, coronary artery disease and hematopoietic stem cell transplant were associated with the primary outcome in a multivariable Cox proportional hazards model. Age and body mass index were associated with the primary outcome in a multivariable competing risk model. CONCLUSIONS: In this large, single-center, retrospective cohort study, female sex was not associated with incident HF in adult patients treated with anthracyclines. CONDENSED ABSTRACT: Female sex is frequently cited as a risk factor for anthracycline cardiotoxicity based on pediatric data, but the role of sex in the development of cardiotoxicity has not been clearly established in adults. In this retrospective cohort study, we assessed the effect of female sex on the development of incident heart failure in adult patients treated with anthracyclines. Using Cox proportional hazards and competing risk regression models, we found that there was no association between female sex and heart failure after treatment with anthracyclines.

Circulating testican-2 is a podocyte-derived marker of kidney health.

In addition to their fundamental role in clearance, the kidneys release select molecules into the circulation, but whether any of these anabolic functions provides insight on kidney health is unknown. Using aptamer-based proteomics, we characterized arterial (A)-to-renal venous (V) gradients for >1,300 proteins in 22 individuals who underwent invasive sampling. Although most of the proteins that changed significantly decreased from A to V, consistent with renal clearance, several were found to increase, the most significant of which was testican-2. To assess the clinical implications of these physiologic findings, we examined proteomic data in the Jackson Heart Study (JHS), an African-American cohort (n = 1,928), with replication in the Framingham Heart Study (FHS), a White cohort (n = 1,621). In both populations, testican-2 had a strong, positive correlation with estimated glomerular filtration rate (eGFR). In addition, higher baseline testican-2 levels were associated with a lower rate of eGFR decline in models adjusted for age, gender, hypertension, type 2 diabetes, body mass index, baseline eGFR, and albuminuria. Glomerular expression of testican-2 in human kidneys was demonstrated by immunohistochemistry, immunofluorescence, and electron microscopy, while single-cell RNA sequencing of human kidneys showed expression of the cognate gene, SPOCK2, exclusively in podocytes. In vitro, testican-2 increased glomerular endothelial tube formation and motility, raising the possibility that its secretion has a functional role within the glomerulus. Taken together, our findings identify testican-2 as a podocyte-derived biomarker of kidney health and prognosis.

Application of Large-Scale Aptamer-Based Proteomic Profiling to Planned Myocardial Infarctions.

BACKGROUND: Emerging proteomic technologies using novel affinity-based reagents allow for efficient multiplexing with high-sample throughput. To identify early biomarkers of myocardial injury, we recently applied an aptamer-based proteomic profiling platform that measures 1129 proteins to samples from patients undergoing septal alcohol ablation for hypertrophic cardiomyopathy, a human model of planned myocardial injury. Here, we examined the scalability of this approach using a markedly expanded platform to study a far broader range of human proteins in the context of myocardial injury. METHODS: We applied a highly multiplexed, expanded proteomic technique that uses single-stranded DNA aptamers to assay 4783 human proteins (4137 distinct human gene targets) to derivation and validation cohorts of planned myocardial injury, individuals with spontaneous myocardial infarction, and at-risk controls. RESULTS: We found 376 target proteins that significantly changed in the blood after planned myocardial injury in a derivation cohort (n=20; P<1.05E-05, 1-way repeated measures analysis of variance, Bonferroni threshold). Two hundred forty-seven of these proteins were validated in an independent planned myocardial injury cohort (n=15; P<1.33E-04, 1-way repeated measures analysis of variance); >90% were directionally consistent and reached nominal significance in the validation cohort. Among the validated proteins that were increased within 1 hour after planned myocardial injury, 29 were also elevated in patients with spontaneous myocardial infarction (n=63; P<6.17E-04). Many of the novel markers identified in our study are intracellular proteins not previously identified in the peripheral circulation or have functional roles relevant to myocardial injury. For example, the cardiac LIM protein, cysteine- and glycine-rich protein 3, is thought to mediate cardiac mechanotransduction and stress responses, whereas the mitochondrial ATP synthase F0 subunit component is a vasoactive peptide on its release from cells. Last, we performed aptamer-affinity enrichment coupled with mass spectrometry to technically verify aptamer specificity for a subset of the new biomarkers. CONCLUSIONS: Our results demonstrate the feasibility of large-scale aptamer multiplexing at a level that has not previously been reported and with sample throughput that greatly exceeds other existing proteomic methods. The expanded aptamer-based proteomic platform provides a unique opportunity for biomarker and pathway discovery after myocardial injury.

Genetic Architecture of the Cardiovascular Risk Proteome.

BACKGROUND: We recently identified 156 proteins in human plasma that were each associated with the net Framingham Cardiovascular Disease Risk Score using an aptamer-based proteomic platform in Framingham Heart Study Offspring participants. Here we hypothesized that performing genome-wide association studies and exome array analyses on the levels of each of these 156 proteins might identify genetic determinants of risk-associated circulating factors and provide insights into early cardiovascular pathophysiology. METHODS: We studied the association of genetic variants with the plasma levels of each of the 156 Framingham Cardiovascular Disease Risk Score-associated proteins using linear mixed-effects models in 2 population-based cohorts. We performed discovery analyses on plasma samples from 759 participants of the Framingham Heart Study Offspring cohort, an observational study of the offspring of the original Framingham Heart Study and their spouses, and validated these findings in plasma samples from 1421 participants of the MDCS (Malmö Diet and Cancer Study). To evaluate the utility of this strategy in identifying new biological pathways relevant to cardiovascular disease pathophysiology, we performed studies in a cell-model system to experimentally validate the functional significance of an especially novel genetic association with circulating apolipoprotein E levels. RESULTS: We identified 120 locus-protein associations in genome-wide analyses and 41 associations in exome array analyses, the majority of which have not been described previously. These loci explained up to 66% of interindividual plasma protein-level variation and, on average, accounted for 3 times the amount of variation explained by common clinical factors, such as age, sex, and diabetes mellitus status. We described overlap among many of these loci and cardiovascular disease genetic risk variants. Finally, we experimentally validated a novel association between circulating apolipoprotein E levels and the transcription factor phosphatase 1G. Knockdown of phosphatase 1G in a human liver cell model resulted in decreased apolipoprotein E transcription and apolipoprotein E protein levels in cultured supernatants. CONCLUSIONS: We identified dozens of novel genetic determinants of proteins associated with the Framingham Cardiovascular Disease Risk Score and experimentally validated a new role for phosphatase 1G in lipoprotein biology. Further, genome-wide and exome array data for each protein have been made publicly available as a resource for cardiovascular disease research.

Aptamer-Based Proteomic Profiling Reveals Novel Candidate Biomarkers and Pathways in Cardiovascular Disease.

BACKGROUND: Single-stranded DNA aptamers are oligonucleotides of ≈50 base pairs in length selected for their ability to bind proteins with high specificity and affinity. Emerging DNA aptamer-based technologies may address limitations of existing proteomic techniques, including low sample throughput, which have hindered proteomic analyses of large cohorts. METHODS: To identify early biomarkers of myocardial injury, we applied an aptamer-based proteomic platform that measures 1129 proteins to a clinically relevant perturbational model of planned myocardial infarction (PMI), patients undergoing septal ablation for hypertrophic cardiomyopathy. Blood samples were obtained before and at 10 and 60 minutes after PMI, and protein changes were assessed by repeated-measures analysis of variance. The generalizability of our PMI findings was evaluated in a spontaneous myocardial infarction cohort (Wilcoxon rank-sum). We then tested the platform's ability to detect associations between proteins and Framingham Risk Score components in the Framingham Heart Study, performing regression analyses for each protein versus each clinical trait. RESULTS: We found 217 proteins that significantly changed in the peripheral vein blood after PMI in a derivation cohort (n=15; P<5.70E-5). Seventy-nine of these proteins were validated in an independent PMI cohort (n=15; P<2.30E-4); >85% were directionally consistent and reached nominal significance. We detected many protein changes that are novel in the context of myocardial injury, including Dickkopf-related protein 4, a WNT pathway inhibitor (peak increase 124%, P=1.29E-15) and cripto, a growth factor important in cardiac development (peak increase 64%, P=1.74E-4). Among the 40 validated proteins that increased within 1 hour after PMI, 23 were also elevated in patients with spontaneous myocardial infarction (n=46; P<0.05). Framingham Heart Study analyses revealed 156 significant protein associations with the Framingham Risk Score (n=899), including aminoacylase 1 (ß=0.3386, P=2.54E-22) and trigger factor 2 (ß=0.2846, P=5.71E-17). Furthermore, we developed a novel workflow integrating DNA-based immunoaffinity with mass spectrometry to analytically validate aptamer specificity. CONCLUSIONS: Our results highlight an emerging proteomics tool capable of profiling >1000 low-abundance analytes with high sensitivity and high precision, applicable both to well-phenotyped perturbational studies and large human cohorts, as well.

Blood pressure response to renal artery stenting in 901 patients from five prospective multicenter FDA-approved trials.

BACKGROUND: Renal artery stent revascularization is commonly used for renovascular hypertension. Clinical predictors associated with blood pressure (BP) improvement after renal artery stent revascularization are not well understood. METHODS: Patient-level data from 901 patients in five prospective multicenter Food and Drug Administration-approved investigational device exemption studies of renal artery stent revascularization was pooled. BP response was defined as reduction of systolic BP (SBP) by >10 mm Hg. Stent patency was defined within each study. Associations of BP reduction were determined by logistic regression. RESULTS: Of 901 patients, complete outcome information was available in 527. Of these, 212/527 (40%) were male, mean age was 63 ± 13 years, 196/544 (36%) were diabetic and 504/527 (96%) had a SBP ≥ 140 mm Hg or DBP ≥ 90 mm Hg at baseline. Compared to baseline, 9-month systolic (164 ± 21 mm Hg vs. 146 ± 22 mm Hg, P < 0.0001) and diastolic (79 ± 13 mm Hg vs. 76 ± 12 mm Hg, P < 0.0001) BP declined significantly. Nine-month stent patency was 90% (305/339). In a univariate analysis, baseline SBP >150 mm Hg (OR = 4.09, CI = 2.74-6.12, P < 0.0001) was positively associated with BP response following renal artery stent revascularization. In a multivariable analysis, baseline SBP remained associated with a positive BP response (OR = 1.76, CI = 1.53-2.03, P < 0.0001). CONCLUSIONS: In the largest pooled dataset of patients treated with renal artery stent revascularization, SBP and DBP were significantly lower at 9-months. Elevated baseline SBP (>150 mm Hg) was strongly associated with BP reduction after the procedure.

Plasma Proteomics of Exercise Blood Pressure and Incident Hypertension.

Importance: Blood pressure response during acute exercise (exercise blood pressure [EBP]) is associated with the future risk of hypertension and cardiovascular disease (CVD). Biochemical characterization of EBP could inform disease biology and identify novel biomarkers of future hypertension. Objective: To identify protein markers associated with EBP and test their association with incident hypertension. Design, Setting, and Participants: This study assayed 4977 plasma proteins in 681 healthy participants (from 763 assessed) of the Health, Risk Factors, Exercise Training and Genetics (HERITAGE; data collection from January 1993 to December 1997 and plasma proteomics from January 2019 to January 2020) Family Study at rest who underwent 2 cardiopulmonary exercise tests. Individuals were free of CVD at the time of recruitment. Individuals with resting SBP ≥160 mm Hg or DBP ≥100 mm Hg or taking antihypertensive drug therapy were excluded from the study. The association between resting plasma protein levels to both resting BP and EBP was evaluated. Proteins associated with EBP were analyzed for their association with incident hypertension in the Framingham Heart Study (FHS; n = 1177) and validated in the Jackson Heart Study (JHS; n = 772) and Multi-Ethnic Study of Atherosclerosis (MESA; n = 1367). Proteins associated with incident hypertension were tested for putative causal links in approximately 700 000 individuals using cis-protein quantitative loci mendelian randomization (cis-MR). Data were analyzed from January 2023 to January 2024. Exposures: Plasma proteins. Main Outcomes and Measures: EBP was defined as the BP response during a fixed workload (50 W) on a cycle ergometer. Hypertension was defined as BP ≥140/90 mm Hg or taking antihypertensive medication. Results: Among the 681 participants in the HERITAGE Family Study, the mean (SD) age was 34 (13) years; 366 participants (54%) were female; 238 (35%) were self-reported Black and 443 (65%) were self-reported White. Proteomic profiling of EBP revealed 34 proteins that would not have otherwise been identified through profiling of resting BP alone. Transforming growth factor ß receptor 3 (TGFBR3) and prostaglandin D2 synthase (PTGDS) had the strongest association with exercise systolic BP (SBP) and diastolic BP (DBP), respectively (TGFBR3: exercise SBP, ß estimate, -3.39; 95% CI, -4.79 to -2.00; P = 2.33 × 10-6; PTGDS: exercise DBP ß estimate, -2.50; 95% CI, -3.29 to -1.70; P = 1.18 × 10-9). In fully adjusted models, TGFBR3 was inversely associated with incident hypertension in FHS, JHS, and MESA (hazard ratio [HR]: FHS, 0.86; 95% CI, 0.75-0.97; P = .01; JHS, 0.87; 95% CI, 0.77-0.97; P = .02; MESA, 0.84; 95% CI, 0.71-0.98; P = .03; pooled cohort, 0.86; 95% CI, 0.79-0.92; P = 6 × 10-5). Using cis-MR, genetically predicted levels of TGFBR3 were associated with SBP, hypertension, and CVD events (SBP: ß, -0.38; 95% CI, -0.64 to -0.11; P = .006; hypertension: odds ratio [OR], 0.99; 95% CI, 0.98-0.99; P < .001; heart failure with hypertension: OR, 0.86; 95% CI, 0.77-0.97; P = .01; CVD: OR, 0.84; 95% CI, 0.77-0.92; P = 8 × 10-5; cerebrovascular events: OR, 0.77; 95% CI, 0.70-0.85; P = 5 × 10-7). Conclusions and Relevance: Plasma proteomic profiling of EBP identified a novel protein, TGFBR3, which may protect against elevated BP and long-term CVD outcomes.

In-hospital and one year outcomes with drug-eluting versus bare metal stents in large native coronary arteries: a report from the Evaluation of Drug-Eluting Stents and Ischemic Events registry.

OBJECTIVES: We sought to compare the clinical outcomes after percutaneous coronary revascularization of large coronary arteries using drug-eluting (DES) or bare-metal (BMS) stents. BACKGROUND: In de novo native coronary lesions with reference diameters of 2.5-3.5 mm, DES reduce target lesion revascularization (TLR) with no increase in death or myocardial infarction (MI). The relative efficacy of DES in larger coronary artery lesions is less certain. METHODS: From the prospective Evaluation of Drug-Eluting Stents and Ischemic Events registry, we identified patients undergoing stenting of de novo lesions in native coronary arteries 3.5-5.0 mm in diameter (n = 1,485). In-hospital and 1-year clinical outcomes were compared for BMS (n = 282) and DES (n = 1,203) patients, using propensity stratification to adjust for differences in potential confounding factors. RESULTS: Most patient characteristics were similar for the two groups, but BMS patients were more likely to have been treated in the setting of ST elevation MI, whereas DES patients had more bifurcation lesions, smaller vessels, and longer total stent lengths. In risk-adjusted analyses, the composite endpoint of 1-year death, MI or TLR was similar for BMS and DES (standardized rate: 11.9% vs. 8.5%, P = 0.10). DES was associated with a 62% reduction in the risk of TLR, although the absolute difference in event rates was small (standardized rates 4.6% vs. 1.8%, P = 0.016). CONCLUSIONS: Among relatively unselected patients undergoing PCI of large native coronary arteries, use of DES was associated with a modest reduction in rates of TLR, with a neutral effect on other ischemic endpoints.

Protein Markers of Diabetes Discovered in an African American Cohort.

Proteomics has been used to study type 2 diabetes, but the majority of available data are from White participants. Here, we extend prior work by analyzing a large cohort of self-identified African Americans in the Jackson Heart Study (n = 1,313). We found 325 proteins associated with incident diabetes after adjusting for age, sex, and sample batch (false discovery rate q < 0.05) measured using a single-stranded DNA aptamer affinity-based method on fasting plasma samples. A subset was independent of established markers of diabetes development pathways, such as adiposity, glycemia, and/or insulin resistance, suggesting potential novel biological processes associated with disease development. Thirty-six associations remained significant after additional adjustments for BMI, fasting plasma glucose, cholesterol levels, hypertension, statin use, and renal function. Twelve associations, including the top associations of complement factor H, formimidoyltransferase cyclodeaminase, serine/threonine-protein kinase 17B, and high-mobility group protein B1, were replicated in a meta-analysis of two self-identified White cohorts-the Framingham Heart Study and the Malmö Diet and Cancer Study-supporting the generalizability of these biomarkers. A selection of these diabetes-associated proteins also improved risk prediction. Thus, we uncovered both novel and broadly generalizable associations by studying a diverse population, providing a more complete understanding of the diabetes-associated proteome.

Plasma proteomic changes in response to exercise training are associated with cardiorespiratory fitness adaptations.

Regular exercise leads to widespread salutary effects, and there is increasing recognition that exercise-stimulated circulating proteins can impart health benefits. Despite this, limited data exist regarding the plasma proteomic changes that occur in response to regular exercise. Here, we perform large-scale plasma proteomic profiling in 654 healthy human study participants before and after a supervised, 20-week endurance exercise training intervention. We identify hundreds of circulating proteins that are modulated, many of which are known to be secreted. We highlight proteins involved in angiogenesis, iron homeostasis, and the extracellular matrix, many of which are novel, including training-induced increases in fibroblast activation protein (FAP), a membrane-bound and circulating protein relevant in body-composition homeostasis. We relate protein changes to training-induced maximal oxygen uptake adaptations and validate our top findings in an external exercise cohort. Furthermore, we show that FAP is positively associated with survival in 3 separate, population-based cohorts.

Protein-metabolite association studies identify novel proteomic determinants of metabolite levels in human plasma.

Although many novel gene-metabolite and gene-protein associations have been identified using high-throughput biochemical profiling, systematic studies that leverage human genetics to illuminate causal relationships between circulating proteins and metabolites are lacking. Here, we performed protein-metabolite association studies in 3,626 plasma samples from three human cohorts. We detected 171,800 significant protein-metabolite pairwise correlations between 1,265 proteins and 365 metabolites, including established relationships in metabolic and signaling pathways such as the protein thyroxine-binding globulin and the metabolite thyroxine, as well as thousands of new findings. In Mendelian randomization (MR) analyses, we identified putative causal protein-to-metabolite associations. We experimentally validated top MR associations in proof-of-concept plasma metabolomics studies in three murine knockout strains of key protein regulators. These analyses identified previously unrecognized associations between bioactive proteins and metabolites in human plasma. We provide publicly available data to be leveraged for studies in human metabolism and disease.

Systemic Markers of Lung Function and Forced Expiratory Volume in 1 Second Decline across Diverse Cohorts.

Rationale: Chronic obstructive pulmonary disease (COPD) is a complex disease characterized by airway obstruction and accelerated lung function decline. Our understanding of systemic protein biomarkers associated with COPD remains incomplete. Objectives: To determine what proteins and pathways are associated with impaired pulmonary function in a diverse population. Methods: We studied 6,722 participants across six cohort studies with both aptamer-based proteomic and spirometry data (4,566 predominantly White participants in a discovery analysis and 2,156 African American cohort participants in a validation). In linear regression models, we examined protein associations with baseline forced expiratory volume in 1 second (FEV1) and FEV1/forced vital capacity (FVC). In linear mixed effects models, we investigated the associations of baseline protein levels with rate of FEV1 decline (ml/yr) in 2,777 participants with up to 7 years of follow-up spirometry. Results: We identified 254 proteins associated with FEV1 in our discovery analyses, with 80 proteins validated in the Jackson Heart Study. Novel validated protein associations include kallistatin serine protease inhibitor, growth differentiation factor 2, and tumor necrosis factor-like weak inducer of apoptosis (discovery ß = 0.0561, Q = 4.05 × 10-10; ß = 0.0421, Q = 1.12 × 10-3; and ß = 0.0358, Q = 1.67 × 10-3, respectively). In longitudinal analyses within cohorts with follow-up spirometry, we identified 15 proteins associated with FEV1 decline (Q < 0.05), including elafin leukocyte elastase inhibitor and mucin-associated TFF2 (trefoil factor 2; ß = -4.3 ml/yr, Q = 0.049; ß = -6.1 ml/yr, Q = 0.032, respectively). Pathways and processes highlighted by our study include aberrant extracellular matrix remodeling, enhanced innate immune response, dysregulation of angiogenesis, and coagulation. Conclusions: In this study, we identify and validate novel biomarkers and pathways associated with lung function traits in a racially diverse population. In addition, we identify novel protein markers associated with FEV1 decline. Several protein findings are supported by previously reported genetic signals, highlighting the plausibility of certain biologic pathways. These novel proteins might represent markers for risk stratification, as well as novel molecular targets for treatment of COPD.

In-hospital and 1-year outcomes with drug-eluting versus bare metal stents in saphenous vein graft intervention: a report from the EVENT registry.

OBJECTIVES: To compare outcomes of patients receiving drug-eluting stents (DES) versus bare metal stents (BMS) during percutaneous coronary intervention (PCI) of saphenous vein bypass grafts (SVG). BACKGROUND: Long-term benefits of DES versus BMS are well established for native vessel PCI. Benefit in patients undergoing SVG intervention is less certain. We used data from a multicenter registry (evaluation of drug eluting stents and ischemic events, EVENT) to compare outcomes among patients treated with DES versus BMS 1-year following SVG interventions. METHODS: Between July 2004 and December 2007, 684 patients in EVENT underwent SVG PCI (515 DES only, 169 BMS only). The primary endpoint was a composite of death, myocardial infarction (MI), and target lesion revascularization between hospital discharge and 1-year follow-up. Propensity score stratification was used to adjust for differences between groups. RESULTS: Baseline demographic and clinical characteristics of patients treated with DES and BMS were similar. The DES group had fewer men and a higher prevalence of prior PCI. Patients receiving DES had less angiographic thrombus, less frequent use of embolic protection devices, greater total stent length, and smaller maximum stent diameters. Unadjusted outcomes between discharge and 1-year follow-up did not differ between the groups. After risk adjustment, the primary outcome was less frequent among patients treated with DES (adjusted HR = 0.48, 95% CI = 0.27-0.84, P < 0.01) with similar relative benefits across the individual endpoints. CONCLUSIONS: Among patients undergoing SVG PCI in a "real world" registry analyzed using propensity score stratification, treatment with DES compared with BMS was associated with reduced MACE at 1 year following PCI.

Methods to limit attrition in longitudinal comparative effectiveness trials: lessons from the Lithium Treatment - Moderate dose Use Study (LiTMUS) for bipolar disorder.

BACKGROUND: High attrition rates, which occur frequently in longitudinal clinical trials of interventions for bipolar disorder, limit the interpretation of results. PURPOSE: The aim of this article is to present design approaches that limited attrition in the Lithium Treatment - Moderate dose Use Study (LiTMUS) for bipolar disorder. METHODS: LiTMUS was a 6-month randomized, longitudinal multisite comparative effectiveness trial that enrolled bipolar participants who were at least mildly ill. Participants were randomized to either low to moderate doses of lithium or no lithium; other treatments needed for mood stabilization were administered in a guideline-informed, empirically supported, and personalized fashion to participants in both treatment arms. RESULTS: Components of the study design that may have contributed to low attrition (16%) among 283 participants randomized included the use of (1) an intent-to-treat design, (2) a randomized adjunctive single-blind design, (3) participant reimbursement, (4) assessment of intent to attend the next study visit (included a discussion of attendance obstacles when intention was low), (5) quality care with limited participant burden, and (6) target windows for study visits. LIMITATIONS: The relationships between attrition and effectiveness and tolerability of treatment have not been analyzed yet. CONCLUSIONS: These components of the LiTMUS design may have limited attrition and may inform the design of future randomized comparative effectiveness trials among similar patients and those from other difficult-to-follow populations.

Rationale and design of the clinical evaluation of the Resolute Zotarolimus-Eluting Coronary Stent System in the treatment of de novo lesions in native coronary arteries (the RESOLUTE US clinical trial).

BACKGROUND: Drug-eluting stents (DES) are commonly used to treat obstructive coronary disease and avoid restenosis. Newer DES have been developed to improve effectiveness and safety. We describe a clinical trial to evaluate a DES with a novel polymer that may improve the antirestenosis effectiveness while maintaining the safety standards of currently Food and Drug Administration-approved DES. METHODS: The RESOLUTE US Trial is a multicenter, nonrandomized trial prospectively designed to compare the Resolute zotarolimus-eluting stent (R-ZES) to the Food and Drug Administration-approved Endeavor ZES using patient-level historical control data, adjusting for baseline covariates through propensity score. The stents differ primarily in the polymer, which, in the R-ZES, is designed to elute zotarolimus over a longer period. The study will enroll up to 1,574 patients with ischemic heart disease due to de novo native coronary lesions suitable for 1- or 2-vessel treatment with stents from 2.25 to 4.0 mm in diameter. The primary end point is target lesion failure at 12 months postprocedure, defined as the composite of cardiac death, target-vessel myocardial infarction (MI), and clinically driven target lesion revascularization by percutaneous or surgical methods. Secondary end points include device, lesion and procedural success, death, MI, cardiac death and MI, composites of these clinical events, and stent thrombosis at each follow-up assessment up to 5 years postprocedure. CONCLUSIONS: The RESOLUTE US Trial (ClinicalTrials.gov #NCT00726453) is a prospective, multicenter, observational study with a patient-level historical control designed to assess the safety and efficacy of the R-ZES for the treatment of de novo lesions in native coronary arteries.

Incidence and clinical outcome of minor surgery in the year after drug-eluting stent implantation: results from the Evaluation of Drug-Eluting Stents and Ischemic Events Registry.

BACKGROUND: The aim of the study was to describe the incidence and consequences of minor surgery after drug-eluting stent (DES) implantation. METHODS: The Evaluation of Drug-Eluting Stents and Ischemic Events (EVENT) Registry prospectively enrolled unselected patients undergoing percutaneous coronary intervention at 47 US centers between July 2004 and December 2007. We examined 8,323 patients who received a DES in EVENT to determine the frequencies of minor surgery and postoperative adverse events. RESULTS: Minor surgery (defined as procedures not requiring a major surgical incision) was performed in 164 (2.0%) of 8,323 patients <1 year after stenting, as follows: pacemaker/defibrillator implantation (46%), eye surgery (17%), orthopedic (9%), dermatologic (8%), endovascular (6%), and gastrointestinal procedures (5%). Compared with patients who did not undergo minor surgery, those who did were older, had more comorbidities, had more extensive coronary disease, and were more likely to have received warfarin after stenting. Only 1 (0.6%, 95% CI 0.0%-3.4%) of 164 patients had an event (stent thrombosis causing myocardial infarction) during the first week after minor surgery; this rate was slightly higher than the background rate of ischemic events in the study population (exact mid P = .01). Clopidogrel use at 12 months was similar between patients who did and those who did not undergo minor surgery (65.2% vs 65.5%, P = .95). CONCLUSIONS: In the EVENT Registry, minor surgery was performed in 2% of patients in the first year after DES implantation. The risk of stent thrombosis during the first week after surgery was increased slightly compared with background rates, but the absolute event rate was low (0.6%).

Segment-specific association between plasma homocysteine level and carotid artery intima-media thickness in the Framingham Offspring Study.

Elevated plasma total homocysteine (tHcy) level is an established risk factor for cardiovascular disease. The relationship between tHcy and carotid artery intima-media thickness (IMT) at the internal carotid artery (ICA)/bulb-IMT and common carotid artery (CCA)-IMT had not been systematically studied, however. Because the ICA/bulb segment is more prone to plaque formation than the CCA segment, differential associations with tHcy at these sites might suggest mechanisms of tHcy action. We examined the cross-sectional segment-specific relationships of tHcy to ICA/bulb-IMT and CCA-IMT in 2499 participants from the Framingham Offspring Study who were free of cardiovascular disease. In multivariate linear regression analysis, ICA/bulb-IMT was significantly higher in the fourth tHcy quartile category compared with the other quartile categories, in both the age- and sex-adjusted and the multivariate-adjusted models (P for trend <.0001 and <.01, respectively). We observed a significant age-by-tHcy interaction for ICA/bulb-IMT (P=.03) and thus stratified the analyses by median age (58 years). A significant positive trend between tHcy and ICA/bulb-IMT was seen in individuals age ≥58 years (P for trend <.01), but not in younger individuals (P for trend=.24) in multivariate-adjusted models. For CCA-IMT, no significant trends were observed in any of the analyses. The segment-specific association between elevated tHcy level and ICA/bulb-IMT suggests an association between tHcy and plaque formation.

Human plasma proteomic profiles indicative of cardiorespiratory fitness.

Maximal oxygen uptake (VO2max) is a direct measure of human cardiorespiratory fitness and is associated with health. However, the molecular determinants of interindividual differences in baseline (intrinsic) VO2max, and of increases of VO2max in response to exercise training (ΔVO2max), are largely unknown. Here, we measure ~5,000 plasma proteins using an affinity-based platform in over 650 sedentary adults before and after a 20-week endurance-exercise intervention and identify 147 proteins and 102 proteins whose plasma levels are associated with baseline VO2max and ΔVO2max, respectively. Addition of a protein biomarker score derived from these proteins to a score based on clinical traits improves the prediction of an individual's ΔVO2max. We validate findings in a separate exercise cohort, further link 21 proteins to incident all-cause mortality in a community-based cohort and reproduce the specificity of ~75% of our key findings using antibody-based assays. Taken together, our data shed light on biological pathways relevant to cardiorespiratory fitness and highlight the potential additive value of protein biomarkers in identifying exercise responsiveness in humans.

Multiomic Profiling in Black and White Populations Reveals Novel Candidate Pathways in Left Ventricular Hypertrophy and Incident Heart Failure Specific to Black Adults.

BACKGROUND: Increased left ventricular (LV) mass is associated with adverse cardiovascular events including heart failure (HF). Both increased LV mass and HF disproportionately affect Black individuals. To understand the underlying mechanisms, we undertook a proteomic screen in a Black cohort and compared the findings to results from a White cohort. METHODS: We measured 1305 plasma proteins using the SomaScan platform in 1772 Black participants (mean age, 56 years; 62% women) in JHS (Jackson Heart Study) with LV mass assessed by 2-dimensional echocardiography. Incident HF was assessed in 1600 participants. We then compared protein associations in JHS to those observed in White participants from FHS (Framingham Heart Study; mean age, 54 years; 56% women). RESULTS: In JHS, there were 110 proteins associated with LV mass and 13 proteins associated with incident HF hospitalization with false discovery rate <5% after multivariable adjustment. Several proteins showed expected associations with both LV mass and HF, including NT-proBNP (N-terminal pro-B-type natriuretic peptide; ß=0.04; P=2×10-8; hazard ratio, 1.48; P=0.0001). The strongest association with LV mass was novel: LKHA4 (leukotriene-A4 hydrolase; ß=0.05; P=5×10-15). This association was confirmed on an alternate proteomics platform and further supported by related metabolomic data. Fractalkine/CX3CL1 (C-X3-C Motif Chemokine Ligand 1) showed a novel association with incident HF (hazard ratio, 1.32; P=0.0002). While established biomarkers such as cystatin C and NT-proBNP showed consistent associations in Black and White individuals, LKHA4 and fractalkine were significantly different between the two groups. CONCLUSIONS: We identified several novel biological pathways specific to Black adults hypothesized to contribute to the pathophysiologic cascade of LV hypertrophy and incident HF including LKHA4 and fractalkine.