Large-Scale Proteomics Identifies Novel Biomarkers and Circulating Risk Factors for Aortic Stenosis.

BACKGROUND: Limited data exist regarding risk factors for aortic stenosis (AS). The plasma proteome is a promising phenotype for discovery of novel biomarkers and potentially causative mechanisms. OBJECTIVES: The aim of this study was to discover novel biomarkers with potentially causal associations with AS. METHODS: We measured 4,877 plasma proteins (SomaScan aptamer-affinity assay) among ARIC (Atherosclerosis Risk In Communities) study participants in mid-life (visit 3 [V3]; n = 11,430; age 60 ± 6 years) and in late-life (V5; n = 4,899; age 76 ± 5 years). We identified proteins cross-sectionally associated with aortic valve (AV) peak velocity (AVmax) and dimensionless index by echocardiography at V5 and with incident AV-related hospitalization after V3 with the use of multivariable linear and Cox proportional hazard regression. We assessed associations of candidate proteins with changes in AVmax over 6 years and with AV calcification with the use of cardiac computed tomography, replicated analysis in an independent sample, performed Mendelian randomization, and evaluated gene expression in explanted human AV tissue. RESULTS: Fifty-two proteins cross-sectionally were associated with AVmax and dimensionless index at V5 and with risk of incident AV-related hospitalization after V3. Among 3,413 participants in the Cardiovascular Health Study, 6 of those proteins were significantly associated with adjudicated moderate or severe AS, including matrix metalloproteinase 12 (MMP12), complement C1q tumor necrosis factor-related protein 1 (C1QTNF1), and growth differentiation factor-15. MMP12 was also associated with greater increase in AVmax over 6 years, greater degree of AV calcification, and greater expression in calcific compared with normal or fibrotic AV tissue. C1QTNF1 had consistent potential causal effects on both AS and AVmax according to Mendelian randomization analysis. CONCLUSIONS: These findings identify MMP12 as a potential novel circulating biomarker of AS risk and C1QTNF1 as a new putative target to prevent AS progression.

Longitudinal Changes in Left Ventricular Diastolic Function in Late Life: The ARIC Study.

BACKGROUND: There is limited data regarding longitudinal changes of diastolic function in the very old, who are at the highest risk for heart failure (HF). OBJECTIVES: This study aims to quantify intraindividual longitudinal changes of diastolic function over 6 years in late life. METHODS: The authors studied 2,524 older adult participants in the prospective community-based ARIC (Atherosclerosis Risk In Communities) study who underwent protocol-based echocardiography at study visits 5 (2011-2013) and 7 (2018-2019). The primary diastolic measures were tissue Doppler e', E/e' ratio, and left atrial volume index (LAVI). RESULTS: Mean age was 74 ± 4 years at visit 5 and 80 ± 4 at visit 7, 59% were women, and 24% were Black. At visit 5, mean e'septal was 5.8 ± 1.4 cm/s, E/e'septal 11.7 ± 3.5, and LAVI 24.3 ± 6.7 mL/m2. Over a mean of 6.6 ± 0.8 years, e'septal decreased by 0.6 ± 1.4 cm/s, E/e'septal increased by 3.1 ± 4.4, and LAVI increased by 2.3 ± 6.4 mL/m2. The proportion with 2 or more abnormal diastolic measures increased from 17% to 42% (P < 0.001). Compared with participants free of cardiovascular (CV) risk factors or diseases at visit 5 (n = 234), those with prevalent CV risk factors or diseases but without prevalent or incident HF (n = 2,150) demonstrated greater increases in E/e'septal and LAVI. Increases of E/e'septal and LAVI were both associated with the development of dyspnea between visits in analyses adjusted for CV risk factors. CONCLUSIONS: Diastolic function generally deteriorates over 6.6 years in late life, particularly among persons with CV risk factors, and is associated with development of dyspnea. Further studies are necessary to determine if risk factor prevention or control will mitigate these changes.

Chronic Kidney Disease, Heart Failure, and Adverse Cardiac Remodeling in Older Adults: The ARIC Study.

BACKGROUND: The associations of kidney dysfunction and damage with heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF), as well as adverse cardiac remodeling, in late-life remain incompletely understood. OBJECTIVES: The authors sought to define the associations between kidney dysfunction and damage and incident HFrEF and HFpEF and cardiac structure and function in late-life. METHODS: This study included 5,170 adults initially free of a heart failure (HF) diagnosis who had estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (UACR) measured at visit 5 (2011-2013) of the ARIC (Atherosclerosis Risk In Communities) study. Multivariable Cox proportional hazards models were used to estimate the associations of eGFR and UACR with incident HF, HFrEF, and HFpEF through 2019. Multivariable linear regression models were used to investigate the associations of eGFR and UACR at visit 5 with changes in cardiac structure and function between visits 5 and 7 in 2,313 participants with available echocardiograms. RESULTS: The mean age of participants was 76 ± 5 years, and 2,225 (43%) were men. The mean eGFR and median UACR were 66 ± 18 mL/min/1.73 m2 and 11 mg/g (25th, 75th percentile: 6, 22 mg/g), respectively. In fully adjusted models, both lower eGFR and higher UACR were associated with greater risk of any HF, HFrEF, and HFpEF. Lower eGFR was associated with larger increases in left ventricular end-diastolic volume index and worsening of diastolic measures. UACR did not associate with changes in cardiac structure or function. CONCLUSIONS: Mild to moderate kidney dysfunction and damage associate with incident HF and adverse cardiac remodeling in late-life.

Inter-observer reproducibility and intra-observer repeatability in 99mTc-pyrophosphate scan interpretation for diagnosis of transthyretin cardiac amyloidosis.

AIM: The purpose of this study was to determine the inter- and intra-observer variability in 99mtechnetium-pyrophosphate (99mTc-PYP) scan interpretation for diagnosis of transthyretin cardiac amyloidosis (ATTR). METHODS AND RESULTS: Our study cohort comprised 100 consecutive subjects referred for 99mTc-PYP imaging based on clinical suspicion of ATTR cardiac amyloidosis. Myocardial 99mTc-PYP uptake was assessed by both visual (comparison of myocardial to rib uptake) and semi-quantitative (heart-to-contralateral lung uptake ratio, H:CL) methods. Twenty scans were analyzed twice, at least 48 hours apart, by each of two independent observers. Patients with visual scores of ≥ 2 on planar imaging as well as myocardial uptake on SPECT/CT were classified as ATTR positive. Diagnosis of ATTR by visual 99mTc-PYP grade was perfectly reproducible [concordance: positive and negative scans 100% (53/53 and 47/47, respectively). Both inter- and intra-observer correlations for H:CL ratio (r2 = 0.90, 0.99 (Observer 1) and 0.98 (Observer 2), respectively) and repeatability values on Bland-Altman plots were excellent. The coefficient of variation (%) for Observers 1 and 2 was 3.21 (2.14 to 4.29) and 7.49 (4.95 to 10.09), respectively. In addition, there was 100% concordance in positive and negative scan interpretation by visual grading between novice CV imagers (< 3 years' experience) and an experienced CV imager (10 years' experience). CONCLUSIONS: This study showed excellent inter-observer reproducibility and intra-observer repeatability of 99mTc-PYP visual scan interpretation and H:CL ratio for diagnosis of cardiac ATTR amyloidosis. Cardiac ATTR amyloidosis can be diagnosed reliably using 99mTc-PYP SPECT/CT by novice and experienced CV imagers.

Coronary vasomotor dysfunction portends worse outcomes in patients with breast cancer.

BACKGROUND: Impaired MFR in the absence of flow-limiting CAD is associated with adverse events. Cardiovascular disease is an important cause of morbidity and mortality in patients with breast cancer. We sought to test the utility of MFR to predict outcomes in a cohort of patients with breast cancer. METHODS: We retrospectively studied consecutive patients with breast cancer or breast cancer survivors who underwent cardiac stress PET imaging from 2006 to 2017 at Brigham and Women's Hospital. Patients with a history of clinically overt CAD, LVEF < 45%, or abnormal myocardial perfusion were excluded. Subjects were followed from time of PET to the occurrence of a first major adverse cardiovascular event (MACE) and all-cause death. RESULTS: The final cohort included 87 patients (median age 69.0 years, 98.9% female, mean MFR 2.05). Over a median follow-up of 7.6 years after PET, the lowest MFR tertile was associated with higher cumulative incidence of MACE (adjusted subdistribution hazard ratio 4.91; 95% CI 1.68-14.38; p = 0.004) when compared with the highest MFR tertile. CONCLUSIONS: In patients with breast cancer, coronary vasomotor dysfunction was associated with incident cardiovascular events. MFR may have potential as a risk stratification biomarker among patients with/survivors of breast cancer.

Association of Left Ventricular Systolic Function With Incident Heart Failure in Late Life.

Importance: Limited data exist regarding the association of subtle subclinical systolic dysfunction and incident heart failure (HF) in late life. Objective: To assess the independent associations of subclinical impairments in systolic performance with incident HF in late life. Design, Setting, and Participants: This study was a time-to-event analysis of participants without heart failure in the Atherosclerosis Risk in Communities (ARIC) study, a prospective, community-based cohort study, who underwent protocol echocardiography at the fifth study visit (January 1, 2011, to December 31, 2013). Findings were validated independently in participants in the Copenhagen City Heart Study (CCHS). Data analysis was performed from June 1, 2018, to February 28, 2020. Exposures: Left ventricular ejection fraction (LVEF), longitudinal strain (LS), and circumferential strain (CS) measured by 2-dimensional and strain echocardiography. Main Outcomes and Measures: Main outcomes were incident adjudicated HF and HF with preserved and reduced LVEF at a median follow-up of 5.5 years (interquartile range, 5.0-5.8 years). Cox proportional hazards regression models adjusted for demographics, hypertension, diabetes, obesity, smoking, coronary disease, estimated glomerular filtration rate, LV mass index, e', E/e', and left atrial volume index. Lower 10th percentile limits were determined in 374 participants free of cardiovascular disease or risk factors. Results: Among 4960 ARIC participants (mean [SD] age, 75 [5] years; 2933 [59.0%] female; 965 [19%] Black), LVEF was less than 50% in only 76 (1.5%). In the 3552 participants with complete assessment of LVEF, LS, and CS, 983 (27.7%) had 1 or more of the following findings: LVEF less than 60%, LS less than 16.0%, or CS less than 23.7%. Modeled continuously or dichotomized, worse LVEF, LS, and CS were each independently associated with incident HF. The adjusted hazard ratio (HR) per SD decrease in LVEF was 1.41 (95% CI, 1.29-1.55); the HR for LVEF less than 60% was 2.59 (95% CI, 1.99-3.37). Similar findings were observed for continuous LS (HR, 1.37; 95% CI, 1.22-1.53) and dichotomized LS (HR, 1.93; 95% CI, 1.46-2.55) and for continuous CS (HR, 1.39; 95% CI, 1.22-1.57) and dichotomized CS (HR, 2.30; 95% CI, 1.64-3.22). Although the magnitude of risk for incident HF or death associated with impaired LVEF was greater using guideline (HR, 2.99; 95% CI, 2.19-4.09) compared with ARIC-based limits (HR, 1.88; 95% CI, 1.58-2.25), the number of participants classified as impaired was less (104 [2.1%] based on guideline thresholds compared with 692 [13.9%] based on LVEF <60%). The population-attributable risk associated with LVEF less than 60% was 11% compared with 5% using guideline-based limits, a finding replicated in 908 participants in the CCHS. Conclusions and Relevance: These findings suggest that relatively subtle impairments of systolic function (detected based on LVEF or strain) are independently associated with incident HF and HF with reduced LVEF in late life. Current recommended assessments of LV function may substantially underestimate the prevalence of prognostically important impairments in systolic function in this population.

High-Sensitivity Cardiac Troponin, Natriuretic Peptide, and Long-Term Risk of Acute Kidney Injury: The Atherosclerosis Risk in Communities (ARIC) Study.

BACKGROUND: Cardiac markers such as high-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-B natriuretic peptide (NTproBNP) are predictors of developing acute kidney injury (AKI) during hospitalization for surgery or revascularization. However, their associations with the long-term risk of AKI in the general population are uncharacterized. METHODS: We conducted a prospective cohort study in 10 669 participants of the Atherosclerosis Risk in Communities Study (visit 4, 1996-1998, mean age, 63 years, 56% female, 22% black race) to examine the association of plasma concentrations of hs-cTnT and NTproBNP with the incident hospitalization with AKI. We used multivariable Cox regression analysis to estimate hazard ratios (HRs). RESULTS: During follow-up, 1907 participants had an incident hospitalization with AKI. Participants with higher concentrations of hs-cTnT had a higher risk of hospitalization with AKI in a graded fashion (adjusted HR, 1.88 [95%CI , 1.59-2.21] for ≥14 ng/L, 1.36 [1.18-1.57] for 9-13 ng/L, and 1.16 [1.03-1.30] for 5-8 ng/L compared to <5 ng/L). The graded association was also observed for NTproBNP (HR, 2.27 [1.93-2.68] for ≥272.7 pg/mL, 1.67 [1.45-1.93] for 142.4-272.6 pg/mL, and 1.31 [1.17-1.47] for 64.0-142.3 pg/mL compared to <64.0 pg/mL). The addition of hs-cTnT and NTproBNP to a model with established predictors significantly improved 10-year risk prediction for hospitalization with AKI (Δc-statistic, 0.015 [95%CI, 0.006-0.024]). CONCLUSIONS: In middle-aged to older black and white adults in the community, higher concentrations of hs-cTnT and NTproBNP were robustly associated with an increased risk of hospitalization with AKI. These results suggest the usefulness of hs-cTnT and NT-proBNP to identify people at risk of AKI in the general population.

Reducing radiation dose from myocardial perfusion imaging in subjects with complex congenital heart disease.

INTRODUCTION: The prevalence of defects and effective radiation dose from various myocardial perfusion imaging (MPI) strategies in congenital heart disease (CHD) is unknown. METHODS: We studied 75 subjects with complex CHD (ages 5 to 80 years) referred for MPI between 2002 and 2015. A rest and exercise or pharmacologic stress MPI was performed using 99mTechnetium sestamibi, 82rubidium or 13N-ammonia, and Sodium iodide SPECT (single-photon emission computed tomography), SPECT/CT or Cadmium zinc telluride (CZT) SPECT or PET (positron emission tomography)/CT scanners. Deidentified images were interpreted semi-quantitatively in three batches: stress only MPI, stress/rest MPI, and stress/rest MPI with taking into account a history of ventricular septal defect repair. Effective radiation dose was estimated for stress/rest MPI and predicted for 1-day stress-first (normal stress scans), and for 2-day stress/rest MPI (abnormal stress scans). RESULTS: The median age was 18.6 years. The most common type of CHD was transposition of the great arteries (63%). Rest/stress MPI was abnormal in 43% of subjects and 25% of the abnormal scans demonstrated reversible defects. Of the subjects with abnormal MPI, 33% had significant underlying anatomic coronary artery obstruction. Estimated mean effective radiation dose ranged from 2.1 ± 0.6 mSv for 13N-ammonia PET/CT to 12.5 ± 0.9 mSv for SPECT/CT. Predicted effective radiation dose was significantly lower for stress-first MPI and for 2-day stress/rest protocols. CONCLUSIONS: Due to the relatively high prevalence of abnormal stress MPI, tailored protocols with a stress-first MPI as well as the use of 2-day protocols and advanced imaging technologies including CZT SPECT, novel image reconstruction software, and PET MPI could substantially reduce radiation dose in complex CHD.

Absolute Quantitation of Cardiac 99mTc-Pyrophosphate Using Cadmium-Zinc-Telluride-Based SPECT/CT.

The primary aims of this study were to determine the correlation between absolute quantitative 99mTc-pyrophosphate metrics and traditional measures of cardiac amyloid burden and to measure the intraobserver repeatability of the quantitative metrics. Methods: We studied 72 patients who underwent 99mTc-pyrophosphate SPECT/CT using a novel general-purpose cadmium-zinc-telluride-based SPECT/CT system. The clinical standard for these studies is visual grading (with grades of 0, 1, 2, and 3 indicating myocardial uptake absent, less than rib uptake, equal to rib uptake, or more than rib uptake, respectively). A visual grade of 2 or more was considered positive. For 72 patients, SUVmax, SUVmean, cardiac amyloid activity (CAA; i.e., SUVmean × left ventricular [LV] volume), and percentage injected dose (%ID) were calculated, and visual grading was performed. The correlation was determined between the 4 quantitative metrics or visual grades and the LV mass index (LVMI) (indexed to body surface area on echocardiography, 67 patients). For a subset of 11 patients, the correlation was determined between the visual or quantitative metrics and the extracellular volume (ECV) on cardiac MRI. Normal linear regression was used to compare the standardized association of each of the 4 quantitative metrics with LVMI, as a surrogate for amyloid burden. Receiver-operating-characteristic curve analysis was used to determine the diagnostic accuracy of quantitative metrics, using visual grading as the reference standard. The intraobserver repeatability of generating quantitative metrics was also determined. Results: All 4 quantitative metrics were highly accurate, with an area under the receiver-operating-characteristic curve of more than 0.96 for diagnosis of transthyretin cardiac amyloidosis. SUVmax, SUVmean, CAA, %ID, and visual grade were moderately positively correlated with LVMI (r = 0.485 for %ID) and strongly positively correlated, albeit in a small cohort, with ECV (r = 0.873, SUVmax). Intraobserver repeatability was excellent, with less than a 2% coefficient of variation for SUVmax, %ID, and CAA and 3.8% for SUVmean All 4 quantitative metrics had a standardized effect of more than 0.324 on LVMI; the largest standardized effect was 0.485, for %ID. Conclusion: In this first (to our knowledge) study of 99mTc-pyrophosphate cardiac imaging using a novel cadmium-zinc-telluride SPECT/CT scanner, SUVmax, SUVmean, CAA, and %ID measured by absolute quantitation of 99mTc-pyrophosphate were moderately correlated with LVMI and strongly correlated, albeit in a small cohort, with ECV. The intraobserver repeatability of generating the quantitative metrics was excellent.

Diagnostic Accuracy of Advanced Imaging in Cardiac Sarcoidosis.

Background The diagnostic yield of cardiac sarcoidosis (CS) by endomyocardial biopsy is limited. Fluorodeoxyglucose (FDG) positron emission tomography (PET) and cardiac magnetic resonance imaging (MRI) may facilitate noninvasive diagnosis, but the accuracy of this approach is not well defined. We aimed to correlate findings from FDG PET and cardiac MRI with histological findings from explanted hearts of patients who underwent cardiac transplantation. Methods We analyzed the explanted heart histology for all patients who underwent cardiac transplant at our center from April 2008 to July 2018 and had pretransplant FDG PET (n=18) or cardiac MRI (n=31). The likelihood of CS based on FDG PET or cardiac MRI was categorized in a blinded fashion using a previously published method. RESULTS: Using a CS probable cutoff for FDG PET resulted in a sensitivity of 100.0% (95% CI, 54.1%-100.0%) and a specificity of 33.3% (95% CI, 9.9%-65.1%). Three of the 9 CS probable by FDG PET cases were found to be arrhythmogenic cardiomyopathy. The test characteristics of cardiac MRI are more challenging to comment on using our data as there was only one confirmed case of CS on post-transplant histological assessment. Of the 8 CS highly probable or probable cases by cardiac MRI, 3 were found to be dilated cardiomyopathy, and 2 were found to be end-stage hypertrophic cardiomyopathy. Conclusions FDG PET and cardiac MRI can help facilitate the diagnosis of CS in patients with advanced heart failure with a high degree of sensitivity but lower specificity.

Cardiovascular phenotype and prognosis of patients with heart failure induced by cancer therapy.

OBJECTIVE: This study compared the clinical features, cardiac structure and function evaluated by echocardiography, cardiopulmonary response to exercise and long-term clinical outcomes between patients with heart failure (HF) induced by cancer therapy (CTHF) and heart failure not induced by cancer therapy (NCTHF). METHODS: We evaluated 75 patients with CTHF and 894 with NCTHF who underwent clinically indicated cardiopulmonary exercise testing, and followed these individuals for a median of 4.5 (3.0-5.8) years, during which 187 deaths and 256 composite events (death, heart transplantation and left ventricular (LV) assistant device implantation) occurred. RESULTS: Compared with NCTHF, patients with CTHF were younger, with lower prevalence of cardiovascular comorbidities, higher LV ejection fraction (LVEF), but similar global longitudinal strain. LV diastolic function (higher E/e' ratio) and compliance (higher end-diastolic pressure/LV end-diastolic volume index ratio) were worse in CTHF and were both associated with adverse outcomes. Despite a favourable clinical profile, peak VO2 and VE/VCO2 slope were similarly impaired in CTHF and NCTHF. In multivariable Cox regression analysis including clinical characteristics, cardiopulmonary exercise testing variables and LVEF, CTHF was associated with a significantly higher risk of death (HR 2.64; 95% CI 1.53 to 4.55; p=0.001) and composite events (HR 1.79; 95% CI 1.10 to 2.91; p=0.019) compared with NCTHF. CONCLUSIONS: CTHF is characterised by a distinct clinical profile, better LVEF but worse LV diastolic properties, and similarly impaired global longitudinal strain, functional capacity and ventilatory efficiency. Accounting for differences in clinical characteristics, CTHF was associated with worse long-term prognosis than NCTHF.

Safety and cardiovascular efficacy of spironolactone in dialysis-dependent ESRD (SPin-D): a randomized, placebo-controlled, multiple dosage trial.

The safety and efficacy of spironolactone is uncertain in end-stage renal disease. We randomized 129 maintenance hemodialysis patients to placebo (n=51) or spironolactone 12.5 mg (n=27), 25 mg (n=26), or 50 mg (n=25) daily for 36 weeks in a double-blind, placebo-controlled, multiple dosage trial to assess safety, tolerability and feasibility and to explore cardiovascular efficacy. The primary safety endpoints were hyperkalemia (potassium > 6.5 mEq/L) and hypotension requiring emergency department visit or hospitalization. Diastolic function was assessed by Doppler echocardiography. 125 participants (97%) completed dose escalation, with no significant difference in permanent study drug discontinuation between the groups (27.5% in placebo versus 16.7% in the combined spironolactone groups and 28% in the 50 mg group). Hyperkalemia frequency was similar between spironolactone and placebo (0.49 versus 0.50 events per patient-year) but demonstrated a significant linear trend due primarily to an increased event rate at the 50 mg dose (0.89 events per patient-year). The primary hypotension outcome was infrequent and similar with spironolactone and placebo (0.11 versus 0 events per patient-year). Gynecomastia was rare and did not differ significantly between groups. Change in diastolic function was similar with spironolactone and placebo. Spironolactone appears safe in carefully monitored maintenance hemodialysis patients, but did not affect cardiovascular parameters in this small study. Hyperkalemia occurs more frequently as dosage increases to 50 mg daily.

Isolated cardiac sarcoidosis: A focused review of an under-recognized entity.

There is accumulating evidence for the existence of a phenotype of isolated cardiac sarcoidosis (ICS), or sarcoidosis that only involves the heart. In the absence of biopsy-confirmed cardiac sarcoidosis (CS), existing diagnostic criteria require the presence of extra-cardiac sarcoidosis as an inclusion criterion for the diagnosis of CS. Consequently, in the absence of a positive endomyocardial biopsy, ICS is not diagnosable by current guidelines. Therefore, there is uncertainty regarding the epidemiology, pathobiology, clinical characteristics, prognosis, and optimal treatment of ICS. This review will summarize the available data related to the prevalence and prognosis of ICS and will discuss challenges surrounding the diagnosis and management of this under-recognized entity.

Kidney Disease Measures and Left Ventricular Structure and Function: The Atherosclerosis Risk in Communities Study.

BACKGROUND: Heart failure is one of the most important complications of chronic kidney disease (CKD). However, few studies comprehensively investigated left ventricular (LV) structure and function in relation to 2 key CKD measures, estimated glomerular filtration rate (eGFR) and urine albumin/creatinine ratio (ACR). METHODS AND RESULTS: Among 4175 ARIC (Atherosclerosis Risk in Communities) participants (aged 66-90 years during 2011-2013), we quantified the association of eGFR and ACR with echocardiogram parameters of LV mass, size, systolic function, and diastolic function. Adjusting for demographic variables, both CKD measures were significantly associated with most echocardiogram parameters. Additionally accounting for other potential confounders, we observed significantly higher LV mass index according to reduced eGFR (82.3 [95% confidence interval (CI), 77.6-87.0] g/m2 for eGFR <30 mL/min per 1.73 m2, 80.9 [95% CI, 77.3-84.6] g/m2 for eGFR 30-44 mL/min per 1.73 m2, and 80.1 [95% CI, 76.7-83.5] g/m2 for eGFR 45-59 mL/min per 1.73 m2 compared with 78.7 [95% CI, 75.3-82.1] g/m2 for eGFR 75-89 mL/min per 1.73 m2; trend P<0.001). Regarding LV size and function, significant differences were observed for some parameters, particularly at eGFR <30 mL/min per 1.73 m2. For ACR, the associations remained significant for most parameters (eg, LV mass index, 91.5 [95% CI, 86.6-96.5] g/m2 for ACR ≥300 mg/g and 82.9 [95% CI, 79.4-86.3] g/m2 for ACR 30-299 mg/g compared with 77.7 [95% CI, 74.4-81.1] g/m2 for ACR <10 mg/g [trend P<0.001]; left arterial volume index, 24.9 [95% CI, 22.9-26.8] and 24.7 [95% CI, 23.4-26.1] mL/m2 compared with 23.4 [95% CI, 22.1-24.7] mL/m2, respectively [trend P=0.010]). Dichotomizing echo parameters with clinical thresholds, the stronger relationships of ACR over eGFR were further evident. CONCLUSIONS: LV mass was related to both CKD measures, whereas LV size and function were robustly associated with albuminuria. These results have implications for pathophysiological processes behind cardiorenal syndrome and targeted cardiac assessment in patients with CKD.

Traditional Risk Factors Versus Biomarkers for Prediction of Secondary Events in Patients With Stable Coronary Heart Disease: From the Heart and Soul Study.

BACKGROUND: Patients with stable coronary heart disease (CHD) have widely varying prognoses and treatment options. Validated models for risk stratification of patients with CHD are needed. We sought to evaluate traditional and novel risk factors as predictors of secondary cardiovascular (CV) events, and to develop a prediction model that could be used to risk stratify patients with stable CHD. METHODS AND RESULTS: We used independent derivation (912 participants in the Heart and Soul Study) and validation (2876 participants in the PEACE trial) cohorts of patients with stable CHD to develop a risk prediction model using Cox proportional hazards models. The outcome was CV events, defined as myocardial infarction, stroke, or CV death. The annual rate of CV events was 3.4% in the derivation cohort and 2.2% in the validation cohort. With the exception of smoking, traditional risk factors (including age, sex, body mass index, hypertension, dyslipidemia, and diabetes) did not emerge as the top predictors of secondary CV events. The top 4 predictors of secondary events were the following: N-terminal pro-type brain natriuretic peptide, high-sensitivity cardiac troponin T, urinary albumin:creatinine ratio, and current smoking. The 5-year C-index for this 4-predictor model was 0.73 in the derivation cohort and 0.65 in the validation cohort. As compared with variables in the Framingham secondary events model, the Heart and Soul risk model resulted in net reclassification improvement of 0.47 (95% CI 0.25 to 0.73) in the derivation cohort and 0.18 (95% CI 0.01 to 0.40) in the validation cohort. CONCLUSIONS: Novel risk factors are superior to traditional risk factors for predicting 5-year risk of secondary events in patients with stable CHD.

Approaches to reducing radiation dose from radionuclide myocardial perfusion imaging.

Radionuclide myocardial perfusion imaging (MPI) plays a vital role in the evaluation and management of patients with coronary artery disease. However, because of a steep growth in MPI in the mid 2000s, concerns about inappropriate use of MPI and imaging-related radiation exposure increased. In response, the professional societies developed appropriate-use criteria for MPI. Simultaneously, novel technology, image-reconstruction software for traditional scanners, and dedicated cardiac scanners emerged and facilitated the performance of MPI with low-dose and ultra-low-dose radiotracers. This paper provides a practical approach to performing low-radiation-dose MPI using traditional and novel technologies.

Temporal trends in the population attributable risk for cardiovascular disease: the Atherosclerosis Risk in Communities Study.

BACKGROUND: The extent to which the relative contributions of traditional cardiovascular risk factors to incident cardiovascular disease (CVD) may have changed over time remains unclear. METHODS AND RESULTS: We studied 13 541 participants (56% women, 26% black) in the Atherosclerosis Risk in Communities Study, aged 52 to 66 years and free of CVD at exams in 1987 through 1989, 1990 through 1992, 1993 through 1995, or 1996 through 1998. At each examination, we estimated the population attributable risks (PAR) of traditional risk factors (hypertension, diabetes mellitus, obesity, hypercholesterolemia, and smoking) for the 10-year incidence of CVD. Overall, the PAR of all risk factors combined appeared to decrease from the late 1980s to the late 1990s (0.58 to 0.53). The combined PAR was higher in women than men in 1987 through 1989 (0.68 versus 0.51, P<0.001) but not by the late 1990s (0.58 versus 0.48, P=0.08). The combined PAR was higher in blacks than whites in the late 1980s (0.67 versus 0.57, P=0.049), and this difference was more pronounced by the late 1990s (0.67 versus 0.48, P=0.002). By the late 1990s, the PAR of hypertension had become higher in women than men (P=0.02) and also appeared higher in blacks than whites (P=0.08). By the late 1990s, the PAR of diabetes mellitus remained higher in women than men (P<0.0001) and in blacks than whites (P<0.0001). CONCLUSIONS: The contribution to CVD of all traditional risk factors combined is greater in blacks than whites, and this difference may be increasing. The contributions of hypertension and diabetes mellitus remain especially high, in women as well as blacks. These findings underscore the continued need for individual as well as population approaches to CVD risk factor modification.

Moving beyond the hazard ratio in quantifying the between-group difference in survival analysis.

In a longitudinal clinical study to compare two groups, the primary end point is often the time to a specific event (eg, disease progression, death). The hazard ratio estimate is routinely used to empirically quantify the between-group difference under the assumption that the ratio of the two hazard functions is approximately constant over time. When this assumption is plausible, such a ratio estimate may capture the relative difference between two survival curves. However, the clinical meaning of such a ratio estimate is difficult, if not impossible, to interpret when the underlying proportional hazards assumption is violated (ie, the hazard ratio is not constant over time). Although this issue has been studied extensively and various alternatives to the hazard ratio estimator have been discussed in the statistical literature, such crucial information does not seem to have reached the broader community of health science researchers. In this article, we summarize several critical concerns regarding this conventional practice and discuss various well-known alternatives for quantifying the underlying differences between groups with respect to a time-to-event end point. The data from three recent cancer clinical trials, which reflect a variety of scenarios, are used throughout to illustrate our discussions. When there is not sufficient information about the profile of the between-group difference at the design stage of the study, we encourage practitioners to consider a prespecified, clinically meaningful, model-free measure for quantifying the difference and to use robust estimation procedures to draw primary inferences.

Cardiac positron emission tomography enhances prognostic assessments of patients with suspected cardiac sarcoidosis.

OBJECTIVES: This study sought to relate imaging findings on positron emission tomography (PET) to adverse cardiac events in patients referred for evaluation of known or suspected cardiac sarcoidosis. BACKGROUND: Although cardiac PET is commonly used to evaluate patients with suspected cardiac sarcoidosis, the relationship between PET findings and clinical outcomes has not been reported. METHODS: We studied 118 consecutive patients with no history of coronary artery disease, who were referred for PET, using [(18)F]fluorodeoxyglucose (FDG) to assess for inflammation and rubidium-82 to evaluate for perfusion defects (PD), following a high-fat/low-carbohydrate diet to suppress normal myocardial glucose uptake. Blind readings of PET data categorized cardiac findings as normal, positive PD or FDG, positive PD and FDG. Images were also used to identify whether findings of extra-cardiac sarcoidosis were present. Adverse events (AE)-death or sustained ventricular tachycardia (VT)-were ascertained by electronic medical records, defibrillator interrogation, patient questionnaires, and telephone interviews. RESULTS: Among the 118 patients (age 52 ± 11 years; 57% males; mean ejection fraction: 47 ± 16%), 47 (40%) had normal and 71 (60%) had abnormal cardiac PET findings. Over a median follow-up of 1.5 years, there were 31 (26%) adverse events (27 VT and 8 deaths). Cardiac PET findings were predictive of AE, and the presence of both a PD and abnormal FDG (29% of patients) was associated with hazard ratio of 3.9 (p < 0.01) and remained significant after adjusting for left ventricular ejection fraction (LVEF) and clinical criteria. Extra-cardiac FDG uptake (26% of patients) was not associated with AE. CONCLUSIONS: The presence of focal PD and FDG uptake on cardiac PET identifies patients at higher risk of death or VT. These findings offer prognostic value beyond Japanese Ministry of Health and Welfare clinical criteria, the presence of extra-cardiac sarcoidosis and LVEF.