Higher docosahexaenoic acid levels lower the protective impact of eicosapentaenoic acid on long-term major cardiovascular events

Introduction

Long-chain omega-3 polyunsaturated fatty acids (OM3 PUFA) are commonly used for cardiovascular disease prevention. High-dose eicosapentaenoic acid (EPA) is reported to reduce major adverse cardiovascular events (MACE); however, a combined EPA and docosahexaenoic acid (DHA) supplementation has not been proven to do so. This study aimed to evaluate the potential interaction between EPA and DHA levels on long-term MACE.

Methods

We studied a cohort of 987 randomly selected subjects enrolled in the INSPIRE biobank registry who underwent coronary angiography. We used rapid throughput liquid chromatography-mass spectrometry to quantify the EPA and DHA plasma levels and examined their impact unadjusted, adjusted for one another, and fully adjusted for comorbidities, EPA + DHA, and the EPA/DHA ratio on long-term (10-year) MACE (all-cause death, myocardial infarction, stroke, heart failure hospitalization).

Results

The average subject age was 61.5 ± 12.2 years, 57% were male, 41% were obese, 42% had severe coronary artery disease (CAD), and 311 (31.5%) had a MACE. The 10-year MACE unadjusted hazard ratio (HR) for the highest (fourth) vs. lowest (first) quartile (Q) of EPA was HR = 0.48 (95% CI: 0.35, 0.67). The adjustment for DHA changed the HR to 0.30 (CI: 0.19, 0.49), and an additional adjustment for baseline differences changed the HR to 0.36 (CI: 0.22, 0.58). Conversely, unadjusted DHA did not significantly predict MACE, but adjustment for EPA resulted in a 1.81-fold higher risk of MACE (CI: 1.14, 2.90) for Q4 vs. Q1. However, after the adjustment for baseline differences, the risk of MACE was not significant for DHA (HR = 1.37; CI: 0.85, 2.20). An EPA/DHA ratio ≥1 resulted in a lower rate of 10-year MACE outcomes (27% vs. 37%, adjusted p-value = 0.013).

Conclusions

Higher levels of EPA, but not DHA, are associated with a lower risk of MACE. When combined with EPA, higher DHA blunts the benefit of EPA and is associated with a higher risk of MACE in the presence of low EPA. These findings can help explain the discrepant results of EPA-only and EPA/DHA mixed clinical supplementation trials.

Association of the Intermountain Risk Score with major adverse health events in patients positive for COVID-19: an observational evaluation of a US cohort

OBJECTIVES

The Intermountain Risk Score (IMRS), composed using published sex-specific weightings of parameters in the complete blood count (CBC) and basic metabolic profile (BMP), is a validated predictor of mortality. We hypothesised that IMRS calculated from prepandemic CBC and BMP predicts COVID-19 outcomes and that IMRS using laboratory results tested at COVID-19 diagnosis is also predictive.

DESIGN

Prospective observational cohort study.

SETTING

Primary, secondary, urgent and emergent care, and drive-through testing locations across Utah and in sections of adjacent US states. Viral RNA testing for SARS-CoV-2 was conducted from 3 March to 2 November 2020.

PARTICIPANTS

Patients aged ≥18 years were evaluated if they had CBC and BMP measured in 2019 and tested positive for COVID-19 in 2020.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was a composite of hospitalisation or mortality, with secondary outcomes being hospitalisation and mortality separately.

RESULTS

Among 3883 patients, 8.2% were hospitalised and 1.6% died. Subjects with low, mild, moderate and high-risk IMRS had the composite endpoint in 3.5% (52/1502), 8.6% (108/1256), 15.5% (152/979) and 28.1% (41/146) of patients, respectively. Compared with low-risk, subjects in mild-risk, moderate-risk and high-risk groups had HR=2.33 (95% CI 1.67 to 3.24), HR=4.01 (95% CI 2.93 to 5.50) and HR=8.34 (95% CI 5.54 to 12.57), respectively. Subjects aged <60 years had HR=3.06 (95% CI 2.01 to 4.65) and HR=7.38 (95% CI 3.14 to 17.34) for moderate and high risks versus low risk, respectively; those ≥60 years had HR=1.95 (95% CI 0.99 to 3.86) and HR=3.40 (95% CI 1.63 to 7.07). In multivariable analyses, IMRS was independently predictive and was shown to capture substantial risk variation of comorbidities.

CONCLUSIONS

IMRS, a simple risk score using very basic laboratory results, predicted COVID-19 hospitalisation and mortality. This included important abilities to identify risk in younger adults with few diagnosed comorbidities and to predict risk prior to SARS-CoV-2 infection.

The history and geographic distribution of a KCNQ1 atrial fibrillation risk allele

The genetic architecture of atrial fibrillation (AF) encompasses low impact, common genetic variants and high impact, rare variants. Here, we characterize a high impact AF-susceptibility allele, KCNQ1 R231H, and describe its transcontinental geographic distribution and history. Induced pluripotent stem cell-derived cardiomyocytes procured from risk allele carriers exhibit abbreviated action potential duration, consistent with a gain-of-function effect. Using identity-by-descent (IBD) networks, we estimate the broad- and fine-scale population ancestry of risk allele carriers and their relatives. Analysis of ancestral migration routes reveals ancestors who inhabited Denmark in the 1700s, migrated to the Northeastern United States in the early 1800s, and traveled across the Midwest to arrive in Utah in the late 1800s. IBD/coalescent-based allele dating analysis reveals a relatively recent origin of the AF risk allele (~5000 years). Thus, our approach broadens the scope of study for disease susceptibility alleles to the context of human migration and ancestral origins.

Randomized controlled trial of once-per-week intermittent fasting for health improvement: the WONDERFUL trial

Aims

Low-density lipoprotein cholesterol (LDL-C) predicts heart disease onset and may be reduced by intermittent fasting. Some studies, though, reported that fasting increased LDL-C; however, no study evaluated LDL-C as the primary endpoint. This randomized controlled trial evaluated the effect of low-frequency intermittent fasting on LDL-C and other biomarkers.

Methods and results

Adults aged 21–70 years were enrolled who were not taking a statin, had modestly elevated LDL-C, had ≥1 metabolic syndrome feature or type 2 diabetes, and were not taking anti-diabetic medication (N = 103). Water-only 24-h fasting was performed twice weekly for 4 weeks and then once weekly for 22 weeks; controls ate ad libitum. The primary outcome was 26-week LDL-C change score. Secondary outcomes (requiring P ≤ 0.01) were 26-week changes in homeostatic model assessment of insulin resistance (HOMA-IR), Metabolic Syndrome Score (MSS), brain-derived neurotrophic factor (BDNF), and MicroCog general cognitive proficiency index (GCPi). Intermittent fasting (n = 50) and control (n = 53) subjects were, respectively, aged 49.3 ± 12.0 and 47.0 ± 9.8 years, predominantly female (66.0% and 67.9%), and overweight (103 ± 24 and 100 ± 21 kg) and had modest LDL-C elevation (124 ± 19 and 128 ± 20 mg/dL). Drop-outs (n = 12 fasting, n = 20 control) provided an evaluable sample of n = 71 (n = 38 fasting, n = 33 control). Intermittent fasting did not change LDL-C (0.2 ± 16.7 mg/dL) vs. control (2.5 ± 19.4 mg/dL; P = 0.59), but it improved HOMA-IR (−0.75 ± 0.79 vs. −0.10 ± 1.06; P = 0.004) and MSS (−0.34 ± 4.72 vs. 0.31 ± 1.98, P = 0.006). BDNF (P = 0.58), GCPi (P = 0.17), and weight (−1.7 ± 4.7 kg vs. 0.2 ± 3.5 kg, P = 0.06) were unchanged.

Conclusions

A low-frequency intermittent fasting regimen did not reduce LDL-C or improve cognitive function but significantly reduced both HOMA-IR and MSS.

Trial registration

 clinicaltrials.gov, NCT02770313.

Abstract 271: Mitochondrial DNA Copy Number in Peripheral Blood Cells is Associated With All -Cause Mortality in Older Cardiovascular Patients

Background: Mitochondrial DNA copy number (Mt CN) is a surrogate marker of mitochondrial function. Variations in Mt CN have been associated with several age-related diseases. Lower Mt CN may indicate impaired cellular energy production whereas higher Mt CN may compensate for energy disbalance but also may lead to cellular damage through oxidative stress. This study evaluated the association of Mt CN and all-cause mortality in older cardiovascular patients (Pt).

Methods: The study was approved by the Intermountain Healthcare Institutional Review Board. Consenting subjects (n=2,253) were participants in the INSPIRE registry undergoing cardiac catheterization at the Intermountain Heart Institute. Total DNA was extracted from EDTA stabilized blood with either Puregene (Qiagen) or Reliaprep (Promega) reagents. Relative Mt CN measurements were performed with multiplexed real-time polymerase chain reaction coamplifying a stable site of Mt D- Loop and a region of a single copy nuclear β-2-microglobulin gene(β2M) and calculated as a ratio of Mt to β2M DNA. Cox regression was used to evaluate the association of Mt CN with all-cause mortality, with adjustment considering 32 covariables. Further adjustment entered the Intermountain Risk Score (IMRS), a validated mortality risk predictor.

Results: Mean Pt age was age 62.3±13.8 yrs.; 65.2% were male; 1,122 (50%) died during 25.4 years of follow-up. Mt CN was lower for males (539±449 vs 654 ± 1053 for females; p=0.004). Mt CN was 616±917 in decedents and 542±438 in survivors (p=0.014). In univariable Cox regression, Quartile 1 versus Quartile 4 of Mt CN was associated with the highest mortality risk (hazard ratio [HR]=1.45, CI=1.22, 1.71, p<0.001). This association remained significant after multivariable adjustment (HR=1.30, CI=1.10, 1.54, p=0.003). There was minimal correlation between IMRS and Mt CN continuous values (r= -0.09 for males, r= -0.13 for females). In Cox regression, adjustment for IMRS and covariables showed Mt CN remained associated with mortality (HR=1.30, CI=1.08, 1.57, p=0.006).

Conclusions: Low Mt CN is independently associated with higher risk of all-cause mortality. Further studies validating this finding and examining potential underlying physiologic protective mechanisms may prove to be of therapeutic and prognostic value.

Abstract 465: High Circulating Levels of 8-OHdG are an Independent Predictor of Subsequent MACE

Objective: Oxidative stress is associated with several cardiovascular risk factors and cardiovascular disease. Damaged cells release cell-free DNA (cfDNA) into the circulation; oxidized cfDNA presence in the plasma indicates a pathological process in the context of oxidative stress. We hypothesized that biomarker of oxidative DNA damage 8-hydroxy- 2’deoxyguanosine (8-OHdG) may be associated with incident major adverse cardiovascular events (MACE).

Methods: Plasma samples from 84 consenting patients undergoing coronary angiography at Intermountain Healthcare were obtained at the time of the procedure and tested for 8-OHdG by ELISA. Study endpoints were subsequent myocardial infarction (MI), stroke and all-cause death (determined by electronic medical records and death certificates) within median follow-up of 10 years (IQR: 8.8, 10.6). Cox-proportional hazard analysis was used for examining MACE rate association by quartile of 8-OHdG.

Results: Mean 8-OHdG was significantly higher for individuals with a subsequent MACE vs those without (124.8 and 98.7 nM, respectively; p<0.006, t-test). No other baseline demographic was significantly associated with 8-OHdG. MACE rates by 8-OHdG quartiles revealed a significant trend (p = 0.0346) (Figure). Hazard ratio increased by 1.653 for every 42 unit increase in 8-OHdG, p=0.006.

Conclusion: High 8-OHdG plasma levels independently predict subsequent MACE. Whether 8-OHdG is contributes etiologically to event causation needs to be determined.

Subsequent Event Risk in Individuals With Established Coronary Heart Disease

Supplemental Digital Content is available in the text.

Background:

The Genetics of Subsequent Coronary Heart Disease (GENIUS-CHD) consortium was established to facilitate discovery and validation of genetic variants and biomarkers for risk of subsequent CHD events, in individuals with established CHD.

Methods:

The consortium currently includes 57 studies from 18 countries, recruiting 185 614 participants with either acute coronary syndrome, stable CHD, or a mixture of both at baseline. All studies collected biological samples and followed-up study participants prospectively for subsequent events.

Results:

Enrollment into the individual studies took place between 1985 to present day with a duration of follow-up ranging from 9 months to 15 years. Within each study, participants with CHD are predominantly of self-reported European descent (38%–100%), mostly male (44%–91%) with mean ages at recruitment ranging from 40 to 75 years. Initial feasibility analyses, using a federated analysis approach, yielded expected associations between age (hazard ratio, 1.15; 95% CI, 1.14–1.16) per 5-year increase, male sex (hazard ratio, 1.17; 95% CI, 1.13–1.21) and smoking (hazard ratio, 1.43; 95% CI, 1.35–1.51) with risk of subsequent CHD death or myocardial infarction and differing associations with other individual and composite cardiovascular endpoints.

Conclusions:

GENIUS-CHD is a global collaboration seeking to elucidate genetic and nongenetic determinants of subsequent event risk in individuals with established CHD, to improve residual risk prediction and identify novel drug targets for secondary prevention. Initial analyses demonstrate the feasibility and reliability of a federated analysis approach. The consortium now plans to initiate and test novel hypotheses as well as supporting replication and validation analyses for other investigators.

Association of Chromosome 9p21 With Subsequent Coronary Heart Disease Events

Supplemental Digital Content is available in the text.

Background:

Genetic variation at chromosome 9p21 is a recognized risk factor for coronary heart disease (CHD). However, its effect on disease progression and subsequent events is unclear, raising questions about its value for stratification of residual risk.

Methods:

A variant at chromosome 9p21 (rs1333049) was tested for association with subsequent events during follow-up in 103 357 Europeans with established CHD at baseline from the GENIUS-CHD (Genetics of Subsequent Coronary Heart Disease) Consortium (73.1% male, mean age 62.9 years). The primary outcome, subsequent CHD death or myocardial infarction (CHD death/myocardial infarction), occurred in 13 040 of the 93 115 participants with available outcome data. Effect estimates were compared with case/control risk obtained from the CARDIoGRAMplusC4D consortium (Coronary Artery Disease Genome-wide Replication and Meta-analysis [CARDIoGRAM] plus The Coronary Artery Disease [C4D] Genetics) including 47 222 CHD cases and 122 264 controls free of CHD.

Results:

Meta-analyses revealed no significant association between chromosome 9p21 and the primary outcome of CHD death/myocardial infarction among those with established CHD at baseline (GENIUS-CHD odds ratio, 1.02; 95% CI, 0.99–1.05). This contrasted with a strong association in CARDIoGRAMPlusC4D odds ratio 1.20; 95% CI, 1.18–1.22; P for interaction <0.001 compared with the GENIUS-CHD estimate. Similarly, no clear associations were identified for additional subsequent outcomes, including all-cause death, although we found a modest positive association between chromosome 9p21 and subsequent revascularization (odds ratio, 1.07; 95% CI, 1.04–1.09).

Conclusions:

In contrast to studies comparing individuals with CHD to disease-free controls, we found no clear association between genetic variation at chromosome 9p21 and risk of subsequent acute CHD events when all individuals had CHD at baseline. However, the association with subsequent revascularization may support the postulated mechanism of chromosome 9p21 for promoting atheroma development.

Extreme erythrocyte macrocytic and microcytic percentages are highly predictive of morbidity and mortality

BACKGROUND

The red cell distribution width (RDW) is associated with health outcomes. Whether non-RDW risk information is contained in RBC sizes is unknown. This study evaluated the association of the percentage of extreme macrocytic RBCs (%Macro, RBC volume > 120 fl) and microcytic RBCs (%Micro, RBC volume < 60 fl) and the RDW-size distribution (RDW-sd) with mortality and morbidity.

METHODS

Patients (females, n = 165,770; males, n = 100,210) at Intermountain Healthcare were studied if they had a hematology panel between May 2014 and September 2016. Adjusted sex-specific associations of %Macro/%Micro and RDW-sd with mortality and 33 morbidities were evaluated.

RESULTS

Among females with fourth-quartile values of %Macro quartile and %Micro (referred to throughout as 4/4), there was an average of 7.2 morbidities versus 2.9 in the lowest risk (LR1) categories, 1/1, 1/2, 2/1, and 2/2 (P < 0.001). Among males, those in the 4/4 category had 8.0 morbidities, while those in the LR1 had 3.4 (P < 0.001). Cox regressions found %Macro/%Micro (4/4 vs. LR1, females: hazard ratio [HR] = 1.97 [95% CI = 1.53, 2.54]; males: HR = 2.17 [CI = 1.72, 2.73]), RDW-sd (quartile 4 vs. 1, females: HR = 1.33 [CI = 1.04, 1.69]; males: HR = 1.41 [CI = 1.10, 1.80]), and RDW (quartile 4 vs. 1, females: HR = 1.59 [CI = 1.26, 2.00]; males: HR = 1.23 [CI = 0.99, 1.52]) independently predicted mortality. Limitations include that the observational design did not reveal causality and unknown confounders may be unmeasured.

CONCLUSIONS

Concomitantly elevated %Macro and %Micro predicted the highest mortality risk and the greatest number of morbidities, revealing predictive ability of RBC volume beyond what is measured clinically. Mechanistic investigations are needed to explain the biological basis of these observations.

FUNDING

This study was supported by internal Intermountain Heart Institute funds and in-kind support from Sysmex America Inc.

Case-Only Survival Analysis Reveals Unique Effects of Genotype, Sex, and Coronary Disease Severity on Survivorship

Survival bias may unduly impact genetic association with complex diseases; gene-specific survival effects may further complicate such investigations. Coronary artery disease (CAD) is a complex phenotype for which little is understood about gene-specific survival effects; yet, such information can offer insight into refining genetic associations, improving replications, and can provide candidate genes for both mortality risk and improved survivorship in CAD. Building on our previous work, the purpose of this current study was to: evaluate LSAMP SNP-specific hazards for all-cause mortality post-catheterization in a larger cohort of our CAD cases; and, perform additional replication in an independent dataset. We examined two LSAMP SNPs—rs1462845 and rs6788787—using CAD case-only Cox proportional hazards regression for additive genetic effects, censored on time-to-all-cause mortality or last follow-up among Caucasian subjects from the Catheterization Genetics Study (CATHGEN; n = 2,224) and the Intermountain Heart Collaborative Study (IMHC; n = 3,008). Only after controlling for age, sex, body mass index, histories of smoking, type 2 diabetes, hyperlipidemia and hypertension (HR = 1.11, 95%CI = 1.01–1.22, p = 0.032), rs1462845 conferred significantly increased hazards of all-cause mortality among CAD cases. Even after controlling for multiple covariates, but in only the primary cohort, rs6788787 conferred significantly improved survival (HR = 0.80, 95% CI = 0.69–0.92, p = 0.002). Post-hoc analyses further stratifying by sex and disease severity revealed replicated effects for rs1462845: even after adjusting for aforementioned covariates and coronary interventional procedures, males with severe burden of CAD had significantly amplified hazards of death with the minor variant of rs1462845 in both cohorts (HR = 1.29, 95% CI = 1.08–1.55, p = 0.00456; replication HR = 1.25, 95% CI = 1.05–1.49, p = 0.013). Kaplan-Meier curves revealed unique cohort-specific genotype effects on survival. Additional analyses demonstrated that the homozygous risk genotype (‘A/A’) fully explained the increased hazard in both cohorts. None of the post-hoc analyses in control subjects were significant for any model. This suggests that genetic effects of rs1462845 on survival are unique to CAD presence. This represents formal, replicated evidence of genetic contribution of rs1462845 to increased risk for all-cause mortality; the contribution is unique to CAD case status and specific to males with severe burden of CAD.

Impact of Testosterone Replacement Therapy on Myocardial Infarction, Stroke, and Death in Men With Low Testosterone Concentrations in an Integrated Health Care System

The aim of this study was to assess the effect of testosterone replacement therapy (TRT) on cardiovascular outcomes. Men (January 1, 1996, to December 31, 2011) with a low initial total testosterone concentration, a subsequent testosterone level, and >3 years of follow-up were studied. Levels were correlated with testosterone supplement use. The primary outcome was major adverse cardiovascular events (MACE), defined as a composite of death, nonfatal myocardial infarction, and stroke at 3 years. Multivariate adjusted hazard ratios (HRs) comparing groups of persistent low (<212 ng/dl, n = 801), normal (212 to 742 ng/dl, n = 2,241), and high (>742 ng/dl, n = 1,694) achieved testosterone were calculated by Cox hazard regression. A total of 4,736 men were studied. Three-year rates of MACE and death were 6.6% and 4.3%, respectively. Subjects supplemented to normal testosterone had reduced 3-year MACE (HR 0.74; 95% confidence interval [CI] 0.56 to 0.98, p = 0.04) compared to persistently low testosterone, driven primarily by death (HR 0.65, 95% CI 0.47 to 0.90). HRs for MI and stroke were 0.73 (95% CI 0.40 to 1.34), p = 0.32, and 1.11 (95% CI 0.54 to 2.28), p = 0.78, respectively. MACE was noninferior but not superior for high achieved testosterone with no benefit on MI and a trend to greater stroke risk. In conclusion, in a large general health care population, TRT to normal levels was associated with reduced MACE and death over 3 years but a stroke signal with high achieved levels suggests a conservative approach to TRT.

Secretory phospholipase A(2)-IIA and cardiovascular disease: a mendelian randomization study

OBJECTIVES

This study sought to investigate the role of secretory phospholipase A2 (sPLA2)-IIA in cardiovascular disease.

BACKGROUND

Higher circulating levels of sPLA2-IIA mass or sPLA2 enzyme activity have been associated with increased risk of cardiovascular events. However, it is not clear if this association is causal. A recent phase III clinical trial of an sPLA2 inhibitor (varespladib) was stopped prematurely for lack of efficacy.

METHODS

We conducted a Mendelian randomization meta-analysis of 19 general population studies (8,021 incident, 7,513 prevalent major vascular events [MVE] in 74,683 individuals) and 10 acute coronary syndrome (ACS) cohorts (2,520 recurrent MVE in 18,355 individuals) using rs11573156, a variant in PLA2G2A encoding the sPLA2-IIA isoenzyme, as an instrumental variable.

RESULTS

PLA2G2A rs11573156 C allele associated with lower circulating sPLA2-IIA mass (38% to 44%) and sPLA2 enzyme activity (3% to 23%) per C allele. The odds ratio (OR) for MVE per rs11573156 C allele was 1.02 (95% confidence interval [CI]: 0.98 to 1.06) in general populations and 0.96 (95% CI: 0.90 to 1.03) in ACS cohorts. In the general population studies, the OR derived from the genetic instrumental variable analysis for MVE for a 1-log unit lower sPLA2-IIA mass was 1.04 (95% CI: 0.96 to 1.13), and differed from the non-genetic observational estimate (OR: 0.69; 95% CI: 0.61 to 0.79). In the ACS cohorts, both the genetic instrumental variable and observational ORs showed a null association with MVE. Instrumental variable analysis failed to show associations between sPLA2 enzyme activity and MVE.

CONCLUSIONS

Reducing sPLA2-IIA mass is unlikely to be a useful therapeutic goal for preventing cardiovascular events.

Randomized cross-over trial of short-term water-only fasting: metabolic and cardiovascular consequences

BACKGROUND AND AIMS

Routine, periodic fasting is associated with a lower prevalence of coronary artery disease (CAD). Animal studies show that fasting may increase longevity and alter biological parameters related to longevity. We evaluated whether fasting initiates acute changes in biomarker expression in humans that may impact short- and long-term health.

METHODS AND RESULTS

Apparently-healthy volunteers (N = 30) without a recent history of fasting were enrolled in a randomized cross-over trial. A one-day water-only fast was the intervention and changes in biomarkers were the study endpoints. Bonferroni correction required p ≤ 0.00167 for significance (p < 0.05 was a trend that was only suggestively significant). The one-day fasting intervention acutely increased human growth hormone (p = 1.1 × 10⁻⁴), hemoglobin (p = 4.8 × 10⁻⁷), red blood cell count (p = 2.5 × 10⁻⁶), hematocrit (p = 3.0 × 10⁻⁶), total cholesterol (p = 5.8 × 10⁻⁵), and high-density lipoprotein cholesterol (p = 0.0015), and decreased triglycerides (p = 1.3 × 10⁻⁴), bicarbonate (p = 3.9 × 10⁻⁴), and weight (p = 1.0 × 10⁻⁷), compared to a day of usual eating. For those randomized to fast the first day (n = 16), most factors including human growth hormone and cholesterol returned to baseline after the full 48 h, with the exception of weight (p = 2.5 × 10⁻⁴) and (suggestively significant) triglycerides (p = 0.028).

CONCLUSION

Fasting induced acute changes in biomarkers of metabolic, cardiovascular, and general health. The long-term consequences of these short-term changes are unknown but repeated episodes of periodic short-term fasting should be evaluated as a preventive treatment with the potential to reduce metabolic disease risk. Clinical trial registration (ClinicalTrials.gov): NCT01059760 (Expression of Longevity Genes in Response to Extended Fasting [The Fasting and Expression of Longevity Genes during Food abstinence {FEELGOOD} Trial]).

Validation and quantification of genetic determinants of lipoprotein-a levels and predictive value for angiographic coronary artery disease

Lipoprotein(a) (Lp[a]) has gained attention as a heritable coronary artery disease (CAD) risk factor and therapeutic target. Two genetic variants in the LPA gene have been reported to influence Lp(a) levels and increase CAD risk. The aim of this study was to prospectively test these variants for their associations with Lp(a) and CAD risk. Participants (n = 1,400) in the Intermountain Heart Collaborative Study Registry who had Lp(a) cholesterol levels determined at coronary angiography were genotyped for rs3798220 and rs1045587 in LPA. Variants were detected by Taqman polymerase chain reaction. Chi-square and linear and logistic regression tests were used as appropriate among genotypes for Lp(a) and angiographic CAD. Age averaged 63 years; 65% were men; and severe CAD was present in 57%, mild CAD in 12%, and no CAD in 31%. Minor allele frequencies were 0.023 for rs3798220 and 0.090 for rs10455872. In multivariate modeling, only rs10455872 (odds ratio [OR] 2.33, 95% confidence interval [CI] 1.67 to 3.33, p = 1.75 × 10⁻⁹) and rs3798220 (OR 1.99, 95% CI 0.99 to 4.00, p = 0.065) contributed to the prediction of elevated Lp(a) cholesterol. Lp(a) cholesterol was weakly associated with CAD (OR 1.17, 95% CI 1.00 to 1.37, p = 0.055). Rs10455872 strongly predicted prevalent CAD (per allele OR 1.43, 95% CI 1.07 to 1.91, p = 0.0172); the effect size for the rare rs3798220 variant was similar (dominant OR 1.47, 95% CI 0.81 to 2.67, p = 0.20), but power was limited to demonstrate significance. The combined genotype explained only a small percentage (≤4%) of variability in Lp(a) cholesterol and prevalence of angiographic CAD. In conclusion, heritable contributions of LPA rs10455872 and rs3798220 to Lp(a) cholesterol levels and to angiographic CAD were prospectively assessed in this study. The percentage of intersubject variability in Lp(a) cholesterol and the percentage of prevalent CAD explained were small.

Cardiovascular risk among patients on clopidogrel anti-platelet therapy after placement of drug-eluting stents is modified by genetic variants in both the CYP2C19 and ABCB1 genes

Long-term (at least one year) dual anti-platelet therapy incorporating aspirin and clopidogrel is currently recommended following percutaneous coronary intervention with placement of a drug-eluting stent (DES). Genetic variants in both the ABCB1 and CYP2C19 genes have been associated with cardiovascular events among patients on clopidogrel. We examined the concurrent contribution of the CYP2C19 *2 and *17 alleles and the ABCB1 3435 alleles to one-year clinical risk among patients (n=1,034 on clopidogrel therapy following the placement of a DES. For CYP2C19*2, event rates were 8.4%, 10.9% and 44.4% for patients with 0, 1 and 2 *2 alleles, respectively (p=0.016). ABCB1 3435 was not associated with events in univariate analysis. However, 72% of patients with a *2 variant also possessed the ABCB1 3435 C allele; among these patients (*2/C genotype) the event rate for myocardial infarction (MI) was 14.2% vs. 6.9% for those lacking both *2 and C alleles (p=0.027) and for MI/death, 16.9% vs. 9.6% (p=0.046). Overall for all genotypes, the presence of the gain-of-function (protective) *17 allele significantly reduced the one-year rate of MI from 11.1% to 7.0% (p=0.045) and trended to reduce the combined rate of MI/death from 13.8% to 10.5% (p=0.182). In conclusion, the ABCB1 3435 locus and the *2 allele combine to impart a significant trend toward increased risk. This trend was largely reversed by the simultaneous carriage of one or two *17 alleles. These findings suggest that assessment of a combined genotype may improve risk assessment.

Association between the chromosome 9p21 locus and angiographic coronary artery disease burden: a collaborative meta-analysis

OBJECTIVES

This study sought to ascertain the relationship of 9p21 locus with: 1) angiographic coronary artery disease (CAD) burden; and 2) myocardial infarction (MI) in individuals with underlying CAD.

BACKGROUND

Chromosome 9p21 variants have been robustly associated with coronary heart disease, but questions remain on the mechanism of risk, specifically whether the locus contributes to coronary atheroma burden or plaque instability.

METHODS

We established a collaboration of 21 studies consisting of 33,673 subjects with information on both CAD (clinical or angiographic) and MI status along with 9p21 genotype. Tabular data are provided for each cohort on the presence and burden of angiographic CAD, MI cases with underlying CAD, and the diabetic status of all subjects.

RESULTS

We first confirmed an association between 9p21 and CAD with angiographically defined cases and control subjects (pooled odds ratio [OR]: 1.31, 95% confidence interval [CI]: 1.20 to 1.43). Among subjects with angiographic CAD (n = 20,987), random-effects model identified an association with multivessel CAD, compared with those with single-vessel disease (OR: 1.10, 95% CI: 1.04 to 1.17)/copy of risk allele). Genotypic models showed an OR of 1.15, 95% CI: 1.04 to 1.26 for heterozygous carrier and OR: 1.23, 95% CI: 1.08 to 1.39 for homozygous carrier. Finally, there was no significant association between 9p21 and prevalent MI when both cases (n = 17,791) and control subjects (n = 15,882) had underlying CAD (OR: 0.99, 95% CI: 0.95 to 1.03)/risk allele.

CONCLUSIONS

The 9p21 locus shows convincing association with greater burden of CAD but not with MI in the presence of underlying CAD. This adds further weight to the hypothesis that 9p21 locus primarily mediates an atherosclerotic phenotype.

A Randomized and Clinical Effectiveness Trial Comparing Two Pharmacogenetic Algorithms and Standard Care for Individualizing Warfarin Dosing (CoumaGen-II)

Background—

Warfarin is characterized by marked variations in individual dose requirements and a narrow therapeutic window. Pharmacogenetics (PG) could improve dosing efficiency and safety, but clinical trials evidence is meager.

Methods and Results—

A Randomized and Clinical Effectiveness Trial Comparing Two Pharmacogenetic Algorithms and Standard Care for Individualizing Warfarin Dosing (CoumaGen-II) comprised 2 comparisons: (1) a blinded, randomized comparison of a modified 1-step (PG-1) with a 3-step algorithm (PG-2) (N=504), and (2) a clinical effectiveness comparison of PG guidance with use of either algorithm with standard dosing in a parallel control group (N=1866). A rapid method provided same-day CYP2C9 and VKORC1 genotyping. Primary outcomes were percentage of out-of-range international normalized ratios at 1 and 3 months and percentage of time in therapeutic range. Primary analysis was modified intention to treat. In the randomized comparison, PG-2 was noninferior but not superior to PG-1 for percentage of out-of-range international normalized ratios at 1 month and 3 months and for percentage of time in therapeutic range at 3 months. However, the combined PG cohort was superior to the parallel controls (percentage of out-of-range international normalized ratios 31% versus 42% at 1 month; 30% versus 42% at 3 months; percentage of time in therapeutic range 69% versus 58%, 71% versus 59%, respectively, all P <0.001). Differences persisted after adjustment for age, sex, and clinical indication. There were fewer percentage international normalized ratios ≥4 and ≤1.5 and serious adverse events at 3 months (4.5% versus 9.4% of patients, P <0.001) with PG guidance.

Conclusions—

These findings suggest that PG dosing should be considered for broader clinical application, a proposal that is being tested further in 3 major randomized trials. The simpler 1-step PG algorithm provided equivalent results and may be preferable for clinical application.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00927862.

Vitamin D dependent effects of APOA5 polymorphisms on HDL cholesterol

OBJECTIVES

Vitamin D and serum lipid levels are risk factors for cardiovascular disease. We sought to determine if vitamin D (25OHD) interacts at established lipid loci potentially explaining additional variance in lipids.

METHODS

1060 individuals from Utah families were used to screen 14 loci for SNPs potentially interacting with dietary 25OHD on lipid levels. Identified putative interactions were evaluated for (1) greater effect size in subsamples with winter measures, (2) replication in an independent sample, and (3) lack of gene-environment interaction for other correlated dietary factors. Maximum likelihood models were used to evaluate interactions. The replicate sample consisted of 2890 individuals from the Family Heart Study. Putative 25OHD receptor binding site modifying SNPs were identified and allele-specific, 25OHD-dependent APOA5 promoter activity examined using luciferase expression assays. An additional sample with serum 25OHD measures was analyzed.

RESULTS

An rs3135506-25OHD interaction influencing HDL-C was identified. The rs3135506 minor allele was more strongly associated with low HDL-C in individuals with low winter dietary 25OHD in initial and replicate samples (p=0.0003 Utah, p=0.002 Family Heart); correlated dietary factors did not explain the interaction. SNP rs10750097 was identified as a putative causative polymorphism, was associated with 25OHD-dependent changes in APOA5 promoter activity in HEP3B and HEK293 cells (p<0.01), and showed similar interactions to rs3135506 in family cohorts. Linear interactions were not significant in samples with serum 25OHD measures; however, genotype-specific differences were seen at deficient 25OHD levels.

CONCLUSIONS

A 25OHD receptor binding site modifying APOA5 promoter polymorphism is associated with lower HDL-C in 25OHD deficient individuals.

Pharmacogenetic warfarin dose refinements remain significantly influenced by genetic factors after one week of therapy

By guiding initial warfarin dose, pharmacogenetic (PGx) algorithms may improve the safety of warfarin initiation. However, once international normalised ratio (INR) response is known, the contribution of PGx to dose refinements is uncertain. This study sought to develop and validate clinical and PGx dosing algorithms for warfarin dose refinement on days 6-11 after therapy initiation. An international sample of 2,022 patients at 13 medical centres on three continents provided clinical, INR, and genetic data at treatment days 6-11 to predict therapeutic warfarin dose. Independent derivation and retrospective validation samples were composed by randomly dividing the population (80%/20%). Prior warfarin doses were weighted by their expected effect on S-warfarin concentrations using an exponential-decay pharmacokinetic model. The INR divided by that "effective" dose constituted a treatment response index . Treatment response index, age, amiodarone, body surface area, warfarin indication, and target INR were associated with dose in the derivation sample. A clinical algorithm based on these factors was remarkably accurate: in the retrospective validation cohort its R(2) was 61.2% and median absolute error (MAE) was 5.0 mg/week. Accuracy and safety was confirmed in a prospective cohort (N=43). CYP2C9 variants and VKORC1-1639 G→A were significant dose predictors in both the derivation and validation samples. In the retrospective validation cohort, the PGx algorithm had: R(2)= 69.1% (p<0.05 vs. clinical algorithm), MAE= 4.7 mg/week. In conclusion, a pharmacogenetic warfarin dose-refinement algorithm based on clinical, INR, and genetic factors can explain at least 69.1% of therapeutic warfarin dose variability after about one week of therapy.

The intermountain risk score predicts incremental age-specific long-term survival and life expectancy

The Intermountain Risk Score (IMRS) encapsulates the mortality risk information from all components of the complete blood count (CBC) and basic metabolic profile (BMP), along with age. To individualize the IMRS more clearly, this study evaluated whether IMRS weightings for 1-year mortality predict age-specific survival over more than a decade of follow-up. Sex-specific 1-year IMRS values were calculated for general medical patients with CBC and BMP laboratory tests drawn during 1999-2005. The population was divided randomly 60% (N = 71,921, examination sample) and 40% (N = 47,458, validation sample). Age-specific risk thresholds were established, and both survival and life expectancy were compared across low-, moderate-, and high-risk IMRS categories. During 7.3 ± 1.8 years of follow-up (range, 4.5-11.1 years), the average IMRS of decedents was higher than censored in all age/sex strata (all P < 0.001). For examination and validation samples, every age stratum had incrementally lower survival for higher risk IMRS, with hazard ratios of 2.5-8.5 (P < 0.001). Life expectancies were also significantly shorter for higher risk IMRS (all P < 0.001): For example, among 50-59 year-olds, life expectancy was 7.5, 6.8, and 5.9 years for women with low-, moderate-, and high-risk IMRS (with mortality in 5.7%, 16.3%, and 37.0% of patients, respectively). In Men, life expectancy was 7.3, 6.8, and 5.4 for low-, moderate-, and high-risk IMRS (with patients having 7.3%, 19.5%, and 40.0% mortality), respectively. IMRS significantly stratified survival and life expectancy within age-defined subgroups during more than a decade of follow-up. IMRS may be used to stratify age-specific risk of mortality in research, clinical/preventive, and quality improvement applications. A web calculator is located at http://intermountainhealthcare.org/IMRS.

Genome-wide significance and replication of the chromosome 12p11.22 locus near the PTHLH gene for peripartum cardiomyopathy

BACKGROUND

Peripartum (PP) cardiomyopathy (CM) is a rare condition of unknown etiology that occurs in late pregnancy or early postpartum. Initial evidence suggests that genetic factors may influence PPCM. This study evaluated and replicated genome-wide association of single nucleotide polymorphisms with PPCM.

METHODS AND RESULTS

Genome-wide single nucleotide polymorphisms in women with verified PPCM diagnosis (n=41) were compared separately with local control subjects (n=49 postmenopausal age-discordant women with parity ≥1 and no heart failure) and iControls (n=654 women ages 30 to 84 years with unknown phenotypes). A replication study of independent population samples used new cases (PPCM2, n=30) compared with new age-discordant control subjects (local2, n=124) and with younger control subjects (n=89) and obstetric control subjects (n=90). A third case set of pregnancy-associated CM cases not meeting strict PPCM definitions (n=29) was also studied. In the genome-wide association study, 1 single nucleotide polymorphism (rs258415) met genome-wide significance for PPCM versus local control subjects (P=2.06×10(-8); odds ratio [OR], 5.96). This was verified versus iControls (P=7.92×10(-19); OR, 8.52). In the replication study for PPCM2 cases, rs258415 (ORs are per C allele) replicated at P=0.009 versus local2 control subjects (OR, 2.26). This replication was verified for PPCM2 versus younger control subjects (P=0.029; OR, 2.15) and versus obstetric control subjects (P=0.013; OR, 2.44). In pregnancy-associated cardiomyopathy cases, rs258415 had a similar effect versus local2 control subjects (P=0.06; OR, 1.79), younger control subjects (P=0.14; OR, 1.65), and obstetric control subjects (P=0.038; OR, 1.99).

CONCLUSIONS

Genome-wide association with PPCM was discovered and replicated for rs258415 at chromosome 12p11.22 near PTHLH. This study indicates a role of genetic factors in PPCM and provides a new locus for further pathophysiological and clinical investigation.

Pharmacogenetic mechanisms underlying unanticipated drug responses

Because most medicines have not been encountered by individuals of our species prior to treatment, it follows that treatment could uncover a previously silent genetic predisposition or could interact with a known genetic variation(s) to produce an unintended outcome. Pharmacogenetics encompasses the discovery, testing, and application of genetic variation as applied to therapeutic treatment and outcome. Two broad divisions of pharmacogenetics are recognized: pharmacokinetics, which describes genetic variations that affect drug metabolism, and pharmacodynamics which describes similar processes that have effects on drug targets, including downstream signaling pathways. The genetic mechanisms that underlie an altered drug response recapitulates most known sources of genomic variation. The most commonly encountered is sequence variation. This includes changes in the primary nucleotide sequence of coding, regulatory, and splice regions of a gene, the product of which affects, or is affected by, a drug. Less common forms of variability in the structure and function of the genome have also been found to underlie an individualized response to medicines. Among these are sequence variation in microRNA (miRNA) binding sites, which affects the ability of miRNA to regulate translation; pharmacoepigenetics, which examines heritable chromatin modifications; and copy number variation. Among the 158 currently registered pharmacogenetic clinical trials, the most frequent conditions or disease processes being studied are cancer, psychiatric disorders, and coagulation/ thrombosis. From this observation, it is postulated that pharmacogenetics has its greatest potential for optimizing the use of drugs with a high rate of failure or adverse outcomes.

Common Variants in 6 Lipid-Related Genes Discovered by High-Resolution DNA Melting Analysis and Their Association with Plasma Lipids

BACKGROUND: Total cholesterol was among the earliest identified risk factors for coronary heart disease (CHD). We sought to identify genetic variants in six genes associated with lipid metabolism and estimate their respective contribution to risk for CHD. METHODS: For 6 lipid-associated genes (LCAT, CETP, LIPC, LPL, SCARB1, and ApoF) we scanned exons, 5' and 3' untranslated regions, and donor and acceptor splice sites for variants using Hi-Res Melting® curve analysis (HRMCA) with confirmation by cycle sequencing. Healthy subjects were used for SNP discovery (n=64), haplotype determination/tagging SNP discovery (n=339), and lipid association testing (n=786). RESULTS: In 17,840 bases of interrogated sequence, 90 variant SNPs were identified; 19 (21.1%) previously unreported. Thirty-four variants (37.8%) were exonic(16 non-synonymous), 28 (31.1%) in intron-exon boundaries, and 28 (31.1%) in the 5' and 3' untranslated regions. Compared to cycle sequencing, HRMCA had sensitivity of 99.4% and specificity of 97.7%. Tagging SNPs (n=38) explained >90% of the variation in the 6 genes and identified linkage disequilibrium (LD) groups. Significant beneficial lipid profiles were observed for CETP LD group 2, LIPC LD groups 1 and 7, and SCARB1 LD groups 1, 3 and 4. Risk profiles worsened for CETP LD group 3, LPL LD group 4. CONCLUSIONS: These findings demonstrate the feasibility, sensitivity, and specificity of HRMCA for SNP discovery. Variants identified in these genes may be used to predict lipid-associated risk and reclassification of clinical CHD risk.

Relation of vitamin D deficiency to cardiovascular risk factors, disease status, and incident events in a general healthcare population

Vitamin D recently has been proposed to play an important role in a broad range of organ functions, including cardiovascular (CV) health; however, the CV evidence-base is limited. We prospectively analyzed a large electronic medical records database to determine the prevalence of vitamin D deficiency and the relation of vitamin D levels to prevalent and incident CV risk factors and diseases, including mortality. The database contained 41,504 patient records with at least one measured vitamin D level. The prevalence of vitamin D deficiency (≤30 ng/ml) was 63.6%, with only minor differences by gender or age. Vitamin D deficiency was associated with highly significant (p <0.0001) increases in the prevalence of diabetes, hypertension, hyperlipidemia, and peripheral vascular disease. Also, those without risk factors but with severe deficiency had an increased likelihood of developing diabetes, hypertension, and hyperlipidemia. The vitamin D levels were also highly associated with coronary artery disease, myocardial infarction, heart failure, and stroke (all p <0.0001), as well as with incident death, heart failure, coronary artery disease/myocardial infarction (all p <0.0001), stroke (p = 0.003), and their composite (p <0.0001). In conclusion, we have confirmed a high prevalence of vitamin D deficiency in the general healthcare population and an association between vitamin D levels and prevalent and incident CV risk factors and outcomes. These observations lend strong support to the hypothesis that vitamin D might play a primary role in CV risk factors and disease. Given the ease of vitamin D measurement and replacement, prospective studies of vitamin D supplementation to prevent and treat CV disease are urgently needed.

The Intermountain Risk Score (including the red cell distribution width) predicts heart failure and other morbidity endpoints

AIMS

The complete blood count (CBC) and basic metabolic profile are common, low-cost blood tests, which have previously been used to create and validate the Intermountain Risk Score (IMRS) for mortality prediction. Mortality is the most definitive clinical endpoint, but medical care is more easily applied to modify morbidity and thereby prevent death. This study tested whether IMRS is associated with clinical morbidity endpoints.

METHODS AND RESULTS

Patients seen for coronary angiography (n = 3927) were evaluated using a design similar to a genome-wide association study. The Bonferroni correction for 102 tests required a P-value of ≤ 4.9 × 10⁻⁴ for significance. A second set of angiography patients (n = 10 413) was used to validate significant findings from the first patient sample. In the first patient sample, IMRS predicted heart failure (HF) (P(trend) = 1.6 × 10(-26)), coronary disease (P(trend) = 2.6 × 10(-11)), myocardial infarction (MI) (P(trend) = 3.1 × 10(-25)), atrial fibrillation (P(trend) = 2.5 × 10(-20)), and chronic obstructive pulmonary disease (P(trend) = 4.7 × 10⁻⁴). Even more, IMRS predicted HF readmission [hazard ratio (HR) = 2.29/category, P(trend) = 1.2 × 10⁻⁶), incident HF (HR = 1.88/category, P(trend) = 0.02), and incident MI (HR = 1.56/category, P(trend) = 4.7 × 10⁻⁴). These findings were verified in the second patient sample.

CONCLUSION

Intermountain Risk Score, a predictor of mortality, was associated with morbidity endpoints that often lead to mortality. Further research is required to fully characterize its clinical utility, but its low-cost CBC and basic metabolic profile composition may make it ideal for initial risk estimation and prevention of morbidity and mortality. An IMRS web calculator is freely available at http://intermountainhealthcare.org/IMRS.

Antilipidemic adherence post-coronary artery disease diagnosis among those with and without an ICD-9 diagnosis of depression

OBJECTIVES

An association between depression and coronary artery disease (CAD) is well established. Poor adherence to cardiac treatments may be one way depression could contribute to the increased risk of coronary events among depressed patients. We sought to evaluate whether adherence to antilipid medication, a therapy shown to be beneficial in secondary prevention of coronary events, differs among CAD patients with and without an ICD-9 depression diagnosis.

METHODS

Patients were included if, at angiography, they were determined to have CAD (stenosis >or=70%), were discharged on an antilipid medication, and re-filled their prescriptions at a participating pharmacy. A patient was determined to have depression (ICD-9 codes 296.2-296.36, 311) if the diagnosis occurred prior to angiography or within 6 months of the CAD diagnosis. Adherence and long-term outcomes were evaluated at 6 months, 1 year, 18 months and 2 years.

RESULTS

A total of 585 patients were included, with 73 (12.5%) having a diagnosis of depression prior to or within 6 months of CAD diagnosis. At all time-points, those with depression had a lower mean adherence compared to those without depression. Differences in adherence rates after adjustment were 7% (P=.001), 6% (P=.02), 13% (P<.0001) and 5% (P=.18) at 6 months, 1 year, 18 months, and 2 years, respectively. Though not statistically significant, there were clinically important associations between adherence and depression on the combined outcome of death, myocardial infarction, and revascularization.

CONCLUSION

Depression was the strongest predictor of antilipidemic medication adherence after 2 years of follow-up among CAD patients. Such results suggest that poor antilipid adherence may be one mechanism by which depression contributes to CAD events.

Joint effects of common genetic variants from multiple genes and pathways on the risk of premature coronary artery disease

OBJECTIVE

The aim of this study is to discover common variants in 6 lipid metabolic genes and construct and validate a genetic risk score (GRS) based on the joint effects of genetic variants in multiple genes from lipid and other pathobiologic pathways.

BACKGROUND

Explaining the genetic basis of coronary artery disease (CAD) is incomplete. Discovery and aggregation of genetic variants from multiple pathways may advance this objective.

METHODS

Premature CAD cases (n = 1,947) and CAD-free controls (n = 1,036) were selected from our angiographic registry. In a discovery phase, single nucleotide polymorphisms (SNPs) at 56 loci from internal discovery and external reports were tested for associations with biomarkers and CAD: 28 promising SNPs were then tested jointly for CAD associations, and a GRS consisting of SNPs contributing independently was constructed and validated in a replication set of familial cases and population-based controls (n = 1,320).

RESULTS

Five variants contributed jointly to CAD prediction in a multigenic GRS model: odds ratio 1.24 (95% CI 1.16-1.33) per risk allele, P = 8.2 x 10(-11), adjusted OR 2.03 (1.53-2.70), fourth versus first quartile. 5-SNP genetic risk score had minor impact on area under the receiver operating characteristic curve (P > .05) but resulted in substantial net reclassification improvement: 0.16 overall, 0.28 in intermediate-risk patients (both P < .0001). GRS(5) predicted familial CAD with similar magnitude in the validation set.

CONCLUSIONS

The Intermountain Healthcare's Coronary Genetics study demonstrates the ability of a multigenic, multipathway GRS to improve discrimination of angiographic CAD. Genetic risk scores promise to increase understanding of the genetic basis of CAD and improve identification of individuals at increased CAD risk.

Association of vitamin D levels with incident depression among a general cardiovascular population

BACKGROUND

Depression is associated with cardiovascular (CV) disease, and it has been hypothesized that vitamin (vit)D deficiency may be associated with depression and a contributing factor to excess CV events. Therefore, we evaluated whether there is an association between vitD and incident depression among a CV population.

METHODS

Patients (N = 7,358) > or =50 years of age, with a CV diagnosis (coronary artery disease, myocardial infarction, congestive heart failure, cerebrovascular accident, transient ischemic accident, atrial fibrillation, or peripheral vascular disease), no prior depression diagnosis, and a measured vitD level were studied. Vitamin D (ng/mL) was stratified into 4 categories: >50 (optimal [O] n = 367), 31 to 50 (normal [N] n = 2,264), 16 to 30 (low [L] n = 3,402), and > or =15 (very low [VL] n = 1,325). Depression was defined by International Classification of Diseases, Ninth Edition, codes: 296.2 to 296.36, 311. VitD categories were evaluated by Cox hazard regression with adjustment by standard CV risk factors.

RESULTS

Age averaged 73.1 +/- 10.2 years, and 58.8% were female. When compared to O, VL, L, and N were associated with depression (adjusted: VL, hazard ratio [HR] 2.70 [1.35-5.40], P = .005; L, HR 2.15 [1.10-4.21], P = .03; N, HR 1.95 [0.99-3.87], P = .06). This association remained even after adjustment by parathyroid hormone levels. Parathyroid hormone was significantly associated with depression, however, became nonsignificant after adjustment by vitD. Winter (December-February) enhanced this association. Significant associations remained when stratifications were made by age (<65, > or =65), sex, and diabetes, although the associations among those age > or =65 and male sex were enhanced.

CONCLUSION

Among a CV population > or =50 years with no history of depression, vitD levels were shown to be associated with incident depression after vitD draw. This study strengthens the hypothesis of the association between vitD and depression.

Integration of genetic, clinical, and INR data to refine warfarin dosing

Well-characterized genes that affect warfarin metabolism (cytochrome P450 (CYP) 2C9) and sensitivity (vitamin K epoxide reductase complex 1 (VKORC1)) explain one-third of the variability in therapeutic dose before the international normalized ratio (INR) is measured. To determine genotypic relevance after INR becomes available, we derived clinical and pharmacogenetic refinement algorithms on the basis of INR values (on day 4 or 5 of therapy), clinical factors, and genotype. After adjusting for INR, CYP2C9 and VKORC1 genotypes remained significant predictors (P < 0.001) of warfarin dose. The clinical algorithm had an R(2) of 48% (median absolute error (MAE): 7.0 mg/week) and the pharmacogenetic algorithm had an R(2) of 63% (MAE: 5.5 mg/week) in the derivation set (N = 969). In independent validation sets, the R(2) was 26-43% with the clinical algorithm and 42-58% when genotype was added (P = 0.002). After several days of therapy, a pharmacogenetic algorithm estimates the therapeutic warfarin dose more accurately than one using clinical factors and INR response alone.

An α 2C -Adrenergic Receptor Polymorphism Alters the Norepinephrine-Lowering Effects and Therapeutic Response of the β-Blocker Bucindolol in Chronic Heart Failure

Background— Adrenergic activation is an important determinant of outcomes in chronic heart failure. Adrenergic activity is regulated in part by prejunctional α 2C -adrenergic receptors (ARs), which exhibit genetic variation in humans. Bucindolol is a novel β-AR blocking agent that also lowers systemic norepinephrine and thus is also a sympatholytic agent. This study investigated whether α 2C -AR polymorphisms affect sympatholytic effects of bucindolol in patients with heart failure.

Methods and Results— In the β-Blocker Evaluation of Survival Trial, adrenergic activation was estimated by systemic venous norepinephrine measured at baseline, 3 months, and 12 months posttreatment in patients treated with placebo or bucindolol. In the β-Blocker Evaluation of Survival Trial AR polymorphism substudy, DNA was collected from 1040 of the 2708 randomized patients, and α 2C -AR gene polymorphisms (α 2C Del322-325 or the wild-type counterpart) were measured by polymerase chain reaction and gel electrophoresis. Patients who were α 2C Del carriers (heterozygotes or homozygotes) exhibited a much greater sympatholytic response to bucindolol (decrease in norepinephrine at 3 months of 153±57 pg/mL, P =0.012 compared with placebo versus decrease of 50±13 pg/mL in α 2C wild type, P =0.0005 versus placebo; P =0.010 by interaction test). α 2C Del carriers had no evidence of a favorable survival benefit from bucindolol (mortality compared with placebo hazard ratio, 1.09; 95% CI, 0.57 to 2.08; P =0.80), whereas bucindolol-treated subjects who were wild type for the α 2C -AR had a 30% reduction in mortality (hazard ratio, 0.70; 95% CI, 0.51 to 0.96; P =0.025).

Conclusions— In the β-Blocker Evaluation of Survival Trial AR polymorphism substudy, the norepinephrine lowering and clinical therapeutic responses to bucindolol were strongly influenced by α 2C receptor genotype.

Validation study of genetic associations with coronary artery disease on chromosome 3q13-21 and potential effect modification by smoking

The CATHGEN study reported associations of chromosome 3q13-21 genes (KALRN, MYLK, CDGAP, and GATA2) with early-onset coronary artery disease (CAD). This study attempted to independently validate those associations. Eleven single nucleotide polymorphisms (SNPs) were examined (rs10934490, rs16834817, rs6810298, rs9289231, rs12637456, rs1444768, rs1444754, rs4234218, rs2335052, rs3803, rs2713604) in patients (N = 1618) from the Intermountain Heart Collaborative Study (IHCS). Given the higher smoking prevalence in CATHGEN than IHCS (41% vs. 11% in controls, 74% vs. 29% in cases), smoking stratification and genotype-smoking interactions were evaluated. Suggestive association was found for GATA2 (rs2713604, p = 0.057, OR = 1.2). Among smokers, associations were found in CDGAP (rs10934490, p = 0.019, OR = 1.6) and KALRN (rs12637456, p = 0.011, OR = 2.0) and suggestive association was found in MYLK (rs16834871, p = 0.051, OR = 1.8, adjusting for gender). No SNP association was found among non-smokers, but smoking/SNP interactions were detected for CDGAP (rs10934491, p = 0.017) and KALRN (rs12637456, p = 0.010). Similar differences in SNP effects by smoking status were observed on re-analysis of CATHGEN. CAD associations were suggestive for GATA2 and among smokers significant post hoc associations were found in KALRN, MYLK, and CDGAP. Genetic risk conferred by some of these genes may be modified by smoking. Future CAD association studies of these and other genes should evaluate effect modification by smoking.

Lack of Association of Tegaserod With Adverse Cardiovascular Outcomes in a Matched Case-Control Study

Tegaserod is a first-in class selective serotonin 4 receptor agonist approved for the treatment of irritable bowel syndrome. In March 2007, the US Food and Drug Administration (FDA) suspended its use citing increased cardiovascular (CV) events in clinical trials. However, there is no known mechanistic basis for an adverse CV effect. To reassess the CV safety of tegaserod, teagaserod-treated patients (pts) in the Intermountain Healthcare database were identified (n = 2603), matched 1:6 with untreated (n = 15,618) patients by age, sex, and date of tegaserod initiation, and followed for an average of 2.5 years. Age averaged 38.6 ± 13.5 years, and 94% were female. Cardiovascular event rates were low and similar in patients treated with tegaserod and matched untreated patients. For the primary composite CV endpoint, 54 (0.35%) untreated and 12 (0.46%) treated pts had an event (treated OR = 1.27, 95% CI: 0.68-2.38, P =.46), with 7 and 0 events, respectively, occurring within 3 months. A total of 12 (0.1%) untreated and 1 (<0.1%) treated pts were hospitalized for a myocardial infarction (MI). 36 (0.2%) untreated and 10 (0.4%) treated pts for a cardiovascular accident, and 1 pt in each group for unstable angina. A total of 6 (<0.1%) untreated and no treated pts died from cardiac causes. Event rates were comparable to expected rates in this population of mostly premenopausal women. This large epidemiologic study failed to confirm a reported large event differential for tegaserod that was noted incidentally in a clinical trials database, suggesting that the prior observation may have been due to chance.

Depression after coronary artery disease is associated with heart failure

OBJECTIVES

The purpose of this study was to evaluate the influence of post-coronary artery disease (CAD) depression diagnosis on heart failure (HF) incidence.

BACKGROUND

Depression has been shown to be a risk factor for poor outcomes among CAD patients. However, little is known about the influence of depression on HF development in CAD patients.

METHODS

Patients (n = 13,708) without a diagnosis of HF and depression (International Classification of Diseases-Ninth Revision [ICD-9] codes: 296.2 to 296.36 and 311) and who were not prescribed antidepressant medication (ADM) at the time of CAD diagnosis (>or=70% stenosis) were studied. For those with available medication records (n = 7,719), patients subsequently diagnosed with depression were stratified by use of ADM. Patients were followed until HF diagnosis (physician-diagnosed or ICD-9 code: 428) or death. Results were analyzed by Cox proportional hazards regression models.

RESULTS

A total of 1,377 patients (10.0%) had a post-CAD clinical depression diagnosis. The incidence of HF among those without a post-CAD depression diagnosis was 3.6 per 100 compared with 16.4 per 100 for those with a post-CAD depression diagnosis. Depression was associated with an increased risk for HF incidence (adjusted hazard ratio [HR]: 1.50, p < 0.0001). Results were similar among those with available follow-up medication information (vs. no depression: depression without ADM use [HR: 1.68, p < 0.0001]; depression with ADM use [HR: 2.00, p < 0.0001]). No difference was found between depressed patients with and without ADM treatment (HR: 0.84, p = 0.24).

CONCLUSIONS

Depression diagnosis was shown to be associated with an increased incidence of HF after CAD diagnosis, regardless of ADM treatment. This finding suggests the need to further study the effect of depression on HF risk among CAD patients.

Exceptional mortality prediction by risk scores from common laboratory tests

BACKGROUND

Some components of the complete blood count and basic metabolic profile are commonly used risk predictors. Many of their components are not commonly used, but they might contain independent risk information. This study tested the ability of a risk score combining all components to predict all-cause mortality.

METHODS

Patients with baseline complete blood count and basic metabolic profile measurements were randomly assigned (60%/40%) to independent training (N = 71,921) and test (N = 47,458) populations. A third population (N = 16,372) from the Third National Health and Nutrition Examination Survey and a fourth population of patients who underwent coronary angiography (N = 2558) were used as additional validation groups. Risk scores were computed in the training population for 30-day, 1-year, and 5-year mortality using age- and sex-adjusted weights from multivariable modeling of all complete blood count and basic metabolic profile components.

RESULTS

Area under the curve c-statistics were exceptional in the training population for death at 30 days (c = 0.90 for women, 0.87 for men), 1 year (c = 0.87, 0.83), and 5-years (c = 0.90, 0.85) and in the test population for death at 30 days (c = 0.88 for women, 0.85 for men), 1 year (c = 0.86, 0.82), and 5 years (c = 0.89, 0.83). In the test, the Third National Health and Nutrition Examination Survey, and the angiography populations, risk scores were highly associated with death (P <.001), and thresholds of risk significantly stratified all 3 populations.

CONCLUSION

In large patient and general populations, risk scores combining complete blood count and basic metabolic profile components were highly predictive of death. Easily computed in a clinical laboratory at negligible incremental cost, these risk scores aggregate baseline risk information from both the popular and the underused components of ubiquitous laboratory tests.

Superior predictive ability for death of a basic metabolic profile risk score

BACKGROUND

The basic metabolic profile (BMP) is a common blood test containing information about standard blood electrolytes and metabolites. Although individual variables are checked for cardiovascular health and risk, combining them into a total BMP-derived score, as to maximize BMP predictive ability, has not been previously attempted.

METHODS

Patients (N = 279,337) that received a BMP and had long-term follow-up for death were studied. Risk models were created in a training group (60% of study population, n = 167,635), validated in a test group (40% of study population, n = 111,702), and confirmed in the NHANES III (Third National Health and Nutrition Examination Survey) participants (N = 17,752). The BMP models were developed for 30-day, 1-year, and 5-year death using logistic regression with adjustment for age and sex. The BMP parameters were categorized as low, normal, or high based on the standard range of normal. Glucose was categorized as normal, intermediate, and high. Creatinine >or=2 mg/dL was further categorized as very high.

RESULTS

Average age was 53.2 +/- 20.1 years, and 44.3% were male. The areas under the curve for the training and test groups for 30-day, 1-year, and 5-year death were 0.887 and 0.882, 0.850 and 0.848, and 0.858 and 0.847, respectively. The predictive ability of these risk scores was further confirmed in the NHANES III population and independent of the Framingham Risk Score.

CONCLUSION

In large, prospectively followed populations, a highly significant predictive ability for death was found for a BMP risk model. We propose a total BMP score as an optimization of this routine baseline test to provide an important new addition to risk prediction.

Genetic variation at the 9p21 locus predicts angiographic coronary artery disease prevalence but not extent and has clinical utility

BACKGROUND

Variants at the 9p21 locus have been associated with coronary heart disease, but their precise disease phenotype and utility for clinical risk assessment are uncertain.

METHODS

Consenting patients with early-onset angiographic coronary artery disease (CAD) (n = 1,011) were compared with matched subjects (n = 545) free of angiographic disease and with a random population sample (n = 565). Cases and controls were genotyped for 4 variants, and ORs for angio-CAD were determined. Findings were validated in a separate set of cases and controls (n = 1,452).

RESULTS

Alleles were highly correlated (r(2) > or = 0.9), and all predicted angio-CAD compared with both control groups. Genotype at rs2383206 (minor allele frequency 45.9%), the most predictive (P < .0001), was associated with an adjusted odds ratio for angio-CAD of 1.39 (95% CI, 1.05-1.85) for heterozygote and 1.73 (1.26-2.37) for homozygote risk-allele carriers and explained 21% of population attributable risk and was independent of traditional risk factors and myocardial infarction. For the comparison of combined cases versus combined control samples (N = 3,573), CAD was predicted by high-risk allele homozygosity at P = 9 x 10(-8). Despite this, extent of disease was not increased. Applied to patients with intermediate Framingham risk scores, 9p21 genotyping modified risk classification in 24%.

CONCLUSIONS

Variants at the 9p21 locus robustly predict angiographic CAD prevalence, independent of standard risk factors, but not CAD extent or myocardial infarction; provide pathophysiological insights; and may be clinically useful in refining coronary heart disease risk classification.

Association of variation in the chromosome 9p21 locus with myocardial infarction versus chronic coronary artery disease

BACKGROUND

A chromosome 9p21 locus is associated with coronary heart disease in 25 independent populations, but multiple clinically distinct phenotypes have been evaluated. Using angiographic coronary artery disease (CAD) phenotyping, this study evaluated whether 9p21 single-nucleotide polymorphisms predict ischemic events (eg, myocardial infarction [MI]) among CAD patients.

METHODS AND RESULTS

Patients undergoing coronary angiography during 1994 to 2007 (population set 1A: n=1748; set 1B: n=1014) were evaluated for association of a 9p21 tagging single-nucleotide polymorphism (rs2383206, A 224 G) with incident MI and death events among patients with angiographically significant CAD. Another hypothesis evaluated rs2383206 in 2 additional angiographic sets of both CAD and non-CAD patients (set 2A: n=2122; set 2B: n=1466) for prevalent MI versus CAD/no MI (and for MI versus non-CAD and CAD/no MI versus non-CAD). No association of rs2383206 was found with events in set 1A (odds ratio, 0.95 per G allele; P trend=0.48) and set 1B (odds ratio, 0.91 per G allele; P trend=0.28) or with MI versus CAD/no MI in set 2A (odds ratio, 0.96 per G allele; P trend=0.57) and set 2B (odds ratio, 0.89 per G allele; P trend=0.21). In contrast, rs2383206 was associated with CAD/no MI compared with non-CAD (set 2A: P trend=0.0001; set 2B: P trend=0.0008).

CONCLUSIONS

The chromosome 9p21 locus was not associated with incident events or prevalent MI, although it did predict CAD diagnosis. This contradicts reports of a 9p21 association with MI, likely because of differences in phenotype assignment. This suggests that high-quality phenotyping for CAD and MI is required to dissect the specific contributions of genetic variation to each stage of coronary heart disease pathophysiology.

Usefulness of routine periodic fasting to lower risk of coronary artery disease in patients undergoing coronary angiography

Coronary artery disease (CAD) is common and multifactorial. Members of the Church of Jesus Christ of Latter-day Saints (LDS, or Mormons) in Utah may have lower cardiac mortality than other Utahns and the US population. Although the LDS proscription of smoking likely contributes to lower cardiac risk, it is unknown whether other shared behaviors also contribute. This study evaluated potential CAD-associated effects of fasting. Patients (n(1) = 4,629) enrolled in the Intermountain Heart Collaborative Study registry (1994 to 2002) were evaluated for the association of religious preference with CAD diagnosis (> or = 70% coronary stenosis using angiography) or no CAD (normal coronaries, <10% stenosis). Consequently, another set of patients (n(2) = 448) were surveyed (2004 to 2006) for the association of behavioral factors with CAD, with routine fasting (i.e., abstinence from food and drink) as the primary variable. Secondary survey measures included proscription of alcohol, tea, and coffee; social support; and religious worship patterns. In population 1 (initial), 61% of LDS and 66% of all others had CAD (adjusted [including for smoking] odds ratio [OR] 0.81, p = 0.009). In population 2 (survey), fasting was associated with lower risk of CAD (64% vs 76% CAD; OR 0.55, 95% confidence interval 0.35 to 0.87, p = 0.010), and this remained after adjustment for traditional risk factors (OR 0.46, 95% confidence interval 0.27 to 0.81, p = 0.007). Fasting was also associated with lower diabetes prevalence (p = 0.048). In regression models entering other secondary behavioral measures, fasting remained significant with a similar effect size. In conclusion, not only proscription of tobacco, but also routine periodic fasting was associated with lower risk of CAD.

Randomized Trial of Genotype-Guided Versus Standard Warfarin Dosing in Patients Initiating Oral Anticoagulation

Background— Pharmacogenetic-guided dosing of warfarin is a promising application of “personalized medicine” but has not been adequately tested in randomized trials.

Methods and Results— Consenting patients (n=206) being initiated on warfarin were randomized to pharmacogenetic-guided or standard dosing. Buccal swab DNA was genotyped for CYP2C9 *2 and CYP2C9 * 3 and VKORC1 C1173T with a rapid assay. Standard dosing followed an empirical protocol, whereas pharmacogenetic-guided dosing followed a regression equation including the 3 genetic variants and age, sex, and weight. Prothrombin time international normalized ratio (INR) was measured routinely on days 0, 3, 5, 8, 21, 60, and 90. A research pharmacist unblinded to treatment strategy managed dose adjustments. Patients were followed up for up to 3 months. Pharmacogenetic-guided predicted doses more accurately approximated stable doses ( P <0.001), resulting in smaller ( P =0.002) and fewer ( P =0.03) dosing changes and INRs ( P =0.06). However, percent out-of-range INRs (pharmacogenetic=30.7%, standard=33.1%), the primary end point, did not differ significantly between arms. Despite this, when restricted to wild-type patients (who required larger doses; P =0.001) and multiple variant carriers (who required smaller doses; P <0.001) in exploratory analyses, results (pharmacogenetic=29%, standard=39%) achieved nominal significance ( P =0.03). Multiple variant allele carriers were at increased risk of an INR of ≥4 ( P =0.03).

Conclusions— An algorithm guided by pharmacogenetic and clinical factors improved the accuracy and efficiency of warfarin dose initiation. Despite this, the primary end point of a reduction in out-of-range INRs was not achieved. In subset analyses, pharmacogenetic guidance showed promise for wild-type and multiple variant genotypes.