Joseph Yeboah

Brachial Flow-Mediated Dilation Predicts Incident Cardiovascular Events in Older Adults The Cardiovascular Health Study

Background— The relationship between impaired brachial flow-mediated dilation (FMD) and subsequent clinical cardiovascular events is not well established, especially in older adults whose FMD is often diminished. We assessed the hypothesis that FMD predicts incident cardiovascular events in a population-based cohort of older adults. Methods and Results— FMD was measured at the 1997 to 1998 Cardiovascular Health Study clinic visit in 2792 adults aged 72 to 98 years (82.7% white, 58.6% women) recruited at 4 clinic sites in the United States. Log-rank test and Cox proportional hazard models were used to examine the association between FMD and adjudicated cardiovascular events. A total of 674 subjects (24.1%) had an adjudicated event over the 5-year follow-up period. Event-free survival rates for cardiovascular events were significantly higher in subjects with FMD greater than the sex-specific medians than in subjects with FMD less than or equal to the sex-specific medians (78.3% versus 73.6%, log-rank P=0.006). FMD remained a significant predictor of cardiovascular events after adjustment for age, gender, diabetes mellitus, cigarette smoking, systolic and diastolic blood pressure, baseline cardiovascular disease status, and total cholesterol (hazard ratio, 0.91 [95% CI, 0.83 to 0.99], P=0.02 per unit SD of FMD) but added only ≈1% to the prognostic accuracy of the best Cox model. Brachial artery diameter was also predictive of CV events in the adjusted Cox proportional hazard model (hazard ratio, 1.12 [95% CI, 1.02 to 1.28], P=0.025) and also added ≈1% to the accuracy of our best Cox model. Conclusions— FMD is a predictor of future cardiovascular events but adds very little to the prognostic accuracy of traditional cardiovascular risk scores/factors in older adults. FMD and brachial artery diameter may have similar predictive values for cardiovascular events in older adults.

Comparison of Novel Risk Markers for Improvement in Cardiovascular Risk Assessment in Intermediate-Risk Individuals

CONTEXT Risk markers including coronary artery calcium, carotid intima-media thickness, ankle-brachial index, brachial flow-mediated dilation, high-sensitivity C-reactive protein (CRP), and family history of coronary heart disease (CHD) have been reported to improve on the Framingham Risk Score (FRS) for prediction of CHD, but there are no direct comparisons of these markers for risk prediction in a single cohort. OBJECTIVE We compared improvement in prediction of incident CHD/cardiovascular disease (CVD) of these 6 risk markers within intermediate-risk participants (FRS >5%-<20%) in the Multi-Ethnic Study of Atherosclerosis (MESA). DESIGN, SETTING, AND PARTICIPANTS Of 6814 MESA participants from 6 US field centers, 1330 were intermediate risk, without diabetes mellitus, and had complete data on all 6 markers. Recruitment spanned July 2000 to September 2002, with follow-up through May 2011. Probability-weighted Cox proportional hazard models were used to estimate hazard ratios (HRs). Area under the receiver operator characteristic curve (AUC) and net reclassification improvement were used to compare incremental contributions of each marker when added to the FRS, plus race/ethnicity. MAIN OUTCOME MEASURES Incident CHD defined as myocardial infarction, angina followed by revascularization, resuscitated cardiac arrest, or CHD death. Incident CVD additionally included stroke or CVD death. RESULTS After 7.6-year median follow-up (IQR, 7.3-7.8), 94 CHD and 123 CVD events occurred. Coronary artery calcium, ankle-brachial index, high-sensitivity CRP, and family history were independently associated with incident CHD in multivariable analyses (HR, 2.60 [95% CI, 1.94-3.50]; HR, 0.79 [95% CI, 0.66-0.95]; HR, 1.28 [95% CI, 1.00-1.64]; and HR, 2.18 [95% CI, 1.38-3.42], respectively). Carotid intima-media thickness and brachial flow-mediated dilation were not associated with incident CHD in multivariable analyses (HR, 1.17 [95% CI, 0.95-1.45] and HR, 0.95 [95% CI, 0.78-1.14]). Although addition of the markers individually to the FRS plus race/ethnicity improved AUC, coronary artery calcium afforded the highest increment (0.623 vs 0.784), while brachial flow-mediated dilation had the least (0.623 vs 0.639). For incident CHD, the net reclassification improvement with coronary artery calcium was 0.659, brachial flow-mediated dilation was 0.024, ankle-brachial index was 0.036, carotid intima-media thickness was 0.102, family history was 0.160 and high-sensitivity CRP was 0.079. Similar results were obtained for incident CVD. CONCLUSIONS Coronary artery calcium, ankle-brachial index, high-sensitivity CRP, and family history were independent predictors of incident CHD/CVD in intermediate-risk individuals. Coronary artery calcium provided superior discrimination and risk reclassification compared with other risk markers.

Association between sleep apnea, snoring, incident cardiovascular events and all-cause mortality in an adult population: MESA

BACKGROUND We assessed the association between sleep apnea, snoring, incident cardiovascular (CV) events and all-cause mortality in the Multi Ethnic Study of Atherosclerosis (MESA) cohort. METHODS Out of 5338 respondents to a sleep questionnaire administered during the second MESA exam period, 208 had physician diagnosed sleep apnea (PDSA), 1452 were habitual snorers (HS) and 3678 were neither a habitual snorer nor had PDSA (normal participants). Cox proportional hazard analysis was used to assess the associations adjusting for age, gender, race/ethnicity, smoking, diabetes mellitus, total cholesterol, HDL, triglycerides, BMI, current alcohol use, benzodiazepine use, BP medications and statin use. RESULTS Over a 7.5 year average follow-up period, 310 adjudicated CV events including MI, stroke, angina, resuscitated cardiac arrest, stroke death and CVD death and 189 deaths occurred. Compared to HS, PDSA was associated with higher incident CV rates in both univariate and multivariable models [hazard ratio (95%); 1.89 (1.22-2.93), p = 0.004 and 1.91 (1.20-3.04), p = 0.007, respectively]. PDSA was also associated with a higher death rates compared with HS [hazard ratio (95%); 2.13 (1.25-3.63), p = 0.006 and 2.70 (1.52-4.79), p = 0.007, respectively]. Compared with normal participants, PDSA had higher incident CV event rates in both univariate and multivariable models [hazard ratio (95%); 2.23 [1.39-3.60], p = 0.001 and 2.16 [1.30-3.58], p = 0.003, respectively]. Similarly, PDSA had a higher death rate compared with normal participants in both the univariate and multivariable models [hazard ratio (95% CI); 2.44 (1.36-4.37), p = 0.003 and 2.71 (1.45-5.08), p =0 .002, respectively]. Habitual snorers had similar incident CV event rates and death rates in both univariate and multivariable models compared with normal participants. CONCLUSION PDSA but not habitual snoring was associated with high incident CV events and all-cause mortality in a multi-ethnic population based study of adults free of clinical CV disease at baseline.

Utility of Nontraditional Risk Markers in Individuals Ineligible for Statin Therapy According to the 2013 American College of Cardiology/American Heart Association Cholesterol Guidelines

Background— In the general population, the majority of cardiovascular events occur in people at the low to moderate end of population risk distribution. The 2013 American College of Cardiology/American Heart Association guideline on the treatment of blood cholesterol recommends consideration of statin therapy for adults with an estimated 10-year atherosclerotic cardiovascular disease (ASCVD) risk ≥7.5% based on traditional risk factors. Whether use of nontraditional risk markers can improve risk assessment in those below this threshold for statin therapy is unclear. Methods and Results— Using data from the Multi-Ethnic Study of Atherosclerosis (MESA), a population sample free of clinical CVD at baseline, we calibrated the Pooled Cohort Equations (cPCE). ASCVD was defined as myocardial infarction, coronary heart disease death, or fatal or nonfatal stroke. Adults with an initial cPCE <7.5% and elevated levels of additional risk markers (abnormal test) whose new calculated risk was ≥7.5% were considered statin eligible: low-density lipoprotein cholesterol ≥160 mg/dL; family history of ASCVD; high-sensitivity C-reactive protein ≥2 mg/dL; coronary artery calcium score ≥300 Agatston units or ≥75th percentile for age, sex, and ethnicity; and ankle-brachial index <0.9. We compared the absolute and relative ASCVD risks among those with versus without elevated posttest estimated risk. We calculated the number needed to screen to identify 1 person with abnormal test for each risk marker, defined as the number of participants with baseline cPCE risk <7.5% divided by the number with an abnormal test reclassified as statin eligible. Of 5185 participants not taking statins with complete data (age, 45–84 years), 4185 had a cPCE risk <7.5%. During 10 years of follow-up, 57% of the ASCVD events (183 of 320) occurred among adults with a cPCE risk <7.5%. When people with diabetes mellitus were excluded, the coronary artery calcium criterion reclassified 6.8% upward, with an event rate of 13.3%, absolute risk of 10%, relative risk of 4.0 (95% confidence interval [CI], 2.8–5.7), and number needed to screen of 14.7. The corresponding numbers for family history of ASCVD were 4.6%, 15.1%, 12%, 4.3 (95% CI, 3.0–6.4), and 21.8; for high-sensitivity C-reactive protein criteria, 2.6%, 10%, 6%, 2.6 (95% CI, 1.4–4.8), and 39.2; for ankle-brachial index criteria, 0.6%, 9%, 5%, 2.3 (95% CI, 0.6–8.6), and 176.5; and for low-density lipoprotein cholesterol criteria, 0.5%, 5%, 1%, 1.2 (95% CI, 0.2–8.4), and 193.3, respectively. Of the 3882 with <7.5% cPCE risk, 431 (11.1%) were reclassified to ≥7.5% (statin eligible) by at least 1 of the additional risk marker criteria. Conclusions— In this generally low-risk population sample, a large proportion of ASCVD events occurred among adults with a 10-year cPCE risk <7.5%. We found that the coronary artery calcium score, high-sensitivity C-reactive protein, family history of ASCVD, and ankle-brachial index recommendations by the American College of Cardiology/American Heart Association cholesterol guidelines (Class IIB) identify small subgroups of asymptomatic population with a 10-year cPCE risk <7.5% but with observed ASCVD event rates >7.5% who may warrant statin therapy considerations.

Prognosis of Individuals With Asymptomatic Left Ventricular Systolic Dysfunction in the Multi-Ethnic Study of Atherosclerosis (MESA)

Background— Limited data exist on the prevalence, associations, and prognosis of individuals with asymptomatic left ventricular systolic dysfunction (ALVSD), especially in populations without previous clinical cardiovascular disease (CVD). Methods and Results— Kaplan-Meier and Cox proportional hazard analyses were used to assess the association between ALVSD, defined as left ventricular ejection fraction <50%, and adjudicated incident congestive heart failure (CHF), all-cause mortality, and CVD events. Of 5004 participants, 112 participants had CHF, 321 had a CVD event, and 278 died after 9 years of follow-up. The overall prevalence of ALVSD was 1.7%, with a higher prevalence in blacks (2.6%). ALVSD had a worse cardiovascular risk profile and was also associated with increased risk in unadjusted and adjusted models for incident CHF (HR [hazard ratio] [95% CI {confidence interval}]: 12.0 [7.04–20.3], P<0.0001 and 8.69 [4.89–15.45], P<0.001 respectively), CVD (HR [95% CI]: 3.32 [1.98–5.58], P<0.001 and 2.21 [1.30–3.73], P=0.003 respectively), and all-cause mortality (HR [95% CI]: 3.47 [2.03–5.94], P<0.0001 and 2.00 [1.13–3.54], P=0.017, respectively). A 10% decrement in left ventricular ejection fraction at baseline was associated with an increase in risk in unadjusted and adjusted models for clinical CHF (HR [95% CI]: 2.17 [1.82–2.63], P<0.0001 and 2.13 [1.73–2.51], P<0.001, respectively) and all-cause mortality (HR [95% CI]: 1.22 [1.05–1.41], P=0.009 and 1.17 [1.00–1.36], P=0.047, respectively). Among the subset of participants with ALVSD, the left ventricular mass index was particularly informative about risk for incident CHF (c-index=0.74). Conclusions— ALVSD is uncommon in individuals without previous clinical CVD, but it is associated with high risk for CHF, CVD, and all-cause mortality. The left ventricular mass index had good discrimination for incident CHF in Multi-Ethnic Study of Atherosclerosis (MESA) participants with ALVSD.

Heart Rate–Corrected QT Interval Is an Independent Predictor of All-Cause and Cardiovascular Mortality in Individuals With Type 2 Diabetes: The Diabetes Heart Study

OBJECTIVE Heart rate–corrected QT (QTc) interval is associated with mortality in the general population, but this association is less clear in individuals with type 2 diabetes. We assessed the association of QTc interval with all-cause and cardiovascular disease (CVD) mortality in the Diabetes Heart Study. RESEARCH DESIGN AND METHODS We studied 1,020 participants with type 2 diabetes (83% European Americans; 55% women; mean age 61.4 years) who were free of atrial fibrillation, major ventricular conduction defects, and antiarrhythmic therapy at baseline. QT duration was automatically calculated from a standard 12-lead electrocardiogram (ECG). Following American Heart Association/American College of Cardiology Foundation recommendations, a linear scale was used to correct the QT for heart rate. Using Cox regression, risk was estimated per 1-SD increase in QTc interval as well as prolonged QTc interval (>450 ms) vs. normal QTc interval for mortality. RESULTS At baseline, the mean (SD) QTc duration was 414.9 ms (18.1), and 3.0% of participants had prolonged QTc. After a median follow-up time of 8.5 years (maximum follow-up time 13.9 years), 204 participants were deceased. In adjusted multivariate models, a 1-SD increase in QTc interval was associated with an 18% higher risk for all-cause mortality (hazard ratio 1.18 [95% CI 1.03–1.36]) and 29% increased risk for CVD mortality (1.29 [1.05–1.59]). Similar results were obtained when QTc interval was used as a categorical variable (prolonged vs. normal) (all-cause mortality 1.73 [0.95–3.15]; CVD mortality 2.86 [1.35–6.08]). CONCLUSIONS Heart rate QTc interval is an independent predictor of all-cause and CVD mortality in this population with type 2 diabetes, suggesting that additional prognostic information may be available from this simple ECG measure.

Id3 Is a Novel Atheroprotective Factor Containing a Functionally Significant Single-Nucleotide Polymorphism Associated With Intima–Media Thickness in Humans

Rationale: The gene encoding the helix–loop–helix transcription factor Id3 (inhibitor of differentiation-3) is located within atherosclerosis susceptibility loci of both mice and humans, yet its influence on atherosclerosis is not known. Objective: The present study sought to determine whether polymorphisms in the ID3 gene were associated with indices of atherosclerosis in humans and if loss of Id3 function modulated atherogenesis in mice. Methods and Results: Six tagging single-nucleotide polymorphisms (SNPs) (tagSNPs) in the human ID3 gene were assessed in participants of the Diabetes Heart Study. One tagSNP, rs11574, was independently associated with carotid intima–media thickness (IMT). The human ID3 variant at rs11574 results in an alanine to threonine substitution in the C terminus. To determine the effect of this polymorphism on the basic function of Id3, site-directed mutagenesis of the human ID3 gene at rs11574 was performed. Results demonstrated a significant reduction in coimmunoprecipitation of the known E-protein partner, E12, with Id3 when it contains the sequence encoded by the risk allele (Id3105T). Further, Id3105T had an attenuated ability to modulate E12-mediated transcriptional activation compared to Id3 containing the ancestral allele (Id3105A). Microarray analysis of vascular smooth muscle cells from WT and Id3−/− mice revealed significant modulation of multiple gene pathways implicated in atherogenesis. Moreover, Id3−/−ApoE−/− mice developed significantly more atherosclerosis in response to 32 weeks of Chow or Western diet feeding than Id3+/+ApoE−/− mice. Conclusions: Taken together, results provide novel evidence that Id3 is an atheroprotective factor and link a common SNP in the human ID3 gene to loss of Id3 function and increased IMT.

Chronic Statin Administration May Attenuate Early Anthracycline-Associated Declines in Left Ventricular Ejection Function

Background Recent studies show an association between statin therapy and a reduced risk of heart failure among breast cancer survivors. Our goal was to evaluate whether statin therapy for prevention of cardiovascular disease (CVD) would ameliorate declines in left ventricular ejection fraction (LVEF) often observed during anthracycline-based chemotherapy (Anth-bC). Methods In 51 participants (33 women and 18 men; aged 48±2 years), we performed CV magnetic resonance (CMR) measurements of LVEF before and 6 months after initiation of Anth-bC for patients with breast cancer, leukemia, or lymphoma. Fourteen individuals received statin therapy, and 37 received no statin. MR image analysts were blinded to participant identifiers. Results Those receiving statins were older and often had diabetes (DM), hypertension (HTN), and hyperlipidemia (HLD). For those receiving statins, LVEF was 56.6±1.4% at baseline and 54.1±1.3% 6 months after initiating anthracycline (p=0.15). For those not receiving a statin, LVEF was 57.5±1.4% at baseline and decreased to 52.4±1.2% over a similar 6 month interval (p=0.0003). In a multivariable model accounting for age, sex, DM, HTN, HLD, and cumulative amount of anthracycline received, LVEF remained unchanged in participants receiving a statin (+ 1.1±2.6%) versus a −6.5±1.5% decline among those not receiving a statin (p=0.03). Conclusion In conclusion, these data highlight that individuals receiving statin therapy for prevention of CVD may experience less deterioration in LVEF upon early receipt of Anth-bC than individuals not receiving a statin. Further studies with large numbers of participants are warranted to determine if statins protect against LVEF decline in patients receiving Anth-bC.

Cancer and Its Association With the Development of Coronary Artery Calcification: An Assessment From the Multi‐Ethnic Study of Atherosclerosis

Background Although cancer and its corresponding therapies are associated with increased ischemic heart disease, the temporal relationship between cancer and the development of coronary artery calcium (CAC), a marker of subclinical atherosclerosis, is unknown. Methods and Results Among 3122 men and women free of cardiovascular disease and cancer in the Multi‐Ethnic Study of Atherosclerosis trial, CAC scoring was performed at baseline (2000–2002) and at follow‐up (2010–2012). Over this 10‐year period, 85 men (age 63.6±8.3 years) and 50 women (age 62.1±9.8 years) were diagnosed with cancer (predominantly breast, lung, or uterine [52%] in women and prostate or colorectal [78%] in men). The other 2987 subjects (age 59.6±9.2 years for men, 59.7±9.4 years for women) remained cancer free. The incidence of new CAC (baseline Agatston score of zero converting to detectable CAC) was modeled with relative risk regression and compared for cancer versus no cancer. Increase in pre‐existing CAC was compared in these groups using linear regression of log transformed CAC. The incidence of CAC was independently associated with cancer history (relative risk 1.32 [P=0.04] and 1.29 [P=0.01] for women and men, respectively). In participants with CAC at baseline, a clear difference of CAC progression was not observed between cancer and noncancer participants (P=0.6 for women, P=0.2 for men). Conclusions A diagnosis of cancer is associated with the development of CAC even after accounting for atherosclerotic risk factors. However, in individuals with pre‐existing CAC, it is not clear whether the presence of cancer accelerates CAC over time.

Implications of the new American College of Cardiology/American Heart Association cholesterol guidelines for primary atherosclerotic cardiovascular disease event prevention in a multi ethnic cohort: Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND The impact of replacing the National Cholesterol Education Program (NCEP)/Adult Treatment Program (ATP) III cholesterol guidelines with the new 2013 American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for primary prevention of cardiovascular disease is unclear. METHODS We used risk factor and 10-year clinical event rate data from MESA, combined with estimates of efficacy of moderate and high-intensity statin therapy from meta-analyses of statin primary prevention trials to estimate (a) the change in number of subjects eligible for drug therapy and (2) the anticipated reduction in atherosclerotic cardiovascular disease (ASCVD) events and increment in type 2 diabetes mellitus (T2DM) associated with the change in cholesterol guidelines. RESULTS Of the 6,814 MESA participants, 5,437 were not on statins at baseline and had complete data for analysis (mean age 61.4±10.3). Using the NCEP/ATP III guidelines, 1,334 (24.5%) would have been eligible for statin therapy compared with 3,015 (55.5%) under the new ACC/AHA guidelines. Among the subset of newly eligible, 127/1,742 (7.3%) had an ASCVD event during 10years of follow-up. Assuming 10years of moderate-intensity statin therapy, the estimated absolute reduction in ASCVD events for the newly eligible group was 2.06% (number needed to treat [NNT] 48.6) and the estimated absolute increase in T2DM was 0.90% (number needed to harm [NNH] 110.7). Assuming 10years of high-intensity statin therapy, the corresponding estimates for reductions in ASCVD and increases in T2DM were as follows: ASCVD 2.70% (NNT 37.5) and T2DM 2.60% (NNH 38.6). The estimated effects of moderate-intensity statins on 10-year risk for ASCVD and T2DM in participants eligible for statins under the NCEP/ATP III were as follows: 3.20% (NNT 31.5) and 1.06% (NNH 94.2), respectively. CONCLUSION Substituting the NCEP/ATP III cholesterol guidelines with the 2013 ACC/AHA cholesterol guidelines in MESA more than doubled the number of participants eligible for statin therapy. If the new ACC/AHA cholesterol guidelines are adopted and extend the primary prevention population eligible for treatment, the risk-benefit profile is much better for moderate-intensity than high-intensity statin treatment.