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Objective To identify temporal trends in the use of exercise treadmill testing (ETT) and cardiorespiratory fitness (CRF) estimated by ETT in metabolic equivalents (METs). Patients and methods We compiled an ETT database of all available treadmill tests—including those with concomitant stress echocardiography and nuclear perfusion imaging studies—performed at Duke University Hospital from January 1, 1970- December 31, 2012. Six different ramp protocols were used in these combined modalities. CRF at maximal exertion was estimated using established metrics. Eligible patients were required to have no missing data on maximal treadmill speed, grade, and protocol. Results The most commonly used ETT protocol was the Bruce (n = 28,877), followed by manual test (n = 7390). Since the 1980’s, the use of ETT for clinical purposes declined substantially; there was a decreased trend in utilization of 9.4% over the decades 1990–1999 and 2000–2009. When standard protocol (Bruce) was assessed in isolation, trends in CRF decreased progressively from 1970 to 2012 (mean METs (standard deviation): 11.7 (4.3) to 10.5 (3.5)). After adjusting for baseline comorbidities, the trend was reduced to a lesser degree. Conclusions The use of ETT at our institution has declined over time, perhaps due to changes in clinical practice. In patients undergoing ETT using the standard Bruce protocol, CRF decreased progressively over the last five decades. Future studies are needed to clarify the etiology of the decrease in use of such a powerful predictor of clinical outcomes in our medical care environment.

A strategy using coronary artery calcium (CAC) screening to refine coronary heart disease risk assessment in moderately high risk (MHR) subjects (10-year risk 10%-20%) has been suggested. The potential impact of this strategy is unknown.Coronary artery calcium screening strategies focused on MHR subjects were modeled in 2,610 subjects aged 30 to 65 years undergoing Framingham risk scoring and CAC assessment in the Dallas Heart Study. The proportions of subjects eligible for imaging and reclassified from MHR to high risk (HR) (10-year risk20%) based upon CAC scores were determined.Only 1.0% of women and 15.4% of men were at MHR by Framingham risk scoring and thus eligible for imaging, and0.1% and 1.1% respectively, changed from MHR to HR using a CAC thresholdor = 400. Coronary artery calcium imaging targeting MHR subjects was also relatively inefficient (100 women, 14.3 men scanned per subject reclassified). Restricting to an older age range (45-65 years) or expanding the MHR group to 6% to 20% risk had virtually no impact on risk assessment in women. In a secondary analysis, a proposed imaging strategy targeting promotion of subjects from lower risk to MHR was more efficient and had greater yield than current recommendations targeting promotion from MHR to HR.Coronary artery calcium screening strategies focused on MHR subjects will have a negligible impact on risk assessment in women and a modest impact in men. Further studies are needed to optimize the use of CAC screening as an adjunct to coronary heart disease risk assessment, especially for women and those at seemingly lower risk.

Family history of premature myocardial infarction (FHMI) may be a useful marker of cardiovascular disease (CVD) risk in young subjects, but comparisons of its implications for CVD risk factor burden, prevalent atherosclerosis, and risk awareness between young men and women have not been reported.We analyzed data from 2404 young subjects with ages 30 to 50 in the Dallas Heart Study, which is a population-based study. Family history of premature MI was defined as a first-degree relative with myocardial infarction (MI) before age 50 (men) or 55 (women). Coronary artery calcification was measured by computed tomography scan, and perceived lifetime risk of MI was assessed by questionnaire. Analyses were sex-stratified.Women with versus without FHMI had an increased composite risk factor burden (or = 2 CVD risk factors, 49.1% vs 39.1%; P.001), an association not seen in men (P = .6). Family history of premature MI was independently associated with coronary artery calcification among women (adjusted odds ratio, 2.0; 95% confidence interval, 1.0-4.1) but not among men (adjusted odds ratio, 1.7; 95% confidence interval, 0.9-3.2). A higher proportion of subjects with FHMI versus no FHMI perceived their lifetime risk of MI to be ator = average in women (59.7% vs 47.4%; P.001) and men (75.0% vs 48.3%; P = .004), with the increment greatest among men (P interaction = .02).Despite a stronger association with CVD risk factors and atherosclerosis prevalence with FHMI among young women compared with men, young women with FHMI demonstrated less CVD risk awareness and worse lifestyle choices. Family history of premature MI may be an especially useful risk assessment tool in young women, and greater efforts are needed to promote CVD risk awareness among young women with FHMI.