Allison, Thomas G.

Background Exercise testing provides valuable information in addition to ST ‐segment changes. The present study evaluated the associations among exercise test parameters and all‐cause mortality in a referral population. Methods and Results We examined conventional cardiovascular risk factors and exercise test parameters in 6546 individuals (mean age 49 years, 58% men) with no known cardiovascular disease who were referred to our clinic for exercise stress testing between 1993 and 2003. The association of exercise parameters with mortality was assessed during a follow‐up of 8.1±3.7 years. A total of 285 patients died during the follow‐up period. Adjusting for age and sex, the variables associated with mortality were: smoking, diabetes, functional aerobic capacity ( FAC ), heart rate recovery ( HRR ), chronotropic incompetence, and angina during the exercise. Adjusting for cardiovascular risk factors (diabetes, smoking, body mass index, blood pressure, serum total, HDL , LDL cholesterol, and triglycerides) and other exercise variables in a multivariable model, the only exercise parameters independently associated with mortality were lower FAC (adjusted hazard ratio [ HR ] per 10% decrease in FAC , 1.21; 95% confidence interval [ CI ], 1.13 to 1.29; P <0.001), and abnormal HRR , defined as failure to decrease heart rate by 12 beats at 1 minute recovery (adjusted HR per 1‐beat decrease, 1.05; 95% CI , 1.03 to 1.07; P <0.001). The additive effects of FAC and HRR on mortality were also highly significant when considered as categorical variables. Conclusion In this cohort of patients with no known cardiovascular disease who were referred for exercise electrocardiography, FAC and HRR were independently associated with all‐cause mortality.

Background: Cardiovascular (CV) disease is the leading cause of death in U.S. women. Although women are becoming more aware of CV disease, there remains a dichotomy between awareness and perceived risk. We sought to characterize this dichotomy in women attracted to a CV health–screening event, in order to improve strategies to reduce CV risk. Methods: During CV health events held in Rochester, Minnesota, from 2007 through 2011, 294 women underwent screening for blood chemistry, body mass index, and blood pressure. Participants also completed surveys about knowledge of CV disease, risk factors, and perceived risk. Risk level was determined from the 2011 American Heart Association Effectiveness-Based Guidelines for Women. Results: Among participants (age, mean [standard deviation], 53 [15.3] years; white, 98%), 99% were aware that CV disease is the leading cause of death in women. Almost half (47%) perceived themselves to be at personal risk, although 65% were determined to be “at risk” and 12% to be at “high risk” according to guidelines, while 22% were uncategorized. Of the 228 participants “at risk” or “high risk,” 48% and 21%, respectively, did not perceive themselves to be at any risk. Conclusions : Women attracted to CV health events were aware that CV disease is the leading cause of death for women. However, the magnitude of awareness did not directly translate into perception or understanding of actual personal risk. To decrease the rate of CV disease in women, continued efforts are needed to personalize the importance of, and the methods for reducing, CV risk factors.

Background— Cardiopulmonary exercise testing (CPX) with measurement of peak oxygen uptake (V o 2 ) is a powerful test for assessment and quantification of functional impairment resulting from cardiovascular disease. The safety of CPX has been established in patients with coronary artery disease and congestive heart failure, but clinical use of CPX in other cardiac diseases has been limited, in part because of a paucity of safety data. This study investigates the safety of CPX in a heterogeneous cohort of patients with a wide variety of underlying high-risk cardiac diagnoses. Methods and Results— This single-center retrospective review examined 5060 CPX studies performed in 4250 unique patients, including 1748 (35%) female subjects and 686 (14%) subjects aged ≥75 years. The primary end point was major adverse event during stress testing. The study population included patients with a variety of high-risk cardiac diseases, including congestive heart failure (n=1289, 25.5%), hypertrophic cardiomyopathy (n=598, 11.8%), pulmonary hypertension (n=194, 3.8%), and aortic stenosis (n=212, 4.2%). This patient population generally had severe functional impairment, including 1192 (24%) patients with peak V o 2 <14 mL/kg/min. Eight adverse events occurred during CPX, for an adverse event rate of 0.16%. The most common adverse event (n=6) was sustained ventricular tachycardia. There were no fatal events. Conclusions— CPX is generally a safe procedure, even in a population with underlying high-risk cardiovascular diagnoses.

OBJECTIVE—The aim of the present study was to assess the diagnostic accuracy of the Adult Treatment Panel III (ATP-III) definition of the metabolic syndrome in identifying insulin-resistant individuals and to explore alternative approaches to improve identification of insulin-resistant individuals among asymptomatic adults from the general population. RESEARCH DESIGN AND METHODS—The sample consisted of 256 non-Hispanic white subjects without treated hypertension or diabetes, from the Rochester (Minnesota) Heart Family Study (123 men and 133 women; aged 20–60 years). Frequently sampled intravenous glucose tolerance tests were performed in all subjects. The reference standard for insulin resistance was determined by Bergman’s minimal model; insulin resistance was defined as an insulin sensitivity index &lt;2 × 10 min−1 · μU−1 · ml−1. Component metabolic syndrome measures included blood pressure determined by sphygmomanometer; fasting serum triglycerides, HDL cholesterol, and glucose concentrations determined enzymatically; and waist circumference determined by tape measure. RESULTS—By ATP-III criteria, the prevalence of metabolic syndrome was 15.6% (16.3% in men and 15.1% in women; P = 0.465). The presence of metabolic syndrome had low sensitivity to identify insulin resistance (45% in men and 39% in women; sex difference, P = 0.137) but high specificity (93% in men and 95% in women; sex difference, P = 0.345). Based on the area under the receiver operating characteristic curve (AUC) constructed by counting metabolic syndrome components as recommended by ATP-III, diagnostic accuracy was fair (AUC = 0.797 in men and 0.747 in women). When component metabolic syndrome measures were considered as quantitative traits rather than dichotomized, use of waist circumference alone, rather than counting metabolic syndrome components, improved diagnostic accuracy for insulin resistance (in men, AUC = 0.906, P = 0.001; in women, AUC = 0.822, P = 0.10). CONCLUSIONS—Application of the ATP-III metabolic syndrome criteria provides good specificity but low sensitivity to screen asymptomatic white adults for insulin resistance. Measuring just waist circumference is simpler and may provide greater accuracy for identifying insulin resistance.