Use of functional aerobic capacity based on stress testing to predict outcomes in normal, overweight, and obese patients.

OBJECTIVE: To determine the poorly studied relationship between functional aerobic capacity (FAC) as measured by treadmill stress testing and mortality in normal, overweight, and obese patients. PATIENTS AND METHODS: Patients were identified retrospectively from the stress testing database at Mayo Clinic in Rochester, Minnesota. We selected 5328 male nonsmokers (mean ± SD age, 51.8±11.5 years) without baseline cardiovascular disease who were referred for treadmill exercise testing between January 1, 1986, and December 31, 1991, and classified them by body mass index (BMI) into normal-weight (18.5-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), and obese (≥30 kg/m(2)) categories. Functional aerobic capacity was assessed by maximal exercise test results based on age- and sex-specific metabolic equivalents, and patients were stratified into fitness quintiles. Cox proportional hazards analysis was used to determine the relationship of all-cause mortality to fitness in each BMI category. RESULTS: There were 322 deaths during 14 years of follow-up. After adjustment for age and exercise confounders, FAC predicted mortality in the 3 BMI groups. Hazard ratios for FAC less than 80% of predicted vs a reference group with normal BMI and fitness (FAC ≥100%) were 1.754 (95% CI, 0.874-3.522), 1.962 (1.356-2.837), and 1.518 (1.056-2.182) for the normal, overweight, and obese groups, respectively. The CIs of the hazard ratios overlapped with no statistically significant differences (P>.05). CONCLUSION: A significant increase in mortality occurs with FAC below 80% of predicted for overweight and obese subjects and below 70% for normal weight subjects. Our results suggest that clinicians need not adjust the standard for low fitness in obese patients.

Exercise as a treatment for the risk of cardiovascular disease.

OPINION STATEMENT: Regular physical activity decreases the risk of cardiovascular disease and modifies multiple cardiovascular risk factors. The optimum amount of exercise continues to generate debate; however, the general recommendation is that all adults should engage in 30 min of moderate-intensity physical activity on five, and preferably all, days of the week. Despite extensive data and recommendations, a significant proportion of the US adult population remains sedentary. Promoting physical activity at a public level remains a major challenge because of the presence of multiple behavioral, physical, and environmental barriers. Health care providers have an opportunity and a responsibility to include exercise counseling in routine office visits.

Predictive value of heart rate recovery and peak oxygen consumption for long-term mortality in patients with coronary heart disease.

Poor exercise capacity and abnormal heart rate (HR) recovery during exercise testing predict poor long-term outcomes. The relationship between these parameters in patients with coronary heart disease (CHD) is unknown. Whether abnormal HR recovery adds to the prognostic value of poor exercise capacity in patients with CHD is unclear. A total of 282 patients (17% women) with stable CHD underwent cardiopulmonary treadmill testing at the end of Phase II cardiac rehabilitation and were followed for a mean of 9.8 +/- 2.9 years. Cox proportional hazards regression with adjustment for low peak oxygen consumption ([peak VO(2)] <19 ml/kg/min for men, <15 ml/kg/min for women), age, and gender was used to test the prognostic significance of HR recovery (HR recovery = peak - 1-minute after peak HR). HR recovery and peak VO(2) correlated mildly (r = 0.35, p <0.001). Both an abnormal HR recovery (<13 beats/min) and a low peak VO(2) were significantly associated with greater mortality in a model including age, gender, low peak VO(2), and abnormal HR recovery (hazard ratio for abnormal HR recovery = 2.16, 95% confidence interval 1.14 to 4.09; hazard ratio for low peak VO(2) = 3.63, 95% confidence interval 2.09 to 6.32). Despite a preserved peak VO(2), the 10-year mortality rate was significantly greater in patients with a HR recovery of <13 beats/min compared with those with a HR recovery of >or=13 beats/min (13.6% vs 5.6%, respectively; p <0.05). In conclusion, in patients with stable CHD undergoing cardiac rehabilitation, the rate of HR recovery provides additional prognostic information beyond the peak VO(2). An abnormal HR recovery identifies a subset of patients at intermediate risk despite a preserved peak VO(2).

Abnormal cardiac structure and function in the metabolic syndrome: a population-based study.

OBJECTIVE: To measure the association between cardiac structure and function abnormalities and isolated metabolic syndrome (metabolic syndrome excluding established hypertension or diabetes mellitus). PARTICIPANTS AND METHODS: We collected data prospectively on a population-based random sample of 2042 Olmsted County, Minnesota, residents aged 45 years or older who underwent echocardiography between January 1, 1997, and September 30, 2000. Metabolic syndrome was defined by National Cholesterol Education Program Adult Treatment Panel III criteria. RESULTS: The prevalence of isolated metabolic syndrome was 21.7% (214/984) in men and 16.7% (177/1058) in women. Left ventricular (LV) mass index was greater (91.7 vs 87.9 g/m2; P=.04) and LV diastolic dysfunction more prevalent (28.2% [50/177] vs 14.9% [81/544]; P<.001) in women with isolated metabolic syndrome than in women without metabolic syndrome; no difference was found in men. When patients with hypertension or diabetes mellitus were included in the cohort, there was a stepwise increase in LV mass index and LV diastolic dysfunction from no metabolic syndrome to isolated metabolic syndrome to metabolic syndrome in women and men. CONCLUSION: Isolated metabolic syndrome, which is associated with increased LV mass index and LV diastolic dysfunction in women, identifies women with evidence of early ventricular dysfunction.

Long-term mortality with multiple treadmill exercise test abnormalities: comparison between patients with and without cardiovascular disease.

BACKGROUND: Poor exercise capacity, abnormal heart rate responses, and electrocardiographic abnormalities during treadmill exercise testing independently predict mortality. The combined relationship of these 3 variables to determine the incremental increase in mortality was compared in groups with and without known cardiovascular disease (CVD). METHODS: Patients referred for treadmill exercise testing during 1986 to 1991 were included. Exercise capacity <74% (of age- and gender-predicted value), heart rate reserve of <68 beat/min, and horizontal or down-sloping ST depression of > or =1 mm were considered abnormal. Cox proportional hazards regression was used to determine all-cause mortality (average follow-up of 16 years) based on the number of exercise test abnormalities (0, 1, 2, or all 3). RESULTS: Among 10,897 patients, 20.9% (n = 2,277) had CVD. Poor exercise capacity and limited heart rate reserve were associated with increased risk of mortality (P < .0001) in both groups; however, abnormal exercise electrocardiogram was associated with an increased risk of mortality in the no-CVD group only (P < .0001). A graded increase in mortality was observed with increase in number of abnormal exercise test results in both groups. Patients without CVD having 2 or 3 abnormal exercise test results had a similar age-adjusted risk of long-term mortality as those with CVD but normal exercise test results, with a hazard ratio comparing these groups = 1.01 (95% CI 0.79-1.28). CONCLUSIONS: The combinatorial approach validates the prognostic significance of multiple exercise test variables. The presence of > or =2 exercise test abnormalities may constitute a "CVD risk equivalent" in patients without CVD.

Drug compliance after stroke and myocardial infarction: a comparative study.

BACKGROUND: Stroke and myocardial infarction (MI) are both life-threatening diseases of vascular origin with a tendency to recur. In both conditions, risk of recurrence is reduced through similar drug regimens. AIM: To determine if compliance with prescribed medication after stroke or MI was similar in the two populations. SETTING AND DESIGN: Retrospective data collection and cross-sectional telephonic survey of patients discharged from a single academic medical center. MATERIALS AND METHODS: Adult patients consecutively discharged over a two-year period with a diagnosis of first-ever stroke (ischemic or hemorrhagic) or first-ever MI (ST-elevation) were identified through ICD-9 codes. Clinical details were abstracted from hospital records. Medication compliance was assessed through a structured telephone interview. STATISTICAL ANALYSIS: Bivariate analysis using Chi-square and Fisher exact tests, to determine the prevalence of noncompliance in stroke versus MI patients and differences in baseline characteristics and multivariate analysis with logistic regression to determine independent predictors of noncompliance. RESULTS: Follow-up data was collected for 298 stroke and 275 MI patients. Compliance was lower in stroke patients (68% stroke patients compliant with at least half their discharge prescriptions versus 90% MI patients; P < 0.001). Literacy and post-discharge follow-up were associated with greater compliance (P < 0.05 for both). Compliance was highest with anti-hypertensive drugs (98% after MI, 78% after stroke), followed by anti-platelet agents (94% after MI, 75% after stroke) and anti-lipid agents (70% after MI, 59% after stroke). Patients reported simply not feeling the need, acquiring fresh medical advice or a perceived lack of benefit, as reasons for not complying with their discharge prescriptions. CONCLUSIONS: Although similar drugs are involved, compliance with prescribed regimens is appreciably lower after stroke than after MI. Our findings underscore the need for better patient education regarding secondary prevention after stroke.