Donald C. Paup

Effects of a prescribed supervised exercise program on mortality and cardiovascular morbidity in patients after a myocardial infarction: The National Exercise and Heart Disease Project∗☆

This study enrolled 651 men with myocardial infarction in five participating centers in a randomized 3 year clinical trial of the effects of prescribed supervised exercise. The subjects, aged to 30 to 64 years, were screened for eligibility 2 to 36 months after their qualifying myocardial infarction. The men in the exercise group pursued intensive exercise in the laboratory for 8 weeks and then in a gymnasium for 34 months. The experience of the exercise group was more favorable than that of the control group in most of the comparisons made. The cumulative 3 year total mortality rate was 7.3 percent for the control group and 4.6 percent for the exercise group; the 3 year rate for recurrent myocardial infarction was 7.0 and 5.3 percent, respectively. Mortality rates in the two groups did not differ significantly, but the data were consistent with an assumption of substantial benefit from exercise. Adjustment for small differences in baseline variables by multivariate methods did not materially alter the estimate of effect of exercise. Certain subgroups showed a greater benefit from exercise.

Fibrinolytic Activity Is Similar in Physically Active Men With and Without a History of Myocardial Infarction

The purpose of this study was to evaluate fibrinolytic potential at rest and after a fibrinolytic stressor in men with a history of myocardial infarction (MI) compared with an age- and activity-matched group of men without coronary artery disease (CAD). All men were currently enrolled in exercise programs. Tissue-type plasminogen activator (TPA) and plasminogen activator inhibitor 1 (PAI-1) activity and antigen levels were measured at rest and after a maximal exercise test. A 2 x 2 (group x time) ANOVA with repeated measures was used to evaluate fibrinolytic potential. Bivariate regressions were conducted to evaluate relations between fibrinolytic potential and maximal oxygen uptake (VO2max). Age was similar between groups (CAD, 57.5 +/- 6.6; non-CAD, 58.1 +/- 7.3 years); however, VO2max was higher in non-CAD subjects (36.2 +/- 6.2 vs 27.5 +/- 5.9 mL.kg-1.min-1). Mean +/- SEM resting TPA and PAI-1 activities were similar between CAD and non-CAD subjects (TPA, 2.8 +/- 0.2 vs 2.8 +/- 0.2 IU/mL; PAI-1, 15.9 +/- 3.1 vs 13.1 +/- 4.1 AU/mL). Both groups showed similar significant increases in TPA activity with exercise (P < .05), and postexercise TPA activity was also similar (CAD, 9.1 +/- 2.0 IU/mL; non-CAD, 11.7 +/- 2.6 IU/mL). Both groups also showed similar significant decreases in PAI-1 activity with exercise (P < .05) and no differences in postexercise PAI-1 activity (CAD, 13.2 +/- 2.5 AU/mL; non-CAD, 10.4 +/- 3.6 AU/mL). Significantly higher resting TPA antigen levels were seen in CAD (14.8 ng/mL) than non-CAD (10.2 ng/mL) subjects (P < .05), but neither group showed significant changes with exercise (CAD, 12.9 ng/mL; non-CAD, 11.8 ng/mL). Resting PAI-1 antigen was similar in the two groups (CAD, 71.4 ng/mL; non-CAD, 74.2 ng/mL) and did not significantly change with exercise (CAD, 77.9 ng/mL; non-CAD, 72.3 ng/mL). VO2max was positively correlated with postexercise TPA activity (r = .52, P < .05) and negatively correlated with resting TPA antigen (r = -.43, P < .05). Resting TPA antigen was also directly correlated with body mass index (r = .63, P < .05). The finding that functional fibrinolytic activity was not different in physically active men with and without CAD contrasts with previous reports. This suggests that matching subjects on the bases of age and habitual physical activity status and controlling exercise intensity are important factors to consider when evaluating fibrinolytic potential.

Fibrinolytic activity is not dependent upon exercise mode in post-myocardial infarction patients

Abstract In this study we investigated possible differences in fibrinolytic activity in cardiac patients while they performed treadmill and cycle ergometry. Thirteen post-myocardial infarction patients completed two maximal exercise tests on treadmill and cycle ergometers. Blood was collected before and after each exercise test and was analyzed for the fibrinolytic variables, tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) activity, and lactate. Maximal oxygen uptake, heart rate, and ventilation were greater (P < 0.05) on the treadmill than during cycle ergometry, however, blood lactate was similar between modes. t-PA activity significantly increased with exercise (P < 0.05) and there was a trend toward a reduction in PAI-1 activity with exercise, but this did not reach statistical significance. The fibrinolytic responses to maximal exercise did not differ between the two modes of exercise studied. Therefore, exercise intensity, but not the mode of exercise, appeared to be the primary determinant of the fibrinolytic response to acute exercise in these patients.

Impact of steady-state and exercise modality on estimating oxygen consumption in men with and without coronary artery disease

PURPOSE This study examined the effect of steady-state on the ability of 15 men with coronary artery disease (CAD) and 13 men without CAD disease (non-CAD) to reach a rate of oxygen consumption (VO2) relative to population norms during treadmill and cycle ergometry exercise testing. METHODS Subjects completed a maximal graded exercise test on the treadmill and cycle ergometry involving 3-minute stages and a submaximal exercise test involving 6-minute stages to 80% of maximal effort. Estimates of VO2 were derived from commonly cited clinical estimation equations. RESULTS Only the Foster equation accurately estimated maximal VO2 during a treadmill graded exercise test in patients with CAD. However, each of cited clinical equations accurately estimated maximal VO2 during a treadmill graded exercise test in the non-CAD group. No equation accurately estimated VO2 at submaximal efforts during treadmill exercise for either group. Cycle ergometry estimation equations accurately estimated VO2 in both groups at maximal effort, but were inconsistent at submaximal efforts. Both the CAD and the non-CAD group reached steady-state VO2 within 3 minutes, at submaximal workloads. CONCLUSIONS The inability to attain an expected VO2 during exercise did not seem related to steady-state VO2 because both CAD and non-CAD groups readily reached steady-state VO2, though the estimation of VO2 remained inaccurate for most treadmill estimation equations. Because VO2 was accurately estimated for cycle ergometry exercise, estimation accuracy seems to be influenced by exercise modality.

1:42 Effects of aerobic exercise on mood and flexibility in patients with lumbar herniated nucleus pulposus

Abstract Purpose of study: The purpose of this study was to assess the effects of moderate intensity aerobic exercise (AE) on mood profile scores and low back flexibility in patients with symptomatic lumbar herniated nucleus pulposus (HNP). Methods used: Seventy-five patients with symptomatic lumbar HNP were randomized into an AE (n=35) group and a control (C) (n=40) group. All patients were assessed at baseline and at the completion of the 12-week study period. The exercise prescription consisted of walking or cycling at 70% of age-predicted maximal heart rate, 4 days per week, for 45 minutes per session. Exercisers filled out a log listing the heart rate, days per week and minutes per exercise session and returned it weekly to the study coordinator. Exercise was unsupervised and performed at home. During the 12-week period, the C group received no exercise intervention but continued to receive usual care. In addition to descriptive statistics, group mean differences were analyzed using Students t tests. Statistical significance was set at the .05 level. of findings: At baseline, only one of the seven Profile of Mood States (POMS) scores, anger, was significantly different, with the AE group demonstrating significantly more anger (ANG). There were no significant differences at baseline in all three low back flexibility measures at baseline: sit and reach (SR), functional reach (FR) and trunk forward flexion (TFF). After the 12-week study, the AE group demonstrated a significant improvement in the following mood profile scores: depression (DEP), ANG, vigor (VIG) and total mood disturbance (TMD). During this same time, the C group demonstrated a significant decrement in the following mood profile scores: confusion (Conf), anxiety (ANX), DEP, ANG, VIG and TMD. FR was significantly improved in the AE group after 12 weeks. No untoward effects of the exercise participation was reported by the patients. Relationship between findings and existing knowledge: There are few data currently regarding AE as a sole exercise treatment for low back pain (LBP) patients. AE has been shown to improve mood profile in LBP patients with mixed diagnoses (after 10 weeks of aerobic exercise) but has not been previously studied as an isolated exercise intervention for LBP patients with symptomatic lumbar HNP. Overall significance of findings: A home-based moderate intensity AE program is safe and associated with improvements in mood profile scores and low back flexibility measures in patients with symptomatic lumbar HNP. Disclosures: No disclosures. Conflict of interest: No conflicts.