Exercise workload, coronary risk evaluation and the risk of cardiovascular and all-cause death in middle-aged men

The aerobic capacity in patients with antisynthetase syndrome and dermatomyositis

BACKGROUND

This study was aimed at evaluating the aerobic capacity of patients with antisynthetase syndrome (ASS) and dermatomyositis (DM) and analyzing possible relationships between aerobic capacity and disease status, cardiovascular diseases and their risk factors.

METHODS

The study was a cross-sectional, single-center study that assessed the aerobic capacity of 22 women (13 with DM and 9 with ASS) who were matched by age and body mass index to 17 healthy women (control group). The aerobic capacity (oxygen uptake [VO₂ peak], anaerobic threshold, respiratory compensation point and time-to-exhaustion) was evaluated using the cardiopulmonary treadmill test. Disease status was assessed using International Myositis Assessment & Clinical Studies Group (IMACS) set scores.

RESULTS

The patients had low IMACS parameters that showed low or absent disease activity. The distribution of cardiovascular diseases and their risk factors was similar between the patients and the control group (P >  0.05) at the time of the analysis. The patients with DM and the control group had similar aerobic capacity. However, the patients with ASS exhibited significantly reduced aerobic capacity (relative VO₂ peak, anaerobic threshold, respiratory compensation point and time to exhaustion) when compared to the control group. In addition, patients with ASS had a lower anaerobic threshold compared to the DM group. There were no significant relationships between the aerobic capacity and disease status, cardiovascular diseases and their risk factors.

CONCLUSION

In contrast to DM patients and healthy individuals, patients with stable ASS have significantly impaired aerobic capacity, which is unlikely to be totally explained by traditional cardiovascular diseases, their risk factors and disease status. Further studies are needed to corroborate our data and to clarify the cause of this reduced aerobic capacity in ASS.

The association between cardiorespiratory fitness and cardiovascular risk may be modulated by known cardiovascular risk factors

BACKGROUND

We aimed to evaluate whether reduced cardiovascular fitness has a direct or indirect effect for the development of cardiovascular disease.

METHODS

We investigated 15,595 men and women who were annually screened in a tertiary medical center. All subjects were free of ischemic heart disease and had completed maximal exercise stress test according to the Bruce protocol at their first visit. Fitness was categorized into age- and sex-specific quintiles (Q) according to Bruce protocol treadmill time with Q1 as lowest fitness. Subjects were categorized at baseline into 3 groups: low fitness (Q1), moderate fitness (Q2-Q4), and high fitness (Q5). The primary end point of the current analysis was the development of a first cardiovascular event during follow-up.

RESULTS

Mean age of study patients was 48 ± 10 years, and 73% were men. A total of 679 events occurred during 92,092 person-years of follow-up. Kaplan-Meier survival analysis showed that the cumulative probability of cardiovascular events at 6 years was significantly higher among subjects with low fitness (P < .001). Low fitness was associated with known cardiovascular risk factors, including hypercholesterolemia (odds ratio [OR] 1.58, 95% CI 1.31-1.89), diabetes mellitus (OR 2.32, 95% CI 1.58-3.41), and obesity (OR 10.46, 95% CI 8.43-12.98). The effect of low fitness on cardiovascular events was no longer significant when including diabetes mellitus, hypercholesterolemia, and obesity as mediators (hazard ratio 0.99, 95% CI 0.82-1.19).

CONCLUSIONS

The association between cardiovascular fitness and adverse cardiovascular outcomes may be modulated through traditional cardiovascular risk factors. These findings need to be further validated in prospective clinical trials.

Fitness level and body composition indices: cross-sectional study among Malaysian adolescent

BACKGROUND

The importance of fitness level on the well-being of children and adolescent has long been recognised. The aim of this study was to investigate the fitness level of school-going Malaysian adolescent, and its association with body composition indices.

METHODS

1071 healthy secondary school students participated in the fitness assessment for the Malaysian Health and Adolescents Longitudinal Research Team (MyHEART) study. Body composition indices such as body mass index for age, waist circumference and waist height ratio were measured. Fitness level was assessed with Modified Harvard Step Test. Physical Fitness Score was calculated using total time of step test exercise and resting heart rates. Fitness levels were divided into 3 categories - unacceptable, marginally acceptable, and acceptable. Partial correlation analysis was used to determine the association between fitness score and body composition, by controlling age, gender, locality, ethnicity, smoking status and sexual maturation. Multiple regression analysis was conducted to determine which body composition was the strongest predictor for fitness.

RESULTS

43.3% of the participants were categorised into the unacceptable fitness group, 47.1% were considered marginally acceptable, and 9.6% were acceptable. There was a significant moderate inverse association (p < 0.001) between body composition with fitness score (r = -0.360, -0.413 and -0.403 for body mass index for age, waist circumference and waist height ratio, respectively). Waist circumference was the strongest and significant predictor for fitness (ß = -0.318, p = 0.002).

CONCLUSION

Only 9.6% of the students were fit. There was also an inverse association between body composition and fitness score among apparently healthy adolescents, with waist circumference indicated as the strongest predictor. The low fitness level among the Malaysian adolescent should necessitate the value of healthy lifestyle starting at a young age.

Prognostic value of demographic factors, pre-test probability scoring, exercise test diagnosis, and inability to exercise in patients with recent onset suspected cardiac chest pain

Aims: To assess the prognostic value of an inconclusive exercise test or inability to exercise in patients with recent onset suspected cardiac chest pain and to determine the independent predictors of events in these patients.

Methods: This was an observational follow-up study of patients presenting to a rapid access chest pain clinic with a history of recent-onset suspected cardiac chest pain as referred by the family practitioner. The main outcome measure was a composite endpoint of death and acute coronary syndrome hospital admission.

Results: The study cohort consisted of 1851 patients in whom a total of 147 events were recorded during a mean follow-up period of 4.1 ± 1.1 years. Those with events were significantly older (65.1 ± 12.5 years versus 56.4 ± 13.2 years, p < 0.001), had higher mean pre-test probability of coronary artery disease (CAD), and had higher prevalence of diabetes (18.4% vs. 13.6%, p < 0.001), hypertension (55.8% vs. 38.7%, p < 0.001), and smoking (36.7% vs. 25.4%, p = 0.03) than those without events. These patients were also more likely to have a positive exercise electrocardiogram (ECG) (15.6% vs. 8.6%, p < 0.001) or not have a diagnostic exercise test because of an inconclusive result or inability to exercise (60.5% vs. 28.6%, p < 0.001). Cox multivariate regression analysis showed that age (hazard ratio, HR 1.03, p < 0.001), pre-test probability of CAD (HR 1.08, p = 0.04), positive exercise ECG (HR 2.94, p < 0.001), and an inconclusive test or inability to exercise (HR 3.45, p < 0.001) were independent predictors of events.

Conclusions: In patients with recent onset suspected cardiac chest pain, not having a diagnostic exercise ECG because of an inconclusive test or inability to exercise is an independent predictor of events and has similar prognostic implications to a positive exercise ECG. In addition, pre-test probability estimation at baseline is a robust indicator of clinical outcome. Future models of care need to incorporate early and increased access to non-exercise cardiac imaging techniques in order to meet the needs of this high-risk subgroup of patients.