Atorvastatin therapy improves exercise oxygen uptake kinetics in post-myocardial infarction patients

Identifying the Role of Flow-Mediated Dilatation Assessment in Acute Coronary Syndromes: A Systematic Review

In the context of the global burden of cardiovascular disease, the development of novel, patient-targeted diagnostic and therapeutic strategies is of paramount importance. Acute coronary syndromes (ACS) comprise a subset of cardiovascular disease, with constantly increasing prevalence requiring urgent attention. Flow-mediated dilatation (FMD), a noninvasive method for the evaluation of endothelial function, has been previously implemented in patients with ACS. A systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted in order to identify all relevant studies assessing the implementation of FMD among patients with ACS. Our review reflects an effort to present all available data regarding the role of FMD to date, a valuable noninvasive and easy accessible diagnostic tool, in the prognosis of patients with ACS. FMD evaluation in patients with ACS reveals a decline in values, indicative of the presence of endothelial function among this distinct patient group. FMD has also been used to assess the response to various treatments, as well as to predict major adverse cardiovascular events. Dynamic responses to interventions highlights its potential in the evolving field of interventional cardiology.

Echocardiographic validation of pulmonary hypertension due to heart failure with reduced ejection fraction in mice

Pulmonary hypertension (PH) associated with left heart diseases is the most prevalent cause of PH. The scarcity of studies exploring the pathophysiology and therapies of group II PH resides in the lack of validated small animal models with non-invasive determination of the presence and severity of PH. Heart failure (HF) was induced in mice by coronary artery ligation. Mice developed PH as evidenced by an elevated right ventricular (RV) systolic pressure and RV hypertrophy. Detailed non-invasive echocardiographic analysis on the left and right ventricles showed impaired left ventricular (LV) systolic and diastolic function. In addition, RV hypertrophy was confirmed by echo and accompanied by impaired function as well as increased pulmonary resistance. Correlation analysis validated the use of the LV wall-motion score index (WMSI) at a threshold value of ≥2.0 as a powerful and reliable indicator for the presence of PH and RV dysfunction. Echocardiography is an accurate non-invasive technique to diagnose PH in a HF mouse model. Moreover, an echocardiographic parameter of infarct size and LV function, the LV WMSI, reliably correlates with the presence of PH, RV hypertrophy and RV dysfunction and could be used to improve efficiency and design of pre-clinical studies.

Statins for acute coronary syndrome

BACKGROUND

The early period following the onset of acute coronary syndrome (ACS) represents a critical stage of coronary heart disease, with a high risk of recurrent events and deaths. The short-term effects of early treatment with statins on patient-relevant outcomes in patients suffering from ACS are unclear. This is an update of a review previously published in 2011.

OBJECTIVES

To assess the effects, both harms and benefits, of early administered statins in patients with ACS, in terms of mortality and cardiovascular events.

SEARCH METHODS

We updated the searches of CENTRAL (2013, Issue 3), MEDLINE (Ovid) (1946 to April Week 1 2013), EMBASE (Ovid) (1947 to 2013 Week 14), and CINAHL (EBSCO) (1938 to 2013) on 12 April 2013. We applied no language restrictions. We supplemented the search by contacting experts in the field, by reviewing the reference lists of reviews and editorials on the topic, and by searching trial registries.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing statins with placebo or usual care, with initiation of statin therapy within 14 days following the onset of ACS, follow-up of at least 30 days, and reporting at least one clinical outcome.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted data. We calculated risk ratios (RRs) for all outcomes in the treatment and control groups and pooled data using random-effects models.

MAIN RESULTS

Eighteen studies (14,303 patients) compared early statin treatment versus placebo or no treatment in patients with ACS. The new search did not identify any new studies for inclusion. There were some concerns about risk of bias and imprecision of summary estimates. Based on moderate quality evidence, early statin therapy did not decrease the combined primary outcome of death, non-fatal myocardial infarction, and stroke at one month (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.80 to 1.08) or four months (RR 0.93, 95% CI 0.81 to 1.06) of follow-up when compared to placebo or no treatment. There were no statistically significant risk reductions from statins for total death, total myocardial infarction, total stroke, cardiovascular death, revascularization procedures, and acute heart failure at one month or at four months, although there were favorable trends related to statin use for each of these endpoints. Moderate quality evidence suggests that the incidence of unstable angina was significantly reduced at four months following ACS (RR 0.76, 95% CI 0.59 to 0.96). There were nine individuals with myopathy (elevated creatinine kinase levels more than 10 times the upper limit of normal) in statin-treated patients (0.13%) versus one (0.015%) in the control groups. Serious muscle toxicity was mostly limited to patients treated with simvastatin 80 mg.

AUTHORS' CONCLUSIONS

Based on moderate quality evidence, due to concerns about risk of bias and imprecision, initiation of statin therapy within 14 days following ACS does not reduce death, myocardial infarction, or stroke up to four months, but reduces the occurrence of unstable angina at four months following ACS. Serious side effects were rare.

Endurance capacity is not correlated with endothelial function in male university students

Background

Endurance capacity, assessed by 1000-meter (1000 m) run of male university students, is an indicator of cardiovascular fitness in Chinese students physical fitness surveillance. Although cardiovascular fitness is related to endothelial function closely in patients with cardiovascular diseases, it remains unclear whether endurance capacity correlates with endothelial function, especially with circulating endothelial microparticles (EMPs), a new sensitive marker of endothelial dysfunction in young students. The present study aimed to investigate the relationship between endurance capacity and endothelial function in male university students.

Methods

Forty-seven healthy male university students (mean age, 20.1±0.6 years; mean height, 172.4±6.3 cm; and mean weight, 60.0±8.2 kg) were recruited in this study. The measurement procedure of 1000 m run time was followed to Chinese national students Constitutional Health Criterion. Endothelium function was assessed by flow-mediated vasodilation (FMD) in the brachial artery measured by ultrasonic imaging, and the level of circulating EMPs was measured by flow cytometry. Cardiovascular fitness indicator - maximal oxygen uptake (VO2 max) - was also measured on a cycle ergometer using a portable gas analyzer.

Results

1000 m run time was correlated with VO₂max (r = −0.399, p<0.05). However, there were no correlations between VO₂max and FMD or levels of circulating CD31+/CD42- microparticles. Similarly, no correlations were found between 1000 m run time and FMD, and levels of circulating CD31+/CD42- microparticles in these male university students (p>0.05).

Conclusion

The correlations between endurance capacity or cardiovascular fitness and endothelial function were not found in healthy Chinese male university students. These results suggest that endurance capacity may not reflect endothelial function in healthy young adults with well preserved FMD and low level of circulating CD31+/CD42-EMPs.

Relationships between maximal oxygen uptake and endothelial function in healthy male adults: a preliminary study

Aerobic capacity, as indicated by maximal oxygen uptake (VO2 max) has an important role in contrasting the traditional cardiovascular risk factors and preventing cardiovascular morbidity and mortality. It is known that endothelial function, measured as flow-mediated dilation (FMD) of the brachial artery, is strictly linked to atherogenesis and cardiovascular risk. However, the relationship between VO2 max and FMD has not been fully investigated especially in healthy non-obese subjects. This preliminary study cross-sectionally investigated the relationship between VO2 max and FMD in 22 non-obese, healthy sedentary male subjects. Dividing the cohort in two subgroups of 11 subjects each according to the median value of VO2 max, the FMD was significantly lower in the subgroup with lower VO2 max (mean ± sem: 7.1 ± 0.7 vs. 9.5 ± 0.8 %; P = 0.035). Absolute VO2 max (mL min(-1)) was significantly and independently correlated with body fat mass (r = -0.50; P = 0.018) and with FMD (r = 0.44; P = 0.039). This preliminary study suggests that maximal oxygen uptake is independently correlated with endothelial function in healthy non-obese adults. These results are also in agreement with the possibility that improving maximal oxygen uptake may have a favorable effect on endothelial function and vice versa.

Statins for acute coronary syndrome

BACKGROUND

The early period following the onset of acute coronary syndromes (ACS) represents a critical stage of coronary heart disease with a high risk for recurrent events and deaths. The short-term effects of early treatment with statins in patients suffering from ACS on patient-relevant outcomes are unclear.

OBJECTIVES

To assess the benefits and harms of early administered statins in patients with ACS from randomized controlled trials (RCTs).

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE, and CINAHL (to 1 February 2010). No language restrictions were applied. We supplemented the search by contacting experts in the field, by reviewing reference lists of reviews and editorials on the topic, and by searching trial registries.

SELECTION CRITERIA

RCTs comparing statins with placebo or usual care, initiation of statin therapy within 14 days following the onset of ACS, and follow-up of at least 30 days reporting at least one clinical outcome.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. We pooled treatment effects and calculated risk ratios (RRs) for all outcomes in the treatment and control groups using a random effects model.

MAIN RESULTS

Eighteen studies (14,303 patients) compared early statin treatment versus placebo or usual care in patients with ACS. Compared to placebo or usual care, early statin therapy did not decrease the combined primary outcome of death, non-fatal myocardial infarction (MI), and stroke at one month (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.80 to 1.08) and four months (RR 0.93, 95% CI 0.81 to 1.06) of follow-up. There were no statistically significant risk reductions from statins for total death, total MI, total stroke, cardiovascular death, revascularization procedures, and acute heart failure at one month and at four months, although there were favorable trends related to statin use for each of these endpoints. The incidence of episodes of unstable angina was significantly reduced at four months following ACS (RR 0.76, 95% CI 0.59 to 0.96). There were nine individuals with myopathy (elevated creatinine kinase levels > 10 times the upper limit of normal) in statin treated patients (0.13%) versus one (0.015%) in the control groups. Serious muscle toxicity was mostly limited to patients treated with simvastatin 80 mg.

AUTHORS' CONCLUSIONS

Based on available evidence, initiation of statin therapy within 14 days following ACS does not reduce death, myocardial infarction, or stroke up to four months, but reduces the occurrence of unstable angina at four months following ACS.

A randomized clinical trial to assess the effect of statins on skeletal muscle function and performance: rationale and study design

Hydroxymethylglutaryl-coenzyme A reductase inhibitors or statins are the most effective medications for reducing elevated concentrations of low-density lipoprotein cholesterol (LDL-C). Statins reduce cardiac events in patients with coronary artery disease and previously healthy persons. Current recommendations for LDL-C treatment goals indicate that more patients will be treated with higher doses of these medications. Statins have been extremely well-tolerated in controlled clinical trials but are increasingly recognized to produce skeletal muscle myalgia, cramps, and weakness. The reported frequency of such mild symptoms is not clear, and muscle performance has not been examined with these medications. Accordingly, the present investigation, the Effect of Statins on Skeletal Muscle Function and Performance (STOMP) study, will recruit approximately 440 healthy persons. Participants will be randomly assigned to treatment with atorvastatin 80 mg/d or placebo. Handgrip, elbow and knee isometric and isokinetic strength, knee extensor endurance, and maximal aerobic exercise performance will be determined at baseline. Participants will undergo repeat testing after 6 months of treatment or after meeting the study definition of statin myalgia. This study will determine the effect of statins on skeletal muscle strength, endurance, and aerobic exercise performance and may ultimately help clinicians better evaluate statin-related muscle and exercise complaints.

Endothelium-dependent vasodilation is associated with exercise capacity in smokers and non-smokers

Smoking is an established cardiovascular risk factor that impairs endothelial function and reduces exercise capacity. Peripheral vascular endothelial function correlates with exercise capacity, but whether this association prevails in smokers is unknown. The purpose of this investigation was to examine the association between endothelial function and exercise capacity in chronic smokers and non-smoking controls. Brachial artery flow-mediated dilation (FMD, endothelium-dependent) following 5 minutes of upper arm occlusion was compared in 26 smokers (age 58 +/- 2 years; 15 female; BMI (body mass index) = 28 +/- 1) and 39 non-smokers (age 58 +/- 2 years; 24 female; BMI = 28 +/- 1) using ultrasound. Exercise treadmill time (ETT) was recorded from a standard Bruce protocol during symptom limited stress testing. There was found to be a significant positive association between FMD and ETT in smokers (r = 0.60, p < 0.05) and non-smokers (r = 0.28, p < 0.05). FMD was significantly lower in smokers versus non-smokers (8.9 +/- 0.9 vs 12.6 +/- 0.7%, p < 0.05). ETT was significantly lower in smokers (425 +/- 35 seconds) versus non-smokers (522 +/- 25 seconds, p < 0.05). After adjusting for FMD, there were no longer group differences in ETT. When patients were matched according to FMD, there were no differences in ETT between smokers and non-smokers. In conclusion, peripheral endothelial dysfunction is a correlate of low exercise capacity in smokers and non-smokers alike. Future research is needed to examine if improving endothelial function will lead to concomitant increases in exercise capacity in chronic smokers.