Decreased Heart Rate Recovery in Patients With Heart Failure Effect of Fluvastatin Therapy

Type 2 Diabetes Complicated With Heart Failure: Research on Therapeutic Mechanism and Potential Drug Development Based on Insulin Signaling Pathway

Type 2 diabetes mellitus (T2DM) and heart failure (HF) are diseases characterized by high morbidity and mortality. They often occur simultaneously and increase the risk of each other. T2DM complicated with HF, as one of the most dangerous disease combinations in modern medicine, is more common in middle-aged and elderly people, making the treatment more difficult. At present, the combination of blood glucose control and anti-heart failure is a common therapy for patients with T2DM complicated with HF, but their effect is not ideal, and many hypoglycemic drugs have the risk of heart failure. Abnormal insulin signaling pathway, as a common pathogenic mechanism in T2DM and HF, could lead to pathological features such as insulin resistance (IR), myocardial energy metabolism disorders, and vascular endothelial disorders. The therapy based on the insulin signaling pathway may become a specific therapeutic target for T2DM patients with HF. Here, we reviewed the mechanisms and potential drugs of insulin signaling pathway in the treatment of T2DM complicated with HF, with a view to opening up a new perspective for the treatment of T2DM patients with HF and the research and development of new drugs.

Statin therapy in heart failure: for good, for bad, or indifferent?

Statins are effective in the prevention of coronary events and the treatment of acute coronary syndromes. However, their efficacy and safety in patients with heart failure (HF) is still a matter of debate. On the basis of literature evidence from subgroup analysis, retrospective, prospective cohort studies, and randomized controlled trials, in this review we try to answer the following question: Is statin therapy in HF patients for good, for bad, or indifferent? Some studies showed a negative impact of low cholesterol levels in patients with severe HF (endotoxin-lipoprotein hypothesis and coenzyme Q10 hypothesis). On the other hand, a large amount of literature demonstrates that in patients with HF, statins have a positive impact on survival and other outcomes, regardless of whether the HF was of ischemic or nonischemic origin, which is related to a combination of mechanisms (pleiotropic effects and cholesterol reduction). Much of this evidence, however, comes from observational and retrospective studies and subgroup analyses of statin use in patients with HF. Randomized clinical trials examining the efficacy of statins in HF (GISSI-HF and CORONA) did not show a benefit in mortality for patients with HF randomized to receive statins. Nevertheless, a meta-analysis found that statin therapy does not decrease all-cause or cardiovascular mortality but significantly decreases the rate of hospitalization for worsening HF and increased left ventricular ejection fraction compared with placebo.

Statins and the autonomic nervous system

Statins (3-hydroxy-3-methylglutaryl-CoA reductase inhibitors) reduce plasma cholesterol and improve endothelium-dependent vasodilation, inflammation and oxidative stress. A ‘pleiotropic’ property of statins receiving less attention is their effect on the autonomic nervous system. Increased central sympathetic outflow and diminished cardiac vagal tone are disturbances characteristic of a range of cardiovascular conditions for which statins are now prescribed routinely to reduce cardiovascular events: following myocardial infarction, and in hypertension, chronic kidney disease, heart failure and diabetes. The purpose of the present review is to synthesize contemporary evidence that statins can improve autonomic circulatory regulation. In experimental preparations, high-dose lipophilic statins have been shown to reduce adrenergic outflow by attenuating oxidative stress in central brain regions involved in sympathetic and parasympathetic discharge induction and modulation. In patients with hypertension, chronic kidney disease and heart failure, lipophilic statins, such as simvastatin or atorvastatin, have been shown to reduce MNSA (muscle sympathetic nerve activity) by 12–30%. Reports concerning the effect of statin therapy on HRV (heart rate variability) are less consistent. Because of their implications for BP (blood pressure) control, insulin sensitivity, arrhythmogenesis and sudden cardiac death, these autonomic nervous system actions should be considered additional mechanisms by which statins lower cardiovascular risk.

Potential autonomic nervous system effects of statins in heart failure

Sympathetic nervous system activation in heart failure, as indexed by elevated norepinephrine levels, higher muscle sympathetic nerve activity and reduced heart rate variability, is associated with pathologic ventricular remodeling, increased arrhythmias, sudden death, and increased mortality. Recent evidence suggests that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) therapy may provide survival benefit in heart failure of both ischemic and nonischemic etiology, and one potential mechanism of benefit of statins in heart failure is modulation of the autonomic nervous system. Animal models of heart failure demonstrate reduced sympathetic activation and improved sympathovagal balance with statin therapy. Initial human studies have reported mixed results. Ongoing translational studies and outcomes trials will help delineate the potentially beneficial effects of statins on the autonomic nervous system in heart failure.

Autonomic nervous system activity and decline as prognostic indicators of cardiovascular and cerebrovascular events: the 'PROOF' Study. Study design and population sample. Associations with sleep-related breathing disorders: the 'SYNAPSE' Study

BACKGROUND

Transversal studies have underlined the association between the decline in autonomic nervous system (ANS) activity and all-cause mortality. However, the predictive value of ANS has never been prospectively assessed in a general population-based cohort.

METHOD

The PROOF (PROgnostic indicator OF cardiovascular and cerebrovascular events) cohort study was designed to prospectively assess the predictive value of ANS activity level in the general population, with regard to cardiovascular and cerebrovascular events, and death. This predictive power will be compared with the usual and newly discovered risk factors for the purposes of developing a risk model.

RESULTS

A prospective cohort of elderly subjects aged 65 years upon study entry were recruited from the electoral list of the city of Saint-Etienne, France. Three initial 2-year examination programs were scheduled for 7 years (2001-2007), followed by late events monitoring. At each examination, ANS activity was assessed along with clinical and biological cardiovascular risk factors, brain MRI, neuropsychological evaluation, physical activity profile, and sleep-related breathing disorders. The main study outcomes are stroke, myocardial infarction and death from any cause. A cohort consisting of 1,011 subjects aged 65.6 (0.8) years was constituted.

CONCLUSION

Despite other selective characteristics, the associations between ANS activity and events will be applicable to other populations.

Should a statin be prescribed to every patient with heart failure?

Chronic heart failure (HF) represents an emerging epidemic since its prevalence is continuously increasing despite advances in treatment. Many recent clinical studies have clearly demonstrated that statin therapy is associated with improved outcomes in HF irrespective of aetiology (ischaemic or not) or baseline cholesterol levels. Indeed, most of the conducted large statin trials and trials in HF have demonstrated a positive effect of statins in HF patients. Furthermore, the use of statins in HF seems to be safe as none of the recent trials has resulted in worse outcomes for HF patients treated with statins. Potential mechanisms through which statins could benefit the failing myocardium include non-sterol effects of statins, as well as effects on nitric oxide and endothelial function, inflammation and adhesion molecules, apoptosis and myocardial remodelling and neurohormonal activation. This review discusses the pathophysiological basis of statin effects on HF and focuses on clinical data for the benefit from statin use in this setting. Until today there are no official recommendations in both the American and the European guidelines regarding the use of statins in HF patients, as the available data come from small observational or larger but retrospective, non-randomised studies. Therefore, HF patients should be treated according to current lipid guidelines. Large randomised clinical trials are underway and will further delineate the role of statin therapy in HF patients. Until more data are available, we could not recommend statin use to every patient with HF irrespective of HF aetiology and baseline cholesterol levels.

Drug Insight: statins for nonischemic heart failure—evidence and potential mechanisms

While 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, also known as statins, have a well-established in role in the treatment and prevention of ischemic coronary artery disease, their utility in the setting of heart failure (HF) and left ventricular (LV) dysfunction remains under investigation. Although a reduction in LDL is the major effect of statin therapy, pleiotropic effects have been demonstrated, which could be responsible for the reduction in morbidity and mortality seen with statin use in patients with HF. Patients with both ischemic and nonischemic HF have been shown to have improved survival with statin therapy, and patients receiving statin therapy are less likely to develop HF. Studies have demonstrated that statins reduce inflammation, improve endothelial function, decrease thrombogenicity, and improve LV and autonomic function. In this Review, we present the literature supporting the pleiotropic effects of statin therapy in patients with HF or LV dysfunction, and discuss the mechanisms by which statins might elicit the improvements in morbidity and mortality seen in these patients.

Association of metabolic syndrome with impaired heart rate recovery and low exercise capacity in young male adults

BACKGROUND

Impaired heart rate recovery (HRR) is a powerful predictor of overall mortality.

AIM

The aim of the present study is to assess HRR in young adult males with metabolic syndrome and to compare HRR with those of obese patients who do not meet the criteria for metabolic syndrome.

PATIENTS AND METHODS

Sixty-four newly diagnosed and untreated young male subjects (24 +/- 3 years) with metabolic syndrome and 40 age and sex matched obese or overweight control subjects (ages 23 +/- 3 years) were enrolled in the study. All subjects performed a symptom limited exercise stress test under the standard Bruce protocol. HRR was calculated in the first, second and third minutes of the recovery period. The relationship between metabolic syndrome and HRR was evaluated via logistic regression analysis and a P-value < 0.05 was accepted as significant.

RESULTS

Body mass index (BMI) was 38.6 +/- 3.68 and 32.22 +/- 2.99 kg/m(2) in the study and control groups, respectively (P < 0.001). Total cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, systolic and diastolic blood pressures and fasting glucose levels were significantly higher in the study group. HRR in the first minute of the recovery period and mean exercise capacity were significantly lower in the study-group patients with metabolic syndrome (P < 0.001 and P = 0.012, respectively).

CONCLUSION

We determined that HRR was impaired in young adult males with metabolic syndrome compared with obese ones who do not meet the criteria of metabolic syndrome. This decreased HRR may have prognostic value in the prediction of vascular events in patients with metabolic syndrome.