Background Beta-blockers Research Articles

Efficacy of trimetazidine on functional capacity in symptomatic patients with stable exertional angina — The VASCO-angina study

Trimetazidine (TMZ) is a metabolic agent of proven efficacy in improving myocardial ischemia and angina. VASCO, a randomised double-blinded, placebo-controlled trial, assessed anti-anginal efficacy and safety of standard and high dose of modified-release TMZ (70 mg/d and 140 mg/d) in symptomatic and asymptomatic patients with chronic ischemic heart disease receiving background atenolol 50mg/d on exercise test parameters. The VASCO-angina study assessed the efficacy of the two doses of TMZ on total exercise duration (TED) and time to 1-mm ST segment depression (T1), in symptomatic patients with chronic stable angina receiving background atenolol treatment. In the all cohort of chronic stable angina patients TMZ significantly improved TED compared to baseline and to placebo. Both doses of TMZ significantly increased TED (p=0.0044 and p=0.0338 for TMZ 140 mg/d and TMZ 70 mg/d, respectively). A greater TED improvement was observed in TMZ 140 mg/d than in TMZ 70 mg/d, although the difference was not significant. Amongst patients with limiting angina during exercise test, both doses of TMZ significantly improved both T1 and TED. No difference in serious adverse events was noted between TMZ and placebo. The VASCO-angina gives evidence for the efficacy and tolerability of standard and high dose of TMZ in improving effort-induced myocardial ischemia and functional capacity in patients with chronic stable angina receiving background beta-blockers.

Abstract 75: Practice-level Variation in use of Recommended Medications among Outpatients with Heart Failure: Insights from the NCDR PINNACLE Program

Background: Beta-blockers (BB) and angiotensin converting enzyme inhibitors (ACE)/angiotensin receptor blockers (ARB) are guideline recommended therapies for ambulatory heart failure patients with reduced left ventricular ejection fraction (HFREF). Real-world use of these therapies is suboptimal. Whether variations in treatment are dominated by practice-level or patient-level factors is unknown. Methods: Practices participating in the NCDR PINNACLE program, a national office-based cardiac quality improvement registry, between July 2008 and December 2010 were evaluated. Rates of treatment with BB and ACE/ARB were evaluated in patients with HFREF (EF ≤40%) and no documented contraindication. Multivariable hierarchical relative risk regression models, including demographics, insurance status, comorbidities and a random effect for practice were used to determine 1) patient-level and 2) practice-level variation in treatment rates. To quantify practice-level variation, the median rate ratio (MRR) was calculated, which estimates the typical rate ratio between two randomly selected practices for patients with identical covariates. In general, MRRs ≥ 1.2 indicate significant variation by practice. The MRR is always >1.0 but can be compared in magnitude to patient-level risks. Results: We studied 12384 patients in 45 practices. The mean practice rate for BB treatment was 87% (IQR 83%-95%; range: 43%-100%), and the mean practice rate of ACE/ARB treatment was 90% (IQR 75%-88%; range: 18%-100%). The MRR was 1.09 for BB and 1.16 for ACE/ARB therapy. For both BB and ACE/ARB, the adjusted MRR for site level variation was larger than the rate ratio for other patient factors. (Table) Conclusions: Although rates of BB and ACE/ARB treatment among outpatients with HFREF are high, clinically meaningful variation by practice is present and explains a larger amount of the observed variance than any patient characteristic. This suggests that addressing practice-level factors represents an important opportunity to improve the use of evidence-based HF therapy.

Beta-blocker prevents sudden cardiac death in patients with hemodialysis

BackgroundBeta blockers were shown to prevent SCD in cardiomyopathy or coronary artery disease patients. Dialysis patients show elevated mortality rates, predominantly due to cardiovascular disease. SCD is now one of the leading causes of death in this population. However, the prevention of SCD remains to be elucidated. MethodsWe conducted a retrospective study of 316 patients from a database of all patients undergoing maintenance hemodialysis and followed up for 4.9years. All patients were followed-up until death. Cox regression analysis was used to adjust the hazard ratio for beta blocker use with time until death. ResultsSCD occurred during the study period in 3 (3.8%) patients in the beta blocker group and in 27 (11.4%) patients in the non-beta blocker group (P=0.047). Death from all causes occurred in 15 (18.8%) patients in the beta blocker group and in 97 (41.3%) patients in the non-beta blocker group (P<0.001). Kaplan–Meier curve showed that the rates of both SCD and all-cause death were lower in the beta blocker group (log-rank test, P=0.028 and P<0.001, respectively). In the Cox regression model, beta blocker use was significantly associated with lower adjusted risk of SCD (multivariate adjusted hazard ratio, 0.201; 95% confidence interval, 0.058–0.693; P=0.011). ConclusionIn hemodialysis patients, beta blocker use was associated with lower risks of SCD and death from all causes. Thus, beta blocker use in this high-risk population may substantially improve outcome.

Abstract 2497: Does Magnitude of Heart Reduction Influence Clinical Outcomes in Patients with Systolic Chronic Heart Failure Receiving Beta-Blockers? A Regression Analysis of Randomised Controlled Trials

Background: Beta-blockers (BBs) improve cardiac function and prolong survival in patients with systolic chronic heart failure (CHF). However, the exact mechanisms underlying these benefits are uncertain. Specifically, it is unclear whether a close relationship exists between heart rate (HR) reduction and clinical outcomes with these agents. We therefore tested this hypothesis within randomised controlled trials (RCTs) of BBs in systolic CHF. Methods: Left ventricular ejection fraction (LVEF) and HR values at baseline and end-study were obtained from available BB RCTs. The relationship between change in HR and all-cause mortality as well as LVEF was determined using regression analysis (SPSS). Results: Thirty-six trials, which included 23,122 patients with mean follow-up of 10.5 months, were analysed for all-cause mortality, LVEF and HR. There was a close relationship between all-cause annualised mortality rate and change in HR (adjusted R2=0.51, p=0.004). A strong correlation between change in HR and change in LVEF (adjusted R2=0.47, p=0.000, Figure ) was also observed. When only trials with &gt;100 patients were included, an even tighter relationship was seen (adjusted R2=0.60, p=0.0004). Conclusions: These analyses indicate that a major contributor to the clinical benefits of BB therapy in systolic CHF is the HR-lowering effect of these agents. Therefore, magnitude of HR reduction may be more important than achievement of target dose in BB treatment of systolic CHF.

Metoprolol Reverses Left Ventricular Remodeling in Patients with Asymptomatic Systolic Dysfunction: The REVERT Trial

Background: Beta-blockers (BB) slow pathologic remodeling and improve outcomes in patients with symptoms due to systolic left ventricular dysfunction (LVD). It is not known whether BB exert similar effects in asymptomatic patients with systolic LVD. The REVERT (Reversal of Ventricular Remodeling with Toprol-XL) Trial tested the hypothesis that BB slow or reverse remodeling in patients with asymptomatic LVD. Stable NYHA I patients with LVEF <0.40 and LV end-diastolic volume index (LVEDVI) >75 ml/m2 were randomized to placebo vs.