Comparison of late mortality in hospitalized patients >70 years of age with systolic heart failure receiving beta blockers versus those not receiving beta blockers

Association is not causation: treatment effects cannot be estimated from observational data in heart failure

Aims

Treatment 'effects' are often inferred from non-randomized and observational studies. These studies have inherent biases and limitations, which may make therapeutic inferences based on their results unreliable. We compared the conflicting findings of these studies to those of prospective randomized controlled trials (RCTs) in relation to pharmacological treatments for heart failure (HF).

Methods and results

We searched Medline and Embase to identify studies of the association between non-randomized drug therapy and all-cause mortality in patients with HF until 31 December 2017. The treatments of interest were: angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, mineralocorticoid receptor antagonists (MRAs), statins, and digoxin. We compared the findings of these observational studies with those of relevant RCTs. We identified 92 publications, reporting 94 non-randomized studies, describing 158 estimates of the 'effect' of the six treatments of interest on all-cause mortality, i.e. some studies examined more than one treatment and/or HF phenotype. These six treatments had been tested in 25 RCTs. For example, two pivotal RCTs showed that MRAs reduced mortality in patients with HF with reduced ejection fraction. However, only one of 12 non-randomized studies found that MRAs were of benefit, with 10 finding a neutral effect, and one a harmful effect.

Conclusion

This comprehensive comparison of studies of non-randomized data with the findings of RCTs in HF shows that it is not possible to make reliable therapeutic inferences from observational associations. While trials undoubtedly leave gaps in evidence and enrol selected participants, they clearly remain the best guide to the treatment of patients.

The use of medications in the secondary prevention of coronary artery disease in the Asian region

BACKGROUND

Cardiovascular diseases, to which coronary artery disease (CAD) is a significant contributor, are a leading cause of long-term morbidity and mortality worldwide. In the years ahead, it is estimated that approximately half of the world's cardiovascular burden will occur in the Asian region. Currently there is a large gap in secondary prevention, with unrealized health gains resulting from underuse of evidence-based medications, including beta-blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), aspirin and other antiplatelet agents, and lipid-lowering drugs. Despite the almost universal recommendation for these drugs in unstable CAD, their under-prescription is well documented for patients with acute heart failure, non-obstructive CAD, and for secondary prevention of CAD.

OBJECTIVE

This article reviews the burden of CAD in Asian countries together with guidelines supporting evidence-based medication use from a secondary prevention perspective.

METHODS

The MEDLINE database was searched from 2000 to 2013, inclusive, for country-specific data related to CAD and supplemented with unpublished registry data.

RESULTS

In the post-discharge setting following hospital admission for acute coronary syndromes, medication prescription rates were low. Beta-blocker prescription rates ranged from 49% in China to 99% in Singapore, ACE-inhibitor/ARB prescription rates ranged from 28% in China to 96% in Singapore, and lipid-lowering therapy rates ranged from 47% in China to 97% in Singapore. Aspirin/antiplatelet drug prescription rates ranged from 86% in Indonesia to 99.5% in Singapore. Recommendations are provided to improve patient outcomes and reduce the disease burden in Asia.

CONCLUSIONS

Despite recommendations issued in international and national guidelines, use of CAD medications in Asia remains suboptimal. In the absence of clear contraindications, all patients with unstable CAD should receive these agents as secondary prevention. This averts the need to target drug use according to risk, with high-risk features paradoxically associated with under-prescribing of such drugs.

Beneficial association of β-blocker therapy on recovery from severe acute heart failure treatment: data from the Survival of Patients With Acute Heart Failure in Need of Intravenous Inotropic Support trial

OBJECTIVES

Beta-blocker therapy is recommended for most patients with chronic heart failure, although such therapy may be discontinued or reduced during hospitalizations. The aim is to determine whether β-blocker use at study entry and/or at discharge has an impact on 31- and 180-day survival.

DESIGN

Survival of Patients With Acute Heart Failure in Need of Intravenous Inotropic Support study was designed as a randomized, double-blind, active-controlled, multi-center study.

SETTING

Multinational.

PATIENTS

A total of 1,327 critically ill patients hospitalized with low-output heart failure in need of inotropic therapy.

INTERVENTION

Levosimendan versus dobutamine.

MEASUREMENTS

All-cause mortality at 31 and 180 days in patients who survived initial hospitalization with/without β-blocker use at entry and/or at discharge.

RESULTS

Patients on β-blockers at entry and at discharge had significantly lower 31-day (p < .0001) and 180-day (p < .0001) mortality compared to patients without β-blockers use at both time points. The association was robust when adjusted for age and co-morbidities (p = .006 at 31 days; p = .003 at 180 days).

CONCLUSIONS

Those results strongly suggest, in severe acutely decompensated heart failure patients, admitted on β-blockers, to continue on them at discharge.