Current guidelines on the management of stable coronary artery disease from the EU and US both recommend β-blockers and calcium channel blockers should be used for the relief of symptoms. [1, 2] However, EU guidelines recommend both β-blockers and calcium channel blockers as first-line treatment whereas the US guidelines only recommend calcium channel blockers when β-blockers ‘are contraindicated or cause unacceptable side effects.’ [2]

Furthermore, there is little data available on the prognostic effect of these drugs. Therefore CLARIFY – the prospective observational Longitudinal Registry oF patients with stable coronary artery disease – aimed to fill this knowledge gap.

This large-scale clinical trial took place across 45 countries and involved 2898 physicians, who each consecutively enrolled 10 to 15 patients. Of these, 22006 received β-blockers and 22004 calcium channel blockers. Inclusion criteria included prior myocardial infarction (MI) >3 months, and/or prior revascularisation >3 months, proven symptomatic MI, and angiographic coronary stenosis >50%, and the primary outcome was all-cause death or MI.

Researchers observed that after 5-years of follow up, there was no significant difference in the rates of all-cause mortality or MI in both the β-blocker and calcium channel blocker groups. Furthermore, there was a significant reduction in the primary end-point in patients who had experienced an MI in the previous year, compared to those whose MI occurred after 1 year – in which case there were no benefits seen with the use of β-blockers. There were no differences in primary end-point in the calcium channel blocker group, regardless of the time since the MI. [3]

The take-home message from the presentation at the ESC 2018 was that “β-blockers should be preferentially used in the first year following MI,” and although both β-blockers and calcium channel blockers should still be used for symptom relief in stable CAD, “mortality benefits should not be assumed.”

References

1. 2013 ESC Guidelines on the Management of Stable Coronary Disease
2. 2012 ACCF/AHA/ACP/AAB/PCNA/SCAI/STS Guideline for the Diagnosis and Management of Patients with Stable Ischaemic Heart Disease
3. https://esc365.escardio.org/Congress/ESC-Congress-2018/Late-Breaking-Pharmacological-Science/181486-clarify-first-line-anti-ischemic-agents-use-and-long-term-clinical-outcomes-in-stable-coronary-artery-disease
4. https://esc365.escardio.org/Congress/ESC-Congress-2018/Late-Breaking-Pharmacological-Science/181080-panel-discussion#video