Study supports conservative management for most stable angina cases

By Nicole MacKee
Conservative management is effective for most cases of stable angina, say researchers who have found that the condition usually resolves without elevated risk of cardiovascular events or the need for revascularisation.

The CLARIFY (Prospective Observational Longitudinal Registry of Patients with Stable Coronary Artery Disease) study, which included more than 32,700 participants from 45 countries, found that among the 7212 (22%) patients with angina at baseline, angina resolved without revascularisation in almost 40% of patients after one year.

Among those without angina at baseline, up to 4.8% of people developed angina per year.

At five years, angina had regressed in 7773 patients, mostly without changes to medical treatment or revascularisation (in 84.4% of patients). Increases or changes to antianginal medications were required to control angina in 11% of patients, while 4.5% of patients underwent revascularisation.

The researchers reported that patients whose angina had resolved within a year with conservative management only were not at higher risk of cardiovascular death or myocardial infarction than those who had never experienced angina (adjusted hazard ratio, 0.97).

‘The low rate of cardiovascular events and favourable evolution of angina in most patients allows for a watchful waiting strategy before failure of medical management is declared,’ the researchers said.

Professor John Horowitz, Emeritus Professor of Cardiology at the University of Adelaide, said he was ‘somewhat surprised’ by the study’s conclusions, noting that the findings may be an example of the regression to the mean phenomenon.

‘These studies usually include a high proportion of patients with only occasional symptoms who may be most likely to improve with passage of time, due to cardiac “repair” mechanisms such as cholesterol reduction or development of collateral vessels,’ Professor Horowitz said.

‘Most previous studies on stable angina suggest that it persists, but rarely kills people, and that it imposes a considerable burden on quality of life.’

He noted that the importance of the Circulation findings was ‘greatly increased’ by two previous pivotal studies – the 2018 ORBITA (Objective Randomised Blinded Investigation with optimal medical Therapy) and the 2019 ISCHEMIA (International Study of Comparative health Effectiveness with Medical and Invasive Approaches) studies – that questioned the role of coronary revascularisation in managing angina.

‘While both of these studies suggest that more patients with angina should be managed with drugs alone, I would be very cautious about assuming that a “wait and it will go away” strategy is the right conclusion; angina can be completely debilitating and very frightening,’ Professor Horowitz said.

‘We still need better antianginal drugs for patients with severe angina. However, as this article implies, perhaps we can be a little more relaxed about mild angina.’
Circulation 2021; 144: 512-523.