ISCHEMIA trial: Invasive treatment only better for angina burden

Invasive therapy does not reduce the risk of major adverse cardiac events compared with optimal medical therapy in patients with stable ischaemic heart disease and moderate-to-severe ischaemia. However, quality-of-life data in patients with angina did indicate significant pain improvement in the invasive arm of the study.

As the largest study of its kind, the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) was one of the most anticipated results at the congress. The investigators randomly assigned 5,179 patients with coronary artery disease at 320 sites in 37 countries to receive 1 of 2 treatment strategies: either ‘invasive’ therapy including early stent implants or bypass surgery, or ‘conservative’ therapy, where patients received only medication (e.g. aspirin, statins) and lifestyle advice.

Prof. Judith Hochman (New York University School of Medicine, USA) presented the results, reporting that over a median follow-up of 3.3 years, there were no differences between the 2 groups in the risk for the primary composite endpoint of time to cardiovascular death, myocardial infarction (MI), or hospitalisation for unstable angina, heart failure, or resuscitated cardiac arrest (HR 0.93; 95% CI 0.80-1.08; P=0.34) [1].

However, the data was slightly more complex, Dr Hochman pointed out, because the curves crossed at 2 years follow-up. At 6 months, the absolute rates favoured the conservative therapy by 1.9%. Yet, at 4 years, the data favoured the patients who had received early angiography prior to percutaneous coronary intervention (PCI) or bypass surgery by 2.2% (13.3% vs 15.5%, respectively). Prof. Hochman underscored that it is unclear what longer follow-up may reveal.

There was no difference between the invasive and conservative strategies in the key secondary endpoints of cardiovascular death or MI (11.7% vs 13.9%; HR 0.90; 95% CI 0.77-1.06; P=0.21) or in all-cause death (6.5% vs 6.4%; HR 1.05; 95% CI 0.83-1.1).

In a parallel quality-of-life study, presented in the same session by Dr John Spertus (Saint Luke's Mid America Heart institute, USA), data showed that revascularisation provided greater relief from angina symptoms than conservative therapy, with 50% of the patients at 1 year reporting no angina symptoms at all, as opposed to just 20% of those in the conservative therapy arm [2].

Although the overall interpretation of this trial was of a neutral outcome, the results suggest that invasive therapy for stable ischaemic heart disease patients needs to be carefully considered in the context of angina burden and background medical therapy, and that optimal coronary revascularisation can be achieved with low procedural complications.

1. Hochman JS, et al. International Study of Comparative Health Effectiveness With Medical and Invasive Approaches: Primary Report of Clinical Outcomes. LBS02, AHA Scientific Sessions 2019, 14-18 November, Philadelphia, USA.
2. Spertus JA, et al. International Study of Comparative Health Effectiveness With Medical and Invasive Approaches: Primary Report of Quality of Life Outcomes. LBS02, AHA Scientific Sessions 2019, 14-18 November, Philadelphia, USA.



Posted on 26 February, 20207 February, 2024