Meta-analysis supports routine invasive strategy in NSTE ACS
MedWire News: A routine invasive strategy reduces long-term rates of cardiovascular death or myocardial infarction (MI) in patients with non-ST-segment elevation acute coronary syndrome (NSTE ACS), indicate meta-analysis findings.
The results, published in the Journal of the American College of Cardiology, also showed that the advantage of a routine over a selective invasive strategy was greatest in high-risk patients.
For the study, researchers analyzed individual patient data from all randomized studies with 5-year outcomes to date, namely FRISC-II (Fragmin and Fast Revascularization during Instability in Coronary Artery Disease), ICTUS (Invasive Versus Conservative Treatment in Unstable Coronary Syndromes), and RITA-3 (Randomized Trial of a Conservative Treatment Strategy Versus an Interventional Treatment Strategy in Patients with Unstable Angina).
Over 5 years, 14.7% of patients randomly assigned to a routine invasive strategy died of cardiovascular causes or suffered MI compared with 17.9% of those assigned to a selective invasive strategy, giving a hazard ratio of 0.81 (p=0.002).
This was mainly driven by the reduction in MI, which occurred in 10.0% of routine-invasive and 12.9% of selective-invasive groups, respectively (HR=0.77, p=0.001).
However, there were also consistent trends in cardiovascular (6.8% vs 8.1%, HR=0.83; p=0.068) and total mortality (10.6% vs 11.7%, HR=0.90; p=0.19), the authors point out.
Using a multivariable risk prediction score to categorize patients into three risk levels, patients in the high-risk group had an absolute reduction of 11.1% in cardiovascular death or MI (HR=0.68) with a routine versus selective invasive strategy, while those in the low- and intermediate-risk groups had more modest 2.0% and 3.8% absolute reductions, respectively.
“However, although the treatment effect was less pronounced in the majority of patients at lower risk, the absolute number of events prevented was greater (20 events in the high-risk group, 31 events in the intermediate-risk, and 35 events in the low-risk patients),” note the authors.
They add that health economic considerations surrounding their finding of a smaller number needed to treat per patient saved in the higher risk group against the greater number of patients saved by also treating lower risk populations “need greater attention when interpreting how trial findings are best applied.”
Keith Fox (University of Edinburgh, UK) and colleagues conclude: “It is remarkable that despite the systemic and diffuse nature of atheromatous disease, and disease progression elsewhere in the vascular system, an early routine revascularization strategy has a treatment benefit that is clearly evident after 5 years.”
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By Caroline Price