The ICTUS (Invasive Versus Conservative Treatment in Unstable Coronary Syndromes) trial compared early invasive strategy with a selective invasive strategy in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS), with elevated markers such as cardiac troponin T. The absence of long-term benefit of an early invasive strategy at 1 and 5 years had already been reported. The aim of the current study was to determine whether any of these strategies offered any clinical benefit after a 10-year follow-up.

The ICTUS trial was a multicenter, randomized, controlled clinical trial that included 1200 patients with NSTE-ACS and positive cardiac troponin T. Patients were enrolled from 2001 to 2003. The study included a 10-year follow-up of death, acute myocardial infarction, and revascularization. The primary endpoint was a composite of death and spontaneous infarction, while the secondary endpoint was a composite of death, infarction (spontaneous or procedure-related), and revascularization.

At 10 years, there were no statistical differences between the two groups (33.8% vs. 29.0%; hazard ratio [HR]: 1.12; 95% confidence interval [CI]: 0.97 to 1.46; p = 0.11). Repeat revascularization occurred in 82.6% of the early invasive group, and in 60.5% of patients in the selective invasive group. There were no other differences, except for the secondary endpoint composite of death and infarction, the rate of which was higher in the early invasive group (37.6% vs. 30.5%; HR: 1.30; 95% CI: 1.07 to 1.58; p = 0.009), but this difference was basically driven by a higher rate of procedure-related infarction (6.5% vs. 2.4%; HR: 2.82; 95% CI: 1.53 to 5.20; p = 0,001).

Conclusion

In patients with non-ST-segment elevation acute coronary syndrome with positive troponin T levels, an early invasive strategy did not reduce the 10-year composite endpoint of death and spontaneous infarction.

Editorial

These findings are against the long-term results of other two studies comparing invasive vs. conservative strategy, the FRISC-II and RITA-3 trials, which reported benefit from more aggressive management of this patient group.

There may be many reasons for the observed differences. An important detail is that, compared with the other studies, the ICTUS trial was the most contemporary and included higher rates of use of stents, glycoprotein IIb/IIIa inhibitors during angioplasty, long-term dual antiplatelet therapy, and high-dose statin treatment.

However, the most important difference among the 3 trials may be the timing for the procedure. In the ICTUS trial, in the early invasive strategy, 97% of patients underwent coronary angiography within 48 h, while the protocol for the RITA-3 and FRISC-II trials allowed a delay of up to 7 days for the index event.

The rate of intervention in the control group is just as important. In the ICTUS study, 53% of patients in the selective invasive group received coronary angiography, while this rate was only 7% and 16% in the FRISC-II and RITA-3 trials, respectively.

All these studies were classified as “invasive vs. conservative treatment” in NSTE-ACS, but their protocols are clearly different and reading the fine print is important in order to understand outcome differences.

Original title: Early Invasive Versus Selective Strategy for Non–ST-Segment Elevation Acute Coronary Syndrome. The ICTUS Trial.

Reference: Niels P.G. Hoedemaker et al. J Am Coll Cardiol 2017;69:1883-93.

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