[Early invasive strategy (<24 h) in high-risk non-ST-elevation acute coronary syndrome: when the guideline recommendations need to be contextualized].

The advantages of an early invasive strategy in non-ST-elevation acute coronary syndromes (NSTE-ACS) are well documented. Less clear is the ideal time to perform it (within 24 h, within 72 h, or during hospitalization after positive non-invasive testing for ischemia). In particular, the class IA recommendation for coronary angiography within 24 h in patients with high-risk NSTE-ACS is controversial. Randomized clinical trials and meta-analyses show neutral effects on mortality, while significant positive results are observed only for secondary outcomes (mainly ischemic recurrences). Favorable effects on major cardiovascular events are reported only in the subgroup analysis of a single randomized trial (TIMACS) or in several trials included in the meta-analyses. Thus, these results are far from conclusive and should stimulate new randomized clinical studies to support them. In fact, the logistical implications that this recommendation implies deserve stronger evidence. It is clear that all patients with NSTE-ACS, especially if high-risk, should have the opportunity to undergo a coronary angiogram during hospitalization. However, in the real world, the strict timeline of the international guidelines may be difficult to follow. Therefore, indications that take into account resource availability and the organizational context should be developed. Several regional indications suggest that even in high-risk patients the 24 h time limit for the invasive strategy should not be mandatory, but timing of angiography should be calibrated on clinical presentation and logistical resources, without any a priori automatism.