Revascularization of NSTEACS populations is done to relieve symptoms, increase quality of life, reduce the incidence of a new infarction, and possibly prolong life and is a class I-recommendation in European Society of Cardiology guidelines on NSTEACS, at least for patients with medium- or high-risk features.1

For most patients with NSTEACS, without need for urgent revascularization, there was an intense debate during the 1990s whether an invasive approach, with routine coronary angiography (followed by revascularization, if feasible) was superior to a more conservative approach, with pharmacological stabilization and coronary angiography only if the patient experienced symptoms or signs of ischemia (spontaneous or during a stress test). These 2 treatment strategies have been compared in a number of randomized trials. Most8–12 but not all1,13,14 of the studies have been in favor of a routine invasive strategy. A meta-analysis of 7 of the earlier trials showed a reduced rate of MI, severe angina, and rehospitalization at the end of a 17-month follow-up for routine invasive vs selective invasive treatment.15 The long-term benefit came with an early hazard during initial hospitalization, with a significantly higher risk of death or MI in the routine invasive strategy arm. Many of the trials included in this meta-analysis do not reflect contemporary management strategies, and the use of stents and glycoprotein IIb/IIIA-inhibitors was low. The current paradigm was challenged by the ICTUS trial, which found no difference between a routine invasive vs a more selective invasive strategy in the composite of death, MI or rehospitalization for angina pectoris within 1 year.16 A small difference in revascularization rate between the 2 groups and a regular use of thienopyridines and a much higher frequency of coronary catheterization in the selective arm in the ICTUS trial may at least partly explain the difference in results between the ICTUS trial and earlier trials.

Thus, in a subgroup of NSTEACS patients with ongoing ischemic signs, there is consensus that early catheterization and, if feasible, revascularization is the preferred treatment strategy.

There is no doubt whatsoever that a routine invasive strategy in men with NSTEACS is indicated, as clearly shown in the FRISC II, RITA 3, and TACTICS-TIMI 18 trials.17–19 A meta-analysis by O’Donoghue et al,20 published in 2008 and including 8 trials (3075 women and 7057 men), showed no significant difference in outcome with a routine invasive vs a more selective invasive strategy in the endpoint of death/MI, either for men or women. The same results were shown in a meta-analysis presented together with data from the OASIS 5 women substudy that included women only but did not reach the required number of patients to draw proper conclusions.21

Thus, to date, there is no definitive evidence against treating women and men alike regarding an invasive approach in NSTEACS even if there is a trend in women toward producing harm rather than benefit. This could of course entirely be caused by lack of power.

In the 2010 guidelines on myocardial revascularization,22 the timing of angiography and intervention is discussed and is summarized in table 11 of this guidelines. Ongoing or recurrent ischemia, dynamic spontaneous ST-changes, deep ST-depression in anterior leads indicating ongoing posterior transmural ischemia, hemodynamic instability, and major ventricular arrhythmia are all indicators for performing emergent coronary angiography. Furthermore, in high-risk patients with a GRACE risk score > 140, angiography should be performed within 24h if possible.

In the early days of percutaneous coronary interventions, data from registries and randomized trials indicated differences in several aspects between the sexes. Women were older and were more likely to have hypertension, diabetes, and heart failure. Women were also more likely to be referred for catheterization in an acute situation.23,24 Most of these early reports indicated increased risk for complications, including in-hospital death, for women after percutaneous coronary intervention. Whether this is true, with the contemporary pharmaceutical treatment of today, must be evaluated, especially in the setting of NSTEACS.25,26 However, despite higher age and comorbidity, women and men had similar long-term outcomes.27–29

In coronary artery bypass surgery (CABG), women had greater early mortality than men in earlier studies. However, after adjustment for differences in baseline risk factors, mortality rates for women have often,30,31 but not always,32 been similar to those of men. All 3 recent studies on sex differences in CABG surgery showed that female sex is associated with an increased risk for death after CABG even after multivariate and propensity score analyses.33–35 As all these studies are based on observational data and on all consecutive CABG surgeries performed, it is not possible to draw conclusions on NSTEACS only. In 1 of the studies,33 51% to 57% of men and women, respectively, had unstable angina whereas in another,34 62% and 68% of men and women, respectively, had either urgent or emergency CABG.

A report from the BARI trial, which randomized patients with multivessel disease to CABG or percutaneous coronary intervention, revealed that women had a significantly lower risk of death, but not of death plus MI, than men.36 This was a post hoc substudy analysis with 27% women, as was the gender analysis in the FRISC II study, in which women who had CABG surgery had 4 times higher in-hospital mortality than men with CABG surgery.37

In view of the above, the discussion about whether there are sex differences in outcomes associated with CABG surgery is still ongoing.