Invasive versus conservative strategy in acute coronary syndromes: The paradox in women's outcomes

Abstract

Background

We explored benefits and risks of an early invasive compared with a conservative strategy in women versus men after non-ST elevation acute coronary syndromes (NSTE-ACS) using the ISACS-TC database.

Methods

From October 2010 to May 2014, 4145 patients were diagnosed as having a NSTE-ACS. We excluded 258 patients managed with coronary bypass surgery. Of the remaining 3887 patients, 1737 underwent PCI (26% women). The primary endpoint was the composite of 30-day mortality and severe left ventricular dysfunction defined as an ejection fraction < 40% at discharge.

Results

Women were older and more likely to exhibit more risk factors and Killip Class ≥ 2 at admission as compared with men. In patients who underwent PCI, peri-procedural myocardial injury was not different among sexes (3.1% vs. 3.2%). Women undergoing PCI experienced higher rates of the composite endpoint (8.9% vs. 4.9%, p = 0.002) and 30-day mortality (4.4% vs. 2.0%, p = 0.008) compared with men, whereas those who managed with only routine medical therapy (RMT) did not show any sex difference in outcomes. In multivariable analysis, female sex was associated with favorable outcomes (adjusted HR for the composite endpoint: 0.72, 95% CI: 0.58–0.91) in patients managed with RMT, but not in those undergoing PCI (adjusted HR: 0.96, 95% CI: 0.61–1.52).

Conclusions

We observed a more favorable outcome in women than men when patients were managed with RMT. Women and men undergoing PCI have similar outcomes. These data suggest caution in extrapolating the results from men to women in an overall population of patients in the context of different therapeutic strategies.

Introduction

According to results from a meta-analysis of eight randomized trials published on 2008, men and high-risk women with non-ST elevation acute coronary syndromes (NSTE-ACS) should be treated with an invasive management strategy, whereas low-risk women should be treated conservatively [1]. The Agency for Healthcare Research and Quality provided confirmation of these data [2]. Although this study is probably the best proof that an invasive strategy is superior in men than in women, it should be pointed out that the records of this analysis are dated. Four of the eight studies took place prior to 2000, and 4 were published prior to 2006. As a consequence, this study offers limited information on contemporary treatments and related outcomes of women with NSTE-ACS.

A further critical point is that current guidelines still recommend that the presence of cardiac biomarkers be used to help identify women who might benefit most from an invasive strategy. However, today the finding of unstable angina has almost disappeared with the advent of high sensitivity troponins [3], [4]. Many patients who in the past would have been diagnosed as having unstable angina will now be diagnosed as having myocardial infarction. Consideration should, therefore, be given to identify further high-risk features, including a high risk GRACE risk score that may prove to be useful for predicting the benefit of an invasive or early invasive strategy in women.

The lack of recent findings on this issue emphasizes the importance of further research. We explored the benefits and risks of an invasive strategy in women versus men with NSTE-ACS using a landmark observational study.