Unstable angina / non ST elevation myocardial infarction women


 * Associate Editor-In-Chief: Smita Kohli, M.D.

Overview of Women with Unstable angina/NSTEMI

 * Although women are traditionally at lower risk for CAD as compared to men at all ages, UA/NSTEMI is still common amongst this group and importantly, women can manifest CAD somewhat differently than men.
 * It is also important to keep in mind that women with CAD are, on average, older than men and are more likely to have comorbidities such as hypertension, diabetes mellitus, and heart failure with preserved systolic function; to manifest angina rather than MI; and, to have atypical symptoms of angina and MI.

Presentation and Diagnosis

 * Diagnosis of UA/NSTEMI based on clinical picture can be challenging in women as they commonly present with atypical symptoms. Commonly, they present with symptoms of similar frequency, duration, and pattern, but more often than men, they have anginal equivalent symptoms such as dyspnea or atypical symptoms.
 * The frequency of ST-segment changes is similar to that for men, but women more often have T-wave inversion.
 * Notably, women less often have elevated troponin levels.

Management
Pharmacotherapy:

Various studies have shown that women tend to receive less intensive pharmacological treatment than men.
 * A consistent pattern is that women are prescribed ASA and other antithrombotic agents less frequently than men. Women derive the same treatment benefit as men from ASA, clopidogrel, anticoagulants, beta blockers, ACE inhibitors, and statins.


 * The findings of a beneficial effect of a direct invasive strategy in women treated with a GP IIb/IIIa antagonist in TACTICS-TIMI 18 supports the similar efficacy of these agents in this cohort of women and men.


 * Despite the clear benefit of antiplatelet and anticoagulant therapy for women with ACS, women are at increased risk of bleeding. In a large community based registry study, 42% of patients with UA/NSTEMI received excessive initial dosing of at least 1 antiplatelet or anticoagulant agent (UFH, LMWH, or GP IIb/IIIa inhibitor).
 * Female sex, older age, renal insufficiency, low body weight, and diabetes were predictors of excessive dosing. **Dosing errors predicted an increased risk of major bleeding.
 * Hence, measures to reduce the risk of bleeding by dosage adjustment to lower dose of ASA, decreasing dose of renally excreted drugs in renal insufficiency should be followed.

Coronary Artery Revascularization:
 * The outlook for women undergoing PCI appears to have improved, as evidenced by the NHLBI PTCA registry.


 * Earlier studies of women undergoing CABG showed that women were less likely to receive internal mammary arteries or complete revascularization and had a higher mortality rate than men.

Most of these trials were underpowered to analyze this subgroup.
 * More recent studies of CABG in patients with ACS show a more favorable outlook for women than previously thought. In fact, the BARI trial of 1,829 patients comparing PTCA and CABG, primarily in patients with UA, showed that the results of revascularization were, if anything, better in women than men when corrected for other factors. Current available trial results show conflicting results regarding initial invasive strategy versus conservative strategy in women, with majority of studies showing that women do worse with direct invasive strategy.


 * In prospective analysis from TACTICS-TIMI 18 study, there was a significant reduction in the primary end point of death, nonfatal MI, or rehospitalization for an ACS with a direct invasive strategy in both men and women. However, these results were confined to women with high-moderate TIMI risk score. Women with low TIMI risk score did worse than men in the same subgroup.


 * FRISC II substudy showed an overall benefit in the invasive strategy group but there was a significant interaction in outcome between treatment strategy, which included a systematic but delayed interventional approach within 7 d of symptom onset, and sex. However, in contrast to its beneficial effect in men, an early invasive strategy did not reduce the risk of future events among women at the end of 1 year. The poor outcome of women was largely driven by a 9.9% death rate at 1 year in women who underwent CABG.

'''Based on the current data, one can infer that women with UA/NSTEMI and high-risk features, including elevated cardiac biomarkers, appear to benefit from an invasive strategy with early intervention and adjunctive GP IIb/IIIa antagonist use. There is no benefit of a direct invasive strategy for low-risk women, and the weight of evidence from the recent randomized clinical trials suggests that there may be excess risk associated with a direct invasive strategy in this group.'''

Prognosis

 * The notion that female sex is a risk factor for poor outcome in UA/NSTEMI has not been confirmed by recent multivariate models. On the other hand, in patients with STEMI, female sex(specially younger females) is an independent risk factor for death as compared to males.
 * Image-enhanced stress testing has similar prognostic value in women as in men and the recommendations for non-invasive stress testing is same as in men.

==ACC / AHA Guidelines (DO NOT EDIT) ==

{{cquote|

Class I
1. Women with UA / NSTEMI should be managed with the same pharmacological therapy as men both in the hospital and for secondary prevention, with attention to antiplatelet and anticoagulant doses based on weight and renal function; doses of renally cleared medications should be based on estimated creatinine clearance. (Level of Evidence: B)

2. Recommended indications for noninvasive testing in women with UA / NSTEMI are similar to those for men. (Level of Evidence: B)

3. For women with high-risk features, recommendations for invasive strategy are similar to those of men. (Level of Evidence: B)

4. In women with low-risk features, a conservative strategy is recommended. (Level of Evidence: B)}}