Safety of Routine Invasive Versus Selective Invasive Therapy in Women with Non-ST-Elevation Acute Coronary Syndrome

Sex Differences in Characteristics and Outcomes among Low-Risk Non-ST-Elevation Acute Coronary Syndrome Patients during Long Term Follow-Up

Previous heterogenous studies show conflicting data about sex-based outcomes of non-ST-elevation acute coronary syndrome (NSTE-ACS) patients. This study evaluated 300 NSTE-ACS patients undergoing a coronary angiography between September 2012 and May 2015 that were managed with all-treatment strategies. The sample was stratified by sex and analyzed for the baseline characteristics and outcomes. The main outcome included major adverse cardiovascular and cerebrovascular events (MACCE), which were a composite of cardiac death, nonfatal myocardial infarction, ischemic stroke or urgent coronary revascularization. The female patients were older (median of 69.0 vs. 63.0 years, p = 0.008) and had lower values of BMI (median of 26.3 vs. 28.2 kg/m², p < 0.001) and eGFR (76.44 ± 22.43 vs. 94.04 ± 27.91 mL/min, p < 0.001). There was no significant difference in the treatment strategies, angiographic characteristics and discharge therapy between the groups (p > 0.05). The female patients had significantly higher unadjusted rates of ischemic stroke (4.2% vs. 0.5%, p = 0.023), cardiac mortality (11.3%, vs. 3.9%, p = 0.022) and MACCE (33.8%, vs. 19.5%, p = 0.014); female sex was a significant predictor of MACCE in the univariate analysis (HR 1.86, 95%CI 1.12–3.09, p = 0.014); and the cumulative incidence of MACCE was higher in female patients (p = 0.014). After the adjustment, the predictive effect of female sex became non-significant (HR 1.60, 95%CI 0.94–2.73, p = 0.083), while there was no difference in the cumulative incidence of MACCE among the propensity score matched cohort (p = 0.177). Female NSTE-ACS patients have worse long-term outcomes compared to their male counterparts. However, the differences disappear after adjustment and propensity score matching. Continuing efforts and health measures are required to alleviate any sex-based differences in the NSTE-ACS population.

Early Invasive Versus Initial Conservative Strategies for Women with Non-ST-Elevation Acute Coronary Syndromes: A Nationwide Analysis

BACKGROUND

Studies conducted largely in men have shown improved outcomes with an early invasive strategy with non-ST-elevation acute coronary syndrome. In contrast, data have been less conclusive in women, with some trials demonstrating potential harm. This study aims to assess whether an early invasive strategy in women is associated with better outcomes in real-world data.

METHODS

Women admitted with a primary diagnosis of non-ST-elevation myocardial infarction or unstable angina were identified from the National Inpatient Sample years 2012 and 2013. The incidence of in-hospital mortality in women with non-ST-elevation acute coronary syndrome undergoing an early invasive strategy versus an initial conservative strategy was compared using a propensity score-matched analysis.

RESULTS

Among 372,080 women with non-ST-elevation acute coronary syndrome, 153,680 (41.3%) were managed with an early invasive strategy and 218,400 (58.7%) were managed with an initial conservative strategy. Propensity score-matched 19,965 women were treated with an early invasive strategy, and 20,009 women were treated with an initial conservative strategy. The risk of in-hospital mortality was lower with an early invasive strategy (2.1% vs 3.8%; odds ratio [OR], 0.55; 95% confidence interval [CI], 0.49-0.62). This benefit was noted in women presenting with non-ST-segment elevation myocardial infarction (OR, 0.52; 95% CI, 0.46-0.58) and was not observed in women with unstable angina (OR, 5.14; 95% CI, 0.47-56.9), P_interaction = .06. A propensity-adjusted analysis yielded similar results (OR, 0.51; 95% CI, 0.45-0.57).

CONCLUSIONS

In this large contemporary observational analysis of women with non-ST-elevation acute coronary syndrome, an early invasive strategy was associated with lower in-hospital mortality. This benefit was observed in women presenting with non-ST-elevation myocardial infarction but not with unstable angina. These findings provide evidence supporting the guideline recommendations for an early invasive strategy in women with non-ST-elevation acute coronary syndrome and high-risk features (eg, troponin positive).

Meta-Analysis of Randomized Trials of Long-Term All-Cause Mortality in Patients With Non-ST-Elevation Acute Coronary Syndrome Managed With Routine Invasive Versus Selective Invasive Strategies

Randomized trials and meta-analyses demonstrated that a routine invasive strategy improves outcomes in patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) compared to a selective invasive strategy. Benefit was driven primarily by a reduction in the risk of myocardial infarction. However, the impact of either strategy on long-term mortality is unknown. Trials that compared a routine invasive strategy versus a selective invasive strategy in patients with NSTE-ACS and reported data on all-cause mortality ≥1 year were included. Summary odds ratios (OR) were constructed using Peto's model for all-cause mortality using the longest available follow-up data. Subgroup analysis was performed for follow-up at 1 to ≤5 years and >5 years. Eight trials with 6,657 patients were available for analysis. At a mean of 10.3 years, the risk of all-cause mortality was similar with both strategies (28.5% vs 28.5%; OR 1.00, 95% confidence interval [CI] 0.90 to 1.12, p = 0.97). This effect was similar on subgroup analysis for follow-up at 1 to ≤5 years (OR 0.89, 95% CI 0.77 to 1.04, p = 0.15) and >5 years (OR 1.02, 95% CI 0.90 to 1.14, p = 0.79). There was no difference in treatment effect across various study-level covariates such as age, gender, diabetes, and positive troponin (all P for interaction >0.05). In conclusion, in patients with NSTE-ACS, both routine invasive and selective invasive strategies have a similar risk of all-cause mortality at ∼10 years. This illustrates there are still opportunities to change the trajectory of mortality events among invasively treated patients with NSTE-ACS.