Sex-based analysis of NSTEMI processes of care and outcomes by hospital: a nationwide cohort study

Background: Contemporary studies demonstrate that non-ST-segment elevation myocardial infarction (NSTEMI) processes of care vary according to sex. Little is known regarding variation in practice between geographical areas and centers.

Methods: We identified 305 014 NSTEMI admissions in the United Kingdom (UK) Myocardial Infarction National Audit Project (MINAP), 2010-2017, including female sex (110 209). Hierarchical, multivariate logistic regression models were fitted assessing for differences in primary outcomes according to sex. Risk standardized mortality rates (RSMR) were calculated for individual hospitals to illustrate correlation with variables of interest. 'Heat-maps' were plotted to show regional and sex-based variation in opportunity-based quality-indicator score (surrogate for optimal processes of care).

Results: Women presented older (77y vs. 69y, P < 0.001) and were more often Caucasian (93% vs. 91%, P < 0.001). Women were less frequently managed with an invasive coronary angiogram (ICA) (58% vs. 75%, P < 0.001) or percutaneous coronary intervention (PCI) (35% vs. 49%, P < 0.001)). In our hospital-clustered analysis, we show positive correlation between the RSMR and increasing proportion of women treated for NSTEMI (R2 = 0.17, P < 0.001). There was clear negative correlation between proportion of women who had an optimum OBQI score during their admission and RSMR (R2 = 0.22, P < 0.001), with weaker correlation in men (R2 = 0.08, P < 0.001). Heat-maps according to clinical commissioning group (CCG) demonstrate significant regional variation in OBQI score, with women receiving poorer quality care throughout the UK.

Conlusion: There was a significant in variation of the management of patients with NSTEMI according to sex, with widespread geographical variation. Structural changes are required to enable improved care for women.