Sex differences in patients with acute coronary syndromes and non-obstructive coronary arteries: Presentation and outcome.

BACKGROUND: A substantial number of patients present with a suspected ACS and non-obstructive coronary arteries; sex differences in these patients are not well understood. This study aims to evaluate the impact of sex on clinical presentation and outcome in patients with suspected acute coronary syndrome (ACS) and non-obstructive coronary arteries with a final diagnosis confirmed by cardiovascular magnetic resonance imaging (CMR). METHODS: Consecutive patients with ACS and non-obstructive coronary arteries (n = 719) with an unclear cause from a single tertiary centre who were referred for CMR were included. The primary endpoint was all-cause mortality. RESULTS: CMR was performed at a median time of 30 days after presentation and identified a diagnosis in 74% of patients. All-cause mortality was 9.5% over a median follow up of 4.9 years, with no significant difference between sexes (8.8% versus 10.1%; p = 0.456). Men were more likely to have non-ischaemic aetiology on CMR than women (55% v 41%, p < 0.001), but were equally likely to have an ischaemic cause (25% v 27%, p = 0.462). Age group (HR 1.58, p < 0.001) and LV ejection fraction (HR 0.98, p = 0.023) were independent predictors of mortality. CONCLUSIONS: There is no difference in all-cause mortality between sexes in patients presenting with suspected ACS and non-obstructive coronary arteries.

Peak Troponin and CMR to Guide Management in Suspected ACS and Nonobstructive Coronary Arteries.

BACKGROUND: Patients presenting with acute coronary syndrome (ACS) and nonobstructive coronary arteries are a diagnostic dilemma. Cardiac magnetic resonance (CMR) has an overall diagnostic yield of ∼75%; however, in ∼25% of patients, CMR does not identify any myocardial injury. Identifying the underlying diagnosis has important clinical implications for patients' management and outcome. OBJECTIVES: The authors sought to assess whether the combination of CMR and peak troponin levels in patients with ACS and nonobstructive coronary arteries would lead to increased diagnostic yield. METHODS: Consecutive patients with ACS and nonobstructive coronary arteries without an obvious cause underwent CMR. The primary endpoint of the study was the diagnostic yield of CMR. The Youden index was used to find the optimal diagnostic cut point for peak troponin T to combine with CMR to improve diagnostic yield. Logistic or Cox regression models were used to estimate predictors of a diagnosis by CMR. RESULTS: A total of 719 patients met the inclusion criteria. The peak troponin T threshold for optimal diagnostic sensitivity and specificity was 211 ng/L. Overall, CMR has a diagnostic yield of 74%. CMR performed <14 days from presentation and with a peak troponin of ≥211 ng/L (n = 198) leads to an improved diagnostic yield (94% vs 72%) compared with CMR performed ≥14 days (n = 245). When CMR was performed <14 days and with a peak troponin of <211 ng/L, the diagnostic yield was 76% (n = 86) compared with 53% (n = 190) when performed ≥14 days. An increase in 1 peak troponin decile increases the odds of the CMR identifying a diagnosis by 20% (OR: 1.20; P = 0.008, 95% CI: 1.05-1.36). CONCLUSIONS: The combination of CMR performed <14 days from presentation and peak troponin T ≥211 ng/L leads to a very high diagnostic yield (94%) on CMR. The diagnostic yield remains high (72%) even when CMR is performed ≥14 days from presentation, but reduces to 53% when peak troponin T was <211 ng/L.