Characteristics and 1-year prognosis of non-obstructive acute coronary syndrome

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Among patients admitted at catheterization laboratory with suspicion of acute coronary syndrome (ACS) a minority have no obstructive epicardial coronary disease (MINOCA). The characteristics and outcomes of this subgroup remains unclear. Purpose The aim of the present study is to characterize MINOCA patients and assess the 1-year prognosis regarding total mortality. Methods A standardized registry was prospectively performed for all ACS patients admitted in a single tertiary care centre during a ten-year period. Patients were divided according to have at least one obstructive coronary artery (G1), defined by a stenosis above 50%, or not (G2) and baseline characteristics were compared between the two groups. All-cause mortality at 30 days and at 1 year were also compared using univariate Cox analysis. Results From 3765 ACS patients admitted during the study period, 461 (12.2%) were included in G2. G2 patients were older (62.6 ± 13.1 vs 66.2 ± 13.7; p < 0.001) and more frequently women (26.3% vs 44.2%; p < 0.001). Smoking was more frequent in G1 (40.0% vs 21.9%; p < 0.001) but the prevalence of hypertension was higher in G2 (55.2% vs 64.2%; p < 0.001). There were no differences regarding dyslipidaemia and diabetes. End-stage chronic kidney disease was higher in G2 (2.4% vs 4.1%; p = 0.025). Regarding the clinical evolution during hospitalization, G2 presented more frequently with Killip-Kimball class ≥II (13.9% vs 19.3%; p = 0.001), but at release there was no difference in the proportion of patients with left ventricular ejection fraction ≤50% (34.8% vs 32.1%; p = 0.286). ACS with ST-segment elevation was more common in G1 (58.8% vs 52.1%; p = 0.006), but no differences were found regarding left and right bundle branch block patterns at presentation. In-hospital and 30-day mortality was not significantly different between groups (5.9% vs 7.4%; p = 0.205). However, at 1-year follow-up, G2 had a worse outcome regarding total mortality (HR (95%CI); 1.473 (1.103-1.969); p = 0.008, figure 1). Conclusion MINOCA patients seem not to be a low-risk group of ACS patients, since in this study they had a higher 1-year mortality than ACS patients with obstructive coronary disease. This higher mortality only became apparent after 30 days from the ACS. A systematic diagnostic work-up for further implementation of the most appropriate treatment should be crucial for getting better outcomes with this group of patients. Abstract Figure.