Background Coronary artery calcium score (CAC) is an objective marker of atherosclerosis. The primary aim is to assess CAC as a risk classifier in stable coronary artery disease (CAD). Hypothesis CAC improves CAD risk prediction, compared to conventional risk scoring, even in the absence of cardiovascular risk factor inputs. Methods Outpatients presenting to a cardiology clinic (n = 3518) were divided into two cohorts: derivation (n = 2344 patients) and validation (n = 1174 patients). Adding logarithmic transformation of CAC, we built two logistic regression models: Model 1 with chest pain history and risk factors and Model 2 including chest pain history only without risk factors simulating patients with undiagnosed comorbidities. The CAD I Consortium Score (CCS) was the conventional reference risk score used. The primary outcome was the presence of coronary artery disease defined as any epicardial artery stenosis≥50% on CT coronary angiogram. Results Area under curve (AUC) of CCS in our validation cohort was 0.80. The AUC of Models 1 and 2 were significantly improved at 0.88 (95%CI 0.86–0.91) and 0.87 (95%CI 0.84–0.90), respectively. Integrated discriminant improvement was >15% for both models. At a pre‐specified cut‐off of ≤10% for excluding coronary artery disease, the sensitivity and specificity were 89.3% and 74.7% for Model 1, and 88.1% and 71.8% for Model 2. Conclusion CAC helps improve risk classification in patients with chest pain, even in the absence of prior risk factor screening.

Background: MI with non-obstructive coronary arteries (MINOCA) is caused by a heterogenous group of conditions with clinically significant sequelae. Aim: This study aimed to compare the clinical characteristics and prognosis of MINOCA with MI with obstructive coronary artery disease (MICAD). Methods: Data on patients with a first presentation of MI between 2011 and 2014 were extracted from the Singapore Cardiac Longitudinal Outcomes Database and patients were classified as having either MINOCA or MICAD. The primary outcomes were all-cause mortality (ACM) and major adverse cardiac events (MACE), defined as a composite of ACM, recurrent MI, heart failure hospitalisation and stroke. Results: Of the 4,124 patients who were included in this study, 159 (3.9%) were diagnosed with MINOCA. They were more likely to be women, present with a non-ST-elevation MI, have a higher left ventricular ejection fraction and less likely to have diabetes, previous stroke or smoking history. Over a mean follow-up duration of 4.5 years, MINOCA patients had a lower incidence of ACM (10.1% versus 16.5%) and MACE (20.8% versus 35.5%) compared with MICAD. On multivariable analysis, patients with MINOCA had a lower risk of ACM (HR 0.42; 95% CI [0.21–0.82]) and MACE (HR 0.42; 95% CI [0.26–0.69]). Within the MINOCA group, older age, higher creatinine, a ST-elevation MI presentation, and the absence of antiplatelet use predicted ACM and MACE. Conclusion: While patients with MINOCA had better clinical outcomes compared with MICAD patients, MINOCA is not a benign entity, with one in five patients experiencing an adverse cardiovascular event in the long term.

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Funding Acknowledgements Type of funding sources: None. Background The coronary artery calcium score (CACS) independently predicts the risk of cardiovascular disease and major adverse cardiovascular events. While previous studies have demonstrated regional and ethnic differences in coronary calcification, the distribution of CACS in Southeast Asian (SEA) adults has not been investigated. Purpose The aim of this study was to determine CACS distribution in a SEA cohort living in Singapore. Methods This study involved 4945 asymptomatic patients who underwent CT coronary angiography and calcium scoring as part of screening for cardiovascular disease. Similar to the MESA study, patients with diabetes were analyzed separately due an increased prevalence of coronary calcification. A nonparametric analytical approach was used to determine CACS distribution stratified by age, gender and ethnicity. Results A positive CACS was seen in 43.7% of the overall SEA cohort with a higher prevalence in males (45.2%) than females (36.7%). The onset and burden of coronary calcification was also earlier and more severe in male subjects. There were no significant differences in CACS distribution amongst the three major ethnic groups in our study (p = 0.177). The presence of coronary calcification (CACS >0) was associated with increasing age, male gender and hypertension. Ethnicity, dyslipidemia, smoking and a family history of coronary artery disease did not significantly affect the presence of CACS. Conclusions This study provides a reference CACS distribution in an asymptomatic SEA population. There were no significant differences in CACS distribution amongst the three major ethnic groups living in Singapore.