The prognostic value of automated coronary calcium derived by a deep learning approach on non-ECG gated CT images from ⁸²Rb-PET/CT myocardial perfusion imaging

Background: Assessment of both coronary artery calcium(CAC) scores and myocardial perfusion imaging(MPI) in patients suspected of coronary artery disease(CAD) provides incremental prognostic information. We used an automated method to determine CAC scores on low-dose attenuation correction CT(LDACT) images gathered during MPI in one single assessment. The prognostic value of this automated CAC score is unknown, we therefore investigated the association of this automated CAC scores and major adverse cardiovascular events(MACE) in a large chest-pain cohort. Method: We analyzed 747 symptomatic patients referred for 82RubidiumPET/CT, without a history of coronary revascularization. Ischemia was defined as a summed difference score≥2. We used a validated deep learning(DL) method to determine CAC scores. For survival analysis CAC scores were dichotomized as low(90 days after scanning) or nonfatal myocardial infarction. Cox proportional hazard analysis were performed to identify predictors of MACE. Results: During 4 years follow-up, 115 MACEs were observed. High CAC scores showed higher cumulative event rates, irrespective of ischemia (nonischemic: 25.8% vs 11.9% and ischemic: 57.6% vs 23.4%, P-values <0.001). Multivariable cox regression revealed both high CAC scores (HR 2.19 95%CI 1.43–3.35) and ischemia (HR 2.56 95%CI 1.71–3.35) as independent predictors of MACE. Addition of automated CAC scores showed a net reclassification improvement of 0.13(0.022–0.245). Conclusion: Automatically derived CAC scores determined during a single imaging session are independently associated with MACE. This validated DL method could improve risk stratification and subsequently lead to more personalized treatment in patients suspected of CAD

Ischaemic Heart Disease : Early Recognition and Risk Disparities

Ischaemic heart disease (IHD) comprises the principal clinical manifestations of coronary artery disease - myocardial infarction, stable and unstable angina pectoris, heart failure and sudden death - and is the leading cause of morbidity and mortality worldwide. The relentlessly growing burden of IHD poses an enormous health economical challenge. We aimed to improve diagnostic strategies for patients suspected of IHD, because early recognition and treatment of IHD reduces the risk of irreversible cardiac injury and improves prognosis. We adopted a twin-track approach. Firstly, we studied whether novel blood-based biomarkers were able to expedite the recognition of IHD among patients presenting with either acute or non-acute chest pain. In a diagnostic accuracy study among patients presenting to the emergency department with suspected acute coronary syndrome, we show that heart-type fatty acid binding protein assays cannot overcome the sensitivity deficit of high-sensitivity troponin measurements for the detection of unstable angina and for the detection of myocardial infarction in the first hours after chest pain onset. Furthermore, we report that in a two-phase biomarker study in a large cohort of stable outpatients undergoing Rubidium-82 PET/CT, no circulating microRNA’s could be identified that have the potential to be used as diagnostic blood-based biomarkers for myocardial ischaemia. The ultimate goal in the field of biomarkers for IHD remains to develop a sensitive and reliable biomarker to detect ischaemic myocardium, irrespective of the presence of myocardial necrosis. Secondly, we investigated whether ethnicity- and sex-based disparities in the prevalence of IHD and associated conditions are present among patients suspected of IHD, and whether these risk disparities should be considered in the diagnostic approach to IHD. In a multi-ethnic cohort study conducted in Singapore and The Netherlands, we observed significant ethnicity-based differences in cardiovascular risk profile, the prevalence of myocardial infarction and unstable angina, revascularisation rates and the severity of coronary heart disease among patients presenting to the emergency department with chest pain. Ethnicity-based differences were also observed in the levels of biomarkers related to coronary artery disease, and in the strength of de association between the biomarkers and severity of coronary artery disease. Despite aforementioned disparities, we demonstrate that the HEART score performs equally well in the risk stratification of Asian compared with Caucasian patients with suspected acute coronary syndrome. Contrastingly, regarding sex-based disparities, men assigned to the low-, intermediate-, or high-risk HEART score had markedly higher 6-week risk of major adverse cardiac events compared to women assigned to the same HEART risk category. Lastly, we provided valuable insight into the disparities in prevalence of diabetes and its impact on Asian and Caucasian patients with heart failure: despite younger age and lower prevalence of obesity, diabetes was 3-fold more common in Asian compared with Caucasian patients with heart failure. All of the above-mentioned results underscore the importance of an ethnicity- and sex-tailored diagnostic approach to IHD, subgroups that are currently not adequately represented in the evidence-based clinical practice guidelines

Prevalence and Clinical Significance of Diabetes in Asian Versus White Patients With Heart Failure

OBJECTIVES: The study sought to compare the prevalence, clinical correlates and prognostic impact of diabetes in Southeast Asian versus white patients with heart failure (HF) with preserved or reduced ejection fraction. BACKGROUND: Diabetes mellitus is common in HF and is associated with impaired prognosis. Asia is home to the majority of the world's diabetic population, yet data on the prevalence and clinical significance of diabetes in Asian patients with HF are sparse, and no studies have directly compared Asian and white patients. METHODS: Two contemporary population-based HF cohorts were combined: from Singapore (n = 1,002, median [25th to 75th percentile] age 62 [54 to 70] years, 76% men, 19.5% obesity) and Sweden (n = 19,537, 77 [68 to 84] years, 60% men, 24.8% obesity). The modifying effect of ethnicity on the relationship between diabetes and clinical correlates or prognosis (HF hospitalization and all-cause mortality) was examined using interaction terms. RESULTS: Diabetes was present in 569 (57%) Asian patients versus 4,680 (24%) white patients (p < 0.001). Adjusting for clinical covariates, obesity was more strongly associated with diabetes in white patients (odds ratio [OR]: 3.45; 95% confidence interval [CI]: 2.86 to 4.17) than in Asian patients (OR: 1.82; 95% CI: 1.13 to 2.96; pinteraction = 0.026). Diabetes was more strongly associated with increased HF hospitalization and all-cause mortality in Asian patients (hazard ratio: 1.50; 95% CI: 1.21 to 1.87) than in white patients (hazard ratio: 1.29; 95% CI: 1.22 to 1.36; pinteraction = 0.045). CONCLUSIONS: Diabetes was 3-fold more common in Southeast Asian compared to white patients with HF, despite younger age and less obesity, and more strongly associated with poor outcomes in Asian patients than white patients. These results underscore the importance of ethnicity-tailored aggressive strategies to prevent diabetes and its complications