Myocardial infarction (MI) in the "young" is a significant problem, however there is scarcity of data on premature coronary heart disease (CHD) and MI in the "young". This may lead to under-appreciation of important differences that exist between "young" MI patients versus an older cohort. Traditional differences described in the risk factor profile of younger MI compared to older patients include a higher prevalence of smoking, family history of premature CHD and male gender. Recently, other potentially important differences have been described. Most "young" MI patients will present with non-ST elevation MI but the proportion presenting with ST-elevation MI is increasing. Coronary angiography usually reveals less extensive disease in "young" MI patients, which has implications for management. Short-term prognosis of "young" MI patients is better than for older patients, however contemporary data raises concerns regarding longer-term outcomes, particularly in those with reduced left ventricular systolic function. Here we review the differences in rate, risk factor profile, presentation, management and prognosis between "young" and older MI patients.

Heavy transluminal calcification as assessed with CT-CA is an independent predictor of failed PCI of CTO. CT-CA may have a role in the work-up of CTO patients prior to PCI.

Application of ASIR reduces the radiation dose of CCTA without affecting the image quality.

Intermediate coronary artery stenosis, defined as visual angiographic stenosis severity of between 30-70%, is present in up to one quarter of patients undergoing coronary angiography. Patients with this particular lesion subset represent a distinct clinical challenge, with operators often uncertain on the need for revascularization. Although international guidelines appropriately recommend physiological pressure-based assessment of these lesions utilizing either fractional flow reserve (FFR) or quantitative flow ratio (QFR), there are specific clinical scenarios and lesion subsets where the use of such indices may not be reliable.Intravascular imaging, mainly utilizing intravascular ultrasound (IVUS) and optical coherence tomography (OCT) represents an alternate and at times complementary diagnostic modality for the evaluation of intermediate coronary stenoses. Studies have attempted to validate these specific imaging measures with physiological markers of lesion-specific ischaemia with varied results. Intravascular imaging however also provides additional benefits that include portrayal of plaque morphology, guidance on stent implantation and sizing and may portend improved clinical outcomes. Looking forward, research in computational fluid dynamics now seeks to integrate both lesion-based physiology and anatomical assessment using intravascular imaging. This review will discuss the rationale and indications for the use of intravascular imaging assessment of intermediate lesions, while highlighting the current limitations and benefits to this approach.