Susan Kim

Evaluation of human coronary vasodilator function predicts future coronary atheroma progression

Objective Coronary vasodilator function and atherosclerotic plaque progression have both been shown to be associated with adverse cardiovascular events. However, the relationship between these factors and the lipid burden of coronary plaque remains unknown. These experiments focus on investigating the relationship between impaired coronary vasodilator function (endothelium dependent (salbutamol) and endothelium independent (glyceryl trinitrate)) and the natural history of atheroma plaque progression and lipid burden using dual modality intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS) imaging. Methods 33 patients with stable chest pain or acute coronary syndrome underwent serial assessment of coronary vasodilator function and intracoronary plaque IVUS and NIRS imaging. Coronary segmental macrovascular response (% change segmental lumen volume (ΔSLV)), plaque burden (per cent atheroma volume (PAV)), lipid core (lipid-rich plaque (LRP) and lipid core burden index (LCBI)) were measured at baseline and after an interval of 12–18 months (n=520 segments). Results Lipid-negative coronary segments which develop into LRP over the study time period demonstrated impaired endothelial-dependent function (−0.24±2.96 vs 5.60±1.47%, P=0.04) and endothelial-independent function (13.91±4.45 vs 21.19±3.19%, P=0.036), at baseline. By multivariate analysis, endothelial-dependent function predicted ∆LCBI (β coefficient: −3.03, 95% CI (−5.81 to −0.25), P=0.033) whereas endothelial-independent function predicted ∆PAV (β coefficient: 0.07, 95% CI (0.04 to 0.10), P<0.0001). Conclusions Epicardial coronary vasodilator function is a determinant of future atheroma progression and composition irrespective of the nature of clinical presentation. Trial registration number ACTRN12612000594820, Post-results.

Meta-analysis of Prevalence and Risk Factors for Delirium After Transcatheter Aortic Valve Implantation

Delirium is a severe and common complication following transcatheter aortic valve implantation (TAVI). We sought to identify the prevalence and risk factors associated with the development of postprocedural delirium in patients aged over 60 years who underwent elective TAVI for aortic stenosis. Overall, 1,051 articles were searched, from which 9 studies were included. The prevalence of delirium following TAVI was higher in studies that assessed delirium for a minimum of 3 consecutive days (24.9%) compared with the studies that did not (2%). There were large effect sizes (d > 0.8) for 3 risk factors: acute kidney injury (odds ratio [OR] 5, p < 0.001), transapical approach (OR 4, p < 0.001) and carotid artery disease (OR 4, p < 0.001), whilst small effect sizes were found for a history of atrial fibrillation, prior stroke/transient ischemic attack, peripheral artery disease, hypertension, and prior cognitive impairment. In conclusion, 23% of patients 60 years and over who underwent TAVI experience delirium, a preventative cause of cognitive impairment and dementia. Recognition of risk factors for delirium after TAVI, such as a history of carotid artery disease, development of acute kidney injury, or use of a transapical approach, provides an opportunity to implement proven delirium preventative measures.

Clinical Outcomes in Trials Evaluating Lipid-Lowering Drugs

While statins have formed the cornerstone of strategies for cardiovascular prevention, the residual risk related to low-density lipoprotein cholesterol (LDL-C) and other lipoprotein factors provides a landscape for development of new therapies. However, a number of lipid-modifying therapies have failed to reduce cardiovascular event rates in contemporary clinical trials of statin-treated patients. The factors considered in outcome measure selection for clinical trials of novel lipid-lowering therapies are reviewed. Evaluation of lipid-modifying drugs in clinical trials spans a spectrum from their effects on conventional circulating lipid parameters through to their impact on atherosclerotic plaque and ultimately clinical outcomes. The design of these trials has an important impact on the result and ultimate interpretation of these studies.