Evaluation of stress myocardial blood flow patterns in patients with apical hypertrophic cardiomyopathy.

Background: Among the other variants, the apical pattern of hypertrophic cardiomyopathy (AHCM) is probably the most important, with possible aneurysmatic evolution.

Methods And Results: We analyzed 12 patients with AHCM who underwent [N]NH-PET/CT. Regional perfusion, stress global myocardial blood flow (MBF), and transmural perfusion patterns were assessed.

Efficacy of Ranolazine in Patients With Symptomatic Hypertrophic Cardiomyopathy: The RESTYLE-HCM Randomized, Double-Blind, Placebo-Controlled Study.

Background: The late sodium current inhibitor ranolazine reverses the main electrophysiological and mechanical abnormalities of human hypertrophic cardiomyopathy (HCM) cardiomyocytes in vitro, suggesting potential clinical benefit. We aimed to assess the effect of ranolazine on functional capacity, symptomatic status, diastolic function, and arrhythmias in HCM.

Methods And Results: In this multicenter, double-blind, phase 2 study, 80 adult patients with nonobstructive HCM (age 53±14 years, 34 women) were randomly assigned to placebo (n=40) or ranolazine 1000 mg bid (n=40) for 5 months.

Effect of different drug classes on reverse remodeling of intramural coronary arterioles in the spontaneously hypertensive rat.

Background: Symptoms and signs of myocardial ischemia in the absence of obstructive coronary disease are common in hypertensive patients. This can be explained by CMD due to adverse remodeling of coronary arterioles which have also been reported in the SHR.

Objective: The aim of this study was to compare the effects of ramipril, perindopril, candesartan, atenolol, amlodipine, indapamide, and HMR1766 on CMD in the SHR.

Defining phenotypes and disease progression in sarcomeric cardiomyopathies: contemporary role of clinical investigations.

Mutations in cardiac sarcomere protein genes are associated with a variety of clinical phenotypes, including hypertrophic (HCM), dilated (DCM), and restrictive (RCM) cardiomyopathy as well as left ventricular non-compaction, with the overlap of morpho-functional manifestations in individual patients and families. Over time, initial phenotypes may undergo profound changes which determine clinical course and disease progression. Although genetic defects causing HCM and DCM have opposite effects at the myofilament level, a number of downstream maladaptive mechanisms, ranging from microvascular dysfunction and ischaemia to myocardial fibrosis and from diastolic dysfunction to abnormal sympathetic activation and arrhythmogenesis, seem to recur in sarcomeric cardiomyopathies, independent of the presenting phenotype.

Coronary microvascular dysfunction: mechanisms and functional assessment.

Obstructive disease of the epicardial coronary arteries was recognized as the cause of angina pectoris >2 centuries ago, and sudden thrombotic occlusion of an epicardial coronary artery has been established as the cause of acute myocardial infarction for >100 years. In the past 2 decades, dysfunction of the coronary microvasculature emerged as an additional mechanism of myocardial ischaemia that bears important prognostic implications. The coronary microvasculature (vessels <300 μm in diameter) cannot be directly imaged in vivo, but a number of invasive and noninvasive techniques, each with relative advantages and pitfalls, can be used to assess parameters that depend directly on coronary microvascular function.

Evaluation of respiratory and cardiac motion correction schemes in dual gated PET/CT cardiac imaging.

Purpose: Cardiac imaging suffers from both respiratory and cardiac motion. One of the proposed solutions involves double gated acquisitions. Although such an approach may lead to both respiratory and cardiac motion compensation there are issues associated with (a) the combination of data from cardiac and respiratory motion bins, and (b) poor statistical quality images as a result of using only part of the acquired data.

Effects of sex on coronary microvascular dysfunction and cardiac outcomes.

Background: Coronary microvascular dysfunction (CMD) is a prevalent and prognostically important finding in patients with symptoms suggestive of coronary artery disease. The relative extent to which CMD affects both sexes is largely unknown.

Methods And Results: We investigated 405 men and 813 women who were referred for evaluation of suspected coronary artery disease with no previous history of coronary artery disease and no visual evidence of coronary artery disease on rest/stress positron emission tomography myocardial perfusion imaging.

Non-invasive anatomic and functional imaging of vascular inflammation and unstable plaque.

Over the last several decades, basic cardiovascular research has significantly enhanced our understanding of pathobiological processes leading to formation, progression, and complications of atherosclerotic plaques. By harnessing these advances in cardiovascular biology, imaging has advanced beyond its traditional anatomical domains to a tool that permits probing of particular molecular structures to image cellular behaviour and metabolic pathways involved in atherosclerosis. From the nascent atherosclerotic plaque to the death of inflammatory cells, several potential molecular and micro-anatomical targets for imaging with particular selective imaging probes and with a variety of imaging modalities have emerged from preclinical and animal investigations.