Alirocumab and plaque volume, calf muscle blood flow, and walking performance in peripheral artery disease: A randomized clinical trial.

Background: The distal superficial femoral artery (SFA) is most commonly affected in peripheral artery disease (PAD). The effects of the proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor alirocumab added to statin therapy on SFA atherosclerosis, downstream flow, and walking performance are unknown.

Methods: Thirty-five patients with PAD on maximally tolerated statin therapy were recruited.

Arterial spin labeling perfusion cardiovascular magnetic resonance of the calf in peripheral arterial disease: cuff occlusion hyperemia vs exercise.

Background: Assessment of calf muscle perfusion requires a physiological challenge. Exercise and cuff-occlusion hyperemia are commonly used methods, but it has been unclear if one is superior to the other. We hypothesized that post-occlusion calf muscle perfusion (Cuff) with pulsed arterial spin labeling (PASL) cardiovascular magnetic resonance (CMR) at 3 Tesla (T) would yield greater perfusion and improved reproducibility compared to exercise hyperemia in studies of peripheral arterial disease (PAD).

Reproducibility of rest and exercise stress contrast-enhanced calf perfusion magnetic resonance imaging in peripheral arterial disease.

Background: The purpose was to determine the reproducibility and utility of rest, exercise, and perfusion reserve (PR) measures by contrast-enhanced (CE) calf perfusion magnetic resonance imaging (MRI) of the calf in normal subjects (NL) and patients with peripheral arterial disease (PAD).

Methods: Eleven PAD patients with claudication (ankle-brachial index 0.67 ±0.

Arterial spin labeling MR imaging reproducibly measures peak-exercise calf muscle perfusion: a study in patients with peripheral arterial disease and healthy volunteers.

Objectives: This study hypothesized that arterial spin labeling (ASL) magnetic resonance (MR) imaging at 3-T would be a reliable noncontrast technique for measuring peak exercise calf muscle blood flow in both healthy volunteers and patients with peripheral arterial disease (PAD) and will discriminate between these groups.

Background: Prior work demonstrated the utility of first-pass gadolinium-enhanced calf muscle perfusion MR imaging in patients with PAD. However, patients with PAD often have advanced renal disease and cannot receive gadolinium.

A nonpeptide angiotensin II type 2 receptor agonist does not attenuate postmyocardial infarction left ventricular remodeling in mice.

Cardiac overexpression of the angiotensin II type 2 receptor (AT2 R) attenuates left ventricular (LV) remodeling after myocardial infarction (MI) in transgenic mice. We hypothesized that a novel nonpeptide AT2 R agonist, compound 21 (C21), would attenuate post-MI LV remodeling. Fifty-nine mice were studied for 28 days after 1-hour surgical occlusion-reperfusion of the left anterior descending coronary artery.

Multifactorial determinants of functional capacity in peripheral arterial disease: uncoupling of calf muscle perfusion and metabolism.

Objectives: We aimed to investigate the pathophysiology of peripheral arterial disease (PAD) by examining magnetic resonance imaging (MRI) and spectroscopic (MRS) correlates of functional capacity.

Background: Despite the high prevalence, morbidity, and cost of PAD, its pathophysiology is incompletely understood.

Methods: Eighty-five patients (age 68 +/- 10 years) with mild-to-moderate PAD (ankle-brachial index 0.

Interaction between bradykinin subtype 2 and angiotensin II type 2 receptors during post-MI left ventricular remodeling.

Angiotensin II type 2 receptor (AT(2)R) overexpression (AT(2)TG) attenuates left ventricular remodeling in a mouse model of anterior myocardial infarction (MI). We hypothesized that the beneficial effects of cardiac AT(2)TG are mediated via the bradykinin subtype 2 receptor (B(2)R). Fourteen transgenic mice overexpressing the AT(2)R (AT(2)TG mice), 10 mice with a B(2)R deletion (B(2)KO mice), 13 AT(2)TG mice with B(2)R deletion (AT(2)TG/B(2)KO mice), and 11 wild-type (WT) mice were studied.

Calf muscle perfusion at peak exercise in peripheral arterial disease: measurement by first-pass contrast-enhanced magnetic resonance imaging.

Purpose: To develop a contrast-enhanced magnetic resonance (MR) technique to measure skeletal muscle perfusion in peripheral arterial disease (PAD).

Materials And Methods: A total of 11 patients (age = 61 +/- 11 years) with mild to moderate symptomatic PAD (ankle-brachial index [ABI] = 0.75 +/- 0.

Reproducibility and reliability of atherosclerotic plaque volume measurements in peripheral arterial disease with cardiovascular magnetic resonance.

A high resolution, noninvasive approach to quantify atherosclerotic plaque in the peripheral vasculature could have significant clinical and research utility. Seventeen patients with peripheral arterial disease (PAD) were studied in a 1.5T CMR scanner.

Dobutamine response and myocardial infarct transmurality: functional improvement after coronary artery bypass grafting--initial experience.

The Investigational Review Board approved the protocol, and all patients provided signed informed consent. The protocol was compliant with HIPAA. The purpose of the study was to prospectively test the hypothesis that addition of low-dose dobutamine and quantification of inotropic reserve in segments with 1%-50% infarct transmurality (IT) would improve the predictive value for functional recovery after revascularization in chronic infarction.

The angiotensin II type 2 receptor and improved adjacent region function post-MI.

Angiotensin II type 2 receptor (AT2-R) overexpression in the mouse heart preserves left ventricular (LV) size and global LV function during post-MI remodeling. We hypothesized that CMR tagging would localize regional improvements in myocardial function during post-MI remodeling in AT2-R cardiac overexpressed transgenic mice (TG), which could explain the preservation of global LV function post-MI. Six male wild-type (WT) C57BL/6 mice and 10 TG mice were studied by CMR at baseline (day 0) and days 1, 7, and 28 post-MI.

Infarct involution and improved function during healing of acute myocardial infarction: the role of microvascular obstruction.

Delayed contrast-enhanced cardiac magnetic resonance imaging (ceCMR) delineates infarct size. The presence of hypoenhancement consistent with microvascular obstruction (MO) signifies larger infarcts with a worse prognosis. We hypothesized that the size of the contrast defect (CD) on ceCMR in acutely infarcted myocardium may change during infarct healing and depend upon the presence of MO.

Magnetic resonance imaging identifies the fibrous cap in atherosclerotic abdominal aortic aneurysm.

Background: MRI can distinguish components of atherosclerotic plaque. We hypothesized that contrast enhancement with gadolinium-DTPA (Gd-DTPA) could aid in the differentiation of plaque components in abdominal aortic aneurysm (AAA).

Methods And Results: Twenty-three patients (19 males, age 70+/-8 years) with AAA underwent MRI on a 1.

Angiotensin II type 2 receptor overexpression preserves left ventricular function after myocardial infarction.

Background: The role of the angiotensin II type 2 receptor (AT2-R) in left ventricular (LV) remodeling may depend on the underlying stimulus. We hypothesized that cardiac AT2-R overexpression in transgenic (TG) mice would attenuate remodeling after myocardial infarction (MI).

Methods And Results: Ten wild-type (WT) C57BL/6 mice and 12 TG mice that overexpress the AT2-R in the heart were studied by cardiac MRI at baseline and days 1, 7, and 28 post-MI induced by 1 hour of occlusion of the LAD followed by reperfusion.