Marked exercise-induced T-wave heterogeneity in symptomatic diabetic patients with nonflow-limiting coronary artery stenosis.

Background: T-wave heterogeneity (TWH) independently predicted cardiovascular mortality in Health Survey 2000 based on 12-lead ECGs recorded at rest. We investigated whether TWH is elevated during exercise tolerance testing (ETT) in symptomatic diabetic patients with nonflow-limiting coronary artery stenosis compared to control subjects without diabetes.

Methods: Cases were all patients (n = 20) with analyzable ECG recordings during both rest and ETT who were enrolled in the Effects of Ranolazine on Coronary Flow Reserve (CFR) in Symptomatic Patients with Diabetes and Suspected or Known Coronary Artery Disease (RAND-CFR) study (NCT01754259); median CFR was 1.

Ranolazine reduces repolarization heterogeneity in symptomatic patients with diabetes and non-flow-limiting coronary artery stenosis.

Background: Experimental evidence suggests that ranolazine decreases susceptibility to ischemia-induced arrhythmias independent of effects on coronary artery blood flow.

Objective: In symptomatic diabetic patients with non-flow-limiting coronary artery stenosis with diffuse atherosclerosis and/or microvascular dysfunction, we explored whether ranolazine reduces T-wave heterogeneity (TWH), an electrocardiographic (ECG) marker of arrhythmogenic repolarization abnormalities shown to predict sudden cardiac death.

Methods: We studied all 16 patients with analyzable ECG recordings during rest and exercise tolerance testing before and after 4 weeks of ranolazine in the double-blind, crossover, placebo-controlled RAND-CFR trial (NCT01754259).

Ranolazine in Symptomatic Diabetic Patients Without Obstructive Coronary Artery Disease: Impact on Microvascular and Diastolic Function.

Background: Treatments for patients with myocardial ischemia in the absence of angiographic obstructive coronary artery disease are limited. In these patients, particularly those with diabetes mellitus, diffuse coronary atherosclerosis and microvascular dysfunction is a common phenotype and may be accompanied by diastolic dysfunction. Our primary aim was to determine whether ranolazine would quantitatively improve exercise-stimulated myocardial blood flow and cardiac function in symptomatic diabetic patients without obstructive coronary artery disease.

Excess Cardiovascular Risk in Women Relative to Men Referred for Coronary Angiography Is Associated With Severely Impaired Coronary Flow Reserve, Not Obstructive Disease.

Background: Cardiovascular disease (CVD) fatality rates are higher for women than for men, yet obstructive coronary artery disease (CAD) is less prevalent in women. Coronary flow reserve (CFR), an integrated measure of large- and small-vessel CAD and myocardial ischemia, identifies patients at risk for CVD death, but is not routinely measured in clinical practice. We sought to investigate the impact of sex, CFR, and angiographic CAD severity on adverse cardiovascular events.

Dose reduction in half-time myocardial perfusion SPECT-CT with multifocal collimation.

Background: Recent technological advances in myocardial perfusion imaging may warrant the use of lower injected activity. We evaluated whether quantitative measures of stress myocardial perfusion defects using Tc-99m sestamibi and low-energy high-resolution (LEHR) collimators are equivalent to lower dose SPECT-CT with cardiac multifocal collimators and software (IQ·SPECT).

Methods: 93 patients underwent one-day rest-stress gated SPECT-CT.

Increased arterial inflammation in individuals with stage 3 chronic kidney disease.

Purpose: While it is well known that patients with chronic kidney disease (CKD) are at increased risk for the development and progression of atherosclerosis, it is not known whether arterial inflammation is increased in mild CKD. The aim of this study was to compare arterial inflammation using F-FDG PET/CT in patients with CKD and in matched controls.

Methods: This restrospective study included 128 patients undergoing FDG PET/CT imaging for clinical indications, comprising 64 patients with stage 3 CKD and 64 control patients matched by age, gender, and cancer history.

Prognostic Value of Coronary Flow Reserve in Patients with Dialysis-Dependent ESRD.

Capillary rarefaction of the coronary microcirculation is a consistent phenotype in patients with dialysis-dependent ESRD (dd-ESRD) and may help explain their excess mortality. Global coronary flow reserve (CFR) assessed by positron emission tomography (PET) is a noninvasive, quantitative marker of myocardial perfusion and ischemia that integrates the hemodynamic effects of epicardial stenosis, diffuse atherosclerosis, and microvascular dysfunction. We tested whether global CFR provides risk stratification in patients with dd-ESRD.

Quantification of coronary flow reserve in patients with ischaemic and non-ischaemic cardiomyopathy and its association with clinical outcomes.

Aims: Patients with left ventricular systolic dysfunction frequently show abnormal coronary vascular function, even in the absence of overt coronary artery disease. Moreover, the severity of vascular dysfunction might be related to the aetiology of cardiomyopathy.We sought to determine the incremental value of assessing coronary vascular dysfunction among patients with ischaemic (ICM) and non-ischaemic (NICM) cardiomyopathy at risk for adverse cardiovascular outcomes.

Interaction of impaired coronary flow reserve and cardiomyocyte injury on adverse cardiovascular outcomes in patients without overt coronary artery disease.

Background: Minimally elevated serum cardiac troponin reflects myocardial injury and is associated with increased mortality, even absent coronary artery disease (CAD). We sought to investigate the relationship between low-level troponin elevation and impaired coronary flow reserve (CFR), an integrated measure of coronary vasomotor function, and to assess their contributions to adverse outcomes in patients without overt CAD.

Methods And Results: Consecutive patients (n=761) undergoing evaluation for suspected CAD with troponin before stress myocardial perfusion positron emission tomography were followed up (median, 2.

Global coronary flow reserve is associated with adverse cardiovascular events independently of luminal angiographic severity and modifies the effect of early revascularization.

Background: Coronary flow reserve (CFR), an integrated measure of focal, diffuse, and small-vessel coronary artery disease (CAD), identifies patients at risk for cardiac death. We sought to determine the association between CFR, angiographic CAD, and cardiovascular outcomes.

Methods And Results: Consecutive patients (n=329) referred for invasive coronary angiography after stress testing with myocardial perfusion positron emission tomography were followed (median 3.

Mineralocorticoid receptor blockade improves coronary microvascular function in individuals with type 2 diabetes.

Reduced coronary flow reserve (CFR), an indicator of coronary microvascular dysfunction, is seen in type 2 diabetes mellitus (T2DM) and predicts cardiac mortality. Since aldosterone plays a key role in vascular injury, the aim of this study was to determine whether mineralocorticoid receptor (MR) blockade improves CFR in individuals with T2DM. Sixty-four men and women with well-controlled diabetes on chronic ACE inhibition (enalapril 20 mg/day) were randomized to add-on therapy of spironolactone 25 mg, hydrochlorothiazide (HCTZ) 12.

Coronary microvascular dysfunction is related to abnormalities in myocardial structure and function in cardiac amyloidosis.

Objectives: The purpose of this study was to test the hypothesis that coronary microvascular function is impaired in subjects with cardiac amyloidosis.

Background: Effort angina is common in subjects with cardiac amyloidosis, even in the absence of epicardial coronary artery disease (CAD).

Methods: Thirty-one subjects were prospectively enrolled in this study, including 21 subjects with definite cardiac amyloidosis without epicardial CAD and 10 subjects with hypertensive left ventricular hypertrophy (LVH).

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.

Assessment of myocardial viability and left ventricular function in patients supported by a left ventricular assist device.

Background: Chronically supported left ventricular assist device (LVAD) patients may be candidates for novel therapies aimed at promoting reverse remodeling and myocardial recovery. However, the effect of hemodynamic unloading with a LVAD on myocardial viability and LV function in chronically supported LVAD patients has not been fully characterized. We aimed to develop a non-invasive imaging protocol to serially quantify native cardiac structure, function, and myocardial viability while at reduced LVAD support.

Preserved coronary flow reserve effectively excludes high-risk coronary artery disease on angiography.

Unlabelled: Myocardial perfusion imaging has limited sensitivity for the detection of high-risk coronary artery disease (CAD). We tested the hypothesis that a normal coronary flow reserve (CFR) would be helpful for excluding the presence of high-risk CAD on angiography.

Methods: We studied 290 consecutive patients undergoing (82)Rb PET within 180 d of invasive coronary angiography.

Prognostic interplay of coronary artery calcification and underlying vascular dysfunction in patients with suspected coronary artery disease.

Objectives: This study sought to evaluate the interrelation of atherosclerotic burden, as assessed by coronary artery calcium (CAC) score and coronary vascular function, as assessed by quantitative estimates of coronary flow reserve (CFR), with respect to prediction of clinical outcomes.

Background: The contribution of coronary vascular dysfunction, atherosclerotic burden, and the 2 combined to cardiac events is unknown.

Method: A total of 901 consecutive patients underwent (82)Rubidium myocardial perfusion imaging (MPI) positron emission tomography (PET) and CAC scan.

Coronary vascular dysfunction and prognosis in patients with chronic kidney disease.

Objectives: This study sought to evaluate whether impaired vasodilator function, an early manifestation of coronary artery disease, which precedes angiographic stenosis, accounts for increased risk among patients with moderate to severe renal dysfunction.

Background: Patients with renal dysfunction are at increased risk of adverse cardiac outcomes, even in the absence of overt myocardial ischemia or infarction.

Methods: We included 866 consecutive patients with moderate to severe renal dysfunction referred for rest and stress myocardial perfusion positron emission tomography and followed them for a median of 1.

Association between coronary vascular dysfunction and cardiac mortality in patients with and without diabetes mellitus.

Background: Diabetes mellitus increases the risk of adverse cardiac outcomes and is considered a coronary artery disease (CAD) equivalent. We examined whether coronary vascular dysfunction, an early manifestation of CAD, accounts for increased risk among diabetics compared with nondiabetics.

Methods And Results: A total of 2783 consecutive patients (1172 diabetics and 1611 nondiabetics) underwent quantification of coronary flow reserve (CFR; CFR=stress divided by rest myocardial blood flow) by positron emission tomography and were followed up for a median of 1.

Aligning coronary anatomy and myocardial perfusion territories: an algorithm for the CORE320 multicenter study.

Background: Appropriate clinical decisions concerning diagnosis and treatment of coronary artery disease rely on correct integration of data on coronary anatomy and myocardial perfusion. The purpose of this article is to introduce a new left ventricular segmentation model for improved alignment of coronary arterial segments and myocardial perfusion territories, designed for the CORE320 study.

Methods And Results: CORE320 is a prospective, multicenter study with a primary objective to evaluate the diagnostic accuracy of 320-row detector computed tomography (CT) to detect coronary artery luminal stenosis and corresponding myocardial perfusion deficits in patients with suspected coronary artery disease compared with the gold standard of conventional coronary angiography and single-photon emission CT myocardial perfusion imaging.

Patient management after noninvasive cardiac imaging results from SPARC (Study of myocardial perfusion and coronary anatomy imaging roles in coronary artery disease).

Objectives: This study examined short-term cardiac catheterization rates and medication changes after cardiac imaging.

Background: Noninvasive cardiac imaging is widely used in coronary artery disease, but its effects on subsequent patient management are unclear.

Methods: We assessed the 90-day post-test rates of catheterization and medication changes in a prospective registry of 1,703 patients without a documented history of coronary artery disease and an intermediate to high likelihood of coronary artery disease undergoing cardiac single-photon emission computed tomography, positron emission tomography, or 64-slice coronary computed tomography angiography.

Improved cardiac risk assessment with noninvasive measures of coronary flow reserve.

Background: Impaired vasodilator function is an early manifestation of coronary artery disease and may precede angiographic stenosis. It is unknown whether noninvasive assessment of coronary vasodilator function in patients with suspected or known coronary artery disease carries incremental prognostic significance.

Methods And Results: A total of 2783 consecutive patients referred for rest/stress positron emission tomography were followed up for a median of 1.

Quantitative relationship between the extent and morphology of coronary atherosclerotic plaque and downstream myocardial perfusion.

Objectives: The purpose of this study was to quantify the effects of coronary atherosclerosis morphology and extent on myocardial flow reserve (MFR).

Background: Although the relationship between coronary stenosis and myocardial perfusion is well established, little is known about the contribution of other anatomic descriptors of atherosclerosis burden to this relationship.

Methods: We evaluated the relationship between atherosclerosis plaque burden, morphology, and composition and regional MFR (MFR(regional)) in 73 consecutive patients undergoing Rubidium-82 positron emission tomography and coronary computed tomography angiography for the evaluation of known or suspected coronary artery disease.