Comparison of (18)F-fluorodeoxyglucose positron emission tomography (FDG PET) and cardiac magnetic resonance (CMR) in corticosteroid-naive patients with conduction system disease due to cardiac sarcoidosis.

PURPOSE: Cardiac sarcoidosis (CS) is a cause of conduction system disease (CSD). (18)F-Fluorodeoxyglucose-positron emission tomography (FDG PET) and cardiac magnetic resonance (CMR) are used for detection of CS. The relative diagnostic value of these has not been well studied. The aim was to compare these imaging modalities in this population. METHODS: We recruited steroid-naive patients with newly diagnosed CSD due to CS. All CS patients underwent both imaging studies within 12 weeks of each other. Patients were classified into two groups: group A with chronic mild CSD (right bundle branch block and/or axis deviation), and group B with new-onset atrioventricular block (AVB, Mobitz type II or third-degree AVB). RESULTS: Thirty patients were included. Positive findings on both imaging studies were seen in 72 % of patients (13/18) in group A and in 58 % of patients (7/12) in group B. The remainder (28 %) of the patients in group A were positive only on CMR. Of the patients in group B, 8 % were positive only on CMR and 33 % were positive only on FDG PET. Patients in group A were more likely to be positive only on CMR, and patients in group B were more likely to be positive only on FDG PET (p = 0.02). Patients in group B positive only on FDG PET underwent CMR earlier relative to their symptomatology than patients positive only on CMR (median 7.0, IQR 1.5 - 34.3, vs. 72.0, IQR 25.0 - 79.5 days; p = 0.03). CONCLUSION: The number of positive FDG PET and CMR studies was different in patients with CSD depending on their clinical presentation. This study demonstrated that CMR can adequately detect cardiac involvement associated with chronic mild CSD. In patients presenting with new-onset AVB and a negative CMR study, FDG PET may be useful for detecting cardiac involvement due to CS.

Transient Ischemic Dilatation during Stress Echocardiography: An Additional Marker of Significant Myocardial Ischemia.

AIM: Left ventricular (LV) transient ischemic dilatation (TID) is not clear how it relates to inducible myocardial ischemia during stress echocardiography (SE). METHODS AND RESULTS: Eighty-eight SEs were examined from the site certification phase of the ISCHEMIA Trial. LV end-diastolic volume (EDV) and end-systolic volume (ESV) were measured at rest and peak stages and the percent change calculated. Moderate or greater ischemia was defined as ≥3 segments with stress-induced severe hypokinesis or akinesis. Optimum cut points in stress-induced percent EDV and ESV change that identified moderate or greater myocardial ischemia were analyzed. Analysis from percentage distribution identified a > 13% LV volume increase in EDV or a > 9% LV volume increase in ESV as the optimum cutoff points for moderate or greater ischemia. Using these definitions for TID, there were 27 (31%) with TIDESV and 12 (14%) with TIDEDV . By logistic regression analysis and receiver operating characteristic curves, the percent change in ESV had a stronger association with moderate or greater myocardial ischemia than that of EDV change. Compared to those without TIDESV , cases with TIDESV had larger extent of inducible wall-motion abnormalities, lower peak stress LVEF, and higher likelihood of moderate or grater ischemia. For moderate or greater myocardial ischemia detection, TIDESV had a sensitivity of 46%, specificity of 83%, positive predictive value of 70%, and negative predictive value of 64%. CONCLUSION: Transient ischemic dilatation by SE is a marker of extensive myocardial ischemia and can be used as an additional marker of higher risk.

Coronary Surgery in Women and the Challenges We Face.

This review was undertaken to understand the dynamics that have shaped our current treatment of women who undergo coronary artery bypass grafting (CABG) and summarize the current literature on surgical revascularization in women. There has been improved access to CABG over the past several decades. Despite this, compared with men, CABG in women involves fewer grafts and less frequent use of arterial grafts, the latter having improved long-term patency compared with saphenous vein grafts. We attempt to determine whether the adverse clinical profile of women, when referred for CABG is responsible for this finding. Female coronary anatomy and pathophysiology are reviewed and an attempt is made to understand how this might affect decisions of selection and outcome measures post CABG. We review the short-term, long-term, and quality of life outcomes in women. These data are taken from large databases, as well as from more recent publications. Randomized controlled trial data and meta-analytic data are used when available. Differential use of and outcomes of surgical strategies, including off-pump CABG and total arterial revascularization, are contrasted with those in men. This review shows that there continues to be widespread differences in surgical approach to coronary artery disease in female vs male patients. We provide evidence suggestive of the existence of issues specific to women that affect selection for surgical procedures and outcomes in women. More work is required to understand the reason for these differences and how to optimize sex-specific outcomes.

Impact of Gender on Arterial Revascularization Strategies for Coronary Artery Bypass Grafting.

BACKGROUND: There are significant gender differences in arterial revascularization approaches in coronary operations. This study addressed these differences to determine whether discrepancies are related to underlying risk profiles or systematic gender bias. METHODS: Changes in gender-specific rates of revascularization approaches were determined in 19,557 patients undergoing isolated coronary artery bypass grafting (CABG). A propensity-balanced group was generated on a subset of 1,254 CABG patients based on 45 pretreatment covariates to assess rates in matched groups (627 patients per group). RESULTS: In the entire cohort, male gender was associated with increased bilateral internal thoracic artery (BITA) use (odds ratio, 1.667; 95% confidence interval [CI], 1.166 to 2.386; p = 0.005). Multiple-arterial grafting increased yearly in both genders, but the rate of increase in BITA use was greater in men (1.59%/year [95% CI, 1.56 to 1.63] vs 1.37%/year [95% CI, 1.30 to 1.45], p < 0.001) as was the use of 3 arteries (1.16%/year [95% CI, 1.13 to 1.20] vs 0.73%/year [95% CI, 0.67 to 0.80), p < 0.001) and the use of any 2 arteries (2.34%/year (95% CI, 2.32 to 2.35) vs 1.92%/year [95% CI, 1.90 to 1.95], p < 0.001). In the propensity-matched group, there was no difference in BITA use (male: 31.9%, female: 30.1%; p = 0.502), BITA use in low-risk patients (male: 46.4%, female: 38.0%; p = 0.126), or radial artery use (male: 44.5%, female: 44.1%; p = 0.994), but use of 3 arteries was greater in men (10.5% vs 7.3%, p = 0.048). CONCLUSIONS: Women receive less complete multiple arterial coronary revascularization than men. This is likely related to later presentation of coronary artery disease in women with higher comorbidity profiles; however, when matched, bias may still exist limiting the option of grafting with 3 arteries to women.

Clinical PET Myocardial Perfusion Imaging and Flow Quantification.

Cardiac PET imaging is a powerful tool for the assessment of coronary artery disease. Many tracers with different advantages and disadvantages are available. It has several advantages over single photon emission computed tomography, including superior accuracy and lower radiation exposure. It provides powerful prognostic information, which can help to stratify patients and guide clinicians. The addition of flow quantification enables better detection of multivessel disease while providing incremental prognostic information. Flow quantification provides important physiologic information, which may be useful to individualize patient therapy. This approach is being applied in some centers, but requires standardization before it is more widely applied.

Obesity and the challenges of noninvasive imaging for the detection of coronary artery disease.

Obesity is a significant health problem that could potentially lead to increased cardiovascular risk. Noninvasive imaging plays an important role in the evaluation of cardiovascular symptoms and risk of these patients. Selection of the appropriate test in the diagnosis of obstructive coronary artery disease in this unique population is important. In this article, we focus on the strengths, limitations, and recommendations of the various noninvasive cardiac imaging modalities available in the detection of obstructive coronary artery disease. We have suggested an algorithm to help direct investigation. Ultimately, patient management should be individualized based on clinical judgement, test availability, and local expertise.

Myocardial viability: it is still alive.

Heart failure presents a significant problem in industrialized countries, with a high prevalence, morbidity, and mortality, where it is most frequently caused by coronary artery disease. Revascularization in patients with symptomatic heart failure has been associated with improved cardiovascular outcomes. Predictors of outcome benefit from revascularization include the presence and extent of hibernating myocardium, ischemia, scar, left ventricular ejection fraction, and renal function. Viability is useful in directing the management of patients with ischemic cardiomyopathy. It is especially useful in those with the highest risk where revascularization decisions are the most difficult. In the absence of definitive prospective randomized data on the benefit of routine viability testing in the management of ischemic cardiomyopathy, physicians will likely continue to use viability testing to assist them with their decision-making process. This review article focuses on the value of viability imaging and the modalities of its measurement, which include PET, SPECT, cardiac MRI, and dobutamine echocardiography. These imaging modalities should be seen as complementary rather than competing methods. In any given clinical setting, the indications, comorbidities, availability, local expertise, sensitivity, specificity, and limitations of each modality need to be considered. When advanced imaging (PET and cardiac MRI) are available, they are generally considered the preferred choice because of their overall higher accuracy. Finally, we explore the role of ischemia in patients with viability and the potential role of neurohormonal and viability imaging in deciding the need for implantable cardiac defibrillator as a primary prevention in patients with severe ischemic cardiomyopathy.

Quantification of myocardial blood flow using PET to improve the management of patients with stable ischemic coronary artery disease.

Cardiac PET has been evolving over the past 30 years. Today, it is accepted as a valuable imaging modality for the noninvasive assessment of coronary artery disease. PET has demonstrated superior diagnostic accuracy for the detection of coronary artery disease compared with single-photon emission computed tomography, and also has a well-established prognostic value. The routine addition of absolute quantification of myocardial blood flow increases the diagnostic accuracy for three-vessel disease and provides incremental functional and prognostic information. Moreover, the characterization of the vasodilator capacity of the coronary circulation may guide proper decision-making and monitor the effects of lifestyle changes, exercise training, risk factor modification or medical therapy for improving regional and global myocardial blood flow. This type of image-guided approach to individualized patient therapy is now attainable with the routine use of cardiac PET flow reserve imaging.

Prognostic value of rubidium-82 positron emission tomography in patients after heart transplant.

BACKGROUND: Cardiac allograft vasculopathy is a key prognostic determinant after heart transplant. Detection and risk stratification of patients with cardiac allograft vasculopathy are problematic. Positron emission tomography using rubidium-82 allows quantification of absolute myocardial blood flow and may have utility for risk stratification in this population. METHODS AND RESULTS: Patients with a history of heart transplant undergoing dipyridamole rubidium-82 positron emission tomography were prospectively enrolled. Myocardial perfusion and left ventricular ejection fraction were recorded. Absolute flow quantification at rest and after dipyridamole stress as well as the ratio of mean global flow at stress and at rest, termed myocardial flow reserve, were calculated. Patients were followed for all-cause death, acute coronary syndrome, and heart failure hospitalization. A total of 140 patients (81% men; median age, 62 years; median follow-up, 18.2 months) were included. There were 14 events during follow-up (9 deaths, 1 acute coronary syndrome, and 4 heart failure admissions). In addition to baseline clinical variables (estimated glomerular filtration rate, previously documented cardiac allograft vasculopathy), relative perfusion defects, mean myocardial flow reserve, and mean stress myocardial blood flow were significant predictors of adverse outcome. CONCLUSIONS: Abnormalities on rubidium-82 positron emission tomography were predictors of adverse events in heart transplant patients. Larger prospective studies are required to confirm these findings.

Computed tomographic coronary angiography for patients with heart failure (CTA-HF): a randomized controlled trial (IMAGE HF Project 1-C).

BACKGROUND: The prevalence of heart failure (HF) is rising in industrialized and developing countries. Though invasive coronary angiography (ICA) remains the gold standard for anatomical assessment of coronary artery disease in HF patients, alternatives are being sought. Computed tomographic coronary angiography (CTA) has emerged as an accurate non-invasive diagnostic tool for coronary artery disease (CAD) and has been demonstrated to have prognostic value. Whether or not CTA can be used in HF patients is unknown. Acknowledging the aging population, the growing prevalence of HF and the increasing financial burden of healthcare, we need to identify non-invasive diagnostic tests that are available, safe, accurate and cost-effective. METHODS/DESIGN: The proposed study aims to provide insight into the efficacy of CTA in HF patients. A multicenter randomized controlled trial will enroll 250 HF patients requiring coronary anatomical definition. Enrolled patients will be randomized to either CTA or ICA (n = 125 per group) as the first test to define coronary anatomy. The primary outcomes will be collected to determine downstream resource utilization. Secondary outcomes will include the composite clinical events and major adverse cardiac events. In addition, the accuracy of CTA for detecting coronary anatomy and obstruction will be assessed in patients who subsequently undergo both CTA and ICA. It is expected that CTA will be a more cost-effective strategy for diagnosis: yielding similar outcomes with fewer procedural risks and improved resource utilization. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01283659. Team grant #CIF 99470.