Niti R. Aggarwal

Aspirin for the Primary Prevention of Cardiovascular Events: A systematic review and meta-analysis comparing patients with and without diabetes

OBJECTIVE The negative results of two randomized controlled trials (RCTs) have challenged current guideline recommendations for using aspirin for primary prevention of cardiovascular events among patients with diabetes. We therefore sought to determine if the effect of aspirin for primary prevention of cardiovascular events and mortality differs between patients with and without diabetes. RESEARCH DESIGN AND METHODS We conducted a systematic search of MEDLINE, EMBASE, Cochrane Library, Web of Science, and Scopus since their inceptions until November 2008 for RCTs of aspirin for primary prevention of cardiovascular events. Blinded pairs of reviewers evaluated studies and extracted data. Random-effects meta-analysis and Bayesian logistic regression were used to estimate the ratios of relative risks (RRs) of outcomes of interest among patients with and without diabetes. A 95% CI that crosses 1.00 indicates that the effect of aspirin does not differ between patients with and without diabetes. RESULTS Nine RCTs with moderate to high methodological quality contributed data to the analyses. The ratios of RRs comparing the benefit of aspirin among patients with diabetes compared with patients without diabetes for mortality, myocardial infarction, and ischemic stroke were 1.12 (95% CI 0.92–1.35), 1.19 (0.82–1.17), and 0.70 (0.25–1.97), respectively. CONCLUSIONS Whereas estimates of benefit among patients with diabetes remain imprecise, our analysis suggests that the relative benefit of aspirin is similar in patients with and without diabetes.

Application of the Appropriateness Criteria for Echocardiography in an Academic Medical Center

BACKGROUND The authors examined the feasibility of application of the American College of Cardiology Foundations appropriateness criteria for transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE) at a large tertiary care practice. METHODS Indications for consecutive TTE and TEE were determined by chart review and classified according to the guidelines as appropriate, inappropriate, or uncertain or, for situations not addressed in the document, nonclassifiable. RESULTS Of the 529 studies reviewed, 469 were appropriate, 23 inappropriate, 1 uncertain, and 36 nonclassifiable. Inappropriate and nonclassifiable studies were more commonly TTE than TEE (P<.001). Inappropriate studies were more common in outpatients than inpatients (P<.001). Nonclassifiable cases included assessment after radiofrequency ablation (33.3%) and preoperative evaluation (8.3%). Disagreement between observers in selection of the criterion was present in 30.8%. CONCLUSIONS Although the study was conducted retrospectively, only 4.7% of classifiable studies were inappropriate. The reproducibility of classification was moderate, and 6.8% of studies were not classifiable. Areas for improvement of the criteria were identified.

Role of cardiac MRI and nuclear imaging in cardiac resynchronization therapy

Cardiac resynchronization has emerged as a highly effective therapy for heart failure. However, up to 40% of patients do not benefit from this treatment. In this Review, we discuss the potential role of MRI and nuclear molecular imaging in providing additional insights into the response to cardiac resynchronization therapy. Variables with potential prognostic and therapeutic values include the evaluation of cardiac dyssynchrony, scar, cardiac sympathetic function, myocardial blood flow, myocardial glucose and oxidative metabolism. Other molecular targets to characterize apoptosis, fatty acid metabolism, angiogenesis and angiotensin-converting enzyme activity will also be described. The potential use of these techniques in identifying and measuring responses to cardiac resynchronization therapy and future areas of research will be explored.

Noncalcified plaque: Relationship between results of multislice computed tomography, risk factors, and late clinical outcome

Background: Contrast‐enhanced multislice computed tomographic angiography (MSCTA) detects noncalcified plaque (NCP) in coronary arteries and associated coronary stenoses. However, the clinical relevance of NCP is poorly defined. Objectives: Our goal was to examine the relationship NCP, risk factors (RFs), and clinical follow‐up in unselected outpatients undergoing MSCTA. Methods: Five hundred six patients undergoing contrast MSCTA were evaluated for NCP (intraluminal density 25 < Hounsfield units < 130). One hundred twenty‐four patients (24.5%) had calcium scores (CAC) of zero. Of these, 111 patients were examined for RFs and followed clinically for a mean of 34 months. Results: Of 124 patients with zero CAC, 111 (89.5%) included 52 (46.8%) with no NCP, 40 (36.0%) with NCP, and mild luminal stenosis, 14 (12.6%) and 5 (4.5%) with NCP causing significant and severe stenosis, respectively. Patients in each group were similar in age but differed significantly in number of RFs. Current or former smokers, hypertensive, and obese patients had more NCP and associated stenosis. At a mean of 34 months, there were no events in the no NCP group, 2/54 (3.7%) events in the NCP without severe stenosis group (one sudden cardiac death and one ventricular tachycardia), and 2/5 (40.0%) patients had revascularization in the NCP with severe stenosis group. Conclusions: (1) In patients with zero CAC, presence of NCP on MSCTA was associated with more RFs, especially smoking, obesity, and hypertension. (2) NCP can result in severe coronary stenosis. (3) NCP detected by MSCTA in patients with zero CAC may identify patients with late cardiac events.

Erratum. Aspirin for the Primary Prevention of Cardiovascular Events. A Systematic Review and Meta-Analysis Comparing Patients With and Without Diabetes. Diabetes Care 2009;32:2300–2306

In the article cited above, Fig. 2 should have shown the pooled relative risks and 95% CI for the effect of aspirin versus control on death, myocardial infarction, and ischemic stroke, respectively, stratified by diabetes status of the trial participants. The published version of the manuscript incorrectly labeled the …

Exuberant mitral annular calcification

Mitral annular calcification (MAC) is a chronic, progressive process characterized by calcium deposition on the mitral valve annulus. There is no current grading system to relay the severity of MAC. The primary purpose of this study was to investigate the extreme end of the severity spectrum in order to describe “exuberant mitral annular calcification”, and a retrospective chart review of all patients with exuberant mitral annulus calcification evaluated at Mayo Clinic Rochester between January 1996 and December 2014 was performed. This is the first study to define criteria of “exuberant mitral annular calcification”, emphasizing the importance of identifying the extreme degree of mitral annular calcification.

HEYDE SYNDROME: AN OFTEN MISSED CAUSE OF BLEEDING IN HYPERTROPHIC CARDIOMYOPATHY

Heyde syndrome is an acquired von Willebrand syndrome (VWS), related to bleeding from gastrointestinal angiodysplasia, in patients with aortic stenosis and obstructive hypertrophic cardiomyopathy (HOCM). The etiology is secondary to destruction of circulating von Willebrand factor multimers by sheer

123I-Meta-Iodobenzylguanidine Guanidine–Guided Ventricular Tachycardia Ablation Will Expanding the Target Improve the Aim?

Catheter ablation is an established therapeutic approach for ventricular tachycardia (VT), especially in patients with drug-refractory VT. Despite advances in modern state-of-the-art ablation techniques and greater operator experience, the VT recurrence rate after ablation still approaches 50% at 6 months in a large series.1 The majority of current VT ablation strategies rely heavily on targeting anatomic and scar-based substrate and include activation and substrate mapping; the latter particularly helpful for patients with hemodynamically unstable or noninducible VT. However, these techniques are limited by multiple technical and nontechnical factors, including challenges posed by the complex 3-dimensional morphology of scar, particularly in an intramyocardial location, possible artifacts because of poor catheter contact, low spatial resolution, and the time-consuming nature of the techniques themselves. Furthermore, VT substrate not only is anatomic and scar-based but also has physiological components, including ischemia, inflammation, metabolism, and autonomic innervation, which are generally not considered when delineating potential targets for VT ablation. These factors may, in part, explain the high rate of VT recurrence after ablation and highlight the need to consider incorporating functional targets such as those available with several noninvasive imaging modalities into electroanatomic mapping to refine targets for catheter ablation of VT.2–4 Article see p 583 In this issue of Circulation: Arrhythmia and Electrophysiology , Klein et al5 present a single-center experience demonstrating the feasibility of integrating iodine-123-labeled- meta -iodobenzylguanidine (123I- m IBG) scintigraphy with voltage mapping for postinfarction VT ablation in 15 patients. Areas defined as denervated by 123I- m IBG were 2.5× larger than scar identified by bipolar voltage mapping. On the contrary, the voltage-defined border zone tended to be larger than the 123I- m IBG transition zone, but this difference was not statistically significant. By bipolar voltage mapping, 36% of VT ablation …

THE DOUBLY OBSTRUCTIVE HYPERTROPHIC CARDIOMYOPATHY

Hypertrophic cardiomyopathy (HCM) often results in mid-systolic left ventricular outflow tract (LVOT) obstruction secondary to basal septal hypertrophy and systolic anterior motion of the mitral valve. However, other etiologies of LVOT obstruction such as subaortic stenosis may also coexist. A 68

Unveiling nonischemic cardiomyopathies with cardiac magnetic resonance.

Cardiomyopathy is defined as a heterogeneous group of myocardial disorders with mechanical or electrical dysfunction. Identification of the etiology is important for accurate diagnosis, treatment and prognosis, but continues to be challenging. The ability of cardiac MRI to non-invasively obtain 3D-images of unparalleled resolution without radiation exposure and to provide tissue characterization gives it a distinct advantage over any other diagnostic tool used for evaluation of cardiomyopathies. Cardiac MRI can accurately visualize cardiac morphology and function and also help identify myocardial edema, infiltration and fibrosis. It has emerged as an important diagnostic and prognostic tool in tertiary care centers for work up of patients with non-ischemic cardiomyopathies. This review covers the role of cardiac MRI in evaluation of nonischemic cardiomyopathies, particularly in the context of other diagnostic and prognostic imaging modalities.