Heartbeat: Highlights from this issue

Catherine M Otto

There are several original research papersof interest in this issue of Heart, withtopics ranging from cardiac risk factorsand prevention, to cardiomyopathies, toarrhythmias and sudden cardiac death.Only a few articles are highlighted here soreaders should consult the table of con-tents for a full listing.

The presence of myocardial fibrosis, asdemonstrated by late gadolinium enhance-ment on cardiac magnetic resonanceimaging (MRI), is helpful in making thediagnosis of hypertrophic cardiomyopathy(HCM) and it has been suggested that theextent of myocardial fibrosis might correl-ate with prognosis. In a prospectivecohort study of 711 adults with HCMwho underwent MRI imaging, suddencardiac death occurred in 3.1% at amedian followup of 3.5 years (see page1851). Although the extent of myocardialfibrosis was a univariate predictor ofsudden cardiac death, the only predictoron multivariable analysis was left ventricu-lar ejection fraction Figure 1.

This study is relevant because it illus-trates the importance of evaluatingimaging findings in relation to clinicaloutcomes, rather than simply in compari-son to other diagnostic data or evenpathologic findings. Lack of informationon the prognostic value of imaging find-ings is one of the major information gapsin development of evidence-based guide-lines for patients with cardiac disease.

In the accompanying editorial,Drs. Jellis and Desai (see page 1825)point out that MRI remains useful forevaluation of the presence, extent and dis-tribution of myocardial hypertrophy;evaluation of subaortic outflow obstruc-tion; and accurate measurement of ven-tricular volumes and ejection fraction. Inpatients with an unclear diagnosis, thepresence and distribution of gadoliniumenhancement may allow diagnosis ofpotentially treatable infiltrative myocardialdisease. Finally, in terms of using MRI forrisk stratification in HCM patients, “thereis still substantial hope of more optimisticfindings in a larger, lengthier well-powered study.”

Figure 1 Predicted 5-year risk (right vertical axis) of reaching the study outcome measuresaccording to amount of fibrosis (A) and LVEF (B). ASCD, aborted sudden cardiac death; CV,cardiovascular; AC, all-cause; SCD, sudden cardiac death. The bars shows the percentage ofpatients (left vertical axis) in each group.

Figure 2 Kaplan–Meier estimates of the probability of the composite event by blood pressurestatus with and without peripheral neuropathy (PN). Composite event includes myocardialinfarction, coronary revascularisation, congestive cardiac failure, stroke and transient ischaemicattack. BP, blood pressure. HRs for PN as compared with no PN are systolic BP <136 mm Hg, HR1.92 (1.30–2.84), p=0.001; systolic BP ≥136 mm Hg, HR 1.66 (1.15–2.38) p=0.006.

Correspondence to Professor Catherine M Otto,Division of Cardiology, University of Washington,Seattle, WA 98195, USA; cmotto@u.washington.edu

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In another outcomes based imagingpaper, Dr Steinberg and colleagues(see page 1871) examined variation inuse of imaging procedures (in addition toelectro-anatomic mapping) during cath-eter ablation for atrial fibrillation in11,525 Medicare patients treated from2007 to 2009. Periprocedural imagingincluded transesophageal echocardiog-raphy (TEE) in 53%, intracardiac echo-cardiography (ICE) in 67% andcomputed tomography (CT) or MRI in50%. Although there was wide variationin the use of imaging among clinicians,pre ablation CT or MRI was associatedwith a lower risk of stroke whereas ICEwas associated with a lower need forrepeat ablation but an increased risk ofbleeding. In this study, TEE was not asso-ciated with any differences in mortality,stroke, bleeding or repeat ablation. It isnaïve to think that more imaging isalways better, even when caring for anindividual patient. This type of rigorousoutcome-based assessment is critical forappropriate allocation of healthcareresources and ensuring optimal patientoutcomes.

As cardiologists, we might not paymuch attention to the issue of diabeticneuropathy in our patients. Perhaps we

should. In a study of 13,043 patients withType 2 diabetes, peripheral neuropathywas associated with a 33% higher risk ofadverse cardiovascular events, even whenadjusted from other known risk factorsFigure 2. (see page 1837)Dr Margariti (see page 1823) discusses

the importance of these findings and spec-ulates that “interventions to preciselytarget risk factor control might attenuatethe excess cardiovascular risk amongthose with peripheral neuropathy”. Shereminds us that cardiac autonomic neuro-nopathy in diabetics is also associatedwith increased microvascular complica-tions and raises the question of whetherdiabetic neuropathy is an indicator ofendothelial cell damage which mightexplain the association with increased car-diovascular risk.A translational medicine article (see

page 1825) reviews the status of tissueengineering for heart valve and vesselreplacement grafts. Promising data areemerging that synthetic materials, treatedwith biologically active factors, mightallow implantation of a “scaffold” thatwill allow growth of the patient’s owncells to form a new blood vessel or heartvalve. This article provides a readablesummary of the science behind this

exciting approach that may soon be a clin-ical reality Figure 3.

The Education in Heart article (seepage 1886) in this issue provides an over-view of testing approaches for ischemicheart disease by Professors Yilmaz andSechtum. This balanced presentation sum-marizes the advantages and disadvantagesof stress echocardiography, nuclear perfu-sion imaging, cardiac magnetic resonanceimaging and computer tomographicimaging of the coronary arteries. Therealso is a brief discussion of microvascularcoronary disease and coronary spasm.

The Image Challenge (see page 1898)in this issue makes an important educa-tional point. See if you can diagnose thecause of myocardial infarction in thisyoung woman. If you disagree with theanswer or have additional comments, usethe “Submit a response” button to theright of the full text article online.

To cite Otto CM. Heart 2014;100:1819–1820.

Heart 2014;100:1819–1820.doi:10.1136/heartjnl-2014-307038

Figure 3 Representation of synthetic scaffold material for vascular and valvular replacement grafts. Synthetic fibres resembling a 3D extracellularmatrix environment can be acquired using techniques like electrospinning, and facilitate cell infiltration and adhesion. Within the fibres, local releaseor presentation of specific factors can guide cell differentiation. The timing and presentation of incorporated factors depends on how they areincorporated into the fibres, varying from strongly bound, minimally leaking dynamics to loosely associated, burst release dynamics. The variousapproaches can be combined to mimic elements of the in vivo damage response, affording elaborate control over the subsequent cellular responseand tissue regeneration. Additional artwork courtesy of Marc Simonet and Rogier Trompert.

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