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{\u0022basePath\u0022:\u0022\\\/\u0022,\u0022pathPrefix\u0022:\u0022\u0022,\u0022highwire\u0022:{\u0022markup\u0022:[{\u0022requested\u0022:\u0022full-text\u0022,\u0022variant\u0022:\u0022full-text\u0022,\u0022view\u0022:\u0022full\u0022,\u0022pisa\u0022:\u0022spmdc;6\\\/1\\\/10\u0022},{\u0022requested\u0022:\u0022long\u0022,\u0022variant\u0022:\u0022full-text\u0022,\u0022view\u0022:\u0022full\u0022,\u0022pisa\u0022:\u0022spmdc;6\\\/1\\\/10\u0022}],\u0022ac\u0022:{\u0022spmdc;6\\\/1\\\/10\u0022:{\u0022access\u0022:{\u0022reprint\u0022:true,\u0022full\u0022:true},\u0022pisa_id\u0022:\u0022spmdc;6\\\/1\\\/10\u0022,\u0022atom_uri\u0022:\u0022\u0022,\u0022jcode\u0022:\u0022spmdc\u0022}}},\u0022googleanalytics\u0022:{\u0022trackOutbound\u0022:1,\u0022trackMailto\u0022:1,\u0022trackDownload\u0022:1,\u0022trackDownloadExtensions\u0022:\u00227z|aac|arc|arj|asf|asx|avi|bin|csv|doc(x|m)?|dot(x|m)?|exe|flv|gif|gz|gzip|hqx|jar|jpe?g|js|mp(2|3|4|e?g)|mov(ie)?|msi|msp|pdf|phps|png|ppt(x|m)?|pot(x|m)?|pps(x|m)?|ppam|sld(x|m)?|thmx|qtm?|ra(m|r)?|sea|sit|tar|tgz|torrent|txt|wav|wma|wmv|wpd|xls(x|m|b)?|xlt(x|m)|xlam|xml|z|zip\u0022,\u0022trackUrlFragments\u0022:1},\u0022ajaxPageState\u0022:{\u0022js\u0022:{\u0022sites\\\/all\\\/libraries\\\/cluetip\\\/jquery.cluetip.js\u0022:1,\u0022sites\\\/all\\\/libraries\\\/cluetip\\\/lib\\\/jquery.hoverIntent.js\u0022:1,\u0022sites\\\/all\\\/libraries\\\/cluetip\\\/lib\\\/jquery.bgiframe.min.js\u0022:1,\u0022sites\\\/all\\\/modules\\\/highwire\\\/highwire\\\/plugins\\\/highwire_markup_process\\\/js\\\/highwire_at_symbol.js\u0022:1,\u0022sites\\\/all\\\/modules\\\/highwire\\\/highwire\\\/plugins\\\/highwire_markup_process\\\/js\\\/highwire_article_reference_popup.js\u0022:1,\u0022sites\\\/all\\\/modules\\\/contrib\\\/google_analytics\\\/googleanalytics.js\u0022:1,\u00220\u0022:1}}});\n\/\/--\u003E\u003C!]]\u003E\n\u003C\/script\u003E\n\u003Clink type=\u0022text\/css\u0022 rel=\u0022stylesheet\u0022 href=\u0022\/\/d282kpwvnogo5m.cloudfront.net\/sites\/default\/files\/advagg_css\/css__ce2QY63WIanKyr8eSq7eavr1XQRRmFD6ZSmwpyJi8lM__zXwFqpqmxrZOXXcd_TpBQpjuELbmIP9wBR5UuTDWAO4__YJWWMMdfCJuAFm5cUEp88OsodhO3ZA-2lzRfoBsSlk4.css\u0022 media=\u0022all\u0022 \/\u003E\n\u003Clink rel=\u0027stylesheet\u0027 type=\u0027text\/css\u0027 href=\u0027\/sites\/all\/modules\/contrib\/panels\/plugins\/layouts\/onecol\/onecol.css\u0027 \/\u003E\u003C\/head\u003E\u003Cbody\u003E\u003Cdiv class=\u0022panels-ajax-tab-panel panels-ajax-tab-panel-sageoa-tab-art\u0022\u003E\u003Cdiv class=\u0022panel-display panel-1col clearfix\u0022 \u003E\n  \u003Cdiv class=\u0022panel-panel panel-col\u0022\u003E\n    \u003Cdiv\u003E\u003Cdiv class=\u0022panel-pane pane-highwire-markup\u0022 \u003E\n  \n      \n  \n  \u003Cdiv class=\u0022pane-content\u0022\u003E\n    \u003Cdiv class=\u0022highwire-markup\u0022\u003E\u003Cdiv xmlns=\u0022http:\/\/www.w3.org\/1999\/xhtml\u0022 id=\u0022content-block-markup\u0022 xmlns:xhtml=\u0022http:\/\/www.w3.org\/1999\/xhtml\u0022\u003E\u003Cdiv class=\u0022article fulltext-view \u0022\u003E\u003Cspan class=\u0022highwire-journal-article-marker-start\u0022\u003E\u003C\/span\u003E\u003Cdiv class=\u0022section abstract\u0022 id=\u0022abstract-1\u0022\u003E\u003Ch2\u003ESummary\u003C\/h2\u003E\n            \u003Cp id=\u0022p-1\u0022\u003E\u201cIn at least 25% of patients with heart failure, some form of ventricular conduction delay will complicate the course of their disease,\u201d according to David A. Kass, MD, Division of Cardiology, Johns Hopkins University School of Medicine.\u003C\/p\u003E\n            \u003Cp id=\u0022p-2\u0022\u003EDr. Kass noted that all rhythm disturbances create electrical \u201cdissonance\u201d in electrical activation and mechanical contraction between and\/or within ventricles, reducing pump efficiency and lowering ejection fraction.\u003C\/p\u003E\n         \u003C\/div\u003E\u003Cul class=\u0022kwd-group\u0022\u003E\u003Cli class=\u0022kwd\u0022\u003Earrhythmias\u003C\/li\u003E\u003Cli class=\u0022kwd\u0022\u003Einterventional\u003C\/li\u003E\u003C\/ul\u003E\u003Cdiv class=\u0022section\u0022 id=\u0022sec-1\u0022\u003E\n         \n         \u003Cp id=\u0022p-3\u0022\u003E\u201cIn at least 25% of patients with heart failure, some form of ventricular conduction delay will complicate the course of their disease,\u201d according to David A. Kass, MD, Division of Cardiology, Johns Hopkins University School of Medicine.\u003C\/p\u003E\n         \u003Cp id=\u0022p-4\u0022\u003EDr. Kass noted that all rhythm disturbances create electrical \u201cdissonance\u201d in electrical activation and mechanical contraction between and\/or within ventricles, reducing pump efficiency and lowering ejection fraction.\u003C\/p\u003E\n         \u003Cp id=\u0022p-5\u0022\u003EThese intra- and interventricular conduction delays are associated with increased all-cause mortality and sudden cardiac death (SCD). \u201cConduction delays can lead to changes in molecular signaling, functional myocardial work area, calcium handling, and conduction dynamics,\u201d Dr. Kass said. \u201cWhat starts as simply an electrical delay quickly becomes far worse.\u201d\u003C\/p\u003E\n         \u003Cp id=\u0022p-6\u0022\u003ERecent genomics studies with mice point to one of the reasons cardiac dyssynchrony can be so dangerous: ventricular matrix remodeling begins very quickly after onset of ventricular pacing contraction abnormalities. \u201cThis is not a situation where pathological changes take years to develop and create problems,\u201d observed Dr. Kass. \u201cWhat the animal studies tell us is that from the moment asynchrony begins the heart begins to compensate and remodel.\u201d\u003C\/p\u003E\n         \u003Cp id=\u0022p-7\u0022\u003EEnter cardiac resynchronization therapy (CRT). Dr. Kass noted that the evidence to date \u201cconfirms that CRT works well to enhance systolic function at a reduced energy cost and oxygen demand. CRT is like tuning up a car,\u201d he said. \u201cIt doesn\u0027t repair worn or failing parts\u2014but it helps them to work at their maximum efficiency, and for longer than they might otherwise.\u201d\u003C\/p\u003E\n      \u003C\/div\u003E\u003Cdiv class=\u0022section\u0022 id=\u0022sec-2\u0022\u003E\n         \u003Ch2 class=\u0022\u0022\u003EEvidence from Clinical Trials\u003C\/h2\u003E\n         \u003Cp id=\u0022p-8\u0022\u003EDr. William T. Abraham, Division of Cardiovascular Medicine, Ohio State University, discussed the data. \u201cThe weight of evidence supporting CRT is substantial,\u201d he said. \u201cMore than four thousand patients have been collectively studied in CRT trials to date. Across the board we have seen consistent improvement in functional cardiac status and increased exercise capacity after CRT. There is also compelling evidence supporting CRT\u0027s association with left ventricular regression (\u201creverse remodeling\u201d), reduced left ventricular volumes and dimensions, and increased ejection fractions.\u201d\u003C\/p\u003E\n         \u003Cp id=\u0022p-9\u0022\u003E\u201cThe InSync Trial was among the earliest studies that supported long-term clinical benefits of CRT in advanced heart failure,\u201d Dr. Abraham said. A series of trials followed, including the MUSTIC, MIRACLE, and MIRACLE ICD trials. \u201cAll of these studies consistently demonstrated statistically significant improvements associated with CRT in quality of life, heart failure staging, and exercise tolerance, along with left ventricular reverse remodeling,\u201d said Dr. Abraham. \u201cSome of the studies also suggested reductions in morbidity and mortality.\u201d\u003C\/p\u003E\n         \u003Cdiv id=\u0022F1\u0022 class=\u0022fig pos-float  odd\u0022\u003E\u003Cdiv class=\u0022highwire-figure\u0022\u003E\u003Cdiv class=\u0022fig-inline-img-wrapper\u0022\u003E\u003Cdiv class=\u0022fig-inline-img\u0022\u003E\u003Ca href=\u0022http:\/\/d282kpwvnogo5m.cloudfront.net\/content\/spmdc\/6\/1\/10\/F1.large.jpg?width=800\u0026amp;height=600\u0026amp;carousel=1\u0022 title=\u0022\u0022 class=\u0022fragment-images colorbox-load\u0022 rel=\u0022gallery-fragment-images-1382808215\u0022 data-figure-caption=\u0022\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003E\u003Cimg class=\u0022fragment-image\u0022 alt=\u0022Figure1\u0022 src=\u0022http:\/\/d282kpwvnogo5m.cloudfront.net\/content\/spmdc\/6\/1\/10\/F1.medium.gif\u0022\/\u003E\u003C\/a\u003E\u003C\/div\u003E\u003C\/div\u003E\u003Cul class=\u0022highwire-figure-links inline\u0022\u003E\u003Cli class=\u00220 first\u0022\u003E\u003Ca href=\u0022http:\/\/d282kpwvnogo5m.cloudfront.net\/content\/spmdc\/6\/1\/10\/F1.large.jpg?download=true\u0022 class=\u0022highwire-figure-link highwire-figure-link-download\u0022 title=\u0022Download Figure1\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003EDownload figure\u003C\/a\u003E\u003C\/li\u003E\u003Cli class=\u00221\u0022\u003E\u003Ca href=\u0022http:\/\/d282kpwvnogo5m.cloudfront.net\/content\/spmdc\/6\/1\/10\/F1.large.jpg\u0022 class=\u0022highwire-figure-link highwire-figure-link-newtab\u0022 target=\u0022_blank\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003EOpen in new tab\u003C\/a\u003E\u003C\/li\u003E\u003Cli class=\u00222 last\u0022\u003E\u003Ca href=\u0022\/highwire\/powerpoint\/16083\u0022 class=\u0022highwire-figure-link highwire-figure-link-ppt\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003EDownload powerpoint\u003C\/a\u003E\u003C\/li\u003E\u003C\/ul\u003E\u003C\/div\u003E\u003C\/div\u003E\n         \u003Cp id=\u0022p-10\u0022\u003EDr. Abraham noted that a particularly engaging research question is the role of CRT in milder forms of heart failure. Should CRT be utilized earlier, in patients with less severe disease? \u201cThe REVERSE trial is looking at this question right now. We should have data within the next 3 to 4 years,\u201d Dr. Abraham said. Meanwhile, the PROSPECT trial may offer preliminary data in the next few months on the role of diagnostic imaging as a tool for patient selection for CRT, according to Dr. Abraham.\u003C\/p\u003E\n      \u003C\/div\u003E\u003Cdiv class=\u0022section\u0022 id=\u0022sec-3\u0022\u003E\n         \u003Ch2 class=\u0022\u0022\u003ECardiac Imaging and CRT: Potential and Promise\u003C\/h2\u003E\n         \u003Cp id=\u0022p-11\u0022\u003ECardiac imaging data from PROSPECT and other studies is eagerly anticipated, said Jeroen J. Bax, MD, Department of Cardiology, Leiden University Medical Center, The Netherlands. While imaging modalities are not yet included in the ACC\/AHA CRT guidelines, they are a critical element in the evolution of CRT protocols.\u003C\/p\u003E\n         \u003Cp id=\u0022p-12\u0022\u003EDr. Bax noted that despite firm evidence of CRT\u0027s efficacy in a majority of patients, between 25 and 30 percent who receive CRT are what he termed \u201cnonresponders.\u201d This phenomenon, Dr. Bax said, \u201chas generally been attributed to poor patient selection. To avoid unnecessary medical expenses as well as procedure risks, we must reduce the number of nonresponders. So how do we do a better job of patient selection when considering CRT?\u201d At least one answer, Dr. Bax contends, lies in bringing some form of cardiac imaging to the patient selection criteria.\u003C\/p\u003E\n         \u003Cp id=\u0022p-13\u0022\u003E\u201cMany investigators as well as working cardiologists recognize that imaging must play a role,\u201d Dr. Bax said. Several studies have noted that an important predictor of non-response to CRT is dyssynchrony within the left ventricle (interventricular dyssynchrony). However, a wide QRS complex may not be the single hallmark of substantial left ventricular dyssynchrony. \u201cThis point is supported by recent studies that demonstrate poor prediction of success when only QRS duration is used,\u201d Dr. Bax said. \u201cECG alone is not enough to weed out responders from nonresponders.\u201d\u003C\/p\u003E\n         \u003Cp id=\u0022p-14\u0022\u003EDr. Bax described research done by his group using tissue Doppler imaging (TDI) to evaluate left ventricular dyssynchrony. (The investigators defined left ventricular dyssynchrony as an electromechanical delay seen on TDI between the septum and lateral wall of \u0026gt;60 ms.) \u201cWe demonstrated that improved identification of responders using TDI in concert with ECG was possible before implantation of a CRT system,\u201d according to Dr. Bax. \u201cA wide QRS may not, by itself, adequately reflect left ventricular dyssynchrony. Indeed, some patients with a wide QRS may not have substantial LV dyssynchrony. More research is needed\u2014but if the data ultimately supports imaging modalities among CRT criteria, we may improve patient selection and response.\u201d\u003C\/p\u003E\n      \u003C\/div\u003E\u003Cdiv class=\u0022section\u0022 id=\u0022sec-4\u0022\u003E\n         \u003Ch2 class=\u0022\u0022\u003ECRT: Cost-Effective or Too Costly?\u003C\/h2\u003E\n         \u003Cp id=\u0022p-15\u0022\u003EWith CRT gaining ground as a treatment modality, Mark A. Hlatky, MD, Professor of Health Research and Policy, Stanford University, discussed the technique\u0027s cost-effectiveness.\u003C\/p\u003E\n         \u003Cp id=\u0022p-16\u0022\u003EIntroduction of new medical technologies is a major reason that health care costs continue to rise, Dr. Hlatky observed. \u201cThe initial cost of implanting a CRT device exceeds $30,000, but the total cost may be even higher depending on its effect on the overall cost of treatment in any given patient. There may be additional costs of treating device complications\u2014 and still more costs if the patient is a non-responder.\u201d\u003C\/p\u003E\n         \u003Cp id=\u0022p-17\u0022\u003EBut CRT may be worth its price tag if it consistently offers significant improvements in survival and quality of life. Dr. Hlatky described cost-effectiveness analysis (CEA), a mathematical tool applied in health care analyses. \u201cCEA calculates dollars spent per number of quality-adjusted life-years (QALY) added by any given medical treatment,\u201d Dr. Hlatky explained. Citing a paper that estimated the cost-effectiveness of CRT at more than $100,000 per life-year gained (Nichol et al. \u003Cem\u003EAnn Intern Med.\u003C\/em\u003E 2004); Dr. Hlatky noted that \u201cthis is not an advantage if compared to the standard benchmark of $50,000 per life-year gained.\u201d\u003C\/p\u003E\n         \u003Cp id=\u0022p-18\u0022\u003EBut the Nichol analysis also showed that the cost-effectiveness of CRT is \u201cvery sensitive to variations in clinical efficacy,\u201d suggesting that improved patient selection to optimize CRT outcomes will confer both clinical and economic importance. \u201cAs our patients do better with CRT, its cost will drop.\u201d\u003C\/p\u003E\n         \u003Cp id=\u0022p-19\u0022\u003E\u201cThe overall weight of evidence suggests that CRT improves functional status and quality of life,\u201d Dr. Hlatky said. \u201cAnd CEA is a helpful instrument to tell us we\u0027re on the right track financially as well. But as with so many arenas of medicine, more studies are needed.\u201d\u003C\/p\u003E\n      \u003C\/div\u003E\u003Cul class=\u0022copyright-statement\u0022\u003E\u003Cli class=\u0022fn\u0022 id=\u0022copyright-statement-1\u0022\u003E\u00a9 2006 MD Conference Express\u003C\/li\u003E\u003C\/ul\u003E\u003Cspan class=\u0022highwire-journal-article-marker-end\u0022\u003E\u003C\/span\u003E\u003C\/div\u003E\u003Cspan id=\u0022related-urls\u0022\u003E\u003C\/span\u003E\u003C\/div\u003E\u003Ca href=\u0022http:\/\/mdc.sagepub.com\/content\/6\/1\/10.abstract\u0022 class=\u0022hw-link hw-link-article-abstract\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003EView Summary\u003C\/a\u003E\u003C\/div\u003E  \u003C\/div\u003E\n\n  \n  \u003C\/div\u003E\n\u003C\/div\u003E\n  \u003C\/div\u003E\n\u003C\/div\u003E\n\u003C\/div\u003E\u003Cscript type=\u0022text\/javascript\u0022 src=\u0022http:\/\/mdc.sagepub.com\/sites\/all\/modules\/highwire\/highwire\/plugins\/highwire_markup_process\/js\/highwire_figures.js?nzm641\u0022\u003E\u003C\/script\u003E\n\u003Cscript type=\u0022text\/javascript\u0022 src=\u0022http:\/\/mdc.sagepub.com\/sites\/all\/modules\/highwire\/highwire\/plugins\/highwire_markup_process\/js\/highwire_openurl.js?nzm641\u0022\u003E\u003C\/script\u003E\n\u003C\/body\u003E\u003C\/html\u003E"}