{"id":908,"date":"2015-12-02T15:30:35","date_gmt":"2015-12-02T15:30:35","guid":{"rendered":"http:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/?p=908"},"modified":"2017-08-21T11:15:51","modified_gmt":"2017-08-21T11:15:51","slug":"primary-care-corner-with-geoffrey-modest-md-atrial-fibrillation-should-we-look-harder-for-it","status":"publish","type":"post","link":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2015\/12\/02\/primary-care-corner-with-geoffrey-modest-md-atrial-fibrillation-should-we-look-harder-for-it\/","title":{"rendered":"Primary Care Corner with Geoffrey Modest MD: Atrial Fibrillation &#8211; Should We Look Harder For It?"},"content":{"rendered":"<p><strong>By Dr. Geoffrey Modest<\/strong><\/p>\n<p>Over the years, I have had several patients who have presented with significant strokes related to\u00a0previously-undetected atrial fibrillation (AF).\u00a0I\u00a0have also had a couple of patients with dementia and no evident prior\u00a0stroke, who on workup\u00a0have had multiple small infarcts, again possibly related to AF. In this light, there was an interesting editorial in JAMA\u00a0(see\u00a0JAMA 2015; 314: 1911)\u00a0\u200b raising the question of whether we should be screening regularly\u00a0for AF. Although not part of their\u00a0argument, I think that the potential and not clearly well-defined relationship between AF and cognitive decline may be part of the incentive to screen\u00a0(see below).\u00a0Their argument is basically (all references are in the text):<\/p>\n<ul>\n<li>AF is really common (1 in 4 lifetime risk in those &gt;40, with 0.5% age 40, increasing to\u00a0up to 15% at age 80)<\/li>\n<li>Treatment is pretty effective: oral anticoagulation (OA)\u00a0reduces stroke risk by 2\/3 and mortality by 1\/3, with relatively small risk of major bleeding (hence the use of pretty universal guidelines to anticoagulate\u00a0if the CHA<sub>2<\/sub>DS<sub>2<\/sub>-VASc score is 2 or greater)<\/li>\n<li>The effectiveness of OA is much more impressive than many of the other recommended screening activities\/interventions<\/li>\n<li>AF is a common cause of stroke:\u00a0a recent Swedish Stroke\u00a0survey of 94K patients with ischemic stroke\u00a0found AF in 31K of them, which is probably an underestimate\u00a0(see Stroke\u00a02014; 45: 2599)<\/li>\n<li>So, can asymptomatic\u00a0AF be picked up by screening??\n<ul>\n<li>A systematic review found that in 123K patients, a single screen\u00a0using either pulse palpation or\u00a0EKG found\u00a0undiagnosed AF\u00a0in 1% of people overall and 1.4% of those &gt;65yo.<\/li>\n<li>The European Society of Cardiology 2012 guidelines on AF\u00a0recommended\u00a0routine checking the pulse of\u00a0patients &gt;=65 years of age, followed by an electrocardiogram as needed, for the\u00a0timely detection\u00a0of AF.<\/li>\n<li>There are\u00a0cheap handheld or smartphone\u00a0EKG-type\u00a0devices which may be useful. Preliminary studies suggest an AF pickup of 1.5-3.0%, all of whom qualified for OA.<\/li>\n<\/ul>\n<\/li>\n<li>Prognosis of incidental AF\n<ul>\n<li>A UK study found people with incidentally detected asymptomatic AF had stroke rate of 4% in 1.5 years\u00a0and all-cause mortality of 7% in those untreated. Those on warfarin had stroke\u00a0and death rates of 1% and 4% respectively<\/li>\n<\/ul>\n<\/li>\n<li>Cost-effectiveness\n<ul>\n<li>\u200bSmartphone based screening in those 65-85yo:\u00a0$4066 per quality-adjusted life-year gained, $20,695 per stroke prevented (i.e., better than most preventative interventions). This age\u00a0group has high incidence of AF and\u00a0essentially all people &gt;65 would qualify for OA<\/li>\n<\/ul>\n<\/li>\n<li>The authors suggest that we in the US follow the European guidelines and check the pulse during office visits.<\/li>\n<\/ul>\n<p>So,\u00a0AF has potentially devastating consequences, with significant morbidity and mortality. A few points:<\/p>\n<ul>\n<li>The relationship between\u00a0AF and\u00a0multi-infarct dementia (MID)\u00a0is not clear,\u00a0and AF is not listed as a risk factor for MID by the NIH. But there was a population-based study (Rotterdam Study) which followed 6514 patients aged &gt;55 and\u00a0found a strong association between dementia and impaired\u00a0cognitive function in those who developed\u00a0AF and were\u00a0&lt;67 yo\u00a0(see <a href=\"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2015\/10\/30\/primary-care-corner-with-geoffrey-modest-md-atrial-fibrillation-and-dementia\/\">https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2015\/10\/30\/primary-care-corner-with-geoffrey-modest-md-atrial-fibrillation-and-dementia\/<\/a>). A recent article on AF and cognition (see<strong>\u00a0<\/strong>Stroke\u00a02015;46:3316-3321) noted that:\n<ul>\n<li>The mechanism is unclear (?multiple small emboli, ?AF-associated\u00a0cerebral hypoperfusion)&#8211; and, evidently, if the mechanism were the latter, it would be hard to attribute the cognitive decline to AF, since there would not necessarily be dectectable infarcts on brain\u00a0imaging.<\/li>\n<li>There have been meta-analyses (see Neurology 2011; 76:914, Ann Intern Med 2013; 158: 338)\u00a0finding &gt;2-fold increased risk of cognitive impairment\u00a0in those with AF and subsequent stroke.<\/li>\n<li>A few meta-analyses have found a 40% increased risk of dementia in those with AF and without stroke (see Heart Rhythm 2012; 9: 1761).<\/li>\n<li>But, as we know, associations are not necessarily causal, and\u00a0AF\/dementia do have shared risk factors.<\/li>\n<li>\u200bAnd, one of my\u00a0concerns is that\u00a0in many of\u00a0these studies, our measurement of dementia (e.g. Mini-mental state exam)\u00a0is a very blunt instrument and does not pick up subtle changes which may be very significant for the person at that time,\u00a0and ultimately\u00a0over years, progress to our definition of dementia.<\/li>\n<\/ul>\n<\/li>\n<li>Given the potential devastation of stroke\/cognitive impairment, as well as the potential damage from other peripheral emboli, it seems to me that we should have a randomized controlled\u00a0intervention\u00a0study looking at treatment for AF and its overall effects. For that study, there would need to be some agreement on the following:\n<ul>\n<li>What is AF? \u00a0Is it a random pick-up on a routine exam (i.e.,\u00a01-minute evaluation for an irregular pulse and then followed by an EKG)? Is it a 24-hour Holter monitor, or a 30-day event monitor??? (clearly there are people with very intermittent, paroxysmal AF who have clinical emboli, and checking a pulse is\u00a0going to find those with sustained AF\u00a0predominantly)<\/li>\n<li>\u200bWhat is cognitive decline? This study should\u00a0include\u00a0doing\u00a0a\u00a0more extensive evaluation for\u00a0subtle cognitive decline (e.g., the Cardiovascular Health Study did look at a few instruments, including the Modified MMSE and Digit Symbol Substitution Test, as well as telephone interviews, finding those with incident AF had faster and\u00a0earlier onset cognitive decline &#8212; see Neurology 2013; 81: 119).<\/li>\n<\/ul>\n<\/li>\n<li>But at this point, I will continue doing what I have been doing: pretty much always checking my own manual blood pressures on patients, after\u00a0waiting several minutes in a reasonably relaxed atmosphere\u00a0(as per prior blogs). In this setting\u00a0I\u00a0sometimes do\u00a0pick\u00a0up AF (and, by the way, the automated cuffs are pretty unreliable for blood pressure measurement\u00a0in\u00a0those with AF, further supporting checking manual blood pressures in those &gt;50yo or so).\u00a0But I\u00a0will now\u00a0add on checking the pulse for irregularities, and then follow the guidelines for treatment when I find AF. And, perhaps more aggressive assessments for AF than pulse-checking at the time of exams\u00a0should be done (given the high prevalence of AF, especially in our aging population, a more intensive AF assessment such as Holter monitoring could be\u00a0a very cost-effective strategy, especially given the dramatic quality-of-life issues associated with stroke\/dementia). But this would need studies to determine.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Primary Care Corner with Geoffrey Modest MD: Atrial Fibrillation &#8211; Should We Look Harder For It?  [&#8230;]<\/p>\n<p><a class=\"btn btn-secondary understrap-read-more-link\" href=\"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2015\/12\/02\/primary-care-corner-with-geoffrey-modest-md-atrial-fibrillation-should-we-look-harder-for-it\/\">Read More&#8230;<\/a><\/p>\n","protected":false},"author":148,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[14283],"tags":[],"class_list":["post-908","post","type-post","status-publish","format-standard","hentry","category-archive"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/posts\/908","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/users\/148"}],"replies":[{"embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/comments?post=908"}],"version-history":[{"count":0,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/posts\/908\/revisions"}],"wp:attachment":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/media?parent=908"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/categories?post=908"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/tags?post=908"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}