{"id":6001,"date":"2026-10-19T09:48:21","date_gmt":"2026-10-19T09:48:21","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-laeknavisindum-sindri-aron-viktorsson\/"},"modified":"2026-10-19T09:48:21","modified_gmt":"2026-10-19T09:48:21","slug":"doktorsvorn-i-laeknavisindum-sindri-aron-viktorsson","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-laeknavisindum-sindri-aron-viktorsson\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed l\u00e6knav\u00edsindum &#8211; Sindri Aron Viktorsson"},"content":{"rendered":"<div class=\"field-items\">\n<div class=\"field-item even\" property=\"content:encoded\">\n<p>F\u00f6studaginn\u00a029.\u00a0n\u00f3vember\u00a0ver\u00a0Sindri Aron Viktorsson\u00a0doktorsritger\u00f0 s\u00edna \u00ed l\u00e6knav\u00edsindum vi\u00f0 L\u00e6knadeild H\u00e1sk\u00f3la \u00cdslands. Ritger\u00f0in ber heiti\u00f0:\u00a0<strong>\u00d3s\u00e6\u00f0arlokuskipti\u00a0vegna\u00a0loku\u00ferengsla\u00a0\u00e1 \u00cdslandi \u2013 \u00c1bendingar,\u00a0fylgikvillar\u00a0og \u00e1rangur.\u00a0Surgical\u00a0Aortic\u00a0Valve\u00a0Replacement\u00a0for\u00a0Aortic\u00a0Stenosis\u00a0in\u00a0Iceland \u2013\u00a0Indications,\u00a0complications,\u00a0and\u00a0outcome.<\/strong>\u00a0<\/p>\n<p>Andm\u00e6lendur eru\u00a0dr. Anders\u00a0Alb\u00e5ge, yfirl\u00e6knir og lektor\u00a0vi\u00f0 Uppsalah\u00e1sk\u00f3la,\u00a0og\u00a0dr. Gunnar \u00de\u00f3r Gunnarsson, lektor vi\u00f0 L\u00e6knadeild H\u00e1sk\u00f3la \u00cdslands.\u00a0\u00a0<\/p>\n<p>Umsj\u00f3narkennari og lei\u00f0beinandi var dr.\u00a0T\u00f3mas Gu\u00f0bjartsson,\u00a0pr\u00f3fessor\u00a0vi\u00f0 L\u00e6knadeild. Auk\u00a0hans\u00a0s\u00e1tu \u00ed doktorsnefnd\u00a0dr.\u00a0Arnar Geirsson, d\u00f3sent\u00a0vi\u00f0 l\u00e6knadeild Yale-h\u00e1sk\u00f3la, dr.\u00a0Karl K. Andersen, pr\u00f3fessor\u00a0vi\u00f0 L\u00e6knadeild,\u00a0Martin Ingi Sigur\u00f0sson, pr\u00f3fessor\u00a0vi\u00f0 L\u00e6knadeild\u00a0og\u00a0Thor Aspelund, pr\u00f3fessor\u00a0vi\u00f0 Mi\u00f0st\u00f6\u00f0 \u00ed l\u00fd\u00f0heilsuv\u00edsindum.\u00a0<\/p>\n<p>Engilbert Sigur\u00f0sson, pr\u00f3fessor og forseti L\u00e6knadeildar, stj\u00f3rnar ath\u00f6fninni sem fer fram \u00ed H\u00e1t\u00ed\u00f0asal H\u00e1sk\u00f3la \u00cdslands og hefst kl.\u00a09:00.<\/p>\n<p>\u00a0<\/p>\n<p>\u00a0<\/p>\n<p><strong>\u00c1grip af ranns\u00f3kn<\/strong><\/p>\n<p>\u00d3s\u00e6\u00f0arlokuskipti eru \u00f6nnur algengasta opna hjartaa\u00f0ger\u00f0in \u00ed hinum vestr\u00e6na heimi, enda talin \u00e1rangursr\u00edk me\u00f0fer\u00f0 vi\u00f0 \u00f3s\u00e6\u00f0arloku\u00ferengslum. A\u00f0ger\u00f0in er umfangsmikil og fylgikvillar gera oft vart vi\u00f0 sig. \u00dear m\u00e1 nefna n\u00fdtilkomi\u00f0 g\u00e1ttatif, br\u00e1\u00f0an n\u00fdrnaska\u00f0a (BNS), endura\u00f0ger\u00f0 vegna mikillar bl\u00e6\u00f0ingar, s\u00fdkingar og hjartsl\u00e1ttar\u00f3regla sem s\u00ed\u00f0an krefst \u00edgr\u00e6\u00f0slu varanlegs gangr\u00e1\u00f0s. Fyrir nokkrum \u00e1rum kom \u00f3s\u00e6\u00f0arloku\u00edsetning (TAVI) til s\u00f6gunnar en \u00fe\u00e1 er l\u00edfr\u00e6nni \u00f3s\u00e6\u00f0arloku komi\u00f0 fyrir me\u00f0 \u00fer\u00e6\u00f0ingart\u00e6kni, oftast \u00ed gegnum n\u00e1raslag\u00e6\u00f0. \u00deessi n\u00fdja t\u00e6kni eykur mikilv\u00e6gi \u00feess a\u00f0 \u00feekkja betur \u00e1rangur hef\u00f0bundinna opinna \u00f3s\u00e6\u00f0arlokuskipta sem enn er helsta me\u00f0fer\u00f0in vi\u00f0 \u00f3s\u00e6\u00f0arloku\u00ferengslum.\u00a0<\/p>\n<p>Tilgangur ranns\u00f3knanna \u00ed \u00feessari ritger\u00f0 er a\u00f0 meta \u00e1bendingar, fylgikvilla og \u00fatkomu \u00f3s\u00e6\u00f0arlokuskipta vegna \u00f3s\u00e6\u00f0arloku\u00ferengsla \u00e1 \u00cdslandi \u00e1 allt a\u00f0 15 \u00e1ra t\u00edmabili. S\u00e9rstaklega var liti\u00f0 \u00e1 skammt\u00edma- og langt\u00edma fylgikvilla me\u00f0 s\u00e9rstaka \u00e1herslu \u00e1 langt\u00edmalifun, en einnig BNS og \u00edgr\u00e6\u00f0slu gangr\u00e1\u00f0s vegna hjartsl\u00e1ttartruflana eftir a\u00f0ger\u00f0ina.\u00a0\u00a0<\/p>\n<p>Ranns\u00f3knirnar fj\u00f3rar voru allar afturskygg\u00f0ar og n\u00e1\u00f0u til sj\u00faklinga sem gengust undir lokuskipti vegna \u00f3s\u00e6\u00f0arloku\u00ferengsla \u00e1 \u00cdslandi \u00e1 \u00e1runum 2002\u20132011 \u00ed ranns\u00f3knum I og II, en ranns\u00f3knir III og IV t\u00f3ku til \u00e1ranna 2002\u20132016. Sj\u00faklingar voru fundnir me\u00f0 leit \u00ed tveimur a\u00f0skildum gagnaskr\u00e1m og var 100% samr\u00e6mi milli skr\u00e1nna. \u00cdtarlegum g\u00f6gnum var safna\u00f0 \u00far sj\u00fakra- og a\u00f0ger\u00f0arskr\u00e1m en stu\u00f0st var vi\u00f0 s\u00e9rstakar mi\u00f0l\u00e6gar skr\u00e1r eins og n\u00fdrnaskilunarsk\u00e1 (ranns\u00f3kn II) og skr\u00e1 yfir gangr\u00e1\u00f0s\u00edsetningar \u00e1 Landsp\u00edtala (ranns\u00f3kn IV). Langt\u00edmalifun sj\u00faklinga var metin og borin saman vi\u00f0 \u00cdslendinga af sama aldri og kyni me\u00f0 Ederer II a\u00f0fer\u00f0inni (ranns\u00f3kn I). T\u00ed\u00f0ni BNS var sko\u00f0u\u00f0 s\u00e9rstaklega (rann\u00f3kn II) og \u00e1h\u00e6ttu\u00fe\u00e6ttir greindir me\u00f0 \u00fev\u00ed a\u00f0 nota fj\u00f6l\u00fe\u00e1tta logist\u00edska a\u00f0hvarfsgreiningu. Einnig voru kanna\u00f0ar breytingar \u00e1 t\u00ed\u00f0ni skammt\u00edma fylgikvilla (ranns\u00f3kn III) me\u00f0 notkun l\u00ednulegrar Poisson-greiningar, auk \u00feess sem langt\u00edma fylgikvillar og lifun voru metin. Loks var t\u00ed\u00f0ni \u00edgr\u00e6\u00f0slu varanlegs gangr\u00e1\u00f0s ranns\u00f6ku\u00f0, b\u00e6\u00f0i innan m\u00e1na\u00f0ar fr\u00e1 a\u00f0ger\u00f0inni en einnig vi\u00f0 langt\u00edmaeftirlit (ranns\u00f3kn IV) og meti\u00f0 hvort sj\u00faklingar v\u00e6ru \u00fe\u00e1 h\u00e1\u00f0ir gangr\u00e1\u00f0num.\u00a0<\/p>\n<p>\u00cd ranns\u00f3kn I reyndist eins \u00e1rs lifun eftir a\u00f0ger\u00f0 92% og fimm \u00e1ra lifun 82%. \u00dea\u00f0 reyndust samb\u00e6rilegar lifunart\u00f6lur vi\u00f0 erlendar ranns\u00f3knir en einnig lifun \u00cdslendinga af sama aldri og kyni (p = 0,08). T\u00ed\u00f0ni BNS \u00ed ranns\u00f3kn II var 22,5% og \u00fe\u00f6rfnu\u00f0ust 4,1% sj\u00faklinga n\u00fdrnaskilunar fyrst eftir a\u00f0ger\u00f0ina. \u00derj\u00e1t\u00edu daga d\u00e1nart\u00ed\u00f0ni reyndist 18% \u00ed h\u00f3pnum sem hlaut BNS samanbori\u00f0 vi\u00f0 2% hj\u00e1 vi\u00f0mi\u00f0unarh\u00f3pi (p &lt;0,001) og var 5 \u00e1ra lifun \u00ed s\u00f6mu h\u00f3pum 66% og 87% (p &lt;0,001). \u00cd fj\u00f6l\u00fe\u00e1ttagreiningu reyndist BNS vera sj\u00e1lfst\u00e6\u00f0ur forsp\u00e1r\u00fe\u00e1ttur 30 daga d\u00e1nart\u00ed\u00f0ni en ekki langt\u00edma lifunar. Ranns\u00f3kn III s\u00fdndi l\u00e6kkun \u00e1 t\u00ed\u00f0ni nokkurra skammt\u00edma fylgikvilla \u00e1 ranns\u00f3knart\u00edmanum, \u00fear me\u00f0 tali\u00f0 n\u00fdtilkomnu g\u00e1ttatifi eftir a\u00f0ger\u00f0 (p = 0,02), BNS (p &lt;0,001) og endura\u00f0ger\u00f0 vegna bl\u00e6\u00f0ingar (p = 0,02), en ekki s\u00e1st \u00fe\u00f3 markt\u00e6k l\u00e6kkun \u00e1 30 daga d\u00e1nart\u00ed\u00f0ni. Langvarandi hjartabilun og segarek voru algengustu langt\u00edma fylgikvillarnir. Varanlegum gangr\u00e1\u00f0 var komi\u00f0 fyrir hj\u00e1 3,9% sj\u00faklinga \u00e1 fyrstu 30 d\u00f6gunum eftir a\u00f0ger\u00f0, en 6,8% til vi\u00f0b\u00f3tar fengu \u00edgr\u00e6ddan gangr\u00e1\u00f0 \u00e1 eftirfylgdart\u00edmanum (mi\u00f0gildi 6,1 \u00e1r). Vi\u00f0 langt\u00edmaeftirlit reyndust 45% af 60 sj\u00faklingum vera h\u00e1\u00f0ir gangr\u00e1\u00f0num en g\u00e1ttasleglarof og sj\u00fakur s\u00ednushn\u00fatur voru algengustu \u00e1bendingar fyrir gangr\u00e1\u00f0s\u00edsetningu.\u00a0<\/p>\n<p>Ranns\u00f3knir I-IV s\u00fdna a\u00f0 lokuskipti eru \u00e1rangursr\u00edk me\u00f0fer\u00f0 vi\u00f0 \u00f3\u00e6\u00f0arloku\u00ferengslum. Auk \u00feess er lj\u00f3st a\u00f0 \u00e1rangur af \u00feessum umfangsmiklu skur\u00f0a\u00f0ger\u00f0um fer batnandi sem a\u00f0allega s\u00e9st \u00e1 l\u00e6gri t\u00ed\u00f0ni \u00fdmissa alvarlegra fylgikvilla. Hluti sj\u00faklinga greinist \u00fe\u00f3 enn me\u00f0 alvarlega fylgikvilla sem geta dregi\u00f0 \u00far l\u00edfsg\u00e6\u00f0um og jafnvel or\u00f0i\u00f0 \u00feeim a\u00f0 aldurtila. Mikilv\u00e6gt er a\u00f0 \u00e1tta sig betur \u00e1 \u00fev\u00ed hva\u00f0a sj\u00faklingar \u00fea\u00f0 eru sem farnast s\u00ed\u00f0ur eftir \u00f3s\u00e6\u00f0arlokuskipti \u00fev\u00ed \u00fear g\u00e6ti TAVI-a\u00f0ger\u00f0 veri\u00f0 heppilegri og \u00e1h\u00e6ttuminni valkostur.<\/p>\n<p>\u00a0<\/p>\n<p><strong>Um doktorsefni\u00f0<\/strong>\u00a0<\/p>\n<p>Sindri Aron\u00a0Viktorsson er f\u00e6ddur\u00a0\u00e1ri\u00f0 1988. Hann lauk Cand.\u00a0med. pr\u00f3fi fr\u00e1\u00a0H\u00e1sk\u00f3la \u00cdslands \u00e1ri\u00f0 2013.\u00a0Sindri Aron\u00a0hefur samhli\u00f0a doktorsn\u00e1mi\u00a0s\u00ednu sinnt kl\u00edn\u00edsku starfi vi\u00f0 skur\u00f0deild Landsp\u00edtala og n\u00fa s\u00ed\u00f0astli\u00f0i\u00f0 \u00e1r veri\u00f0 vi\u00f0 s\u00e9rn\u00e1m \u00ed almennum skur\u00f0l\u00e6kningum vi\u00f0\u00a0Dartmouth-Hitchcock-h\u00e1sk\u00f3lasj\u00fakrah\u00fasi\u00f0 \u00ed New\u00a0Hampshire, Bandar\u00edkjunum.\u00a0Foreldrar\u00a0Sindra Arons\u00a0eru\u00a0Viktor J\u00f3nsson\u00a0og\u00a0Gu\u00f0r\u00fan R\u00f6gn J\u00f3nsd\u00f3ttir. Maki\u00a0Sindra Arons\u00a0er\u00a0Hanna Krist\u00edn Skaftad\u00f3ttir\u00a0og d\u00f3ttir\u00a0\u00feeirra er\u00a0Emil\u00eda Sara Bjarnd\u00eds, 8 m\u00e1na\u00f0a. Fyrir \u00e1 Sindri Aron soninn Benedikt \u00c1rna, 7 \u00e1ra og auk \u00feess tvo\u00a0stj\u00fapsyni, Benedikt Bjarna, 11 \u00e1ra, og Mikael Bj\u00f6rn, 9 \u00e1ra.\u00a0<\/p>\n<p>\u00a0<\/p>\n<p><strong>Abstract<\/strong>\u00a0<\/p>\n<p>Surgical aortic valve replacement (SAVR) is the second most common open-heart operation in the western world, and it is still the gold standard in treating patients with aortic stenosis (AS). Although it is regarded as a safe and effective treatment, complications can occur, including postoperative atrial fibrillation (poAF), acute kidney injury (AKI), excessive bleeding that requires reoperation, infection, and arrythmia requiring permanent pacemaker placement. In recent years, transcatheter aortic valve implantation (TAVI) has emerged as a treatment option for AS, where a biological valve is implanted via catheterization, most commonly the femoral artery. The rapid development of this novel technology calls for detailed information on the application and efficacy of conventional SAVR, more so now than ever before.<\/p>\n<p>The aim of this thesis has been to evaluate the indications, complications, and clinical outcomes of SAVR for AS in a whole nation over a period of up to 15 years. Special consideration was given to short-term and long-term complications such as AKI and permanent pacemaker placement, and also to long-term survival.<\/p>\n<p>All of the studies performed were retrospective in nature and included all patients who underwent SAVR in Iceland for AS during the years 2002\u20122011 in Studies I and II, and during 2002\u20122016 in Studies III and IV. Patients were identified from two separate databases, with a 100% cross-match between the databases. Detailed data were collected on each patient from the medical records and operative notes, with specific data obtained from particular data registries such as a dialysis database (Study II) and a pacemaker database (Study IV). Long-term survival of the patients was estimated and compared to that of individuals from the Icelandic population of the same age and gender using the Ederer II method (Study I). The rate of AKI was calculated (Study II), with risk factors being analyzed using multivariable logistic regression. Changes in the incidence of short-term complications were assessed using a Poisson linear analysis (Study III), with long-term complications and survival also being examined. Finally, permanent pacemaker implantation incidence\u2015both within 30 days of the operation and in the long-term\u2015was examined (Study IV) while determining whether the patients were pacemaker-dependent.<\/p>\n<p>In Study I, one-year and five-year survival was 92% and 82%, respectively, which was comparable to that in other studies, and also relatively similar to the survival of Icelanders of the same age and gender (p = 0.08). The incidence of AKI in Study II was 22.5%, with postoperative dialysis being required in 4.1% of the patients. Mortality within 30 days was 18% in the AKI group and 2% in the non-AKI group (p &lt; 0.001), with a 5-year survival rate of 66% and 87%, respectively (p &lt; 0.001). In a multivariable analysis, AKI was found to be an independent predictor of operative mortality but not of long-term survival. Study III demonstrated the decline in the incidence of several short-term complications during the study period, including poAF (p = 0.02), AKI (p &lt; 0.001), and reoperation for bleeding (p = 0.02), with no significant change in operative mortality. Chronic heart failure and embolic events were the most common long-term complications. A permanent pacemaker was implanted in 3.9% of patients within the first 30 days after surgery, and 6.8% of all patients had a pacemaker implanted during follow-up (median 6.1 years). During long-term follow-up, 45% of the 60 patients were dependent on their pacemaker, with atrio-ventricular block and sick-sinus syndrome being the most common indications.<\/p>\n<p>Studies I\u2012IV demonstrate that SAVR is an effective treatment for AS. The outcome of the procedure is improving, as demonstrated by a decline in the incidence of several major complications. Even so, some patients do develop such complications, which can affect both morbidity and mortality. Thus, it is important to determine which patients are more likely to suffer from these serious complications, as TAVI may prove to be a better treatment alternative for them.<\/p>\n<\/div><\/div>","protected":false},"featured_media":1214,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2019-11-29T09:00:00+00:00","_phd_date_end":"2019-11-29T13:00:00+00:00","_phd_location":"","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"\u00d3s\u00e6\u00f0arlokuskipti vegna loku\u00ferengsla \u00e1 \u00cdslandi \u2013 \u00c1bendingar, fylgikvillar og \u00e1rangur. Surgical Aortic Valve Replacement for Aortic Stenosis in Iceland \u2013 Indications, complications, and outcome","_phd_source_url":"https:\/\/gamli.hi.is\/vidburdir\/doktorsvorn_i_laeknavisindum_sindri_aron_viktorsson","_phd_source_node_id":"325911","_phd_source_type":"vidburdir","_phd_member_id":209,"footnotes":""},"phd_school":[60,67],"phd_discipline":[69],"class_list":["post-6001","phd_defence","type-phd_defence","status-publish","has-post-thumbnail","hentry","phd_school-heilbrigdisvisindasvid","phd_school-laeknadeild","phd_discipline-phd-i-laeknavisindum"],"_links":{"self":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6001","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence"}],"about":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/types\/phd_defence"}],"version-history":[{"count":0,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6001\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media\/1214"}],"wp:attachment":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media?parent=6001"}],"wp:term":[{"taxonomy":"phd_school","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_school?post=6001"},{"taxonomy":"phd_discipline","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_discipline?post=6001"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}