Johannes Lagethon Bjørnstad

• Dukefoss, Henrik B.; Andresen, Kristoffer; Harbo, Markus Borge; Hasselberg, Nina Eide; Grødem, Herman & Korsæth, Truls [Show all 18 contributors for this article] (2026). Validation of shear wave elastography for assessing myocardial fibrosis in patients with end-stage heart failure. European Heart Journal-Cardiovascular Imaging. ISSN 2047-2404. 27(4), p. 778–787. doi: 10.1093/ehjci/jeaf375. Full text in Research Archive
• Bjørnstad, Johannes Lagethon; Waagan, Sandra Stedje; Tegnander, Tiril Karina & Longva, Anne Madsi (2025). Survival and cause of death after isolated primary aortic valve replacement at Oslo University Hospital (2012-2021): a retrospective registry-based study. Open heart. 12(1). doi: 10.1136/openhrt-2025-003312. Full text in Research Archive Show summary

  Background The treatment of aortic valve disease has changed following the introduction of transcatheter aortic valve replacement (TAVR). Hence, the selection of patients for surgical aortic valve replacement (AVR) is changing. Thus, we aimed to study survival and causes of death following surgical AVR at a large Scandinavian Centre in the period 2012–21. Methods Information about the surgical procedure, survival and cause of death was obtained from the National Norwegian Health Registries. The latest clinical information about the deceased patients was made available from the local hospitals and examined to evaluate the causes of death from The Norwegian Cause of Death Registry. Results From 2012 to 2021, the number of surgical implantations of aortic valve bioprostheses (AVR(b)) and patient age at the time of surgery decreased. Outcomes were excellent, with 30-day survival of 98.6% following AVR(b) and 99.8% following AVR(m). 1-year survival after AVR(b) improved from 96.4% in the first half to 98.4% in the second half of the study period, probably due to a reduction of operative risk during the study period. Non-cardiovascular mortality was the most frequent cause of death, followed by cancer, cardiovascular and valve-related death. Deaths due to cerebral bleeding or stroke were the least frequent with 10-year estimators of 1.3% and 1.6% following AVR(m) and AVR(b), respectively. The inter-rater reliability between The Norwegian Cause of Death Registry and the journal information provided was moderate, with an unweighted Cohen’s kappa of 0.56 (0.47–0.64). Conclusions Valve-related death and death from cerebral bleeding or stroke was rare after surgical AVR. Survival was high and improved during the study period. Surgical AVR may be performed safely in low-risk patients.

• Andreassen, Arne K.; Bjørnstad, Johannes Lagethon; Gude, Einar; Nilsen-Hoel, Tom; Broch, Kaspar & Ravnestad, Håvard [Show all 8 contributors for this article] (2025). Hjertetransplantasjon i Norge 1983–2023. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 145(12). doi: 10.4045/tidsskr.24.0552. Full text in Research Archive Show summary

  Bakgrunn I november 2023 var det 40 år siden hjertetransplantasjon ble introdusert som et behandlingstilbud ved alvorlig hjertesvikt i Norge. Internasjonale registerdata viser en median overlevelse i overkant av 11 år etter transplantasjon, og de fleste sentrene utfører 10–19 transplantasjoner årlig. Hensikten med denne studien var å gi en oversikt over resultater etter hjertetransplantasjon i Norge. Materiale og metode Studien er en retrospektiv observasjonsstudie av hjertetransplanterte pasienter ved Oslo universitetssykehus, Rikshospitalet i perioden 6.11.1983–31.12.2023, med fokus på pasient- og donorkarakteristika, overlevelse og komplikasjoner. Resultater I tidsrommet 6.11.1983–31.12.2005 ble det i median utført 24 (interkvartilbredde 21–27) hjertetransplantasjoner årlig, mot 32 (29–35) i perioden 1.1.2006–31.12.2023. Blant 1 078 førstegangstransplanterte var median overlevelse 13,4 år (95 % konfidensintervall (KI) 12,7 til 14,4). Median overlevelse var 11,0 år (95 % KI 9,3 til 12,9) for pasienter transplantert 6.11.1983–31.12.1993, 13,1 år (95 % KI 11,7 til 15,4) for pasienter transplantert 1.1.1994–31.12.2003 og 14,8 år (95 % KI 13,5 til 16,8) for pasienter transplantert 1.1.2004 - 31.12.2013. Dette var til tross for stadig økende donoralder og flere transplanterte som kom direkte fra intensivavdeling (ikke elektivt) eller som hadde mekanisk støtte. Overlevelsen var best for pasienter uten iskemisk årsak til hjertesvikt. Ulike former for kreft, sammen med kronisk/progressiv transplantatsvikt (hjerteinfarkt, plutselig død med kjent utvikling av graftsklerose/koronarsykdom/fibrose i graftet), utgjorde de vanligste dødsårsakene. Fortolkning Det har vært en jevn bedring av overlevelsen etter hjertetransplantasjon i Norge. Vårt senter er blant de med høyest aktivitet i verden, og Rikshospitalets resultater er på høyde med de fremste internasjonalt.

• Røed-Undlien, Henriette; Schultz, Nina Haagenrud; Amundsen, Erik Koldberg; Wollmann, Birgit Malene Tovik; Molden, Espen & Akerkar, Rupali Rajendra [Show all 7 contributors for this article] (2024). Does in vitro hemolysis affect measurements of plasma apixaban concentration by UPLC-MS and anti-Xa assay? International Journal of Laboratory Hematology (IJLH). ISSN 1751-5521. 46(5), p. 946–952. doi: 10.1111/ijlh.14311. Full text in Research Archive Show summary

  Introduction: Hemolytic interference may impact various laboratory tests, including coagulation analyses. Apixaban is the most commonly used direct oral anticoagulant in Norway, and there is lacking knowledge on how apixaban concentration measure- ments might be influenced by hemolysis. Moreover, hemolysis-induced alterations in apixaban levels could potentially impact the risk of bleeding in specific clinical scenar- ios. We wanted to study whether hemolysis would increase apixaban concentration and investigate the impact of hemolytic interference on apixaban concentration measurements. Methods: Blood samples from 20 apixaban-treated patients and 8 healthy controls were hemolyzed in vitro by a freeze method. The degree of hemolysis was measured with plasma free hemoglobin (PfHb) at baseline and two levels of hemolysis. Apixa- ban concentration was measured in plasma using both the chromogenic anti-Xa method and the ultraperformance liquid chromatography mass spectrometry (UPLC-MS). Thrombin generation assay was performed to assess coagulability. Results: UPLC-MS measurements showed a mean concentration change of 1.66% (±3.2%, p = 0.005) and anti-Xa assay showed a mean concentration change of 3.37% (±6.5%, p = 0.09) with increasing hemolysis. Thrombin generation lagtime decreased, and endogenous thrombin potential and peak thrombin increased with increasing hemolysis in both the control group and the apixaban group. Conclusion: Apixaban concentration measurements by anti-Xa assay and UPLC-MS were not affected by hemolysis to a clinically relevant extent. Furthermore, hemolysis did not lead to hypocoagulability when assessed by thrombin generation.

• Røed-Undlien, Henriette; Schultz, Nina Haagenrud; Husebråten, Inger; Wollmann, Birgit Malene Tovik; Akerkar, Rupali Rajendra & Molden, Espen [Show all 8 contributors for this article] (2024). Apixaban removal during emergency surgery for type A acute aortic dissection: a prospective cohort study. International Journal of Surgery (IJS). ISSN 1743-9191. 110(12), p. 7782–7790. doi: 10.1097/JS9.0000000000002137. Full text in Research Archive Show summary

  Background: Acute type A aortic dissection (ATAAD) has a high mortality, and acute aortic repair is the only curative treatment. In patients treated with factor Xa (FXa) inhibitors, the risk of severe disease-related complications such as cardiac tamponade and hemodynamic shock must be balanced against the potential for severe perioperative bleeding. The aim was to study intraoperative changes in plasma levels of the FXa inhibitor apixaban when using hemoadsorption during acute thoracic aortic repair. Materials and methods: This is a single-center prospective cohort study. Eight apixaban-treated patients presenting with ATAAD underwent acute thoracic aortic repair with intraoperative hemoadsorption with CytoSorb. Apixaban concentrations were measured at the start of cardiopulmonary bypass (CPB) and after 5, 15, 30, 60, and 90 min of CPB, at CPB weaning, 30 min after CPB weaning and 24 h postoperatively, using ultraperformance liquid chromatography–mass spectrometry (UPLC-MS). Results: After 30 min of CPB with hemoadsorption, mean apixaban concentration ( ± SD) was reduced by 59% from 108 ( ± 69) μg/l to 44 ( ± 20) μg/l (P = 0.009). There was a further reduction to 37 ( ± 17) μg/l at CPB weaning (P = 0.008). Apixaban concentration displayed an increase to 56 ( ± 29) μg/l 24 h postoperatively (P = 0.01). In-hospital mortality was 25%. The mean 24H chest tube drainage volume was 621 ( ± 136) ml. Conclusion: Intraoperative hemoadsorption lowers apixaban levels in patients undergoing emergency surgery for ATAAD. Further research is needed to determine its impact on perioperative bleeding complications and mortality.

• Mortensen, Michael; Nilsen, Roy Miodini; Kvalheim, Venny Lise; BJØRNSTAD, JOHANNES; Svendsen, Øyvind Sverre & Haaverstad, Rune [Show all 7 contributors for this article] (2023). The influence of socio-demographic and clinical factors on sick leave and return to work after open-heart surgery: a nationwide registry-based cohort study. European Heart Journal - Quality of Care and Clinical Outcomes. ISSN 2058-5225. 10(5), p. 431–445. doi: 10.1093/ehjqcco/qcad064. Full text in Research Archive Show summary

  Aims To estimate sick leave (SL) duration after first-time elective open-heart surgery and identify factors contributing to increased SL. Methods and results A retrospective nationwide cohort study combined data from the Norwegian Register for Cardiac Surgery and SL data from the Norwegian Labour and Welfare Administrations. All able-bodied adults who underwent first-time elective open-heart surgery in Norway between 2012 and 2021 were followed until 1 year after surgery. The impact of socio-demographic and clinical factors on SL after surgery was analysed using logistic regression and odds ratios. Of 5456 patients, 1643 (30.1%), 1798 (33.0%), 971 (17.8%), 1035 (18.9%), and 9 (0.2%) had SL of <3, 3–6, 6–9, and 9–12 months, and 1 year, respectively. SL >6 months was associated with female gender, primary education only, and average annual income. Post-operative stroke, post-operative renal failure, New York Heart Association Functional Classification system (NYHA) score >3, earlier myocardial infarction, and diabetes mellitus increased the odds of SL >6 months. Conclusion This study demonstrates that socio-demographic and clinical factors impact SL after first-time elective open-heart surgery. Patients who experience a stroke or develop renal failure after surgery have the highest odds of SL >6 months. Females and patients with low education levels, earlier myocardial infarction, or NYHA scores III–IV have a two-fold chance of SL >6 months. The findings allow for future investigations of pre- and post-surgery interventions that can most effectively reduce SL and aid return to work.

• Røed-Undlien, Henriette; Schultz, Nina Haagenrud; Lunnan, Asbjørn; Husebråten, Inger; Wollmann, Birgit Malene Tovik & Molden, Espen [Show all 7 contributors for this article] (2022). In Vitro Apixaban Removal By CytoSorb Whole Blood Adsorber: An Experimental Study. Journal of Cardiothoracic and Vascular Anesthesia. ISSN 1053-0770. 36(6), p. 1636–1644. doi: 10.1053/j.jvca.2022.01.038. Full text in Research Archive Show summary

  Objectives The use of unopposed oral anticoagulants while undergoing cardiothoracic surgery is associated with severe bleeding and increased morbidity. The aim of this experimental study was to examine if the apixaban concentration in reconstituted blood could be reduced in an in vitro setup by the use of CytoSorb whole blood adsorber, and to study how this affected global coagulation assays. Design and Setting An experimental study performed in a laboratory. Participants An in vitro setup with reconstituted whole blood. Interventions Reconstituted whole blood spiked with apixaban circulated in an in vitro circuit with the CytoSorb 300 mL device connected. Measurements and Main Results Blood samples were drawn at 0, 5, 15, 30, 60, and 120 minutes of adsorption. The apixaban concentration was measured at each time point. In addition, the global coagulation assays, thromboelastometry clotting time and thrombin generation, were performed, and the results were compared with baseline values obtained before spiking blood with apixaban. After 30 minutes of adsorption, the mean apixaban concentration was reduced from 414.3 (±69.1) ng/mL to 33 (±11.4) ng/mL. Thrombin generation showed maximum effect after 60 minutes, and the thromboelastometry clotting time was close to baseline values after 120 minutes. Conclusions In this in vitro study, apixaban concentrations were effectively reduced, and the clotting time and thrombin generation assays were normalized by the use of CytoSorb whole blood adsorber.

• Helgeland, Erik; Andresen, Kristoffer; Dumont, Karl-Andreas & BJØRNSTAD, JOHANNES (2020). Leaflet fracture and embolization from an On-X mechanical mitral valve. JTCVS Techniques. p. 140–143. doi: 10.1016/j.xjtc.2020.06.021. Full text in Research Archive
• Bjørnstad, Johannes; Khan, Adil Mahboob; Røed-Undlien, Henriette; Bendz, Bjørn; Nygård, Ståle & Nilsen-Hoel, Tom [Show all 7 contributors for this article] (2020). Operative survival in patients with acute aortic disease in the era of newer oral anticoagulants. Open heart. 7:e001278(2), p. 1–9. doi: 10.1136/openhrt-2020-001278. Full text in Research Archive Show summary

  The aim of this study was the analysis of the risk associated with direct oral anticoagulants (DOACs) in patients undergoing non-elective operations on the proximal aorta due to aortic disease.Methods and resultsData from the department’s register of cardiac surgery was analysed retrospectively with emphasis on operative mortality. 135 non-elective operations for proximal aortic disease (October 2016 to 2018) were identified, of which 19 died during the first 90 days. DOAC use was the top-ranked risk factor in the univariate analysis with a HR of 9.6 (3.1 to 29), p=0.00007. Using a Cox proportional hazards model including the most relevant risk factors, the risk associated with DOAC use remained significant with a HR of 6.1 (1.4 to 26.3), p=0.015. We did not find increased risk associated with warfarin use.In patients undergoing non-elective operations on the proximal aorta due to aortic disease, the use of DOAC is associated with increased operative mortality.

• Bjørnstad, Johannes Lagethon; Helgeland, Erik; Geiran, Odd & Fiane, Arnt Eltvedt (2020). Er EXCEL studien relevant for norske forhold? Hjerteforum. ISSN 0802-1465. 33(3), p. 22–28. Full text in Research Archive
• Nuru, Abdul; Weltzien, Joachim Hagesveen; Sandvik, Leiv; Tønnessen, Theis & BJØRNSTAD, JOHANNES (2019). Short- and long-term survival after isolated coronary artery bypass grafting, the impact of gender and age. Scandinavian Cardiovascular Journal. ISSN 1401-7431. p. 1–6. doi: 10.1080/14017431.2019.1646430. Full text in Research Archive Show summary

  Objectives. Assess the short- and long-term survival for patients who underwent isolated coronary artery bypass grafting (CABG) and evaluate the impact of gender and age. Furthermore to assess the long-term survival in the CABG group compared to the general population. Design. This study included 4044 consecutive patients who underwent isolated CABG at Oslo University Hospital, Ullevål, in Oslo, Norway in the time period from 01 January 2003 to 31 December 2015. Patient data was collected retrospectively from the quality register at the department. Information on survival status was obtained from the Norwegian National Registry. Life expectancy data for the general population was gained from Statistics Norway. Results. Female patients were significantly older than male patients at the time of surgery (mean age 67.0 and 63.9 years, respectively, p < .001), and had significantly lower 30-day survival (mortality was 1.4% and 0.6%, respectively, p = .017). Male gender was independently associated with lower long-term survival (p = .0037) in a multivariate analysis. Male patients aged less than 60 years also showed significantly lower long-term survival (SMR = 1.84, 95% CI = 1.49–2.25) compared to the age-matched general population. Among patients older than 60 years, survival was similar to survival in the age-matched general population. Conclusions. Survival was excellent for patients undergoing surgery. Despite increased age and operative mortality, female patients had better adjusted long-time survival than male patients. There was lower long-term survival among male patients aged less than 60 compared to the general population. Our findings may help clinicians in selecting appropriate patients for surgery.

• Majak, Piotr; Lunde, Ida Gjervold; Hasic, Almira; Husebye, Trygve Guttorm; Christensen, Geir Arve & Tønnessen, Theis [Show all 7 contributors for this article] (2015). Reduced visfatin levels in aortic stenosis increase after aortic valve replacement and may contribute to reverse left ventricular remodelling. Journal of Cardiovascular Surgery. ISSN 0021-9509. 56(3), p. 483–492. Full text in Research Archive
• Skrbic, Biljana; Engebretsen, Kristin V Thunheim; Strand, Mari Elen; Lunde, Ida Gjervold; Herum, Kate Louise Møller & Marstein, Henriette [Show all 12 contributors for this article] (2015). Lack of collagen VIII reduces fibrosis and promotes early mortality and cardiac dilatation in pressure overload in mice. Cardiovascular Research (CVR). ISSN 0008-6363. 106(1), p. 32–42. doi: 10.1093/cvr/cvv041. Full text in Research Archive
• Engebretsen, Kristin V Thunheim; Skårdal, Kristine; Bjørnstad, Sigrid; Marstein, Henriette; Skrbic, Biljana & Sjaastad, Ivar [Show all 9 contributors for this article] (2014). Attenuated development of cardiac fibrosis in left ventricular pressure overload by SM16, an orally active inhibitor of ALK5. Journal of Molecular and Cellular Cardiology. ISSN 0022-2828. 76, p. 148–157. doi: 10.1016/j.yjmcc.2014.08.008. Full text in Research Archive
• Nygård, Ståle; Reitan, Trond; Clancy, Trevor; Nygaard, Vegard; BJØRNSTAD, JOHANNES & Skrbic, Biljana [Show all 9 contributors for this article] (2014). Identifying pathogenic processes by integrating microarray data with prior knowledge. BMC Bioinformatics. 15(1). doi: 10.1186/1471-2105-15-115. Full text in Research Archive Show summary

  Background It is of great importance to identify molecular processes and pathways that are involved in disease etiology. Although there has been an extensive use of various high-throughput methods for this task, pathogenic pathways are still not completely understood. Often the set of genes or proteins identified as altered in genome-wide screens show a poor overlap with canonical disease pathways. These findings are difficult to interpret, yet crucial in order to improve the understanding of the molecular processes underlying the disease progression. We present a novel method for identifying groups of connected molecules from a set of differentially expressed genes. These groups represent functional modules sharing common cellular function and involve signaling and regulatory events. Specifically, our method makes use of Bayesian statistics to identify groups of co-regulated genes based on the microarray data, where external information about molecular interactions and connections are used as priors in the group assignments. Markov chain Monte Carlo sampling is used to search for the most reliable grouping. Results Simulation results showed that the method improved the ability of identifying correct groups compared to traditional clustering, especially for small sample sizes. Applied to a microarray heart failure dataset the method found one large cluster with several genes important for the structure of the extracellular matrix and a smaller group with many genes involved in carbohydrate metabolism. The method was also applied to a microarray dataset on melanoma cancer patients with or without metastasis, where the main cluster was dominated by genes related to keratinocyte differentiation. Conclusion Our method found clusters overlapping with known pathogenic processes, but also pointed to new connections extending beyond the classical pathways.

• Engebretsen, Kristin V Thunheim; Lunde, Ida Gjervold; Strand, Mari Elen; Sjaastad, Ivar; Marstein, Henriette & Skrbic, Biljana [Show all 12 contributors for this article] (2013). Lumican is increased in experimental and clinical heart failure, and its production by cardiac fibroblasts is induced by mechanical and proinflammatory stimuli. The FEBS Journal. ISSN 1742-464X. 280(10), p. 2382–2398. doi: 10.1111/febs.12235. Full text in Research Archive
• Engebretsen, Kristin V Thunheim; Wæhre, Anne; BJØRNSTAD, JOHANNES; Skrbic, Biljana; Sjaastad, Ivar & Behmen, Dina [Show all 11 contributors for this article] (2013). Decorin, lumican, and their GAG chain-synthesizing enzymes are regulated in myocardial remodeling and reverse remodeling in the mouse. Journal of applied physiology. ISSN 8750-7587. 114(8), p. 988–997. doi: 10.1152/japplphysiol.00793.2012. Full text in Research Archive
• Skrbic, Biljana; BJØRNSTAD, JOHANNES; Marstein, Henriette; Carlson, Cathrine Rein; Sjaastad, Ivar & Nygård, Ståle [Show all 9 contributors for this article] (2013). Differential regulation of extracellular matrix constituents in myocardial remodeling with and without heart failure following pressure overload. Matrix Biology. ISSN 0945-053X. 32(2), p. 133–142. doi: 10.1016/j.matbio.2012.11.011. Full text in Research Archive
• Majak, Piotr; Braathen, Bjørn; BJØRNSTAD, JOHANNES & Tønnessen, Theis (2012). GDF-15 is increased during early reperfusion following aortic valve replacement. Scandinavian Cardiovascular Journal. ISSN 1401-7431. 46(2), p. 99–106. doi: 10.3109/14017431.2011.649489. Full text in Research Archive
• Bjørnstad, Johannes L.; Skrbic, Biljana; Sjaastad, Ivar; Bjørnstad, Sigrid; Christensen, Geir Arve & Tønnessen, Theis (2012). A mouse model of reverse cardiac remodelling following banding-debanding of the ascending aorta. Acta Physiologica. ISSN 1748-1708. 205(1), p. 92–102. doi: 10.1111/j.1748-1716.2011.02369.x. Full text in Research Archive
• BJØRNSTAD, JOHANNES; Skrbic, Biljana; Marstein, Henriette; Hasic, Almira; Sjaastad, Ivar & Louch, William Edward [Show all 9 contributors for this article] (2012). Inhibition of SMAD2 phosphorylation preserves cardiac function during pressure overload. Cardiovascular Research (CVR). ISSN 0008-6363. 93(1), p. 100–110. doi: 10.1093/cvr/cvr294. Full text in Research Archive
• Majak, Piotr; BJØRNSTAD, JOHANNES; Braathen, Bjørn; Lunde, Ida Gjervold; Husebye, Trygve Guttorm & Christensen, Geir Arve [Show all 7 contributors for this article] (2012). Endothelin-1 in the Human Myocardium and Circulating Plasma: Evaluation before, during and after Correction of Aortic Stenosis with Aortic Valve Replacement. Cardiology. ISSN 0008-6312. 123(1), p. 1–10. doi: 10.1159/000339756. Full text in Research Archive
• BJØRNSTAD, JOHANNES; Sjaastad, Ivar; Nygård, Ståle; Hasic, Almira; Ahmed, Muhammad Shakil & Attramadal, Håvard [Show all 9 contributors for this article] (2011). Collagen isoform shift during the early phase of reverse left ventricular remodelling after relief of pressure overload. European Heart Journal. ISSN 0195-668X. 32(2), p. 236–245. doi: 10.1093/eurheartj/ehq166. Full text in Research Archive
• Majak, Piotr; Bjørnstad, Johannes; Vengen, Øystein; Neverdal, Nils Olav; Husebye, Trygve & Woldbæk, Per R [Show all 10 contributors for this article] (2010). Plasma IL-18 and IL-18BP are altered differently in reverse remodeling following aortic valve replacement. Scandinavian Cardiovascular Journal. ISSN 1401-7431. 44(2), p. 113–118. doi: 10.3109/14017430903426902. Full text in Research Archive
• Bjørnstad, Johannes; Pillgram-Larsen, Johan & Tønnessen, Theis (2009). Coronary artery dissection and acute myocardial infarction following blunt chest trauma. World Journal of Emergency Surgery. 14(4). Full text in Research Archive
• Bjørnstad, Johannes; Neverdal, Nils Olav; Vengen, Øystein; Knudsen, Cathrine Wold; Husebye, Trygve & Pepper, John [Show all 9 contributors for this article] (2008). Alterations in circulating activin A, GDF-15, TGF-beta 3 and MMP-2,-3, and-9 during one year of left ventricular reverse remodelling in patients operated for severe aortic stenosis. European Journal of Heart Failure. ISSN 1388-9842. 10(12), p. 1201–1207. doi: 10.1016/j.ejheart.2008.09.010. Full text in Research Archive

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• Mortensen, Michael; Nilsen, Roy Miodini; Kvalheim, Venny Lise; BJØRNSTAD, JOHANNES; Svendsen, Øyvind Sverre & Haaverstad, Rune [Show all 7 contributors for this article] (2025). Sykefravær etter hjertekirurgi. Full text in Research Archive
• Røed-Undlien, Henriette; Schultz, Nina Haagenrud; Lunnan, Asbjørn; Husebråten, Inger Marie; Wollmann, Birgit Malene Tovik & Molden, Espen [Show all 7 contributors for this article] (2024). Corrigendum to < IN-VITRO APIXABAN REMOVAL BY CYTOSORB® WHOLE BLOOD ADSORBER. AN EXPERIMENTAL STUDY.> <[Journal of Cardiothoracic and Vascular Anesthesia 36/6 (2024) 1636 – 1644]> (Journal of Cardiothoracic and Vascular Anesthesia (2022) 36(6) (1636–1644), (S1053077022000726), (10.1053/j.jvca.2022.01.038)). Journal of Cardiothoracic and Vascular Anesthesia. ISSN 1053-0770. doi: 10.1053/j.jvca.2024.03.039. Full text in Research Archive
• Mortensen, Michael; Nilsen, Roy Miodini; Kvalheim, Venny Lise; BJØRNSTAD, JOHANNES; Svendsen, Øyvind Sverre & Haaverstad, Rune [Show all 7 contributors for this article] (2023). The impact of clinical and sociodemographic factors on sick leave after cardiac surgery. Full text in Research Archive
• Afifi, Rim Abu; Lundblad, Runar & Bjørnstad, Johannes Lagethon (2022). Resultater etter kirurgisk behandling av atrieflimmer. Hjerteforum. ISSN 0802-1465. 35(4), p. 27–36. Full text in Research Archive
• Mortensen, Michael; Nilsen, Roy Miodini; Kvalheim, Venny Lise; BJØRNSTAD, JOHANNES; Svendsen, Øyvind Sverre & Haaverstad, Rune [Show all 7 contributors for this article] (2022). Kliniske og sosiodemografiske faktorer som fører til lengre sykemelding etter hjertekirurgi. Full text in Research Archive
• Bjørnstad, Johannes Lagethon; Helgeland, Erik; Geiran, Odd & Fiane, Arnt Eltvedt (2021). Hjertekirurgi og hjerneskade. Hjerteforum. ISSN 0802-1465. 34(2), p. 104–105. Full text in Research Archive
• Bjørnstad, Johannes & Bendz, Bjørn (2020). Periprocedural myocardial injury in the EXCEL trial. European Heart Journal. ISSN 0195-668X. 41(17), p. 1703–1703. doi: 10.1093/eurheartj/ehaa182. Full text in Research Archive
• Bjørnstad, Johannes Lagethon; Fiane, Arnt Eltvedt; Svennevig, Jan Ludvig & Geiran, Odd (2019). Norsk hjertekirurgiregister, et forskriftsregulert nasjonalt medisinsk kvalitetsregister. Hjerteforum. ISSN 0802-1465. 32(1), p. 42–54. Full text in Research Archive
• Engebretsen, Kristin V Thunheim; Skårdal, Kristine; Bjørnstad, S; Marstein, Henriette; Skrbic, Biljana & Sjaastad, Ivar [Show all 9 contributors for this article] (2013). Inhibiting phosphorylation of SMAD2/3 by the small molecule SM16 in left ventricular pressure overload reduces fibrosis and signs of heart failure, possibly due to better diastolic function. Full text in Research Archive
• Skrbic, Biljana; Engebretsen, Kristin V Thunheim; Strand, Mari Elen; Marstein, Henriette; Sjaastad, Ivar & Lunde, Ida Gjervold [Show all 10 contributors for this article] (2013). Lack of collagen type 8 in pressure overload causes left ventricular dilatation and overt heart failure in mice, suggesting a role in transition to heart failure in patients with aortic stenosis. Circulation. ISSN 0009-7322. 128, p. A14408–A14408. Full text in Research Archive
• Skrbic, Biljana; Engebretsen, Kristin V Thunheim; Strand, Mari Elen; Marstein, Henriette; Sjaastad, Ivar & Lunde, Ida Gjervold [Show all 10 contributors for this article] (2013). Lack of collagen type 8 in pressure overload causes left ventricular dilatation and overt heart failure in mice, suggesting a role in transition to heart failure in patients with aortic stenosis. Full text in Research Archive
• Engebretsen, Kristin V Thunheim; Lunde, Ida Gjervold; Wæhre, Anne; Strand, Mari Elen; Sjaastad, Ivar & Marstein, Henriette [Show all 11 contributors for this article] (2012). The collagen-organizing proteoglycan lumican is increased in experimental and clinical heart failure and its production by cardiac fibroblasts is induced by pro-inflammatory and mechanical stimuli. Full text in Research Archive
• Skrbic, Biljana; Engebretsen, Kristin V Thunheim; Marstein, Henriette; Sjaastad, Ivar; Christensen, Geir Arve & BJØRNSTAD, JOHANNES [Show all 7 contributors for this article] (2012). Reduction in collagen type 8 might be involved in transition from compensated hypertrophy to left ventricular dilatation and overt heart failure in pressure overload. Full text in Research Archive
• Engebretsen, Kristin V Thunheim; BJØRNSTAD, JOHANNES; Skrbic, Biljana; Marstein, Henriette; Sjaastad, Ivar & Wæhre, Anne [Show all 8 contributors for this article] (2011). Correction of left ventricular pressure overload leads to altered myocardial expression of small leucine rich proteoglycans. Full text in Research Archive
• Skrbic, Biljana; BJØRNSTAD, JOHANNES; Marstein, Henriette; Sjaastad, Ivar; Nygård, Ståle & Christensen, Geir Arve [Show all 7 contributors for this article] (2011). Reduksjon i kollagen VIII kan være involvert i venstre ventrikkel dilatasjon og overgang fra kompensert hypertrofi til dekompensert hjertesvikt ved trykkoverbelastning. Full text in Research Archive
• Skrbic, Biljana; BJØRNSTAD, JOHANNES; Marstein, Henriette; Sjaastad, Ivar; Nygård, Ståle & Christensen, Geir Arve [Show all 7 contributors for this article] (2011). Reduction in collagen type 8 might be involved in transition from compensated hypertrophy to left ventricular dilatation and overt heart failure in pressure overload. Full text in Research Archive
• Nygård, Ståle; Reitan, Trond; Clancy, Trevor; Nygaard, Vegard; BJØRNSTAD, JOHANNES & Tønnessen, Theis [Show all 8 contributors for this article] (2011). Identifying pathogenic signaling and regulatory networks by integrating microarray data with prior knowledge. Full text in Research Archive
• Engebretsen, Kristin V Thunheim; BJØRNSTAD, JOHANNES; Skrbic, Biljana; Marstein, Henriette; Sjaastad, Ivar & Wæhre, Anne [Show all 8 contributors for this article] (2011). Endret nivå av small leucine rich proteoglycans i en musemodell som etterligner pasienter operert for aortastenose. Full text in Research Archive
• Nygård, Ståle; Reitan, Trond; Clancy, Trevor; Nygaard, Vegard; BJØRNSTAD, JOHANNES & Tønnessen, Theis [Show all 8 contributors for this article] (2011). Identifying pathogenic signaling and regulatory networks by integrating microarray data with prior knowledge. Full text in Research Archive
• BJØRNSTAD, JOHANNES; Sjaastad, Ivar; Nygård, Ståle; Finsen, Alexandra; Hasic, Almira & Christensen, Geir Arve (2010). The pro-inflammatory adipocytokine visfatin might play a role regulating cardiac metabolism in human and experimental aortic stenosis. European Journal of Heart Failure. Supplements. ISSN 1567-4215. 9, p. S220–S220. Full text in Research Archive
• BJØRNSTAD, JOHANNES; Skrbic, Biljana; Marstein, Henriette; Sjaastad, Ivar; Louch, William Edward & Christensen, Geir Arve [Show all 7 contributors for this article] (2010). Inhibiting phosphorylation of SMAD2 preserves cardiac function during pressure overload by attenuating left ventricular SERCA2 loss. Full text in Research Archive
• Nygård, Ståle; Nygaard, Vigdis; Clancy, Trevor; BJØRNSTAD, JOHANNES; Skrbic, Biljana & Sjaastad, Ivar [Show all 9 contributors for this article] (2010). Integrating microarray gene expression data with prior knowledge about molecular interactions for identification of important heart failure pathways. Full text in Research Archive
• Skrbic, Biljana; BJØRNSTAD, JOHANNES; Marstein, Henriette; Sjaastad, Ivar; Nygård, Ståle & Christensen, Geir Arve [Show all 7 contributors for this article] (2010). Reduction in collagen VIII might be involved in transition from compensated hypertrophy to overt heart failure in pressure overload. Full text in Research Archive
• Nygård, Ståle; Nygaard, Vigdis; Clancy, Trevor; BJØRNSTAD, JOHANNES; Skrbic, Biljana & Tønnessen, Theis [Show all 8 contributors for this article] (2010). Integrating microarray gene expression data with prior knowledge about molecular interactions for identification of important heart failure pathways. Full text in Research Archive
• BJØRNSTAD, JOHANNES; Sjaastad, Ivar; Nygård, Ståle; Hasic, Almira; Ahmed, Muhammad Shakil & Attramadal, Håvard [Show all 9 contributors for this article] (2009). Reverse remodeling of the left ventricle during the early phase after relief of pressure overload in a mouse model. European Heart Journal, Supplement. ISSN 1520-765X. 30, p. 218–218. Full text in Research Archive
• BJØRNSTAD, JOHANNES; Sjaastad, Ivar; Nygård, Ståle; Finsen, Alexandra; Hasic, Almira & Attramadal, Håvard [Show all 9 contributors for this article] (2009). Reverse remodeling of the left ventricle during the early phase after relief of pressure overload in a mouse model. Hjerteforum. ISSN 0802-1465. 22, p. 110–110. Full text in Research Archive
• BJØRNSTAD, JOHANNES; Skrbic, Biljana; Marstein, Henriette; Sjaastad, Ivar; Christensen, Geir Arve & Tønnessen, Theis (2009). Inhibiting phosphorylation of SMAD2 preserves cardiac function during pressure overload. Circulation. ISSN 0009-7322. 120, p. S857–S857. Full text in Research Archive
• BJØRNSTAD, JOHANNES; Skrbic, Biljana; Marstein, Henriette; Sjaastad, Ivar; Christensen, Geir Arve & Tønnessen, Theis (2009). Inhibiting phosphorylation of SMAD2 preserves cardiac function during pressure overload. Full text in Research Archive
• BJØRNSTAD, JOHANNES; Sjaastad, Ivar; Finsen, Alexandra; Nygård, Ståle; Hasic, Almira & Christensen, Geir Arve (2008). Reversible pressure overload alters expression of actin binding and extracellular matrix genes. Full text in Research Archive
• Bjørnstad, Johannes Lagethon & Tønnessen, Theis (2011). The TGFβ/SMAD signalling system and extracellular matrix changes in myocardial remodelling and reverse remodelling following correction of pressure overload. Universitetet i Oslo. ISSN 9788282641395. Full text in Research Archive

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