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Coming dissertations at MedFak

  • Risk factors for incident heart failure and atrial fibrillation in an elderly population : The role of cardiac conduction and heart rate variability Author: Bozena Ostrowska Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-518489 Publication date: 2024-02-13 09:37

    Heart failure (HF) and atrial fibrillation (AF) are epidemic diseases, frequently coexisting, sharing risk factors and conferring poor prognosis. Identification of individuals at high risk of HF and AF may enable early treatment and improve the prognosis. Reliable prediction models for daily clinical practice are lacking. Early modification and treatment of risk factors may reduce the incidence of AF and HF. Because atrial structure and function abnormalities increase the risk of AF, ECG indices reflecting atrial pathology may prove useful in predicting AF and HF.

    The main objectives were to evaluate whether:

    • P-wave duration (Pdur) and PR-interval in V1 predicted incident HF and incident AF (Paper I-II)
    • low frequency/high frequency (L-F/H-F) ratio, a marker of autonomic balance, predicted incident HF (Paper IV)
    • combining selected ECG variables or the L-F/H-F ratio with traditional risk factors improved the performance of the traditional HF prediction model (Paper III-IV).

    The Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) with 15 years of follow-up was used for all four studies. After applying the exclusion criteria, 836 subjects were evaluated for incident HF (Paper I, III-IV) and 877 subjects for incident AF (Paper II). Cox proportional hazard analysis related ECG-derived variables to incident HF and incident AF. Study III used machine learning to determine which ECG variables correlated to incident HF. C-statistic was used to test whether adding selected ECG variables to traditional HF risk factors improved the performance of the HF prediction model.

    Short Pdur was significantly associated with incident HF (Paper I) and incident AF (Paper II). Of 134 ECG variables, high R-wave amplitude variation (SD Ramp) had the highest predictive value for HF (Paper III). A decreased L-F/H-F ratio significantly predicted HF (Paper IV). Adding eight selected ECG variables (Paper III) and the L-F/H-F ratio (Paper IV) to the traditional risk factors significantly improved HF predictive performance by 11.7% and 3.3%, respectively.

    In conclusion, the ECG may prove useful for predicting incident HF and AF beyond the traditional risk factors. An autonomic imbalance may precede the development of HF.

  • Articulation and velopharyngeal function in patients with cleft lip and/or palate : Outcome predictors Author: Åsa Okhiria Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-519479 Publication date: 2024-02-09 09:22

    Cleft lip and/or palate is the most common congenital craniofacial malformation, requiring multidisciplinary treatment, including surgery and often speech therapy. Palatal surgery restores the anatomical barrier between the oral and nasal cavities as well as the palatal function needed for normal speech.

    The present thesis aimed to investigate factors thought to impact surgical and speech outcomes. These factors include the timing of surgery, surgical technique, the surgeon's experience, cleft type, and cleft width.

    Study I investigated the impact of cleft type and width on velopharyngeal function (VPF) and secondary surgery rates from ages three to 16. Cleft width was associated with increased surgery rates and signs of velopharyngeal insufficiency (VPI) at ages three and five. Contrary to some previous studies, surgery rates and speech outcomes were not associated with cleft type at any age.

    Study II examined VPF and articulation development between ages five and ten in children adopted from China compared to Swedish-born children. Adoptees had palatoplasty later and had more severe articulation difficulties at both ages. The number of adoptees and non-adoptees with VPI was similar, but fewer adoptees had competent VPF.

    Study III explored different types of intra-velar veloplasty and the impact of cleft width and surgeon experience on outcomes in 5-year-old children. Radical muscle dissection was not superior to intra-velar veloplasty reinforced by the palatopharyngeal muscle. Cleft width had a more significant impact on secondary surgery rates and VPF than did surgical technique—neither affected articulation proficiency.

    Study IV examined the association between cleft type and width and surgical and speech outcomes, especially articulation, in 5-year-old children. Cleft width, not type, indicated articulation proficiency. The same errors occurred across all cleft types. Neither cleft type nor width was significantly associated with secondary surgery rates or VPF.

    The present thesis highlights the importance of considering various factors when predicting secondary palatal surgery rates and speech outcomes. Cleft width significantly affects secondary surgery rates, VPF, and articulation proficiency, while cleft type and surgical technique do not. Adopted children are at higher risk of persistent articulation errors, which may partly be due to their later palatoplasty. 

  • The epidemiology of risk factors and short- and long-term outcome in the Swedish intensive care cohort Author: Björn Ahlström Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-519461 Publication date: 2024-01-31 12:00

    The sepsis syndrome is present in ¼ to ⅓ of patients in intensive care units (ICUs) worldwide. The short-term prognosis is grim, with a 30-day mortality of 30–35%; however, the long- term outcomes are now being explored, as multi-professional follow-up after ICU care is increasingly being implemented. In 2020 the first and second waves of another severe infection, the Coronavirus disease 2019 (Covid-19) hit Sweden. The number of ICU beds were scaled up by several hundred percent while we simultaneously tried to understand the disease. Reports on risk factors for adverse outcomes in Covid-19 started to appear, but we needed to know more. Thus, we initiated this project aiming at assessing sepsis as an independent risk factor for later morbidity and mortality. Subsequently, with the onset of the pandemic, our focus shifted to identifying risk factors for adverse outcomes in Covid-19 and describing the functional recovery after severe Covid-19. We used the Swedish Intensive Care Registry and several governmental registries to this end.

    In Cox regression, we compared one-year ICU sepsis survivors without previous dementia with ICU patients without sepsis, finding no increased risk of dementia during follow- up. In a similar cohort, we assessed the impact of sepsis on long-term mortality and causes of death in a series of Cox and multinomial models. We found a surprisingly small overall association between sepsis and mortality and a persistently increased risk of infectious causes of death in sepsis patients. We compared the prevalence of several common comorbidities and medications as risk factors for ICU admission and mortality in ICU patients with Covid-19 with that of age- and sex-matched population controls and in patients discharged alive with those that were deceased at discharge. We found associations between several comorbidities and medications with these adverse outcomes. To better understand the meaning of these comorbidities as risk factors for short-term mortality, we compared them in logistic regression models on patients with Covid-19, sepsis and acute respiratory distress syndrome (ARDS). We found very similar impacts from the comorbidities; however, greater age was more associated with mortality in Covid-19 than in either sepsis or ARDS. Finally, we investigated the long-term functional recovery in ICU patients with Covid-19 compared to hospital-admitted patients with Covid-19 and population controls matched to the ICU group. The ICU patients had a markedly impeded recovery that was not explained by demographics or comorbidities in statistical models.

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