Studies of risks associated with atrial fibrillation
Sammanfattning
Aim: To investigate temporal trends in the risk of mortality and stroke associated with incident
atrial fibrillation (AF) in Sweden. To investigate the risk of morbidity and mortality associated
with prevalent and incident AF in patients with chronic heart failure with preserved (CHF-PEF) or
reduced left ventricular ejection fraction (CHF-REF) enrolled in two large randomised trials.
Methods: In Papers I and II, we utilized Swedish National Hospital Discharge Registry linked
with the cause-specific death registers. The hospital discharge registry has been in operation since
the 1960s and has operated on a nation-wide basis since 1987. From this source all patients
discharged from a Swedish hospital with a first diagnosis of AF were collected, and data
regarding age, gender and registered comorbidities were obtained and compared by 5-year
periods. Paper III utilized data from the Carvedilol Or Metoprolol European Trial (COMET).
Paper IV utilized data from the Candesartan in Heart failure-Assessment of Reduction in
Morbidity and mortality (CHARM) programme.
Results: The incidence of ischemic strokes up to 3-years after a first diagnosis of AF was 11.6%
1987-1991 (period 1) and 9.6% 2002-2006 (period 4), corresponding to a 17.5% relative decrease,
the decrease mainly occurred during 1997-2001 (period 3), with small changes before and
thereafter. The incidence of hemorrhagic strokes was 1.0% period 1 and 1.3% period 4, a 37.2%
relative increase. The total number of strokes thus declined during the observation period. The
decline in the total stroke incidence in AF patients was higher than that seen in the rest of the
Swedish population. 3-year mortality was 34% during period 1 and 26% period 4, corresponding
to a 23% relative decrease in mortality during the observation period. Patients diagnosed with any
of previous stroke, chronic heart failure, acute coronary syndrome and diabetes mellitus had high
but declining 3-year mortality rates during the observation period, regardless of age and sex.
Patients without the prespecified comorbidities had lower case-fatality, especially in younger
patients, but improvements in survival were smaller. Patients with CHF and AF had an increased
risk of mortality and morbidity compared to patients in sinus rhythm, regardless of LVEF at
baseline. Patients with CHF-REF had the highest absolute morbidity and mortality in CHARM
trial, but patients with CHF-PEF had higher relative increase in morbidity and mortality with AF.
New onset AF during the follow-up was a strong predictor of mortality and morbidity in both
studies, regardless of baseline LVEF.
Conclusions: Patients discharged from a Swedish hospital with a first diagnosis of atrial
fibrillation had moderate decreases in stroke incidence and mortality during a 20 year observation
period. Although treatment and management of AF and its associating conditions, have improved
dramatically during the last 30 years, AF is still associated with an excess morbidity and
mortality. Even when patients with important comorbidities are excluded from the analysis, there
is a considerable mortality among patients with AF. In a prespecified analysis of two large
randomized trials with CHF and AF, AF was associated with increased morbidity and mortality
both when present and when occurring during study follow-up, regardless of baseline EF.
Keywords: Atrial fibrillation, stroke, ischemic, hemorrhagic, mortality, temporal trends, ejection
fraction, preserved, chronic heart failure, new onset, cohort study, randomised controlled trial.
Delarbeten
I. Olsson LG, Swedberg K, Lappas G, Stewart S, Rosengren A. Trends in stroke incidence after hospitalization for atrial fibrillation in Sweden 1987 to 2006. Manuscript II. Olsson LG, Swedberg K, Lappas G, Stewart S, Rosengren A. Trends in mortality after hospitalization for atrial fibrillation in Sweden 1987 to 2006. Manuscript III. Swedberg K, Olsson LG, Charlesworth A, et al. Prognostic relevance of atrial fibrillation in patients with chronic heart failure on long-term treatment with beta-blockers: results from COMET. Eur Heart J 2005;26:1303-8. ::pmid::15767288 IV Olsson LG, Swedberg K, Ducharme A, et al. Atrial fibrillation and risk of clinical events in
chronic heart failure with and without left ventricular systolic dysfunction: results from the
candesartan in heart failure-assessment of reduction in mortality and morbidity (CHARM)
program. J Am Coll Card 2006;47:1997-2004. ::pmid::16697316
Examinationsnivå
Doctor of Philosophy (Medicine)
Universitet
University of Gothenburg. Sahlgrenska Academy
Institution
Institute of Medicine. Department of Emergeny and Cardiovascular Medicine
Disputation
Fredagen den 5 november 2010, kl 13.00, Östraaulan, Centralkliniken SU/Östra, Göteborg
Datum för disputation
2010-11-05
E-post
lars.g.olsson@ltdalarna.se
Datum
2010-10-25Författare
Olsson, Lars
Nyckelord
atrial fibrillation
stroke
mortality
chronic heart failure
ischemic
hemorrhagic
temporal trends
ejection fraction
preserved
new onset
cohort study
randomised controlled trial
Publikationstyp
Doctoral thesis
ISBN
978-91-628-8171-9
Språk
eng