Effect of oral anticoagulant therapy on mortality in end-stage renal disease patients with atrial fibrillation: a prospective study.
BACKGROUND
The aim of this study was to evaluate, in a cohort of haemodialysis patients with atrial fibrillation (AF), the relationship between oral anticoagulant therapy (OAT) and mortality, thromboembolic events and haemorrhage.


METHODS
Two hundred and ninety patients with AF were prospectively followed for 4 years. Warfarin and antiplatelet intake, age, dialytic age, comorbidities, CHA2DS2-VAScand HAS-BLED scores were considered as predictors of risk of death, thromboembolism and bleeding events. In patients taking OAT, the international normalized ratio (INR) was assessed and the percentage time in the target therapeutic range (TTR) was calculated.


RESULTS
At recruitment, 134/290 patients were taking warfarin. During follow-up there were 170 deaths, 28 thromboembolic events and 95 bleedings. After balancing for treatment propensity, intention-to-treat analysis on OAT intake at recruitment did not show differences in total mortality, thromboembolic events and bleedings, while the as-treated analysis, accounting for treatment switch, showed that patients taking OAT at recruitment had a significantly lower mortality than those not taking it [hazard ratio, HR 0.53 (95% confidence interval 0.28-0.90), p = 0.04], with a decrease of thromboembolic events [HR 0.36 (0.13-1.05), p = 0.06], and an increase of bleedings [HR 1.79 (0.72-4.39), p = 0.20], both non-significant. Among patients taking OAT at recruitment, those continuing to take warfarin had a significant reduction in the risk of total [HR 0.28 (0.14-0.53), p < 0.001] and cardiovascular [HR 0.21 (0.11-0.40), p < 0.001] mortality compared to patients stopping OAT.


CONCLUSIONS
In haemodialysis patients with AF, continuously taking warfarin is associated with a reduction of the risk of total and cardiovascular mortality.
Department of Medicine and Surgery, University of Milano-Bicocca, Via Cadore 48, 20900, Monza (MB), Italy. simonetta.genovesi@unimib.it.|Nephrology Unit, San Gerardo Hospital, Monza, Italy. simonetta.genovesi@unimib.it.
Simonetta
S
Genovesi
Center of Biostatistics for Clinical Epidemiology, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.
Paola
P
Rebora
Nephrology Unit, San Carlo Borromeo Hospital, Milan, Italy.
Maurizio
M
Gallieni
Department of Medicine and Surgery, University of Milano-Bicocca, Via Cadore 48, 20900, Monza (MB), Italy.|Nephrology Unit, San Gerardo Hospital, Monza, Italy.
Andrea
A
Stella
Nephrology Unit, Infermi Hospital, Rimini, Italy.
Fabio
F
Badiali
Nephrology Unit, S. Uboldo Hospital, Cernusco sul Naviglio, Italy.
Ferruccio
F
Conte
Nephrology Unit, S. Maria Nuova Hospital, Reggio Emilia, Italy.
Sonia
S
Pasquali
Nephrology Unit, IRCCS Multimedica, Sesto S. Giovanni, Italy.
Silvio
S
Bertoli
Nephrology Unit, Ospedali Riuniti, Bergamo, Italy.
Patrizia
P
Ondei
Nephrology Unit, S. Anna Hospital, Como, Italy.
Giuseppe
G
Bonforte
Nephrology Unit, Bassini Hospital, Cinisello, Milan, Italy.
Claudio
C
Pozzi
Center of Biostatistics for Clinical Epidemiology, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.
Emanuela
E
Rossi
Center of Biostatistics for Clinical Epidemiology, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.
Maria Grazia
MG
Valsecchi
Nephrology Unit, S. Orsola-Malpighi Hospital, Bologna, Italy.
Antonio
A
Santoro
D000284:Administration, Oral; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality*; D015897:Comorbidity; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced / Q000401:mortality; D006801:Humans; D057194:Intention to Treat Analysis; D007558:Italy; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage; D016016:Proportional Hazards Models; D011446:Prospective Studies; D065840:Protective Factors; D006435:Renal Dialysis / Q000009:adverse effects / Q000401:mortality*; D012307:Risk Factors; D013923:Thromboembolism / Q000175:diagnosis / Q000401:mortality* / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome; D014859:Warfarin / Q000008:administration & dosage* / Q000009:adverse effects
D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors; D014859:Warfarin
Atrial fibrillation; Bleeding; Haemodialysis; Mortality; Stroke; Warfarin