title: Subclinical Hypothyroidism Might Increase the Risk of Postoperative Atrial Fibrillation after Aortic Valve Replacement.
abstract: Background To evaluate the influence of subclinical hypothyroidism (SCH) on the development of postoperative atrial fibrillation (AF) in patients undergoing aortic valve replacement surgery with extracorporeal circulation. Methods A prospective study in a tertiary hospital between July 2005 and December 2013 in which all patients undergoing aortic valve replacement with no other valve surgery were consecutively included. Patients who were in preoperative sinus rhythm were selected and they underwent thyroxine (T4) and thyroid-stimulating hormone determination in the month before surgery. Postoperative AF was defined as the development of AF during hospital admittance. Descriptive analysis and binary logistic regression were performed for the target variable. Results A total of 467 patients were studied, with 35 cases of SCH. The incidence of postoperative AF was 57% in the group with SCH versus 30.3% (p = 0.001) in the group without hypothyroidism, without significant differences in other postoperative complications. In the logistic regression analysis, the independent predictors of postoperative AF were SCH, age, and aortic clamping time. SCH multiplies the odds ratio of postoperative AF by 3.14 (95% confidence interval: 1.24-7.96). Conclusion SCH behaves like a risk factor for the development of postoperative AF in patients undergoing aortic valve replacement with extracorporeal circulation. Other studies are needed to determine whether preoperative T4 replacement therapy and/or more aggressive AF prophylaxis can prevent this complication in patients undergoing aortic valve replacement.
authors.affiliation: Department of Cardiac Surgery, Hospital of Leon, Leon, Spain.
authors.forename: Jose
authors.initials: J
authors.lastname: Martínez-Comendador
authors.affiliation: Department of Anesthesiology, Hospital of Leon, Leon, Spain.
authors.forename: Jose Miguel
authors.initials: JM
authors.lastname: Marcos-Vidal
authors.affiliation: Department of Cardiac Surgery, Hospital of Leon, Leon, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Gualis
authors.affiliation: Department of Cardiac Surgery, Hospital of Leon, Leon, Spain.
authors.forename: Carlos Esteban
authors.initials: CE
authors.lastname: Martin
authors.affiliation: Department of Cardiac Surgery, Hospital of Leon, Leon, Spain.
authors.forename: Elio
authors.initials: E
authors.lastname: Martin
authors.affiliation: Department of Cardiac Surgery, Hospital of Leon, Leon, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Otero
authors.affiliation: Department of Cardiac Surgery, Hospital of Leon, Leon, Spain.
authors.forename: Mario
authors.initials: M
authors.lastname: Castaño
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery*; D058070:Asymptomatic Diseases; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation; D006801:Humans; D007037:Hypothyroidism / Q000175:diagnosis / Q000209:etiology*; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D015995:Prevalence; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D062606:Tertiary Care Centers; D013997:Time Factors; D016896:Treatment Outcome