Early and late stroke after mitral valve replacement with a mechanical prosthesis: risk factor analysis of a 24-year experience.
OBJECTIVE
We evaluated risk factors for mortality and stroke after mechanical mitral valve replacement between May 1977 and December 2001.


METHODS
Early and late mortality and stroke were assessed. Potential predictors of mortality and stroke were entered into a Cox proportional hazards model. Actuarial survival and freedom from stroke were determined by a log-rank test.


RESULTS
Mitral valve replacement was performed in 812 patients. Concomitant procedures included left atrial appendage closure in 493 (61%) patients, tricuspid annuloplasty-replacement in 348 (43%) patients, maze procedure in 185 (23%) patients, plication of the left atrium in 148 (18%) patients, and other procedures in 151 (19%) patients. Five-year actuarial survival was 91.1% +/- 2.3%. Freedom from stroke at 8 years was significantly better in patients with sinus rhythm versus atrial fibrillation (P <.001). Ninety-nine percent of patients with mitral valve replacement combined with a maze procedure were free from stroke, whereas only 89% of patients with mitral valve replacement alone were free from stroke at 8 years after surgical intervention. Seventy-two patients had late stroke; sixty-five patients (90%) were in atrial fibrillation, and 47 (65%) patients had the left atrial appendage closed. Multivariate analysis showed that late atrial fibrillation (odds ratio, 3.39; 95% confidence interval, 1.72-6.67; P =.0001) and omission of the maze procedure (odds ratio, 3.40; 95% confidence interval, 1.14-10.14; P =.003) were the significant risk factors for late stroke.


CONCLUSIONS
Persistent atrial fibrillation was the most significant risk factor for late stroke after mechanical mitral valve replacement. Restoration of sinus rhythm with a maze procedure nearly eliminated the risk of late stroke, whereas neither closure of the left atrial appendage nor therapeutic anticoagulation prevented this complication.
Bando
Ko
K
Department of Cardiovascular Surgery, National Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka, Japan. kobando@hsp.ncvc.go.jp
Kobayashi
Junjiro
J
Hirata
Mitsuhiro
M
Satoh
Toshihiko
T
Niwaya
Kazuo
K
Tagusari
Osamu
O
Nakatani
Satoshi
S
Yagihara
Toshikatsu
T
Kitamura
Soichiro
S
D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000453:epidemiology / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006349:Heart Valve Diseases / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation*; D017052:Hospital Mortality; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery*; D009017:Morbidity; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000188:drug therapy / Q000209:etiology* / Q000401:mortality; D019106:Postoperative Hemorrhage / Q000453:epidemiology / Q000209:etiology; D011237:Predictive Value of Tests; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D020521:Stroke / Q000188:drug therapy / Q000453:epidemiology / Q000209:etiology*; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents