Late incidence and determinants of stroke after aortic and mitral valve replacement

Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada.
The Annals of thoracic surgery (Impact Factor: 3.85). 08/2004; 78(1):77-83; discussion 83-4. DOI: 10.1016/j.athoracsur.2003.12.058
Source: PubMed


Stroke is a devastating complication in patients with prosthetic valves, but characterization of its late occurrence from a large cohort is lacking.
Three thousand one hundred eighty-nine adult patients who underwent a total of 3,576 operations for left-heart valve replacement were managed with contemporary anticoagulation guidelines and prospectively followed in a dedicated clinic. Total follow-up was 20,096 patient years. Bootstrapped survival analysis was used to determine the impact of patient and valve related factors on the incidence of stroke.
Most strokes were embolic. Linearized embolic stroke rates were 1.3% +/- 0.2% per year for aortic bioprostheses, 1.4% +/- 0.2% per year for aortic mechanical valves, 1.3% +/- 0.3% per year for mitral bioprostheses, and 2.3% +/- 0.4% per year for mitral mechanical valves (p = 0.002, vs other implant types). Age more than 75 years, female gender, and smoking were independent risk factors after aortic and mitral valve replacement. Atrial fibrillation, coronary disease, and tilting-disc mechanical prostheses were independent predictors of embolic stroke after aortic valve replacement. Preoperative left ventricular (LV) dysfunction was an independent risk factor in patients with mitral prostheses. Primary operative indication, diabetes, redo status, or the presence of two prosthetic valves were not associated with an increased hazard. The addition of acetyl salicylic or dipyridamole to warfarin anticoagulation did not significantly lower embolic stroke risk in patients with mechanical prostheses.
Approximately 20% of patients with valve prostheses have an embolic stroke by 15 years after valve replacement. Some risk factors such as the avoidance of smoking, mitral mechanical prostheses, aortic tilting-disc valves, and proceeding to mitral surgery before LV dysfunction occurs are potentially modifiable.

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Available from: Pierre Bedard, Mar 12, 2014
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    • "The linearised complication rate in our series may seem higher than the literature data with a longer follow-up. However, we studied the first 2 years when the embolic risk is significantly higher [22] [23]. A Canadian study [24] in 2004 on 586 MMVRs with post-operative TTE gave 2.3 events per 100 patientyears of sequelar post-embolic stroke, comparable with our rate (2.2 events for 100 patient-years). "
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    ABSTRACT: The French Cardiology Society (SFC) systematically recommends (Class I) transesophageal echocardiography (TEE) after any mitral valve replacement with a mechanical prosthesis (MMVR). Taking into account the increasing workload of echocardiography laboratories, our attitude was to propose that only post-operative transthoracic echocardiography (TTE) is performed. The purpose of this study was to evaluate the possible risks of this simplified procedure. We performed a precise analysis of one full year of practice of MMVR with exhaustive follow-up for the first 2 years concentrating on thromboembolic complications. From January to December 2003, 84 MMVRs (46 after rheumatic fever, 22 degenerative disease, 11 infective endocarditis (IE) and 5 ischemia) were conducted in 45 women and 39 men of average age 61 years. Early mortality (<30 days) concerned 5 patients (5.9%). A control TTE to determine normal prosthetic function was performed 7+/-2 days after surgery and this revealed 2 cases of nonobstructive thrombosis which were treated medically, 3 cases of paraprosthetic regurgitation, and 1 vegetation due to underlying IE. Actuarial survival was 90.5% at 1 year and 83.3% at 2 years. After a mean follow-up of 179.3 patient-years, 5 patients were reoperated (5.9%): 1 for IE, 1 for paravalvular regurgitation, 1 for mitral valve insufficiency with haemolysis, and 2 for obstructive prosthetic valve thromboses. In addition there were 2 cases of prosthetic valve thrombosis, 8 ischemic strokes (2 ministrokes, 6 sequelar strokes), and 1 peripheral embolism. The global thromboembolic complication rate was therefore 6.1 per 100 patient-years (n=11). There were 4 hemorrhagic events, i.e. a rate of 2.2 events per 100 patient-years. 63% of the 1193 INR conducted were within the target range (3-4.5), 26% were below 3 and 11% were greater than 4.5. 35% of patients with thromboembolic complications had an INR<3. Morbidity and mortality during the first 2 years after MMVR were relatively high but equivalent to the values of comparable series in the literature. These complications would not have been reduced by a more precise screening based on early TEE. Despite the increasingly litigious nature of the doctor-patient relationship, it would probably be excessive to oppose that this guideline was not followed in a dispute; in particular as it is difficult to apply this measure as echocardiography departments are overworked.
    Full-text · Article · Apr 2008 · Archives of Cardiovascular Diseases
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    • "Prosthesis-related complications were recorded according to the Guidelines for Reporting Morbidity and Mortality after Cardiac Valvular Operations [5]. Briefly, stroke was defined as the presence of a neurological deficit lasting more than three weeks and was confirmed with computerized tomography of the head [4] [5]. Bleeding events were classified as major if they required surgery, hospital admission, blood transfusion, were intracranial in location, or caused death. "
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    ABSTRACT: The current trend towards decreasing the age for selection of a tissue over a mechanical prosthesis has led to a dilemma for patients aged 50-65 years. This cohort study examines the long-term outcomes of mechanical versus bioprosthetic valves in middle-aged patients. Patients (N = 659) aged between 50 and 65 years who had first-time aortic valve replacement (AVR) and/or mitral valve replacement (MVR) with contemporary prostheses were followed prospectively after surgery. The total follow-up was 3,402 patient-years (mean 5.1 +/- 4.1 years; maximum 18.3 years). Outcomes were examined with multivariate actuarial methods. A composite outcome of major adverse prosthesis-related events (MAPE) was defined as the occurrence of reoperation, endocarditis, major bleeding, or thromboembolism. Ten-year survival was 73.2 +/- 4.2% after mechanical AVR, 75.1 +/- 12.6% after bioprosthetic AVR, 74.1 +/- 4.6% after mechanical MVR, and 77.9 +/- 7.4% after bioprosthetic MVR (P=NS). Ten-year reoperation rates were 35.4% and 21.3% with aortic and mitral bioprostheses, respectively. Major bleeding occurred more often following mechanical MVR (hazard ratio [HR]: 3.3; 95% confidence interval [CI] 1.2, 9.0; P = 0.022), and the incidence of any thromboembolic event was more common after mechanical MVR (HR: 4.7; CI 1.4, 13.3; P = 0.01). Overall freedom from MAPE at 10 years was 70.2 +/- 4.1% for mechanical AVR patients, 41.0+/-30.3% for bioprosthetic AVR patients, 53.3 +/- 8.8% for mechanical MVR patients, and 61.2 +/- 9.2% for bioprosthetic MVR patients. Although a trend existed towards more MAPE amongst middle-age patients with tissue valves, multivariate analysis did not identify the presence of a bioprosthesis as an independent risk factor for MAPE (HR: 1.3; CI 0.9, 2.0; P = 0.22). In middle-aged patients, MAPE may occur more often in patients with bioprosthetic valves, but definitive conclusions necessitate the accumulation of additional follow-up. At present, these data do not support lowering the usual cutoff for implantation of a tissue valve below the age of 65.
    Full-text · Article · Oct 2006 · European Journal of Cardio-Thoracic Surgery
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    • "Outcomes † Mortality after valve replacement was defined either as early/perioperative (i.e. in hospital or within 30 days of operation) or late. † Stroke was defined as the presence of a neurological deficit lasting more than 3 weeks [1] [2]. Patients diagnosed with a stroke after 1986 had computerized tomography of the head. "
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    ABSTRACT: To examine the multiple impacts of valve replacement on the lives of young adults. Patients (N=500) between age 18 and 50 who had aortic valve replacement (AVR) and/or mitral valve replacement (MVR) with contemporary prostheses were followed annually. Events, functional status, and quality of life were examined with regression models. Median follow-up was 7.1+/-5.3 years (maximum 26.7 years). Five, 10, and 15-year survival was 92.7+/-1.7, 88.3+/-2.4 and 80.1+/-4.7% after AVR, and 93.1+/-2.3, 79.5+/-4.3 and 71.5+/-5.4% after MVR, respectively. Survival decreased with concomitant coronary disease (hazard ratio (HR): 4.5) and preoperative LV grade (HR: 2.0/grade increase) in AVR patients, and with atrial fibrillation (HR: 5.5), coronary disease (HR: 5.7), preoperative left atrial diameter (HR: 3.0/cm increase) and NYHA class (HR: 2.1/class increase) in MVR patients. Despite reoperation, late survival was equivalent between bioprostheses and mechanical valves in both implant positions. The ten-year cumulative incidence of embolic stroke was 6.3+/-2.4% for mechanical AVR patients, 6.4+/-2.9% for bioprosthetic AVR patients, 12.7+/-3.9% for mechanical MVR patients, and 3.1+/-3.1% for bioprosthetic MVR patients. Atrial fibrillation (HR: 2.8) and smoking (HR: 4.0) were risk factors for stroke in MVR patients. In AVR patients, SF-12 physical scores, freedom from recurrent heart failure, and freedom from disability were significantly higher in bioprosthetic than mechanical valve patients. Career or income limitations were more often subjectively linked to a mechanical prosthesis in both implant positions. Late outcomes of modern prosthetic valves in young adults remain suboptimal. Bioprostheses deserve consideration in the aortic position, as mechanical valves are associated with lower physical capacity, a higher prevalence of disability, and poorer disease perception. Early surgical referral and atrial fibrillation surgery may improve survival after MVR.
    Full-text · Article · Apr 2005 · European Journal of Cardio-Thoracic Surgery
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