The risk of stroke in the early postoperative period following mitral valve replacement

All patients (285) undergoing mitral valve replacement (MVR) with aCarpentier-Edwards (C-E) bioprosthesis +/- coronary bypass grafts (CABG)were reviewed (109 men and 176 women with a median age of 70 years).Overall, the 5-year survival rate was 58.9%, 62.7% for MVR (199 patients)and 50.1% for MVR+CABG (86 patients). Late survival was adversely affectedby the operative time variables of NYHA class IV, older (> or = 70years) age, low (> or = 56%) ejection fraction (EF), and the additionalperformance of associated procedures+CABG with MVR (P < or = 0.001). The5-year freedom from stroke rate was 89.2%, 89.1% for MVR and 90.2% for MVR+/- CABG. Advanced heart class was the only significant variable associatedwith a greater risk of late stroke (P < or = 0.01). Neither chronicpreoperative atrial fibrillation nor operative obliteration of the leftatrial appendage increased or decreased the late risk of stroke in patientsfollowing MVR. Hazard function for stroke occurring in the firstpostoperative year (first 48 h excluded to discount intraoperative events)demonstrated the highest rate within the first month (40%), rapidlydiminishing thereafter. This pattern was reproduced in the 12-year hazardfunction in that the rate of stroke occurrence was greatest in the firstyear (6.7%) following implantation. The mean stroke rate over 12 years was2.5%. Strokes following MVR +/- CABG are more likely to occur in older andmore compromised patients, and the higher early rate is not reflected inthe mean rate. A more aggressive approach to early anticoagulation with IVheparin, Coumadin, and possibly antiplatelet therapy is advocated to reducethis complication rate.