Impaired Left Ventricular Function Does Not Predict Worse Late Outcome after Isolated Mitral Valve Surgery.

BACKGROUND AND AIM OF THE STUDY: The best timing for mitral valve surgery remains controversial. Decreased left ventricular function (LVF) is considered to be a predictor for increased mortality and is therefore an indication for surgery. The study aim was to investigate the independent effect of preoperative LVF on early and late mortality after mitral valve surgery. METHODS: Patients undergoing isolated mitral valve surgery between January 1998 and December 2010 at a single center were included for the analysis. Patients without recorded LVF, with active endocarditis, or patients lost to follow up were excluded. Patients were allocated to three groups based on their left ventricular ejection fraction (LVEF) measured using echocardiography as good (>50%), moderate (35-50%) or poor (<35%). A Cox regression analysis was performed to identify independent risk factors for late survival. RESULTS: A total of 549 patients underwent isolated mitral valve surgery. The 30-day mortality was not statistically different between groups (p = 0.579), and late survival was similar in all groups (log-rank, p = 0.130). A moderate or poor LVF was not identified as a risk factor for late mortality (HR 1.4 [0.9-2.2], p = 0.179; HR 1.8 [0.7-4.4], respectively, p = 0.213). The difference remained insignificant after correction for other risk factors (HR 1.4 [0.8-2.3], p = 0.192; HR 2.4 [0.9-6.7], respectively, p = 0.09). CONCLUSION: A reduced LVF is not an independent risk factor for short- and long-term all-cause mortality in patients undergoing isolated mitral valve surgery for non-ischemic mitral valve disease.

Clamping versus nonclamping thoracoscopic box ablation in long-standing persistent atrial fibrillation.

OBJECTIVE: To compare clinical outcomes of clamping devices and linear nonclamping devices for isolation of the posterior left atrium (box) in thoracoscopic ablation of long-standing persistent atrial fibrillation. METHODS: Eighty patients who underwent thoracoscopic pulmonary vein and box isolation using a bipolar clamping device (42 patients) or bipolar nonclamping device (38 patients) to create the roof/inferior lesions for box isolation were included from 2 centers. Follow-up consisted of 24-hour Holter at regular intervals. Freedom from AF during 1-year follow-up and catheter repeat interventions were compared between groups. RESULTS: Acute intraoperative electrical isolation of the box compartment was significantly higher in the clamping group than in the nonclamping group (100% and 79%, respectively, P < .01). At 1-year follow-up, 91% of the clamping group and 79% of the nonclamping group were in sinus rhythm. During 1-year follow-up, recurrence rates did not significantly differ between the 2 groups (P = .08). Repeat catheter interventions were required in 10% of the clamping group and 21% of the nonclamping group (P = .15). Conduction gaps in the roof or inferior lesions were found in 1 patient (2%) in the clamping group versus 4 patients (11%) in the nonclamping group (P = .13). CONCLUSIONS: Thoracoscopic pulmonary vein and box isolation are highly effective in restoring sinus rhythm in long-standing persistent atrial fibrillation on short-term follow-up. Comparison of clamping and nonclamping devices revealed lower rates of intraoperative exit block of the box in the nonclamping group. However, this did not translate into a significant difference in atrial fibrillation freedom at short-term (1-year) follow-up.

Poststernotomy mediastinitis and the role of broken steel wires: retrospective study.

OBJECTIVE: Mediastinitis is a severe complication of cardiac surgery. Sternal instability is concomitantly present in most cases. Broken steel wires may cause sternal instability. In this study, the role of broken steel wires in sternal closure was evaluated in patients who developed poststernotomy mediastinitis. METHODS: Preoperative, perioperative, and postoperative data of patients who underwent thoracic surgery between 1996 and 2006 were retrieved from the SUMMIT registry database. Patients needing reoperation for mediastinitis were identified. Patients' charts and chest radiographs from initial surgery to reoperation for mediastinitis were reviewed. RESULTS: Forty-five patients developed postoperative mediastinitis needing reoperation (0.6%). Because of loss to follow-up, 31 patients were evaluated. Eight patients (25.8%) presented fractured steel wires. Most of the broken steel wires (87.5%) manifested at the cranial site of figure-of-eight configurations. In the patients without broken steel wires, mediastinitis manifested after 14 days compared with 38 days in the patients with broken wires. Time until mediastinitis was not significantly different (P = 0.229). The mean time until steel wire disruption was 14 days (range, 4-48 days). CONCLUSIONS: Broken steel wires were observed before mediastinitis became manifest. Fracturing occurred mainly at the cranial site of figure-of-eight configurations. The results of the present study emphasize that closure technique plays a prominent role in the development of mediastinitis. Because mediastinitis is associated with an increased risk for early morbidity, attention should be paid to patients presenting with broken steel wires. New techniques for median sternotomy closure are needed that are less prone to mechanical fatigue than are steel wires.