Early postoperative bridging anticoagulation after mechanical heart valve replacement: a systematic review and meta-analysis.

OBJECTIVE: To perform a systematic review and meta-analysis of studies evaluating anticoagulation during the early postoperative period following mechanical heart valve implantation. METHODS: Five literature databases were searched to assess the rates of bleeding and thromboembolic events among patients receiving oral anticoagulation (OAC), both with and without bridging anticoagulation therapy with unfractionated heparin (UFH) or subcutaneous low molecular weight heparin (LMWH). The studies' results were pooled via a mixed effects meta-analysis. Heterogeneity (I(2) ) and publication bias were both evaluated. RESULTS: Twenty-three studies including 9534 patients were included. The bleeding rates were 1.8% (95% confidence interval CI 1.0-3.3) in the group receiving OAC, 2.2% (95% CI 0.9-5.3) in the OAC + UFH group, and 5.5% (95% CI 2.9-10.4) in the OAC + LMWH group (P = 0.042). The thromboembolic event rate was 2.1% (95% CI 1.5-2.9) in the group receiving OAC, as compared with 1.1% (95% CI 0.7-1.8) when the bridging therapy groups were combined as follows: OAC + UFH and OAC + LMWH (P = 0.035). Most of the analyses showed moderate heterogeneity and negative test results for publication bias. CONCLUSIONS: Bridging therapy following cardiac valve surgery was associated with a lower thromboembolic event rate, although the difference was small, with considerable overlap of the CIs. Direct comparisons are missing. Bridging therapy with UFH appears to be safe; however, this observation has a risk of bias. Early bridging therapy with LMWH appears to be associated with consistently high bleeding rates across multiple analyses. On the basis of the quality of the included studies, more trials are necessary to establish the clinical relevance of bridging therapy and the safety of LMWH.

Thrombolytic therapy or surgery for valve prosthesis thrombosis: systematic review and meta-analysis.

BACKGROUND: Prosthetic heart valve thrombosis is a life-threatening condition for which treatment has not been evaluated by randomized trials. OBJECTIVES: To compare surgery with thrombolytic therapy for the treatment of prosthetic valve thrombosis. METHODS: A comprehensive systematic review was carried out by independent researchers using PubMed, Web of Knowledge, HINARI, LILACS and EMBASE, including papers indexed up to 23 October 2013 with at least 10 patients, evaluating one or both treatment options. Outcomes of interest were death, stroke, bleeding, embolic events and success. Study quality was assessed by the Newcastle-Ottawa Scale (ranges from 0 to 9). Comprehensive Meta Analysis Software was used to pool study results, for publication bias analysis and for meta-regression. RESULTS: Forty-eight studies were included (2302 patients). No randomized study was identified, and all were observational in design. Study quality varied from 4 to 6 stars using the Newcastle-Ottawa Scale. Mortality for surgery was 18.1% (95%CI, 14.6-22.1; I(2) , 62% [42-75]), while mortality for thrombolytic therapy was 6.6% (95% CI, 4.8-8.9; I(2) , 0% [0-13]). Surgical mortality appeared to increase with NYHA-class, according to meta-regression. Other results related to surgery and thrombolytic therapy, respectively, were: embolic events, 4.6% (2.9-7.3) and 12.8% (10.8-15.2); stroke, 4.3%,(2.7-6.6%) and 5.6%,(4.3-7.4%); success rate, 81.9% (77.2-85.8) and 80.7% (75.6-85.0); bleeding, 4.6% (2.9-7.1) and 6.8% (5.4-8.6); and death or stroke, 19.0% (14.8-24.2) and 11.4% (8.7-14.7). CONCLUSION: Mortality in patients treated by thrombolytic therapy for valve prosthesis thrombosis is significantly lower than in patients treated surgically. As we cannot yet ascertain whether this difference is due to the treatment alone, more studies are now necessary to further clarify these findings.