Meta-Analysis of Usefulness of Anticoagulation After Transcatheter Aortic Valve Implantation

Antithrombotic strategies after transcatheter aortic valve implantation: Insights from a network meta-analysis

OBJECTIVES

We aimed to investigate the efficacy and safety of different antithrombotic strategies in patients undergoing transcatheter aortic valve implantation (TAVI) using network meta-analyses.

BACKGROUND

Meta-analyses comparing single antiplatelet therapy (SAPT) vs. dual antiplatelet therapy (DAPT), ± oral anticoagulant (OAC) was conducted to determine the appropriate post TAVI antithrombotic regimen. However, there was limited direct comparisons across the different therapeutic strategies.

METHODS

MEDLINE and EMBASE were searched through December 2018 to investigate the efficacy and safety of different antithrombotic strategies (SAPT, DAPT, OAC, OAC + SAPT, and OAC + DAPT) in patients undergoing TAVI. The main outcome were all-cause mortality, major or life-threatening bleeding events, and stroke.

RESULTS

Our search identified 3 randomized controlled trials and 10 nonrandomized studies, a total of 20,548 patients who underwent TAVI. All OACs were vitamin K antagonists. There was no significant difference on mortality except that OAC + DAPT had significantly higher rates of mortality compared with others (p < .05, I² = 0%). SAPT had significantly lower rates of bleeding compared with DAPT, OAC+SAPT, and OAC+DAPT (hazard ratio [HR]: 0.59 [0.46-0.77], p < .001, HR: 0.58 [0.34-0.99], p = .045, HR: 0.41 [0.18-0.93], p = .033, respectively, I² = 0%). There was no significant difference on stroke among all antithrombotic strategies.

CONCLUSION

Patients who underwent TAVI had similar all-cause mortality rates among different antithrombotic strategies except OAC+DAPT. Patients on SAPT had significantly lower bleeding risk than those on DAPT, OAC + SAPT, and OAC + DAPT. Our results suggest SAPT is the preferred regimen when there is no indication for DAPT or OAC. When DAPT or OAC is indicated, DAPT + OAC should be avoided.

Single versus Dual Antiplatelet Therapy after Transcatheter Aortic Valve Implantation: A Systematic Review and Meta-Analysis

OBJECTIVES

Although dual antiplatelet therapy (DAPT) with aspirin and clopidogrel is currently recommended in patients after transcatheter aortic valve implantation (TAVI), this practice is not supported by sufficient evidence. This study was performed to compare DAPT to single antiplatelet therapy (SAPT).

METHODS

An electronic search was completed of PubMed, Embase, Ovid Medline, Web of Science, and Cochrane Central Register of Controlled Trials. Studies comparing DAPT versus SAPT in patients undergoing TAVI were included.

RESULTS

Seven studies incorporating 1,445 patients were eligible for the present meta-analysis. There were no significant differences on 30-day all-cause mortality (OR 1.19, 95% CI 0.63-2.25, p = 0.593), 6-month all-cause mortality (OR 1.11, 95% CI 0.49-2.53, p = 0.796), or 1-year all-cause mortality (OR 1.19, 95% CI 0.63- 2.25, p = 0.593). DAPT was associated with an increased risk for 30-day (OR 2.91, 95% CI 1.85-4.58, p < 0.01), 6-month (OR 2.54, 95% CI 1.26-5.10, p < 0.001), and 1-year major and lethal bleeding (OR 2.65, 95% CI 1.04-6.77, p = 0.041) based on 896, 337, and 583 patients, respectively, compared to SAPT.

CONCLUSION

Compared to SAPT, DAPT was not shown to be superior in reducing thrombotic events, but presented an increased risk of major/life-threatening bleeding. More randomized controlled trials are needed to provide further evidence.

On-pump transapical cardioscopic mitral valve replacement with cardiac arrest: short-term results in a porcine survival model

OBJECTIVES

Favourable outcomes with mitral annuloplasty have been achieved with transapical cardioscopic (TAC) surgery in a survival animal model. In addition, experimental TAC on a non-survival animal model also showed adequate access to remove the native mitral valve and implant a prosthetic valve, but the surgical procedure took a long time and lacked follow-up data. The goal of this study was to develop a clinically translatable TAC mitral valve replacement (MVR) procedure using technical and instrumental refinements to reduce the surgical time and to evaluate functional recovery and short-term durability using a survival porcine model. We hypothesized that MVR could be achieved with subannular implantation of the bioprosthesis via the TAC approach.

METHODS

TAC MVR using the Hancock II™ (Medtronic)® mitral prosthesis was performed in 6 pigs via an incision over the xiphoid process, under cardiopulmonary bypass and cardiac arrest. COR-KNOT® and minimally invasive cardiac surgery instruments were used. Haemodynamics, echocardiography, cardiac computed tomography, ventriculography and electrocardiography were used to evaluate the function of the mitral prosthesis and left ventricle, coronary system and conduction system in the perioperative period and 4 weeks later.

RESULTS

A postimplant examination showed that the mitral prosthesis was competent, without a paravalvular leak. The left ventricular ejection fraction was comparable to preoperative values (65.2 ± 4.1 vs 67.2 ± 7.9). The bypass, cross-clamp and implant times were 177.2 ± 44.2 min, 135.3 ± 47.6 min and 94.0 ± 41.2 min, respectively. The prosthesis was in a good position. The apical scar was intact and not aneurysmal 4 weeks after the implant. The valve was properly sutured to the annulus, without a postimplant paravalvular leak. All animals recovered after 1 month of follow-up with preserved ventricular function and normal wall motion.

CONCLUSIONS

We successfully managed to replace the mitral valve with a biological prosthesis via the apex with encouraging bypass and cross-clamp times. This technique may provide an alternative for a selected group of patients with diseased mitral valves who have indications for MVR and still in a high-risk redo setting with conventional sternotomy or minimally invasive cardiac surgery-MVR.