No antithrombotic therapy was associated with a comparable rate of net adverse clinical events (NACEs) to single-antiplatelet therapy (SAPT) or dual-antiplatelet therapy (DAPT), according to a new OCEAN-TAVI Registry analysis. Yusuke Kobari, MD, of the Keio University School of Medicine, Tokyo, and colleagues reported these findings in a manuscript published online Monday and in the Jan. 9 issue of JACC: Cardiovascular Interventions. The OCEAN-TAVI (Optimized transCathEter vAlvular iNtervention) Registry was a nationwide observational, multicenter study conducted at 15 collaborating hospitals in Japan that enrolled 6,587 patients who had undergone TAVR between October 2013 and May 2020. Of these, patients on anticoagulation, antiplatelet other than aspirin or clopidogrel, non-elective TAVI and patients with no device success or perioperative complications were excluded from this analysis. A total of 3,575 patients were finally included in the study and were categorized into three groups a) no antithrombotic therapy (n=293), b) SAPT with either aspirin or clopidogrel (n=1,354) and c) DAPT (aspirin plus clopidogrel, n=1,928). The primary outcome was the incidence of NACEs, defined as a composite of cardiovascular death, stroke, myocardial infarction and life-threatening or major bleeding during median follow-up period of 841 days interquartile range: 597-1,340 days). The safety endpoints were incidence of all bleeding, including minor and major or life-threatening bleeding, according to the Valve Academic Research Consortium-2 (VARC-2) criteria. At baseline, the average age was 83 years in the non-antiplatelet group vs. 85 years in SAPT group vs. 84 years in DAPT group. The major comorbidities of the included cohort were diabetes, hypertension and hyperlipidemia. Patients in the no-antiplatelet-therapy and SAPT groups had a higher rate of Academic Research Consortium-High Bleeding Risk than those in the DAPT group. Echocardiographic parameters were comparable among the three groups at baseline. The study demonstrated that the incidence of NACEs was similar among the groups (none vs. SAPT: adjusted HR [aHR]: 1.18; 95% confidence interval [CI]: 0.77-1.79; p= 0.45; none vs. DAPT: aHR: 1.09; 95% CI: 0.74- 1.62; p=0.67). The rate of all bleeding was lower in patients in the non-antithrombotic group compared to the DAPT group but was similar to that of SAPT patients (none vs SAPT: aHR: 0.63; 95% CI: 0.33-1.19; p=0.12; none vs DAPT: aHR: 0.51; p=0.04). The valve performance including mean gradient and indexed effective orifice area was similar among the groups. Leaflet thrombosis was detected in 8.5% of the group without antithrombotic therapy on follow-up multidetector computed tomography (MDCT) scans. The main limitations of study included its retrospective and observational design. The study analysis did not consider changes in medication regimen during the follow-up period. Also, the leaflet thrombosis was not quantified in the SAPT or DAPT group. In an accompanying editorial, Vincent Auffret, MD, PhD, of the University of Rennes, France, and colleagues commended the authors for their thought-provoking study and stated that the study findings unlock a novel and interesting prospective that warrants further confirmation in the North American or European population. Further, they said that though the study was reassuring without an alarmingly high rate of subclinical leaflet thrombosis in the no-antiplatelet group, a systematic evaluation with MDCT scans remains necessary in these groups, as subclinical leaflet thrombosis may be associated with higher rate of symptomatic hemodynamic valve deterioration. Sources: Kobari Y, Inohara T, Tsuruta H, et al. No Antithrombotic Therapy After Transcatheter Aortic Valve Replacement: Insight From the OCEAN-TAVI Registry. JACC Cardiovasc Interv 2023;16:79–91. Auffret V, Guedeney P, Leurent G, et al. Antithrombotic After TAVR: No Treatment, No Problem? JACC Cardiovasc Interv 2023;16:92–93. Image Credit: luchschenF – stock.adobe.com