Anticoagulation versus antiplatelet or no therapy in patients undergoing bioprosthetic valve implantation: a systematic review and meta-analysis

Benefit of Anticoagulation Early After Surgical Aortic Valve Replacement Using Bioprosthetic Valves

OBJECTIVE

To compare all-cause mortality and thromboembolic events in patients undergoing surgical aortic valve replacement (sAVR) receiving anticoagulation with warfarin versus patients with no systemic anticoagulation.

PATIENTS AND METHODS

Using data from the OptumLabs Data Warehouse, we investigated adult patients having bioprosthetic sAVR with or without coronary artery bypass from January 1, 2007, through December 31, 2019. Patients were classified into groups of nonwarfarin or warfarin (≥30 days of continuous prescription coverage after sAVR). One-to-one propensity score (PS) matching was used to adjust for group differences.

RESULTS

Of 10,589 patients having sAVR, 7659 (72.3%) were in the nonwarfarin group and 2930 (27.7%) were in the warfarin group. After PS matching, 2930 pairs of patients were analyzed. Median follow-up was 4.1 months (interquartile range [IQR], 2.6-7.4 months) for the warfarin group and 21.3 months (IQR, 7.8-24.0 months) for the nonwarfarin group. Overall mortality was lower for the warfarin group than for the nonwarfarin group (hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.47 to 1.00; P=.047), and there was a trend toward decreased cumulative incidence of thromboembolic events (subdistribution HR [SHR], 0.62; 95% CI, 0.35 to 1.07; P=.09). Cumulative incidence of major bleeding events was higher for the warfarin group vs the nonwarfarin group (SHR, 1.94; 95% CI, 1.28 to 2.94; P=.002). Results were similar in a subgroup analysis of patients undergoing isolated sAVR.

CONCLUSION

During the prescription coverage period, warfarin use after bioprosthetic sAVR was associated with lower all-cause mortality and decreased risk of thromboembolism compared with not receiving warfarin. However, warfarin use was associated with an increased risk of major bleeding events.

Anticoagulation After Bioprosthetic Aortic Valve Replacement: Are We Following the Guidelines?

BACKGROUND

Guideline-directed medication adherence is considered an important quality measure after cardiac surgery. We evaluated compliance with the American College of Cardiology/American Heart Association guidelines for warfarin use after surgical aortic valve replacement (sAVR) using bioprostheses and examined potential variations in anticoagulation practice over time.

METHODS

Using the OptumLabs Data Warehouse, we investigated adult patients having bioprosthetic sAVR with or without coronary artery bypass (2007-2019). Early postoperative warfarin use was defined as ≥30 days of continuous prescription coverage after sAVR.

RESULTS

Among 10 730 adult patients having sAVR, 3071 (28.6%) received warfarin early postoperatively. Median length of warfarin prescription coverage was 4.5 months (interquartile range, 3.0-8.9 months). However, only 11.1% (736/6634) had warfarin prescription coverage of 3 to 6 months in compliance with the most recent guidelines. Yearly warfarin prescription rate did not change significantly during the 13-year period (P = .386). Compared with patients from the non-warfarin group, those receiving warfarin prescriptions were older and more likely to be male and to have atrial fibrillation, congestive heart failure, chronic pulmonary disease, and CHA₂DS₂-VASc score ≥2; warfarin use was also greater in patients receiving prescriptions for other cardiac medications (P < .05).

CONCLUSIONS

Anticoagulation after sAVR as reflected by warfarin prescriptions may be underused; the rates of warfarin use have not changed in the last decade. Although additional studies are needed to confirm the benefit of early anticoagulation after sAVR, these results indicate that guideline recommendations are not followed by most clinicians. The findings highlight a potentially important area for quality improvement.

[Aortic stenosis: An update]

Aortic stenosis remains one of the most frequent valvulopathy worldwide, burdened with great mortality and morbidity, and for which there is not yet an effective preventive approach, although the pathophysiological mechanisms involved in its development are better understood nowadays. Its cure, however, has been revolutionized in the last decade by the advent of transcatheter aortic valve implantation, or TAVI (also named transcatheter aortic valve replacement or TAVR). The technique of TAVI has been refined and its indications has been extended, following the publication of large randomized controlled trials where it was compared to surgical aortic valve replacement with favorable results. Consequently, transfemoral TAVR has become the first line of treatment in case of symptomatic severe aortic valve stenosis. In this review, we describe the pathophysiological mechanisms leading to severe aortic stenosis and the main ongoing randomized controlled trials targeting them. We describe the indication for surgical or percutaneous aortic valve replacement and the main complications following the procedure.

The Characteristics, Long-Term Outcomes, Risk Factors, and Antithrombotic Therapy in Chinese Patients With Atrial Fibrillation and Bioprosthetic Valves

Introduction: There were few data about the clinical profiles and long-term outcomes in Chinese patients with atrial fibrillation (AF) and bioprosthetic valves.

Methods: The retrospective study enrolled 903 patients with bioprosthetic valve replacement at our hospital and discharged with a diagnosis of AF from January 2010 to December 2018.

Results: The median age was 65.6 (61.9–69.1) years, and 548 (60.7%) patients were women. During a follow-up period of 3.84 (2.64–5.51) years, 68 (1.8 per 100 person-years) patients died, 81 (2.1 per 100 person-years) patients developed thromboembolism, and 23 (0.6 per 100 person-years) patients experienced major bleeding. The CHA₂DS₂-VASc score, as a categorical variable (low, moderate, or high risk), predicted the risk of thromboembolism with the C-statistic of 0.6 (95% CI: 0.511–0.689, p = 0.046). The incidence of the CHA₂DS₂-VASc score increment was 11.6 per 100 person-years, and the annual reclassification rate of stroke risk (from a low or moderate group to a higher group) was 12.7%. The current proportion of oral anticoagulants was 52.3, 59, and 63.2%, respectively, in the low, moderate, and high stroke risk groups. Age (OR: 1.04, 95% CI: 1.01–1.06, p = 0.01), left atrial size (OR: 1.05, 95% CI: 1.03–1.08, p < 0.001), and rheumatic heart disease (OR: 1.49, 95% CI: 1.05–2.10, p = 0.025) were positively associated with the use of oral anticoagulants. The history of chronic kidney disease (OR: 0.20, 95% CI: 0.05–0.76, p = 0.018), prior surgical ablation (OR: 0.33, 95% CI: 0.24–0.47, p < 0.001), and antiplatelet agent use (OR: 0.08, 95% CI: 0.05–0.13, p < 0.001) were inversely related to the use of oral anticoagulants. Higher admission estimated glomerular filtration rate (HR: 0.515, 95% CI: 0.311–0.853, p = 0.01), left ventricular ejection fraction (HR: 0.961, 95% CI: 0.931–0.992, p = 0.014), concomitant surgical ablation (HR: 0.348, 95% CI: 0.171–0.711, p = 0.004), and rheumatic heart disease history (HR: 0.515, 95% CI: 0.311–0.853, p = 0.01) were associated with a lower risk of death. Surgical ablation (HR: 0.263, 95% CI: 0.133–0.519, p < 0.001) and oral anticoagulants (HR: 0.587, 95% CI: 0.375–0.918, p = 0.019) were related to a lower risk of thromboembolism.

Conclusion: Chinese patients with AF and bioprosthetic valve(s) were relatively young and had a high prevalence of rheumatic heart disease with few comorbidities. The percentage of mitral bioprosthetic valve replacement was high. The proportion of concomitant surgical ablation or surgical left atrial appendage occlusion or exclusion was relatively low. The thromboembolic events were the major long-term adverse events. The anticoagulation therapy was underused in patients at moderate or high stroke risk. The CHA₂DS₂-VASc score was verified to be used for predicting stroke risk in this population. The stroke risk dynamically changed; it needed to be reestimated once the risk factor changed.

Comparison of Frequency of Late Gastrointestinal Bleeding With Transcatheter Versus Surgical Aortic Valve Replacement

Improvements in technology and operator experience have led to exponential growth of transcatheter aortic valve implantation (TAVI) programs. Late bleeding complications were recently highlighted after TAVI with a high impact on morbidity. The purpose of the present study was to assess the incidence and financial impact of late Gastrointestinal (GI) bleeding after TAVI, and compare with the surgical cohort. Retrospective analysis of the National Readmissions Database was performed from January 2011 to December 2014, and patients who underwent TAVI or surgical aortic valve replacement (SAVR) were identified. Incidence of readmission with a diagnosis of GI bleeding was utilized as the primary end point. Overall, 43,357 patients were identified who underwent TAVI, whereas 310,013 patients underwent SAVR. Compared with SAVR, TAVI patients were older (81 vs 68y, p < 0.001), more women (48% vs 36%, p < 0.001), and had higher Elixhauser Comorbidity Index (6 vs 5, p < 0.001). Hospital stay was shorter with TAVI (5 vs 8 days, p < 0.001), but raw in-hospital mortality rates were similar (4.2% vs 3.8%, p = 0.022). In the TAVI cohort, 3.3% of patients were rehospitalized for GI bleeding compared with 1.5% of the SAVR cohort (p < 0.001). Average time to bleeding readmission was similar between cohorts (92 vs 84 days, p = 0.049). After multivariable adjustment, TAVI remained significantly associated with readmissions for GI bleeding compared with SAVR Adjusted Odds Ratio (AOR 1.54 [1.38 to 1.71], p < 0.001). In this national cohort study, TAVI was associated with more frequent readmissions for late GI bleeding compared with SAVR. In conclusion, strategies to reduce late GI bleeding may serve as important targets for improvement in overall quality of care.

Comparison of Lipoprotein(a)-Levels in Patients ≥70 Years of Age With Versus Without Aortic Valve Stenosis

Although lipoprotein(a) (Lp[a]) is linked with aortic valve calcification and clinical aortic valve stenosis (AVS) in middle-aged cohorts, patients aged ≥70 years represent a majority of patients with AVS, in which mechanisms leading to AVS may differ. We sought to determine whether Lp(a) distinguishes patients ≥70 years with and without AVS. We matched 484 patients ≥70 years with AVS, scheduled for transcatheter aortic valve implantation with 484 patients without AVS by age group and gender. Lp(a) levels were compared in patients with and without AVS and stratified by presence and absence of clinical coronary artery disease (CAD) manifestation. A total of 968 patients (mean age 80 ± 5 years, 48% women) were included. When comparing patients with and without AVS, no difference in Lp(a) was observed (AVS: 17 [8; 56] mg/dl, no AVS: 18.5 [8.5; 57] mg/dl, p = 0.56). In contrast, patients with clinical CAD manifestation had higher Lp(a) levels than those without clinical CAD manifestation (coronary artery disease: 19 [9; 60] mg/dl, no coronary artery disease 15 [7; 44] mg/dl, p = 0.0006). In regression analysis, no significant association of Lp(a) with AVS was observed in unadjusted (OR [95% CI]: 0.98 [0.91 to 1.06], p = 0.59) and risk factor-adjusted models (0.98 [0.90 to 1.06], p = 0.57). However, Lp(a) was independently associated with clinical CAD manifestation (unadjusted: 1.14 [1.04 to 1.24], p = 0.003, risk factor adjusted: 1.17 [1.07 to 1.27], p = 0.0006). In conclusion, in a large cohort of patients ≥70 years, Lp(a) was associated with clinical CAD manifesation, but not with AVS. Our results suggest that in patients over 70 years, the development of AVS is not influenced by Lp(a).