Safety and Use of Anticoagulation After Aortic Valve Replacement With Bioprostheses: A Meta-Analysis

Antithrombotic therapy after heart valve surgery: contemporary practice in the UK

OBJECTIVES

There is a lack of high-quality data informing the optimal antithrombotic drug strategy following bioprosthetic heart valve replacement or valve repair. Disparity in recommendations from international guidelines reflects this. This study aimed to document current patterns of antithrombotic prescribing after heart valve surgery in the UK.

METHODS

All UK consultant cardiac surgeons were e-mailed a custom-designed survey. The use of oral anticoagulant (OAC) and/or antiplatelet drugs following bioprosthetic aortic valve replacement or mitral valve replacement, or mitral valve repair (MVrep), for patients in sinus rhythm, without additional indications for antithrombotic medication, was assessed. Additionally, we evaluated anticoagulant choice following MVrep in patients with atrial fibrillation.

RESULTS

We identified 260 UK consultant cardiac surgeons from 36 units, of whom 103 (40%) responded, with 33 units (92%) having at least 1 respondent. The greatest consensus was for patients undergoing bioprosthetic aortic valve replacement, in which 76% of surgeons favour initial antiplatelet therapy and 53% prescribe lifelong treatment. Only 8% recommend initial OAC. After bioprosthetic mitral valve replacement, 48% of surgeons use an initial OAC strategy (versus 42% antiplatelet), with 66% subsequently prescribing lifelong antiplatelet therapy. After MVrep, recommendations were lifelong antiplatelet agent alone (34%) or following 3 months OAC (20%), no antithrombotic agent (20%), or 3 months OAC (16%). After MVrep for patients with established atrial fibrillation, surgeons recommend warfarin (38%), a direct oral anticoagulant (37%) or have no preference between the 2 (25%).

CONCLUSIONS

There is considerable variation in the use of antithrombotic drugs after heart valve surgery in the UK and a lack of high-quality evidence to guide practice, underscoring the need for randomized studies.

Interdisciplinary Surgical Treatments and Long-Term Outcomes of Lumbar Spinal Tumors With Retroperitoneal Involvements: A Retrospective Case Series Study

Purpose

Surgical treatments are technically challenging for lumbar spinal tumor (LST) with extensive retroperitoneal involvements. Our study aimed to report the experience and outcomes concerning interdisciplinary surgical collaborations in managing such LSTs.

Patients and Methods

Nine patients underwent interdisciplinary surgical treatments which were performed by specialists, namely, spinal, vascular, and urinary surgeries. Data on clinical characteristics were collected, and the Visual Analogue Scale (VAS) and the Japanese Orthopaedic Association Score (JOAS) were used in the evaluation before and after surgery. The postoperative complications and the long-term outcomes were reported as well.

Results

The interdisciplinary work included double J catheter indwelling (n = 9), nephrostomy (n = 5), replacement of the common iliac vein (n = 2), abdominal aorta repair (n = 3), and vital vessel repair (n = 8). The early-stage complications included complaints of moderate low back pain and slight implant shift (n = 1, 11.1%) and tardive ureterodialysis (n = 1, 11.1%). The 3- and 5-year disease-free survival rates were 76.2 ± 14.8 and 50.8 ± 23.0%, respectively, during the mean follow-up of 34.6 ± 17.9 months (range, 9.5–68.7). Besides this, more blood loss was associated with recurrent and metastatic tumor status (p = 0.043) and surgery time >5 h (p = 0.023). Remarkable pain relief and favorable quality of life were achieved based on the postoperative VAS (3.3 ± 0.9, p < 0.001) and JOAS (16.6 ± 0.5, p < 0.001).

Conclusions

The treatments of LSTs with wide-range retroperitoneal involvements require interdisciplinary surgical collaborations to lower the risks and improve the long-term outcomes. High-quality prospective cohort studies with large samples are warranted to establish general surgical protocols in managing LSTs with extensive retroperitoneal involvements.

Nonusefulness of Antithrombotic Therapy After Surgical Bioprosthetic Aortic Valve Replacement

Controversy persists regarding the advisability of anticoagulation for the early period after biological surgical aortic valve replacement (AVR). We aim to examine the impact of various antithrombotic regimens on outcomes in a large cohort of biological AVR patients. Records of 1,111 consecutive adult patients who underwent surgical biological AVR at our institution between 2013 and 2017 were reviewed. Outcomes included stroke, bleeding, and death at 3 and 12 months. Treatment regimens included (1) no therapy, (2) anticoagulants (warfarin or Factor Xa inhibitors), (2) antiplateles (various), and (4) anticoagulants + antiplatelets. Kaplan-Meier analysis was used to track outcomes, and Cox-proportional hazards regression models were conducted to analyze effects of different therapies on adverse events. At 3 months, thromboembolic events were low and not significantly different between the no therapy group (2.2%) and anticoagulation (2.8%) or anticoagulation + antiplatelet (3.6%) or all groups (3.7%). The antiplatelet group was just significantly lower, at 2.2%. However, this was driven by non-stroke cardiovascular events in patients with coronary artery disease. The incidence of death at 3 months was low and not significantly different between all groups. At 12 months, there were no thromboembolic benefits between groups, but bleeding events were significantly higher in the anticoagulation group (no therapy (1.4%), anticoagulation (8.4%), antiplatelet (4.5%), anticoagulation + antiplatelet (7.9%)). In conclusion, none of the antithrombotic regimens showed benefits in stroke or survival at 3 or 12 months after biological AVR. Anticoagulation increased bleeding events. Routine anticoagulation after biological AVR appears to be unnecessary and potentially harmful.

Improved long-term outcome of surgical AVR for AS: Results from a population-based cohort

BACKGROUND

The aim of this retrospective study was to determine changes in outcomes after surgical aortic valve replacement (SAVR) for aortic stenosis (AS) in Iceland over a 15-year period.

METHODS

We included 587 patients who underwent SAVR for AS in Iceland during the period 2002-2016, with a total follow-up of 3245 patient-years. Short-term and long-term outcomes, 30-day mortality, and long-term survival (Kaplan-Meier) were analyzed. Univariate linear regression and univariate and multinomial logistic regression analyses were performed on preoperative and perioperative variables. Poisson regression analysis was used to evaluate changes in rates of short-term outcomes.

RESULTS

Mean age was 71 years, 65.1% were males, and mean EuroSCORE II was 3.9. Mean preoperative aortic valve area increased significantly (0.013 cm² /year; P < .001) and mean aortic cross-clamp time declined (108 minutes, 2.8 min/year; P < .001). The rate of complications decreased, including new-onset atrial fibrillation (60.9% overall, decreased by 3.1%/year, P = .02), acute kidney injury (17.1%, 7.6%/year, P < .001), and reoperation for bleeding (12.5%, 6.3%/year, P = .02). Operative mortality did not change (5.4%); nor did 1- and 5-year overall survival (92.5% and 81.6%, respectively). Notable long-term events were chronic heart failure (27.7 admissions/100 patient-years), embolic event (15.9/100 patient-years), and bleeding (13.0/100 patient-years).

CONCLUSIONS

Results of SAVR in this well-defined nationwide cohort of patients in Iceland have improved. This may be related to the patients having less severe AS at the time of operation and shorter operating times, as reflected by lower rates of short-term complications. However, the rate of long-term complications did not change significantly, with prosthetic valve-specific events being rare.

Influence of warfarin on cardiac and cerebrovascular events following bioprosthetic aortic valve replacement: A nationwide cohort study

OBJECTIVE

The need for anticoagulation treatment following bioprosthetic aortic valve replacement remains controversial. We investigated the associations of warfarin treatment with the risks of major adverse cardiac and cerebrovascular events, including mortality, bleeding incidents, and reoperation requirement after bioprosthetic aortic valve replacement surgery.

METHODS

We identified 1086 patients who received first bioprosthetic aortic valve replacement between 2001 and 2010 using Taiwan's National Health Insurance Database. Patients were excluded for prior use of warfarin, warfarin use for >3 months, dual valve procedures, prior valve surgeries, or concomitant surgeries. Enrolled patients were divided into 2 groups according to whether they were warfarin-naïve or received warfarin for <3 months postsurgery. After propensity score matching, 282 patients not receiving warfarin were matched to 282 patients receiving warfarin for <3 months. Patients were followed-up for minimum 36 months.

RESULTS

Patients receiving warfarin were younger and showed less frequent kidney disease than those who did not use warfarin. The warfarin group demonstrated a gross decrease in major adverse cardiac and cerebrovascular events. Patients receiving warfarin for <30 days were at an even lower risk for major adverse cardiac and cerebrovascular events than those treated for ≥30 days. No significant difference in bleeding or reoperation risk was observed between warfarin users and warfarin nonusers. Similar findings remained after propensity-score matching but the benefit of short-term warfarin use diminished in a younger population.

CONCLUSIONS

Short-term use of postoperative warfarin (especially <30 days) following bioprosthetic aortic valve replacement may be associated with a reduction in MACCE compared with nonuse.

Association Between Antithrombotic Medication Use After Bioprosthetic Aortic Valve Replacement and Outcomes in the Veterans Health Administration System

Importance

The recommendations about antithrombotic medication use after bioprosthetic aortic valve replacement (bAVR) vary.

Objectives

To describe the post-bAVR antithrombotic medication practice across the Veterans Health Administration (VHA) and to assess the association between antithrombotic strategies and post-bAVR outcomes.

Design, Setting, and Participants

Retrospective cohort study. Multivariable modeling with propensity scores was conducted to adjust for differences in patient characteristics across the 3 most common antithrombotic medication strategies (aspirin plus warfarin sodium, aspirin only, and dual antiplatelets). Text mining of notes was used to identify the patients with bAVR (fiscal years 2005-2015).

Main Outcomes and Measures

This study used VHA and non-VHA outpatient pharmacy data and text notes to classify the following antithrombotic medications prescribed within 1 week after discharge from the bAVR hospitalization: aspirin plus warfarin, aspirin only, dual antiplatelets, no antithrombotics, other only, and warfarin only. The 90-day outcomes included all-cause mortality, thromboembolism risk, and bleeding events. Outcomes were identified using primary diagnosis codes from emergency department visits or hospital admissions.

Results

The cohort included 9060 veterans with bAVR at 47 facilities (mean [SD] age, 69.3 [8.8] years; 98.6% male). The number of bAVR procedures per year increased from 610 in fiscal year 2005 to 1072 in fiscal year 2015. The most commonly prescribed antithrombotic strategy was aspirin only (4240 [46.8%]), followed by aspirin plus warfarin (1638 [18.1%]), no antithrombotics (1451 [16.0%]), dual antiplatelets (1010 [11.1%]), warfarin only (439 [4.8%]), and other only (282 [3.1%]). Facility variation in antithrombotic prescription patterns was observed. During the 90-day post-bAVR period, adverse events were uncommon, including all-cause mortality in 127 (1.4%), thromboembolism risk in 142 (1.6%), and bleeding events in 149 (1.6%). No differences in 90-day mortality or thromboembolism were identified across the 3 antithrombotic medication groups in either the unadjusted or adjusted models. Patients receiving the combination of aspirin plus warfarin had higher odds of bleeding than patients receiving aspirin only in the unadjusted analysis (odds ratio, 2.58; 95% CI, 1.71-3.89) and after full risk adjustment (adjusted odds ratio, 1.92; 95% CI, 1.17-3.14).

Conclusions and Relevance

These data demonstrate that bAVR procedures are increasingly being performed in VHA facilities and that aspirin only was the most commonly used antithrombotic medication strategy after bAVR. The risk-adjusted results suggest that the combination of aspirin plus warfarin does not improve either all-cause mortality or thromboembolism risk but increases the risk of bleeding events compared with aspirin only.

Antithrombotic therapy management of adult and pediatric cardiac surgery patients

Despite the development of catheter-based interventions for ischemic and valvular heart disease, hundreds of thousands of people undergo open heart surgery annually for coronary artery bypass graft (CABG), valve replacement or cardiac assist device implantation. Cardiac surgery patients are unique because therapeutic anticoagulation is required during cardiopulmonary bypass. Developmental hemostasis and altered drug metabolism affect management in children. This narrative review summarizes the current evidence-based and consensus guidelines regarding perioperative, intraoperative and postoperative antithrombotic therapy in patients undergoing cardiac surgery. Anticoagulation preoperatively is required in the setting of cardiac arrhythmias, prior valve replacement or history of venous thromboembolism. In patients with ischemic heart disease, aspirin is continued in the perioperative period, whereas oral P2Y12 antagonists are withheld for 5-7 days to reduce the risk of perioperative bleeding. Intraoperative management of cardiopulmonary bypass in adults and children includes anticoagulation with unfractionated heparin. Variability in dose-response to heparin and influence of other medical conditions on dosing and reversal of heparin make intraoperative anticoagulation challenging. Vitamin K antagonist therapy is the standard anticoagulant after mechanical heart valve or left ventricular assist device (LVAD) implantation. Longer duration of dual antiplatelet therapy is recommended after CABG if patients undergo surgery because of acute coronary syndrome. Antiplatelet therapy after LVAD implantation includes aspirin, dipyridamole and/or clopidogrel in children and aspirin in adults. A coordinated approach between hematology, cardiology, anesthesiology, critical care and cardiothoracic surgery can assist to balance the risk of thrombosis and bleeding in patients undergoing cardiac surgery.

Impact of Antithrombotic Regimen on Mortality, Ischemic, and Bleeding Outcomes after Transcatheter Aortic Valve Replacement

Introduction

Optimal antithrombotic therapy after transcatheter aortic valve replacement (TAVR) remains unclear. We evaluated the association between antithrombotic regimens and outcomes in TAVR patients.

Methods

We retrospectively analyzed consecutive patients who underwent TAVR at a single academic center from April 2009 to March 2014. Antithrombotic regimens were classified as single or dual antiplatelet therapy (AP), single antiplatelet plus anticoagulant (SAC), or triple therapy (TT). The primary endpoint was a composite of death, myocardial infarction (MI), stroke, and major bleeding. Adjusted hazard ratios (HRs) were obtained with best subset variable selection methods using bootstrap resampling.

Results

Of 246 patients who underwent TAVR, 241 were eligible for analysis with 133, 88, and 20 patients in the AP, SAC, and TT groups, respectively. During a median 2.1-year follow-up, 53.5% had at least one endpoint—the most common was death (68%), followed by major bleeding (23%), stroke (6%), and MI (3%). At 2 years, the composite outcome occurred in 70% of TT, 42% of SAC, and 31% of AP patients. Compared to AP, adjusted HRs for the composite outcome were 2.88 [95% Confidence intervals (CI) (1.61–5.16); p = 0.0004] and 1.66 (95% CI [1.13-2.42]; p = 0.009) in the TT and SAC groups, respectively. Mortality rates at 2 years were 61% in the TT, 32% in the SAC, and 26% in the AP groups (p = 0.005).

Conclusions

The risk of the composite outcome of death, MI, stroke, or major bleeding at 2-year follow-up was significantly higher in TAVR patients treated with TT or SAC versus AP, even after multivariate adjustment.

Antithrombotic Therapy After Transcatheter Aortic Valve Implantation

Current guidelines for patients who are undergoing transcatheter aortic valve implantation but who do not require anticoagulation recommend double antiplatelet therapy for 3-6 months after the procedure, followed by aspirin indefinitely. However, these guidelines are based on expert consensus rather than clinical trials. Several randomized trials are currently evaluating alternative antithrombotic strategies, and recommendations will likely change when their results become available.

Anticoagulation After Heart Valve Replacement or Transcatheter Valve Implantation

Valvular heart disease is prevalent and represents a significant contributor to cardiac morbidity and mortality. Several options for valve replacement exist, including surgical replacement and transcatheter valve implantation. Prosthetic valves lead to increased risk of thromboembolic disease; therefore, antithrombotic therapy after valve replacement is indicated. For patients with mechanical prostheses, indefinite vitamin K antagonist and antiplatelet therapy are the mainstays of treatment. There is no consensus regarding optimal antithrombotic therapy after bioprosthetic valve replacement, although vitamin K antagonist therapy of varying duration in addition to antiplatelet therapy is recommended by guidelines. Dual-antiplatelet therapy is commonly used after transcatheter valve implantation; however, alternative antithrombotic regimens are being studied. Further studies are needed to identify the optimal regimen, intensity, and duration of antithrombotic therapy after surgical bioprosthetic valve replacement and transcatheter valve implantation.