Dual Versus Single Antiplatelet Therapy in Patients Undergoing Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-analysis

Increased utilization of bioprosthetic aortic valve technology:Trends, drivers, controversies and future directions

Introduction: Bioprosthetic valves (BPV) implanted surgically or by transcatheter valve implantation (TAVI) comprise an overwhelming majority of substitute aortic valves implanted worldwide.Areas Covered: Prominent drivers of this trend are: 1) BPV patients have generally better outcomes than those with a mechanical valve, and remain largely free of anticoagulation and its consequences; 2) BPV durability has improved over the years; and 3) the expanding use of TAVI and valve-in-valve (VIV) procedures permitting interventional management of structural valve degeneration (SVD). Nevertheless, key controversies exist: 1) optimal anticoagulation regimens for surgical and TAVI BPVs; 2) the incidence, mechanisms and mitigation strategies for SVD; 3) the use of VIV for treatment of SVD, and 4) valve selection recommendations for difficult cohorts, (e.g. patients 50-70 years, patients <50, childbearing age women). This communication reviews trends in and drivers of BPV utilization, current controversies, and future directions affecting BPV use.Expert Opinion: Long-term data are needed in several areas related to aortic BPV use, including anticoagulation/antiplatelet therapy, especially following TAVI. TAVI and especially VIV durability and optimal use warrant will benefit greatly from long-term data. Certain populations may benefit from such high-quality data on multi-year outcomes, particularly younger patients.

Neurologic complications of heart surgery

Cardiac surgeries are commonly associated with neurologic complications. The type and complexity of the surgery, as well as patients' comorbidities, determine the risk for these complications. Awareness and swift recognition of these complications may have significant implications on management and prognosis. Recent trials resulted in an expansion of the time window to treat patients with acute ischemic stroke with intravenous thrombolysis and/or mechanical thrombectomy using advanced neuroimaging for screening. The expanded time window increases the reperfusion treatment options for patients that suffer a periprocedural ischemic stroke. Moreover, there is now limited data available to help guide management of intracerebral hemorrhage in patients undergoing treatment with anticoagulation for highly thrombogenic conditions, such as left ventricular assist devices and mechanical valves. In addition to cerebrovascular complications patients undergoing heart surgery are at increased risk for seizures, contrast toxicity, cognitive changes, psychological complications, and peripheral nerve injuries. We review the neurological complications associated with the most common cardiac surgeries and discuss clinical presentation, diagnosis and management strategies.

Fatal Ovarian Hemorrhage Associated With Anticoagulation Therapy in a Yucatan Mini-Pig Following Venous Stent Implantation

Swine models are commonly utilized in endovascular research for development of intravascular interventions and medical device development. As part of a pilot study for a venous vascular stent device, a 5-year-old female Yucatan mini-pig underwent bilateral external iliac vein stent placement under general anesthesia. To reduce thrombotic complications by reduction of thrombus formation on wires, sheaths, and catheters, the pig was heparinized with a total of 300 IU/kg of heparin, establishing an activated clotting time (ACT) of 436 s. The ACT had returned to below 200 s by the end of the procedure. To prevent postoperative thrombosis, the pig received an anticoagulation therapy protocol consisting of enoxaparin, clopidogrel, and aspirin. There were no complications during the immediate postoperative period. However, the pig died 4 days after surgery. Necropsy established the cause of death as abdominal exsanguination due to severe, acute, intra-ovarian hemorrhage, most likely related to ovulation. Life-threatening ovarian hemorrhage is occasionally seen in women with congenital or acquired bleeding disorders; to our knowledge this is the first report of fatal ovarian hemorrhage in an animal enrolled in a pre-clinical research trial.

Single or dual antiplatelet therapy after transcatheter aortic valve replacement: an updated systemic review and meta-analysis

Background

Although current guidelines recommend dual antiplatelet therapy (DAPT) with aspirin and clopidogrel as an antiplatelet strategy after transcatheter aortic valve replacement (TAVR), it is not based on clinical evidence. Here we aim to review updated evidence systemically and assess safety and efficacy of the two antiplatelet regimens.

Methods

PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched to retrieve studies involving single antiplatelet therapy (SAPT) versus DAPT after TAVR. We screened the records and extracted the data from publications independently. Relative risks (RRs) and the corresponding 95% confidence intervals (CIs) were used to compare the efficacy and safety of SAPT with that of DAPT in fixed-effects model with Mantel-Haenszel method. The quality of evidence was assessed by the scoring system, GRADE (Grading of Recommendations Assessment, Development, and Evaluation).

Results

A total of 2,489 patients from 8 studies were enrolled in this meta-analysis. Compared with DAPT, SAPT was associated with a lower all-cause mortality (RR =0.57; 95% CI, 0.36-0.89; P=0.014) and major/life-threatening bleeding (RR =0.62; 95% CI, 0.50-0.76; P=0.000) in 30 days. Furthermore, there was no significant difference found between SAPT and DAPT group in terms of 30-day stroke (RR =0.85; 95% CI, 0.45-1.63; P=0.631) and death beyond 3 months (RR =0.96; 95% CI, 0.81-1.15; P=0.664).

Conclusions

This meta-analysis suggests that compared with DAPT, SAPT after TAVR is more likely to lead to a decline of 30-day mortality along with the reduced risk of bleeding and no increased risk of stroke. However, more clinical data and evidence from randomized controlled trials are warranted to clarify the optimal post-TAVR antiplatelet strategy.

Diagnosis and Management of Rare Case of Mesenteric Hematoma Rupture after Transcatheter Aortic Valve Replacement (TAVR): A Case Report and Review of the Literature

We present a case of a 78-year-old female with history of diastolic heart failure and paroxysmal atrial fibrillation on apixaban presenting with worsening shortness of breath. She underwent transesophageal echocardiogram showing severe aortic stenosis with a valve area of 0.8 cm2. Coronary angiography did not reveal significant coronary artery disease. CT of chest, abdomen, and pelvis did not show any evidence of hematoma or dissection. Patient was scheduled for transfemoral TAVR. Patient's apixaban was discontinued prior to the procedure. She received heparin during the procedure. She successfully underwent left transfemoral aortic valve replacement. Shortly after the procedure, she complained of abdominal pain and became hypotensive. Blood pressure was 76/44 mm of Hg (MAP 58). Hemoglobin dropped to 8.1 g/dl (baseline 13). Stat CT abdomen and pelvis showed a large volume of hemorrhage in the peritoneal cavity. CTA of abdomen showed no evidence of aortic aneurysm or dissection but active extravasation below the inferior aspect of the spleen. Catheterization of the superior mesenteric artery (SMA) identified ileal branch of SMA as the source of bleeding. Embolization using gel foam slurry followed by a coil insertion was performed. Repeat angiogram demonstrated continued extravasation through arcade collaterals. A rapid exploration of the abdominal cavity revealed ruptured mesenteric hematoma. Evacuation of hematoma was performed. Portion of small ileum and bleeding mesenteric branch vessel was resected. Her condition stabilized with no postoperative bleeding and she was discharged on warfarin postoperatively. Use of antithrombotic therapy increases risk of bleeding in TAVR patients. Mesenteric hematoma rupture if not identified can be life-threatening. We believe that this is the first reported case of mesenteric hematoma rupture after a TAVR procedure.

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.

Transcatheter aortic valve implantation in a patient with aplastic anemia

Aplastic anemia is a syndrome involving pancytopenia caused by bone marrow insufficiency. Pancytopenia increases the surgical risk of bleeding and infection. Here, we report a successful transcatheter aortic valve implantation (TAVI) in a patient with aplastic anemia. The patient was a 76-year-old woman who was admitted to our hospital with syncope. Laboratory testing showed pancytopenia, and echocardiography revealed severe aortic valve stenosis. Although the log.EuroSCORE and STS Score were not overly high, because of the presence of pancytopenia, surgical aortic valve replacement was considered too high risk, making her a candidate for TAVI. In this case, the patient's pancytopenia was so severe that even TAVI without preparation was considered high risk. In light of this, we carried out a two-day preoperative administration of granulocyte colony-stimulating factor and transfused packed red blood cells and platelet concentrates. TAVI was performed via the left femoral artery using the cut-down procedure under general anesthesia. The postoperative course was uneventful, and she was discharged on the sixth postoperative day. With adequate preoperative preparation, TAVI may be performed safely in high-risk patients with hematologic disorders. <Learning objective: Transcatheter aortic valve implantation (TAVI) is widely performed for aortic stenosis patients at high surgical risk. Although patients with severe pancytopenia can be candidates for TAVI, severe pancytopenia may increase the surgical risk even for TAVI. To reduce the risk, adequate preparations before the procedure are required. Here, we report the preoperative preparation before TAVI that lowered the surgical risk in a patient with severe pancytopenia.>.

Variation in post-TAVR antiplatelet therapy utilization and associated outcomes: Insights from the STS/ACC TVT Registry

BACKGROUND

Dual antiplatelet therapy (DAPT) is recommended following transcatheter aortic valve replacement (TAVR); however, the optimal antiplatelet strategy is undefined, and little is known about practice patterns. We aimed to describe contemporary practice patterns of antiplatelet therapy and their relationship to outcomes post-TAVR.

METHODS

The population was derived from the National Cardiovascular Data Registry, Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapies Registry with Center for Medical Services linkage for 1-year outcomes from October 1, 2011 to June 30,2016. The primary outcome measured was DAPT use in patients without anticoagulation. Secondary outcomes included death, major bleeding, myocardial infarction (MI), and stroke at 1 year.

RESULTS

Overall, 16,694 patients underwent transfemoral TAVR at 444 hospitals and were discharged without anticoagulation. Among these, 13,546 (81.1%) patients were discharged on DAPT, whereas 3,148 patients (18.9%) were discharged on monotherapy. Patients discharged on DAPT versus monotherapy were similar in age, sex, and most comorbid illnesses but had higher rates of coronary artery disease (64.6% vs 52.3%; P < .01) and peripheral artery disease (25.2% vs 22.3%; P < .01). Hospital prescribing patterns varied significantly (median frequency of DAPT 85.7%, interquartile range 94.1%-74.2%). DAPT (vs monotherapy) patients had a similar mortality risk at 1 year (adjusted hazard ratio 0.92, 95% CI 0.81-1.05), significantly higher risk for major bleeding (1.48, 1.10-1.99), and similar hazard for stroke (1.04, 0.83-1.31) and MI (1.00, 0.72-1.39).

CONCLUSIONS

In the United States, most patients were discharged on DAPT following TAVR. Practice patterns varied significantly among hospitals. Patients discharged with DAPT had a similar adjusted risk of mortality, stroke, and MI compared to antiplatelet monotherapy, although risk for bleeding was significantly higher. Future investigation is needed to define the optimal antiplatelet therapy for patients undergoing TAVR.

Single versus dual anti-platelet therapy post transcatheter aortic valve implantation: a meta-analysis of randomized controlled trials

The purpose of this systematic review and meta-analysis was to assess the 30-days safety (bleeding and vascular events) and efficacy (reduction in major stroke, myocardial infarction and mortality) of single anti-platelet (SAPT) versus dual anti-platelet (DAPT) after transcatheter aortic valve implantation (TAVI). We used a meta-analytic method with Mantel-Haenszel methods to calculate the odds ratio (OR) and 95% confidence interval (CI). Only randomized clinical trials that compared 30-days safety and efficacy based on Valve Academic Research Consortium criteria were included. Studies that included patients on anticoagulants were excluded. Our analysis included three studies with a total of 421 patients (210 SAPT and 211 DAPT). Life-threatening and major bleeding as well as major vascular complications was similar between SAPT and DAPT. Similarly, major stroke, myocardial infarction and mortality was also comparable between the two groups. The combined outcomes of 30-day mortality, life-threatening and major bleeding showed tendency toward lower event rates in SAPT compared to DAPT (9.5 vs. 15.6%, OR 0.57; 95% CI 0.31-1.03, p = 0.06). In conclusion, SAPT provided similar safety without adding incremental efficacy compared to DAPT but showed tendency of lower combined endpoints of 30-day mortality, life-threatening and major bleeding.

Meta-Analysis of Studies Comparing Dual- Versus Mono-Antiplatelet Therapy Following Transcatheter Aortic Valve Implantation

Current guidelines recommend dual-antiplatelet therapy (DAPT) after transcatheter aortic valve implantation (TAVI), although some studies suggest mono-antiplatelet therapy is equally efficacious with an improved safety profile. We performed a meta-analysis of studies comparing DAPT with mono-antiplatelet therapy after TAVI. Study quality and heterogeneity were assessed using Jadad score, Newcastle-Ottawa Scale, and Cochran's Q statistics. Mantel-Haenszel odds ratios (ORs) were calculated using fixed effect models as the primary analysis. Eight studies including 2,439 patients met the inclusion criteria. At 30 days, DAPT was associated with an increased risk of all-cause mortality (OR 2.06, 95% confidence interval [CI] 1.34 to 3.18, p = 0.001), major or life-threatening bleeding (OR 2.04, 95% CI 1.60 to 2.59, p <0.001), and major vascular complications (OR 2.15, 95% CI 1.51 to 3.06, p <0.001). There was no difference in the rate of the combined end point of stroke or transient ischemic attack, or myocardial infarction. Outcome data up to 6 months were available in 5 studies; all-cause mortality and stroke were similar between groups, although major or life-threatening bleeding was more frequent with DAPT. In conclusion, in patients undergoing TAVI, DAPT is associated with increased risk at 30 days of all-cause mortality, major or life-threatening bleeding, and major vascular complications without a decrease in ischemic complications; at 6 months, the excess bleeding risk persisted. These data suggest a safety concern with DAPT and justify further investigation of the optimal antiplatelet therapy regimen after TAVI.

Comparison of single versus dual antiplatelet therapy after TAVR: A systematic review and meta-analysis

OBJECTIVE

We aim to evaluate the efficacy of dual versus single anti-platelet therapy (SAPT) after TAVR through a systematic review and meta-analysis of published research.

BACKGROUND

Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel is a commonly practiced strategy after transcatheter aortic valve replacement (TAVR). However, there is lack of sufficient evidence supporting this approach.

METHOD

We searched PubMed, EMBASE, the Cochrane Central Register of Controlled trials, and the clinical trial registry maintained at clinicaltrials.gov for randomized control trials (RCT) and observational studies comparing DAPT with SAPT post TAVR. Event rates were compared using a forest plot of relative risk with 95% confidence intervals using a random-effects model assuming inter-study heterogeneity.

RESULTS

A total of six studies (3 RCTs and 3 observational studies, n = 840) were included in the final analysis. Compared to SAPT, DAPT was associated with increased risk of significant bleeding (life threatening and major) [RR = 2.52 (95% CI 1.62-3.92, P < 0.0001)] with the number needed to harm for major or life-threatening bleeding calculated to be 10.4. There was no significant difference in the incidence of stroke [RR = 1.06 (95% CI, 0.43-2.60, P = 0.90)], spontaneous myocardial infarction [RR = 2.08 (95% CI, 0.56-7.70, P = 0.27)] and all-cause mortality [RR = 1.18 (95% CI, 0.68-2.05, P = 0.56] in the DAPT and SAPT groups.

CONCLUSION

In this small meta-analysis of DAPT versus SAPT after TAVR, DAPT did not prevent stroke, myocardial infarction or death while the risk of bleeding was higher. Results from ongoing trials are awaited to determine the best anti-thrombotic approach after TAVR.

Feasibility and safety of vitamin K antagonist monotherapy in atrial fibrillation patients undergoing transcatheter aortic valve implantation

AIMS

We aimed to assess the efficacy and safety of vitamin K antagonist (VKA) monotherapy in atrial fibrillation (AF) patients undergoing transcatheter aortic valve implantation (TAVI).

METHODS AND RESULTS

In 735 TAVIs since 2008 we identified 167 patients suffering from concomitant AF who received either VKA monotherapy (n=77), VKA plus single antiplatelet therapy (SAPT, n=41) or a triple anticoagulation regimen (n=49). Thromboembolic as well as bleeding complications were analysed for six months after TAVI. Only one minor bleeding and no thromboembolic events occurred after VKA therapy had been initiated post TAVI. Compared to patients being treated with additional either single or dual antiplatelet therapy, the incidence of major/life-threatening bleeding complications was significantly lower in the VKA mono group (0/77 [VKA mono] vs. 3/41 [VKA+SAPT; p=0.04] vs. 4/49 [triple anticoagulation; p=0.02]). Analysis of a combined endpoint of post-procedural death, stroke, embolism and major bleeding revealed a significant superiority of VKA monotherapy compared to VKA plus SAPT or DAPT, respectively (5/77 vs. 9/41 [p=0.02] vs. 14/49 [p=0.002]).

CONCLUSIONS

VKA therapy without additional antiplatelet treatment is effective and safe in AF patients undergoing TAVI.

Can TAVI patients receive aspirin monotherapy as patients after surgical aortic bioprosthesis implantation? Data from the Polish Registry - POL-TAVI

BACKGROUND

This observational analysis investigated in-hospital safety and efficacy of periprocedural antithrombotic/antiplatelet therapy used in TAVI patients included into the Polish Nationwide Cardiac Surgical and Cardiology Registry of Transcatheter Aortic Valve Implantation (POL-TAVI).

METHODS AND RESULTS

All patients who underwent TAVI in the participating centers between 2013 and 2014 were included. The primary endpoints were: severe bleeding, vascular complications, thromboembolic events, myocardial infarction, 30-days mortality, defined according to Valve Academic Research Consortium scale 2. A total of 827 patients were included; 35-93years old (79.31±7.53); 457 (55.29%) women. Endpoints noted: severe bleeding - 130 (15.72%) pts, vascular complications - 135 (16.32%) pts, thromboembolic events - 29 (3.5%) pts, myocardial infarction - 24 (2.90%) pts, deaths - 58 (7.01%) pts. Aspirin premedication, resulted in the least number of vascular complications (OR 0.56 95%CI [0.345-0.938]; p=0.027). Aspirin after TAVI reduced the risk of vascular complications (OR 0.089 95%CI [0.0217-0.372]; p=0.001) and bleeding (OR 0.138 95%CI [0.043-0.447]; p=0.001) with no adverse impact on efficacy endpoints. Beneficial safety profile of postprocedural aspirin monotherapy remained significant in comparison to all other types of prophylaxis also in propensity score analysis: OR 0.068 95%CI [0.009-0.529]; p=0.01 for vascular complications, OR 0.176 95%CI [0.049-0.627]; p=0.007 for bleeding. NNT for vascular complications and bleeding with postprocedural aspirin prophylaxis was 5.5 and 6.42, respectively.

CONCLUSION

Aspirin after TAVI appears to be beneficial than currently recommended dual antiplatelet therapy; therefore, it might be considered as TAVI antithrombotic prophylaxis.

Clinical trials in transcatheter aortic valve replacement

PURPOSE OF REVIEW

Clinical trials in transcatheter aortic valve replacement (TAVR) have been essential in establishing the effectiveness as well as the limitations of this exciting and disruptive technology. This review will focus on clinical trials related to TAVR that have been presented in the past year or are currently enrolling, as well as future trials that are in the planning stages.

RECENT FINDINGS

The currently available devices have gone through iterations to improve safety and outcomes, including lower profiles to reduce bleeding complications as well as adding a sealing skirt or allowing for re-positioning in order to decrease para-valvular regurgitation and need for a permanent pacemaker. The intermediate-risk clinical trials will be finishing soon and will be followed by low-risk trials. Ancillary devices will likely continue to expand the access to this therapy. One of the main challenges moving forward will be the post-TAVR pharmacotherapy.

SUMMARY

Recently, improvements in first-generation devices have led to improved outcomes. Current trials evaluating novel TAVR platforms and lower risk patients as well as ancillary devices will likely continue to expand the access to this therapy.

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

BACKGROUND

The American College of Cardiology guidelines recommend 3 months of anticoagulation after replacement of the aortic valve with a bioprosthesis. However, there remains great variability in the current clinical practice and conflicting results from clinical studies. To assist clinical decision making, we pooled the existing evidence to assess whether anticoagulation in the setting of a new bioprosthesis was associated with improved outcomes or greater risk of bleeding.

METHODS AND RESULTS

We searched the PubMed database from the inception of these databases until April 2015 to identify original studies (observational studies or clinical trials) that assessed anticoagulation with warfarin in comparison with either aspirin or no antiplatelet or anticoagulant therapy. We included the studies if their outcomes included thromboembolism or stroke/transient ischemic attacks and bleeding events. Quality assessment was performed in accordance with the Newland Ottawa Scale, and random effects analysis was used to pool the data from the available studies. I(2) testing was done to assess the heterogeneity of the included studies. After screening through 170 articles, a total of 13 studies (cases=6431; controls=18210) were included in the final analyses. The use of warfarin was associated with a significantly increased risk of overall bleeding (odds ratio, 1.96; 95% confidence interval, 1.25-3.08; P<0.0001) or bleeding risk at 3 months (odds ratio, 1.92; 95% confidence interval, 1.10-3.34; P<0.0001) compared with aspirin or placebo. With regard to composite primary outcome variables (risk of venous thromboembolism, stroke, or transient ischemic attack) at 3 months, no significant difference was seen with warfarin (odds ratio, 1.13; 95% confidence interval, 0.82-1.56; P=0.67). Moreover, anticoagulation was also not shown to improve outcomes at time interval >3 months (odds ratio, 1.12; 95% confidence interval, 0.80-1.58; P=0.79).

CONCLUSIONS

Contrary to the current guidelines, a meta-analysis of previous studies suggests that anticoagulation in the setting of an aortic bioprosthesis significantly increases bleeding risk without a favorable effect on thromboembolic events. Larger, randomized controlled studies should be performed to further guide this clinical practice.