Antithrombotic management after aortic valve replacement with biological prosthesis: a meta-analysis

BACKGROUND

We aimed to summarise the existing knowledge regarding antithrombotic medications following surgical aortic valve replacement (SAVR) using a biological valve prosthesis.

METHODS

We performed a meta-analysis of studies that reported the results of using antithrombotic medication to prevent thromboembolic events after SAVR using a biological aortic valve prosthesis and recorded the outcomes 12 months after surgery. Since no randomised controlled trials were identified, observational studies were included. The analyses were conducted separately for periods of 0-12 months and 3-12 months after surgery. A random effects model was used to calculate pooled outcome event rates and 95% confidence intervals (CIs).

RESULTS

The search yielded eight eligible observational studies covering 6727 patients overall. The lowest 0- to 12-month mortality was observed in patients with anticoagulation (2.0%, 95% CI 0.4-9.7%) and anticoagulation combined with antiplatelet therapy (2.2%, 95% CI 0.9-5.5%), and the highest was in patients without antithrombotic medication (7.3%, 95% CI 3.6-14.2%). Three months after surgery, mortality was lower in anticoagulant patients (0.5%, 95% CI 0.1-2.6%) than in antiplatelet patients (3.0%, 95% CI 1.2-7.4%) and those without antithrombotics (3.5%, 95% CI 1.3-9.3%). There was no eligible evidence of differences in stroke rates observed among medication strategies. At 0- to 12-month follow-up, all antithrombotic treatment regimens resulted in an increased bleeding rate (antiplatelet 4.2%, 95% CI 2.9-6.1%; anticoagulation 7.5%, 95% CI 3.8-14.4%; anticoagulation combined with antiplatelet therapy 8.3%, 95% CI 5.7-11.8%) compared to no antithrombotic medication (1.1%, 95% CI 0.4-3.4%). At 3- to 12-month follow-up, there was up to an eight-fold increase in the bleeding rate in patients with anticoagulation combined with antiplatelet therapy when compared to those with no antithrombotic medication. Overall, the evidence certainty was ranked as very low.

CONCLUSION

Although this meta-analysis reveals that anticoagulation therapy has a beneficial tendency in terms of mortality at 1 year after biological SAVR and suggests potential advantages in continuing anticoagulation beyond 3 months, it is limited by very low evidence certainty. The imperative for cautious interpretation and the urgent need for more robust randomised research underscore the complexity of determining optimal antithrombotic strategies in this patient population.

Dexmedetomidine Pretreatment Confers Myocardial Protection and Reduces Mechanical Ventilation Duration for Patients Undergoing Cardiac Valve Replacement under Cardiopulmonary Bypass

PURPOSE

The study aims to assess the effects of dexmedetomidine (Dex) pretreatment on patients during cardiac valve replacement under cardiopulmonary bypass.

METHODS

For patients in the Dex group (n = 52), 0.5 μg/kg Dex was given before anesthesia induction, followed by 0.5 μg/kg/h pumping injection before aortic occlusion. For patients in the control group (n = 52), 0.125 ml/kg normal saline was given instead of Dex.

RESULTS

The patients in the Dex group had longer time to first dose of rescue propofol than the control group (P = 0.003). The Dex group required less total dosage of propofol than the control group (P = 0.0001). The levels of cardiac troponin I (cTnI), creatine kinase isoenzyme MB (CK-MB), malondialdehyde (MDA), and tumor necrosis factor-α (TNF-α) were lower in the Dex group than the control group at T4, 8 h after the operation (T5), and 24 h after the operation (T6) (P <0.01). The Dex group required less time for mechanical ventilation than the control group (P = 0.003).

CONCLUSION

The study suggests that 0.50 µg/kg Dex pretreatment could reduce propofol use and the duration of mechanical ventilation, and confer myocardial protection without increased adverse events during cardiac valve replacement.

Multi-modality imaging in aortic stenosis: an EACVI clinical consensus document

In this EACVI clinical scientific update, we will explore the current use of multi-modality imaging in the diagnosis, risk stratification, and follow-up of patients with aortic stenosis, with a particular focus on recent developments and future directions. Echocardiography is and will likely remain the key method of diagnosis and surveillance of aortic stenosis providing detailed assessments of valve haemodynamics and the cardiac remodelling response. Computed tomography (CT) is already widely used in the planning of transcutaneous aortic valve implantation. We anticipate its increased use as an anatomical adjudicator to clarify disease severity in patients with discordant echocardiographic measurements. CT calcium scoring is currently used for this purpose; however, contrast CT techniques are emerging that allow identification of both calcific and fibrotic valve thickening. Additionally, improved assessments of myocardial decompensation with echocardiography, cardiac magnetic resonance, and CT will become more commonplace in our routine assessment of aortic stenosis. Underpinning all of this will be widespread application of artificial intelligence. In combination, we believe this new era of multi-modality imaging in aortic stenosis will improve the diagnosis, follow-up, and timing of intervention in aortic stenosis as well as potentially accelerate the development of the novel pharmacological treatments required for this disease.

Early-Term Results of Rapid-Deployment Aortic Valve Replacement versus Standard Bioprosthesis Implantation Combined with Coronary Artery Bypass Grafting

OBJECTIVES

Aortic stenosis is highly prevalent among patients with concomitant coronary artery disease. Surgical aortic valve replacement with coronary artery bypass grafting is usually the treatment of choice for patients with severe aortic stenosis and significant coronary disease. The aim of this study was to evaluate the outcome and hemodynamic results of the implantation of rapid-deployment valves (Rapid-Deployment Edwards Intuity Valve System [RDAVR]) versus conventional sutured valves (CSAVR) in combined surgery.

METHODS

Between January 2012 and January 2017, 120 patients underwent replacement via RDAVR and 133 patients underwent replacement using CSAVR with concomitant coronary bypass grafting. Clinical and echocardiographic data were compared.

RESULTS

The mean age was 76 ± 7 for RDAVR patients and 74 ± 6 years for CSAVR patients (p = 0.054); 48% in the RDAVR group were female versus 17% in the CSAVR group (p <0.002). Other characteristics such as diabetes mellitus, body-mass index, chronic obstructive pulmonary disease, nicotine consumption, and extracardiac arteriopathy were similar. Coronary three-vessel disease was more common in the RDAVR group (42.5 vs. 27.8%, p = 0.017). Both mean EuroSCORE II (6.6 ± 5.4 vs. 4.3 ± 3.0, p = 0.001) and STS score (5.4 ± 4.4 vs. 3.4 ± 2.4, p = 0.001) were significantly higher in the RDAVR group. Mean cross-clamp time (82 ± 25 vs. 100 ± 30 minutes, p < 0.001) and cardiopulmonary bypass time (119 ± 38 vs. 147 ± 53 minutes, p < 0.001) were shorter with RDAVR. The mean number of bypass grafts, length of hospital and ICU stays, and mechanical ventilation time were not statistically significant different. Hospital mortality was 2.5% for RDAVR and 9.7% for CSAVR (p = 0.019). There was a similar rate of stroke (5.8 vs. 6.0%, p = 0.990) and postoperative delirium (14.1 vs. 15.8%, p = 0.728). Mean gradients were 8.2 ± 4.1 mm Hg in the RDAVR group vs. 11.3 ± 4.6 mm Hg in the CSAVR group (p = 0.001) at discharge.

CONCLUSION

RDAVR combined with coronary artery bypass grafting (CABG) can be performed extremely safely. Cross-clamp and cardiopulmonary bypass times can be significantly reduced with rapid deployment aortic valve system in the scenario of combined CABG. RDAVR resulted in lower gradients than CSAVR in patients implanted with prostheses of the same size.

Valvular heart disease: shifting the focus to the myocardium

Adverse cardiac remodelling is the main determinant of patient prognosis in degenerative valvular heart disease (VHD). However, to give an indication for valvular intervention, current guidelines include parameters of cardiac chamber dilatation or function which are subject to variability, do not directly reflect myocardial structural changes, and, more importantly, seem to be not sensitive enough in depicting early signs of myocardial dysfunction before irreversible myocardial damage has occurred. To avoid irreversible myocardial dysfunction, novel biomarkers are advocated to help refining indications for intervention and risk stratification. Advanced echocardiographic modalities, including strain analysis, and magnetic resonance imaging have shown to be promising in providing new tools to depict the important switch from adaptive to maladaptive myocardial changes in response to severe VHD. This review, therefore, summarizes the current available evidence on the role of these new imaging biomarkers in degenerative VHD, aiming at shifting the clinical perspective from a valve-centred to a myocardium-focused approach for patient management and therapeutic decision-making.

Antiplatelet therapy after transcatheter aortic valve implantation: a systematic review and meta-analysis

OBJECTIVES

The aim of this study was to compare antithrombotic regimens after transcatheter aortic valve implantation (TAVI) in patients without an indication for long-term anticoagulation. TAVI is a safe and effective approach for patients with symptomatic severe aortic stenosis and an intermediate-to-high surgical risk. Nevertheless, the antithrombotic regimen after procedure remains controversial.

METHODS

We systematically searched PubMed, Embase and Cochrane databases for interventional studies comparing single antiplatelet therapy with double antiplatelet therapy after TAVI. A meta-analysis was carried out to compare thrombotic and bleeding events between both strategies.

RESULTS

Four randomized clinical trials were included comprising a total of 1085 patients. Our meta-analysis revealed a higher odds ratio (OR) of major bleeding events (pooled OR 2.45, 95% confidence interval (CI) 1.29-4.67; P < 0.01; I2 = 0%) and minor bleeding (pooled OR 1.73, 95% CI 1.12-2.66; P = 0.01; I2 = 0%) for the double antiplatelet therapy group compared with the single antiplatelet therapy group. There was no difference between groups in the risk of stroke (pooled OR 1.04, 95% CI 0.58-1.86; P = 0.91; I2 = 0%), myocardial infarction (pooled OR 2.10, 95% CI 0.75-5.84; P = 0.16, I2 = 0%) and all-cause mortality (pooled OR 1.07, 95% CI 0.63-1.86; P = 0.08; I2 = 0%) after TAVI.

CONCLUSIONS

Our pooled analysis suggests that for patients who underwent TAVI, double antiplatelet therapy compared with single antiplatelet therapy alone increased the risk of bleeding without reducing mortality and ischaemic events.

Myocardial Scar and Mortality in Severe Aortic Stenosis

Supplemental Digital Content is available in the text.

Background:

Aortic valve replacement (AVR) for aortic stenosis is timed primarily on the development of symptoms, but late surgery can result in irreversible myocardial dysfunction and additional risk. The aim of this study was to determine whether the presence of focal myocardial scar preoperatively was associated with long-term mortality.

Methods:

In a longitudinal observational outcome study, survival analysis was performed in patients with severe aortic stenosis listed for valve intervention at 6 UK cardiothoracic centers. Patients underwent preprocedural echocardiography (for valve severity assessment) and cardiovascular magnetic resonance for ventricular volumes, function and scar quantification between January 2003 and May 2015. Myocardial scar was categorized into 3 patterns (none, infarct, or noninfarct patterns) and quantified with the full width at half-maximum method as percentage of the left ventricle. All-cause mortality and cardiovascular mortality were tracked for a minimum of 2 years.

Results:

Six hundred seventy-four patients with severe aortic stenosis (age, 75±14 years; 63% male; aortic valve area, 0.38±0.14 cm²/m²; mean gradient, 46±18 mm Hg; left ventricular ejection fraction, 61.0±16.7%) were included. Scar was present in 51% (18% infarct pattern, 33% noninfarct). Management was surgical AVR (n=399) or transcatheter AVR (n=275). During follow-up (median, 3.6 years), 145 patients (21.5%) died (52 after surgical AVR, 93 after transcatheter AVR). In multivariable analysis, the factors independently associated with all-cause mortality were age (hazard ratio [HR], 1.50; 95% CI, 1.11–2.04; P=0.009, scaled by epochs of 10 years), Society of Thoracic Surgeons score (HR, 1.12; 95% CI, 1.03–1.22; P=0.007), and scar presence (HR, 2.39; 95% CI, 1.40–4.05; P=0.001). Scar independently predicted all-cause (26.4% versus 12.9%; P<0.001) and cardiovascular (15.0% versus 4.8%; P<0.001) mortality, regardless of intervention (transcatheter AVR, P=0.002; surgical AVR, P=0.026 [all-cause mortality]). Every 1% increase in left ventricular myocardial scar burden was associated with 11% higher all-cause mortality hazard (HR, 1.11; 95% CI, 1.05–1.17; P<0.001) and 8% higher cardiovascular mortality hazard (HR, 1.08; 95% CI, 1.01–1.17; P<0.001).

Conclusions:

In patients with severe aortic stenosis, late gadolinium enhancement on cardiovascular magnetic resonance was independently associated with mortality; its presence was associated with a 2-fold higher late mortality.

Feasibility of transcatheter aortic valve implantation in patients with coronary heights ≤7 mm: insights from the transcatheter aortic valve implantation Karlsruhe (TAVIK) registry

OBJECTIVES

Transcatheter aortic valve implantation (TAVI) in patients with low coronary heights is generally denied but is not impossible. Information about these high-risk procedures is sparse.

METHODS

Since May 2008, data of more than 3000 patients who had TAVI were prospectively collected in the institutional TAVI Karlsruhe registry. Characteristics, peri- and postoperative outcome of patients with low coronary heights of ≤7 mm were analysed according to the Valve Academic Research Consortium-2.

RESULTS

Eighty-six patients with an average coronary height of 6.4 ± 1.1 mm (mean age 81.0 ± 5.3 years, logistic EuroSCORE I 19.6 ± 13.3%) were treated. TAVI was performed in 72 transfemoral (83.7%) and 14 transapical (16.3%) cases using 44 CoreValve/Evolut R (51.2%), 21 Sapien XT/S3 (24.4%), 14 ACURATE (16.3%), 5 Lotus (5.8%) and 2 Portico (2.3%) prostheses. Ten procedures were valve-in-valve (VinV) TAVI (VinV, 11.6%). The 72-h, 30-day, 1-year and follow-up (3.0 ± 1.6 years) mortality rates were 2.3%, 8.0%, 10.5% and 26.7%, respectively. Within 30 days, 4 cardiac deaths and 3 non-cardiac deaths occurred (4.7% and 3.5%). Three coronary obstructions (3.5%) occurred-2 during VinV TAVI. One patient was connected to extracorporeal circulation that could not be weaned later due to an unsuccessful percutaneous coronary intervention. Another patient, the only conversion (1.2%), required delayed surgical valve replacement. The third patient died of right heart failure after aortic dissection. The procedural success rate was 95.3%. VinV procedures were associated with increased follow-up deaths (P < 0.001; hazard ratio 7.96).

CONCLUSIONS

Coronary-related complications in TAVI procedures in patients with coronary heights ≤7 mm occurred less frequently, but once they occurred, they were serious. These TAVI procedures are feasible, with a high procedural success rate, but meticulous preoperative planning should be mandatory. In VinV procedures, the follow-up mortality rate is increased; therefore, we do not recommend these procedures.