Prosthetic Valve Thrombosis

Contemporary Multi-modality Imaging of Prosthetic Aortic Valves

With the aging of the general population and the rise in surgical and transcatheter aortic valve replacement, there will be an increase in the prevalence of prosthetic aortic valves. Patients with prosthetic aortic valves can develop a wide range of unique pathologies compared to the general population. Accurate diagnosis is necessary in this population to generate a comprehensive treatment plan. Transthoracic echocardiography is often insufficient alone to diagnose many prosthetic valve pathologies. The integration of many imaging modalities, including transthoracic echocardiography, transesophageal echocardiography, cardiac computed tomography, cardiac magnetic resonance imaging, and nuclear imaging, is necessary to care for patients with prosthetic valves. The purpose of this review is to describe the strengths, limitations, and contemporary use of the different imaging modalities necessary to diagnose prosthetic valve dysfunction.

Surgery Versus Thrombolytic Therapy for the Management of Left-Sided Prosthetic Valve Thrombosis Without Hemodynamic Compromise: A Systematic Review and Meta-Analysis

BACKGROUND

The optimal strategy in prosthetic heart valve thrombosis (PVT) remains controversial, with no randomized trials and conflicting observational data. We performed a systematic review and meta-analysis of evidence comparing systemic thrombolysis and cardiac surgery in PVT.

METHODS AND RESULTS

We searched PubMed, the Cochrane Library, and Embase for studies on treatment strategies in patients with left-sided PVT since 2000. The primary outcome was death, and the secondary outcomes were major bleeding and thromboembolism during follow-up (International Prospective Register of Systematic Reviews No. CRD42022384092). We identified 2298 studies, of which 16 were included, comprising 1389 patients with PVT (mean age, 50.4±9.3 years; 60.0% women). Among them, 67.2% were New York Heart Association stage III/IV at admission. Overall, 48.1% were treated with systemic thrombolysis and 51.9% with cardiac surgery. The mortality rate was 10.8% in the thrombolysis group and 15.3% in the surgery group. The pooled risk difference for death with systemic thrombolysis was 1.13 (exact CI, 0.74-1.79; ζ2=0.89; P<0.001) versus cardiac surgery. Rates of both transient ischemic attack and non-central nervous system embolism were higher in the thrombolysis group (P=0.002 and P=0.02, respectively). Treatment success, major bleeding, and stroke were similar between groups. Sensitivity analysis including studies that used low-dose or slow-infusion thrombolysis showed that the mortality rate was lower, and treatment success was higher, in patients referred to systemic thrombolysis, with similar rates of other secondary outcomes.

CONCLUSIONS

There is evidence to suggest that thrombolysis might be the preferred option for the management of PVT without cardiogenic shock, pending future randomized controlled trials or larger observational studies.

Mechanical Aortic Valve Thrombosis Successfully Treated With Intravenous Thrombolytic Therapy: A Case Report

Mechanical prosthetic valves, like all foreign bodies, are thrombogenic, requiring anticoagulation to avoid thrombosis and reduce the risk of catastrophic stroke. We reported a case of a 42-year-old female that developed mechanical valve thrombosis and was successfully treated with low infusion thrombolytic therapy using alteplase (tPA, tissue plasminogen activator).

Comparison between surgery and fibrinolytic therapy in prosthetic valve thrombosis: A systematic review and meta-analysis

BACKGROUND

Prosthetic valve thrombosis (PVT) is a rare but life-threatening complication. Surgery and fibrinolytic therapy (FT) are the two main treatment options for PVT. The choice between surgery and FT has always been a matter of debate. Previous studies have shown that although the mortality rate is higher in surgery, complications are less frequent than in FT. We aimed to perform a systematic review and meta-analysis to compare the results of surgery and FT in PVT.

METHODS

A systematic review of the literature was performed through Medline, Embase, Scopus, and Web of Science, encompassing all studies comparing surgery and FT in PVT. The rate of each complication and risk ratio (RR) of complications in surgery and FT were assessed using random-effects models.

RESULTS

Fifteen studies with 1235 patients were included in the meta-analysis. The pooled risk of the mortality was not significantly different between FT and surgery in patients with PVT (pooled RR = 0.78, 95% confidence interval [CI]: 0.38-1.60, I² = 61.4%). The pooled risks of thromboembolic events (pooled RR = 4.70, 95% CI: 1.83-12.07, I² = 49.6%) and major bleeding (pooled RR = 2.45, 95% CI: 1.09-5.50, I² = 41.1%) and PVT recurrence (pooled RR = 2.06 95% CI: 1.29-3.27, I² = 0.0%) were significantly higher in patients who received FT.

CONCLUSION

Surgery may be safer and with fewer complications than FT for PVT treatment. However, randomized clinical trials are needed to determine the proper treatment for PVT.

Editorial commentary: Cutting the Gordian knot of right-sided prosthetic valve thrombosis

With limited data available for the tricuspid valve, there are no stringent recommendations in the current guidelines (ESC 2021). Valve replacement for the right-sided heart is inherently problematic and bears the potential for complications - including prosthetic valve thrombosis (PVT). The purpose of this editorial is to review the key features of this clinical scenario and to outline the essential aspects for optimized patient management and improved outcome. Depending on the clinical presentation of PVT, either immediate surgery, thrombolysis, or anticoagulation may be considered - with the sole intensification of anticoagulation likely being the most inferior. Given the high risk of re-thrombosis, a dedicated follow-up program is essential to identify complications early and offer adequate treatment.

Clinical and Surgical Evaluations of Reoperation After Mechanical Mitral Valve Replacement Due to Different Etiologies

Background:

This study aimed to evaluate the clinical and surgical characteristics of patients who required reoperation after mechanical mitral valve replacement (MVR).

Methods:

We retrospectively identified 204 consecutive patients who underwent reoperation after mechanical MVR between 2009 and 2018. Patients were categorized according the reason for reoperation (perivalvular leakage, thrombus formation, or pannus formation). The patients' medical and surgical records were studied carefully and the rates of in-hospital complications were calculated.

Results:

The mean age was 51±12 years and 44% of the patients were male. The reasons for reoperation were perivalvular leakage (117 patients), thrombus formation (35 patients), and pannus formation (52 patients). The most common positions for perivalvular leakage were at the 6–10 o'clock positions (proportions of ≥25% for each hour position). Most patients had an interval of &gt;10 years between the original MVR and reoperation. The most common reoperation procedure was re-do MVR (157 patients), and 155 of these patients underwent concomitant cardiac procedures. There were 10 in-hospital deaths and 32 patients experienced complications. The 10-year survival rate was 82.2 ± 3.9% in general, and the group of lowest rate was patients with PVL (77.5 ± 5.2%). The independent risk factors were “male” (4.62, 95% CI 1.57–13.58, P = 0.005) and “Hb &lt;9g/dL before redo MV operation” (3.45, 95% CI 1.13–10.49, P = 0.029).

Conclusion:

Perivalvular leakage was the most common reason for reoperation after mechanical MVR, with a low survival rate in long term follow-up relatively.

Clinical Outcomes of Mechanical Prosthetic Valve Thrombosis

Objective

To evaluate characteristics and outcomes of patients presenting with mechanical prosthetic valve thrombosis in a tertiary cardiac center in Pakistan.

Methods

This was a prospective and interventional study conducted at Rawalpindi Institute of Cardiology over a period of two years. The clinical characteristics of patients presenting with clinical suspicion of prosthetic valve thrombosis were recorded. They were, then, subjected to streptokinase, redo surgery and heparin based on their hemodynamic stability, thrombus burden and surgical risk. The patients were then followed for the outcomes of the study.

Results

Out of 576 patients with mechanical valve replacement during the study period, 70 patients had developed prosthetic valve thrombosis. Out of 70 patients, there were 41 female (58.50%) and 29 male (41.50%) participants. The mean age of the participants was 48.40±15.00 years. The overall incidence of mechanical prosthetic valve thrombosis was 12.15%. There were 30 patients (42.80%) with a suboptimal international normalized ratio (INR) and 28 patients (40.00%) were non-compliant to warfarin therapy. The overall incidence of adverse clinical outcome was 18.00%, while the overall mortality rate was 10.00%. The mortality was higher for patients who underwent redo surgery (16.60%) as compared to patients who had received fibrinolytic therapy (9.60%).

Conclusion

Poor compliance with warfarin and suboptimal INR are the important factors causing mechanical prosthetic valve. Because of lower mortality rate, fibrinolysis with streptokinase is a reasonable treatment option for mechanical prosthetic valve thrombosis.

Validation of pressure drop assessment using 4D flow MRI-based turbulence production in various shapes of aortic stenoses

PURPOSE

To validate pressure drop measurements using 4D flow MRI-based turbulence production in various shapes of stenotic stenoses.

METHODS

In vitro flow phantoms with seven different 3D-printed aortic valve geometries were constructed and scanned with 4D flow MRI with six-directional flow encoding (ICOSA6). The pressure drop through the valve was non-invasively predicted based on the simplified Bernoulli, the extended Bernoulli, the turbulence production, and the shear-scaling methods. Linear regression and agreement of the predictions with invasively measured pressure drop were analyzed.

RESULTS

All pressure drop predictions using 4D Flow MRI were linearly correlated to the true pressure drop but resulted in different regression slopes. The regression slope and 95% limits of agreement for the simplified Bernoulli method were 1.35 and 11.99 ± 21.72 mm Hg. The regression slope and 95% limits of agreement for the extended Bernoulli method were 1.02 and 0.74 ± 8.48 mm Hg. The regression slope and 95% limits of agreement for the turbulence production method were 0.89 and 0.96 ± 8.01 mm Hg. The shear-scaling method presented good correlation with an invasively measured pressure drop, but the regression slope varied between 0.36 and 1.00 depending on the shear-scaling coefficient.

CONCLUSION

The pressure drop assessment based on the turbulence production method agrees well with the extended Bernoulli method and invasively measured pressure drop in various shapes of the aortic valve. Turbulence-based pressure drop estimation can, as a complement to the conventional Bernoulli method, play a role in the assessment of valve diseases.

Acute Presentation of Bioprosthetic Mitral Valve Thrombosis in a Patient on Venoarterial Extracorporeal Membranous Oxygenation

The management of patients presenting with bioprosthetic valve thrombosis presents a major clinical challenge from a diagnostic and management standpoint. This patient population becomes especially challenging to manage when presenting with cardiogenic shock and additional risks for bleeding. In this clinical conference, the authors present the case of a 64-year-old male who developed intraoperative bioprosthetic mitral valve thrombosis and cardiogenic shock necessitating support with venoarterial extracorporeal membrane oxygenation. The discussion focuses on the diagnostic challenges with transesophageal echocardiography and the difficulty in determining the proper approach to systemic anticoagulation.