Surgical management of mechanical valve thrombosis: twenty-six years' experience

Mechanical prosthetic valve thrombosis in current era: 5-year follow-up

Introduction

The incidence of prosthetic valve dysfunction (stuck valve) is variable and is dependent on various factors. There are studies from Indian groups that have emphasized the success of thrombolysis; however, none of them reported a follow-up. This study was designed to emphasize on the follow-up of these patients at midterm.

Material and methods

The patients of prosthetic valve thrombosis between period of January 2013 and December 2017 were included in this retrospective observational study. Sixty-six patients were admitted with stuck valve during this period. Thrombolysis was preferred modality of treatment. Survivors were followed up with serial echocardiography, which included estimation of left ventricular and valve functions.

Results

Of a total of 66 patients, 59 were of stuck mitral valve and 7 stuck aortic valve. The event happened at a mean of 48.86 ± 48.80 months after index operation of valve replacement using mechanical valve prosthesis. The median age was 40.27 ± 10.8 years with 39 males and 27 females. Thrombolysis was successful in 61 patients with a mortality of 5 (7.57%). During a mean follow-up of 22.7 ± 20.9 months, 42 patients were alive with 14 (22.95%) patients dead and 5 patients lost to follow-up. The average follow-up was 18.7 ± 22.7 months before death.

Conclusion

Following good early results after thrombolysis, patients of prosthetic heart valve thrombosis experience high mortality within 2 years of follow-up. These patients require frequent follow-up to avoid early mortality.

Index of deterioration of patients with mechanical prosthetic heart valve thrombosis

Background

Mechanical prosthetic heart valves are known for their durability; however, a malfunctioning prosthesis can deteriorate rapidly to become a life-threatening complication. Our aim was to calculate a numerical index to express the rate of clinical deterioration of patients presenting with a mechanical prosthetic heart valve thrombosis (PVT), called the index of deterioration (ID), and to evaluate its usefulness in predicting hospital outcomes.

Results

The median ID and range were (0.43, 0.03-3) NYHA class/day. A higher ID was significantly related to early development of PVT after native valve replacement, younger age, female gender, pregnancy, non-compliance to oral anticoagulation (OAC), low LVEF%, high mean pressure gradient across a mitral prosthesis, raised serum creatinine, and SGOT on admission (P < 0.05). Independent predictors were early presentation after native valve replacement, female gender, and non-compliance to OAC (P < 0.05).

ID correlated positively with the need for urgent/emergency surgery, and the durations of cardiopulmonary bypass, postoperative mechanical ventilation, and positive inotropes. ID correlated negatively with the postoperative LVEF% (P < 0.05). Median ID of the 21 mortalities (0.75, 0.1-3) was > 2.1 times that of survivors (0.35: 0.03−2; P = 0.002), and the median ID of the 29 cases with postoperative complications (0.5, 0.1-1.5) was 2.5 times that of the 39 uneventful cases (0.2, 0.03-2; P = 0.011). The ID significantly predicted both mortality (odds ratio 3.87; 1.33-1.29; P = 0.013) and mortality and hospital complications (odds ratio 4.77; 1.49-15.2; P = 0.008). The respective discriminating abilities were AUC 0.734 (0.616-0.852; P = 0.002) and 0.724 (0.61-0.835; P < 0.001). EuroScore II correlated positively with ID (r = 0.571; P < 0.001) but showed better discriminative abilities.

Conclusion

The simple index of deterioration was useful in monitoring deterioration and predicting hospital progression and outcomes in patients presenting with PVT.

Thrombolytic therapy or surgery for valve prosthesis thrombosis: systematic review and meta-analysis

BACKGROUND

Prosthetic heart valve thrombosis is a life-threatening condition for which treatment has not been evaluated by randomized trials.

OBJECTIVES

To compare surgery with thrombolytic therapy for the treatment of prosthetic valve thrombosis.

METHODS

A comprehensive systematic review was carried out by independent researchers using PubMed, Web of Knowledge, HINARI, LILACS and EMBASE, including papers indexed up to 23 October 2013 with at least 10 patients, evaluating one or both treatment options. Outcomes of interest were death, stroke, bleeding, embolic events and success. Study quality was assessed by the Newcastle-Ottawa Scale (ranges from 0 to 9). Comprehensive Meta Analysis Software was used to pool study results, for publication bias analysis and for meta-regression.

RESULTS

Forty-eight studies were included (2302 patients). No randomized study was identified, and all were observational in design. Study quality varied from 4 to 6 stars using the Newcastle-Ottawa Scale. Mortality for surgery was 18.1% (95%CI, 14.6-22.1; I(2) , 62% [42-75]), while mortality for thrombolytic therapy was 6.6% (95% CI, 4.8-8.9; I(2) , 0% [0-13]). Surgical mortality appeared to increase with NYHA-class, according to meta-regression. Other results related to surgery and thrombolytic therapy, respectively, were: embolic events, 4.6% (2.9-7.3) and 12.8% (10.8-15.2); stroke, 4.3%,(2.7-6.6%) and 5.6%,(4.3-7.4%); success rate, 81.9% (77.2-85.8) and 80.7% (75.6-85.0); bleeding, 4.6% (2.9-7.1) and 6.8% (5.4-8.6); and death or stroke, 19.0% (14.8-24.2) and 11.4% (8.7-14.7).

CONCLUSION

Mortality in patients treated by thrombolytic therapy for valve prosthesis thrombosis is significantly lower than in patients treated surgically. As we cannot yet ascertain whether this difference is due to the treatment alone, more studies are now necessary to further clarify these findings.

Study on construction of nano tPA plasmid to prevent thrombosis after mechanical valve replacement in dogs

BACKGROUND

Mechanical valve is inclined to induce thrombosis. We intend to elucidate the transfection of nano tissue-type plasminogen activator (tPA) gene plasmid to prevent thrombosis after tricuspid mechanical valve replacement in dogs.

METHODS

A dog model of mechanical tricuspid valve replacement was constructed. A constructed chitosan nano tPA gene plasmid was used to transfect the dog cardiocytes at the same time of tricuspid valve replacement. The effect of this gene on the survival of dogs, anticoagulation (prothrombin time, INR and D-dimer contents, thrombosis in heart), and the expressions of tPA were observed.

RESULTS

Nano tPA gene plasmid was successfully constructed and transfected into cardiocytes. The gene could significantly increase the survival of animals and the contents of D-dimer (P < 0.01), and could prevent thrombus formation on mechanical valves, but there was no significant difference of prothrombin time and INR between two groups (P > 0.05).

CONCLUSION

The constructed nano tPA gene plasmid could prevent thrombus formation after mechanical valve replacement, which provides a clue for clinical use.