As originally published in 1994: Prosthetic valve obstruction: thrombolysis versus operation. Updated in 2000

Dysfunction of mechanical heart valve prosthesis: experience with surgical management in 48 patients

BACKGROUND

Dysfunction of mechanical heart valve prostheses is an unusual but potentially lethal complication after mechanical prosthetic valve replacement. We seek to report our experience with mechanical valve dysfunction regarding etiology, surgical techniques and early outcomes.

METHODS

Clinical data of 48 patients with mechanical valve dysfunction surgically treated between October 1996 and June 2011 were analyzed.

RESULTS

Mean age was 43.7±10.9 years and 34 were female (70.8%). The median interval from primary valve implantation to dysfunction was 44.5 months (range, 1 hour to 20 years). There were 21 emergent and 27 elective reoperations. The etiology was thrombosis in 19 cases (39.6%), pannus in 12 (25%), thrombosis and pannus in 11 (22.9%), improper disc orientation in 2 (4.1%), missing leaflet in 1 (2.1%), excessively long knot end in 1 (2.1%), endogenous factor in 1 (2.1%) and unidentified in 1 (2.1%). Surgical procedure was mechanical valve replacement in 37 cases (77.1%), bioprosthetic valve replacement in 7 (14.9%), disc rotation in 2 (4.2%) and excision of excessive knot end in 1 (2.1%). Early deaths occurred in 7 patients (14.6%), due to low cardiac output in 3 (6.3%), multi-organ failure in 2 (4.2%) and refractory ventricular fibrillation in 2 (4.2%). Complications occurred in 10 patients (20.8%).

CONCLUSIONS

Surgical management of mechanical valve dysfunction is associated with significant mortality and morbidity. Earlier identification and prompt reoperation are vital to achieving better clinical outcomes. The high incidence of thrombosis in this series highlights the need for adequate anticoagulation and regular follow-up after mechanical valve replacement.

Transesophageal echocardiography improves risk assessment of thrombolysis of prosthetic valve thrombosis: results of the international PRO-TEE registry

OBJECTIVES

The goal of this study was to evaluate whether quantitation of thrombus burden with transesophageal echocardiography (TEE) can help risk-stratify patients undergoing thrombolysis of prosthetic valve thrombosis (PVT).

BACKGROUND

Thrombolytic therapy of PVT has an unpredictable risk of embolization and complications.

METHODS

An international registry of patients with suspected PVT undergoing two-dimensional/Doppler and TEE before thrombolysis was established. All TEE studies were reviewed and quantitated by a single observer blinded to all data.

RESULTS

From 1985 to 2001, 107 patients (71 females; age 24 to 86 years) from 14 centers (6 in the U.S.) were identified. The majority of cases involved the mitral valve (79 mitral, 13 aortic, and 15 tricuspid). Hemodynamic success rate was achieved in 85% and was similar across valves. Overall complications were observed in 17.8%, and death in 5.6%. Predictors of complications were: New York Heart Association (NYHA) functional class, presence of shock, sinus tachycardia, hypotension, previous history of stroke, thrombus extension beyond the valve ring, and thrombus area. Multivariate analysis demonstrated that two variables were independent predictors of complications: thrombus area by TEE (odds ratio [OR] 2.41 per 1 cm2 increment, 95% confidence interval [CI] 1.12 to 5.19) and prior history of stroke (OR 4.55, 95% CI 1.35 to 15.38). A thrombus area <0.8 cm2 identified patients at lower risk for complications from thrombolysis, irrespective of NYHA functional class.

CONCLUSIONS

In PVT, the thrombus size imaged with TEE is a significant independent predictor of outcome. Transesophageal echocardiography can identify low-risk groups for thrombolysis irrespective of symptom severity and is therefore recommended in the management of prosthetic valve thrombosis.

The safety and efficacy of repeated courses of tissue-type plasminogen activator in patients with stuck mitral valves who did not fully respond to the initial thrombolytic course

In carefully selected patients with stuck mitral valves, thrombolytic therapy is becoming an established therapeutic modality. However, the management of patient with a suboptimal response to an initial thrombolytic course is unclear. The objective was to evaluate the efficacy and safety of re-administration of tissue-type plasminogen activator (rt-PA) in patients with stuck mitral valves in whom the first thrombolytic course has failed to restore normal prosthetic valve function. The study group included patients who received rt-PA and did achieve a full restoration of valve function after the initial course. Data were gathered on the safety and success rates of additional thrombolytic courses in the same hospitalization period, and their predictors. Twelve patients with stuck mitral valves experienced a total of 13 episodes in which a full resolution of leaflet abnormality was not achieved after the initial thrombolytic course. A repeated thrombolytic course was attempted in 10 patients (11 episodes). Six patients (60%) showed full success rate with repeated thrombolysis, one (10%) showed partial success, and three patients (30%) had no improvement following the second course. These last three were those with initial failure. Age, gender, valve model, worst functional class, time since valve implantation and International Normalized Ratio (INR) levels were similar in both groups. No major adverse events were noted. In this small group of patients with stuck mitral valves, re-administration of rt-PA after a partial response to an initial thrombolytic course was effective and safe. However, total failure of the first thrombolytic course predicted inefficiency of further courses.