Mechanical cardiac valve thrombosis in patients in critical hemodynamic compromise

Valve obstruction is a life threatening complication of mechanical valve prosthesis.

From 1985 to 1993, 29 consecutive patients were hospitalized in our intensive care unit for mechanical prosthetic valve thrombosis (PVT). There were 12 men and 17 women aged 25-75 years (57 +/- 12). Prosthetic valve location was mitral in 14 patients, aortic in 6, aortic and mitral in 9. PVT occurred from 15 days to 174 months (67 +/- 52 months) after surgery. Delay from first symptoms to hospitalization ranged from 1 to 45 days (11 +/- 11).

First clinical symptoms were progressive left heart failure in 17 patients, stroke in 6, and chest pain in 6. Furthermore, acute myocardial infarction was later documented in 3. Left heart failure NYHA III-IV was present in 26 patients (90%) on admission and 10 of those were in cardiogenic shock. Anticoagulation regimen was inadequate in 13 cases (45%). It has been recently stopped in 8 patients and incorrectly conducted in 5. Total hospital mortality was 41.3% (12). It was independent of type and position of the valve prosthesis. Diagnosis of PVT was only made at autopsy in 3 patients who died of recurrent myocardial infarction (2) or cardiogenic shock (1). Five further patients died before any surgery could be attempted (cardiac arrest: 2, cardiogenic shock: 3). Valve replacement could be done in 21 cases, 7 of whom were in cardiogenic shock and 9 had severe pulmonary edema. Four patients died after surgery, the operative mortality was 19%.

PVT remains a serious complication of mechanical heart valve prostheses. Overall mortality rate is high, related to difficulty to diagnosis, delay to hospitalization and severe clinical condition at admission. In our study, operative risk remained acceptable even when the clinical presentation was severe.