Key Points
- To measure the incidence and frequency of cerebral embolic signals via transcranial Doppler in patients with identical mechanical heart valves and determine correlating clinical characteristics.
- Evaluated 92 patients with Carbomedics bileaflet mechanical valves across three surgical timelines—perioperative (group 1, n=36), 1 year postoperative (group 2, n=34), and 5 years postoperative (group 3, n=22)—plus 15 healthy controls.
- Conducted transcranial Doppler ultrasound monitoring of the right middle cerebral artery to record microembolic signals.
- Asymptomatic embolic signals were detected in 87% of all valve recipients (77.8% in group 1, 91.2% in group 2, and 95.5% in group 3) compared with 0% in preoperative patients and healthy controls, with incidence (P = .04) and frequency (P = .002) increasing over implantation duration.
- A significant positive correlation occurred between embolic signal frequency and prosthetic valve size (r = .4326, P = .00001).
- Patients with a prior history of cerebrovascular symptoms exhibited a significantly higher median embolic signal rate (60 signals/hour, n=14) than asymptomatic patients (11 signals/hour, n=42; P = .04).
Structured PICO
PPopulation92 patients with Carbomedics bileaflet mechanical heart valves (36 examined before and immediately after implantation, 34 at 1 year post-surgery, 22 at 5 years post-surgery) and 15 healthy control subjects.
IInterventionTranscranial Doppler monitoring of the right middle cerebral artery
CComparatorHealthy control subjects and pre-operative baseline (for group 1)
OOutcomeIncidence and frequency of cerebral embolic signalssurrogate
Cerebral embolic signals are frequently detected in patients with mechanical heart valves, and their frequency increases with time since implantation, valve size, and a history of cerebrovascular events.