What is the clinical evidence from this study?

Study design: Observational. Population: Mechanical prosthetic heart valve dysfunction (n=62). Intervention: 64-slice multidetector computed tomography (MDCT). Primary outcome: Mean attenuation value (Hounsfield Units) and discrimination of pannus from thrombus (AUC 0.96, 95% CI 0.91-0.99, p=<0.001).

December 1, 2015

Sixty-Four–Section Cardiac Computed Tomography in Mechanical Prosthetic Heart Valve Dysfunction

Q: What are the key findings of this study?

64-slice MDCT accurately distinguished pannus from thrombus in prosthetic valve dysfunction, with an AUC of 0.96 (95% CI 0.91-0.99; P<0.001).

Key Result

64-slice MDCT accurately distinguished pannus from thrombus in prosthetic valve dysfunction, with an AUC of 0.96 (95% CI 0.91-0.99; P<0.001).

Study Design

Type

Observational (n=62)

Structured PICO

Does 64-slice MDCT accurately distinguish between pannus and thrombus in patients with suspected mechanical prosthetic valve dysfunction?

Population

62 patients (mean age 44 years, 63% female) with suspected mechanical prosthetic valve dysfunction assessed by transesophageal echocardiography.

Exposure

64-slice multidetector computed tomography (MDCT) to measure attenuation values (Hounsfield Units) of periprosthetic masses.

Comparator

Definitive diagnosis by thrombolysis response or surgical findings (thrombus vs. pannus).

Outcome

Discrimination between pannus and thrombus based on MDCT attenuation values (Hounsfield Units).surrogate

64-slice MDCT attenuation values can accurately distinguish between pannus and thrombus in mechanical prosthetic valve dysfunction, guiding the selection of thrombolysis versus surgery.

Main Result

Effect estimate: AUC 0.96 (95% CI 0.91-0.99)

Absolute Event Rate: 87% vs 322%

p-value: p=<0.001

Abstract

BACKGROUND: Distinguishing pannus and thrombus in patients with prosthetic valve dysfunction is essential for the selection of proper treatment. We have investigated the utility of 64-slice multidetector computed tomography (MDCT) in distinguishing between pannus and thrombus, the latter amenable to thrombolysis. METHODS AND RESULTS: Sixty-two (23 men, mean age 44±14 years) patients with suspected mechanical prosthetic valve dysfunction assessed by transesophageal echocardiography were included in this prospective observational trial. Subsequently, MDCT was performed before any treatment was started. Periprosthetic masses were detected by MDCT in 46 patients, and their attenuation values were measured as Hounsfield Units (HU). Patients underwent thrombolysis unless contraindicated, and those with a contraindication or failed thrombolysis underwent surgery. A mass which was completely lysed or surgically detected as a clot was classified as thrombus, whereas a mass which was surgically detected as tissue overgrowth was classified as pannus. A definitive diagnosis could be achieved in 37 patients with 39 MDCT masses (22 thrombus and 17 pannus). The mean attenuation value of 22 thrombotic masses was significantly lower than that in 17 pannus (87±59 versus 322±122; P90) is associated with reduced lysis rates.