Predictors of response to cardiac resynchronization therapy (PROSPECT)--study design.

BACKGROUND: Cardiac resynchronization therapy (CRT) is currently indicated in patients with moderate to severe heart failure, a wide QRS complex and significant left ventricular dysfunction despite optimal medical therapy. Adoption of these criteria for CRT results in a favorable response in only two thirds of candidates. METHODS: "Predictors of response to cardiac resynchronization therapy (PROSPECT)," a prospective, multicenter, nonrandomized study, aims to identify echocardiographic measures of dyssynchrony and evaluate their ability to predict response to CRT. PROSPECT will enroll approximately 300 patients in up to 75 centers in the United States, Asia, and Europe with clinical follow-up for 6 months. We will prospectively and individually test a variety of conventional echocardiographic and tissue Doppler imaging parameters against measures of clinical response. The primary response criteria are improvement in the heart failure Clinical Composite Score and left ventricular reverse remodeling. Enrollment began in March 2004 and is expected to conclude early 2005.

Usefulness of the peak velocity difference by tissue Doppler imaging technique as an effective predictor of response to cardiac resynchronization therapy.

Cardiac resynchronization therapy (CRT) improves symptoms and functional status in heart failure patients; however, current selection criteria need improvement. A novel tissue Doppler imaging parameter, the peak velocity difference (PVD), defined as the greatest difference in time to peak velocity between any of 6 left ventricular regions, may better select responders to CRT. Subjects were divided into 2 groups based on the PVD. Clinical and echocardiographic parameters significantly improved in subjects with dyssynchrony by the baseline PVD and had a better overall response to CRT.