Author + information
- Received September 4, 2008
- Revision received August 3, 2009
- Accepted August 10, 2009
- Published online May 1, 2010.
- Paul S. Chan, MD, MSc⁎,⁎ (, )
- Taiyeb Khumri, MD⁎,
- Eugene S. Chung, MD†,
- Stefano Ghio, MD‡,
- Kimberly J. Reid, MSc⁎,
- Bart Gerritse, PhD§,
- Brahmajee K. Nallamothu, MD, MPH∥ and
- John A. Spertus, MD, MPH⁎
- ↵⁎Reprint requests and correspondence:
Dr. Paul S. Chan, St. Luke's Mid America Heart Institute, 5th Floor, 4401 Wornall Road, Kansas City, Missouri 64111
Objectives This study sought to assess the prognostic utility of echocardiographic dyssynchrony for health status improvement after cardiac resynchronization therapy (CRT).
Background Echocardiographic measures of dyssynchrony have been proposed for patient selection for CRT, but prospective validation studies are lacking.
Methods A prospective cohort of 324 patients from 53 centers with moderate to severe heart failure, left ventricular dysfunction, QRS ≥130 ms, and available echocardiographic and health status information were identified from the PROSPECT (Predictors of Response to Cardiac Re-Synchronization Therapy) trial, which evaluated the prognostic utility of dyssynchrony measures in CRT recipients. The association of 12 echocardiographic dyssynchrony parameters with 6-month improvement in health status, as measured by the Kansas City Cardiomyopathy Questionnaire (KCCQ), was assessed both as a continuous variable and by responder status (ΔKCCQ ≥+10 points reflecting moderate to large improvement).
Results Of 12 pre-defined dyssynchrony parameters, only 3 were consistently reported: interventricular mechanical delay (IVMD), left ventricular filling time relative to the cardiac cycle (LVFT), and left ventricular pre-ejection interval. After multivariable adjustment, IVMD (+5.18, 95% confidence interval [CI]: +0.76 to +9.60; p = 0.02) and LVFT (+5.19, 95% CI: +0.45 to +0.94; p = 0.03) were independently associated with 6-month improvements in KCCQ. Patients with 6-month improvements in KCCQ had lower subsequent mortality (adjusted hazard ratio [HR] for each 5-point improvement: 0.83; 95% CI: 0.72 to 0.93; p = 0.03). Additionally, IVMD was associated with CRT responder status (for ΔKCCQ ≥+10 points: odds ratio [OR]: 1.85; 95% CI: 1.12 to 3.05; p = 0.03), whereas LVFT was not (OR: 1.63; 95% CI: 0.85 to 3.11; p = 0.14). Patients classified as health status responders had a 76% lower subsequent risk of all-cause mortality (adjusted HR: 0.24; 95% CI: 0.07 to 0.84; p = 0.03).
Conclusions The presence of pre-implantation IVMD and LVFT was associated with 6-month health status improvement, and IVMD was associated with a significant CRT response. These echocardiographic factors may help clinicians counsel patients regarding their likelihood of symptomatic improvement with CRT. (PROSPECT: Predictors of Response to Cardiac Re-Synchronization Therapy; NCT00253357)
Medtronic Inc. provided funding and manufactured the cardiac resynchronization therapy system used in this study. Dr. Chung has received a research grant for PROSPECT investigators from Medtronic (≥$10,000) and is a consultant/advisory board member for Medtronic (<$10,000). Dr. Ghio has received a research grant for PROSPECT investigators (<$10,000), is a consultant/advisory board member for the Medtronic steering committee (<$10,000), and has received a grant for ECHO core laboratory (≥$10,000). Dr. Gerritse is an employee at Medtronic, Inc., and owns approximately $10,000 worth of Medtronic stock shares. Dr. Spertus has received a research grant from Medtronic (<$10,000), and has developed and owns the copyrights for the Kansas City Cardiomyopathy Questionnaire.
- Received September 4, 2008.
- Revision received August 3, 2009.
- Accepted August 10, 2009.
- American College of Cardiology Foundation