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Acute and Chronic Response to CRT in Narrow QRS Patients

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Abstract

Previous studies suggest that CRT may benefit narrow QRS patients with mechanical dyssynchrony (MD). We conducted an acute and chronic study, evaluating the response of heart failure patients with a narrow QRS to cardiac resynchronization therapy (CRT). ESTEEM-CRT was a multi-center, single-arm, feasibility study that evaluated ICD-indicated, medically-optimized patients with EF ≤ 35%, NYHA class III heart failure, QRS duration <120 ms, and MD as defined by the standard deviation of time to peak systolic velocity of 12 segments (Ts-SD). Sixty-eight patients received a CRT defibrillator, exercise testing, and echo exams, and 47 of these patients underwent invasive hemodynamic testing at implant. Follow-up was at 6 and 12 months. The average maximal improvement in LV dP/dtmax was minor (2 ± 2%). NYHA and quality of life scores were substantially improved at 6 and 12 months (P < 0.001), while exercise capacity and LV volumes were unchanged. The echo indices of MD were difficult to collect, discordant, and failed to predict clinical outcomes. ESTEEM-CRT patients with a narrow QRS and MD as defined in this study did not improve as measured by acute hemodynamics, chronic exercise performance, or reverse remodeling. These multi-center results support the notion that dyssynchrony indices are ineffective or at least require greater refinement for the selection of narrow QRS patients for CRT.

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Abbreviations

AV:

Atrio-ventricular

CRT:

Cardiac resynchronization therapy

CRT-D:

CRT defibrillator

dP/dtmax :

The maximum rate of pressure change over time during systole

EF:

Ejection fraction

EDD:

End-diastolic diameter

EDV:

End-diastolic volume

ESD:

End-systolic diameter

ESV:

End-systolic volume

ICD:

Implantable cardioverter defibrillator

LV:

Left ventricle

MD:

Mechanical dyssynchrony

NYHA:

New York Heart Association

TDI:

Tissue Doppler imaging

Ts:

Time to peak systolic velocity

Ts-SD:

Standard deviation of Ts from 12 segments around the heart

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Acknowledgements

The authors thank the ESTEEM-CRT patients, investigators, and institutions for their participation; Dr. Michael Higginbotham for his CPX Core Lab analysis; and Dr. John Merlino and Dr. J.P. Sun for their echocardiographic Core Lab analyses.

Conflicts of Interest

T. Donahue—consultant (Medtronic), stock ownership (none), other equity or patent ownership (none).

I. Niazi—consultant (St. Jude Medical, Medtronic, Osprey Medical).

A. Leon—none.

M. Stucky—employee of Boston Scientific CRV.

K. Herrmann—employee of Boston Scientific CRV.

Financial sources

This study was sponsored by Boston Scientific CRV.

Author information

Authors and Affiliations

  1. Ochsner Medical Center, New Orleans, LA, USA

    Tim Donahue

  2. St. Luke’s Medical Center, Milwaukee, WI, USA

    Imran Niazi

  3. Emory School of Medicine, Atlanta, GA, USA

    Angel Leon

  4. Boston Scientific CRV, St. Paul, MN, USA

    Michael Stucky & Keith Herrmann

  5. Triangle Heart Associates, 2609 North Duke St., Durham, NC, 27516, USA

    Tim Donahue

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  1. Tim Donahue
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on behalf of the ESTEEM-CRT Investigators

Corresponding author

Correspondence to Tim Donahue.

Appendix A

Appendix A

The following investigators and institutions participated in the ESTEEM-CRT study:

Dr. Tim Donahue (Principal Investigator), Ochsner Medical Center, New Orleans, USA; Dr. Angel Leon, Emory School of Medicine, Atlanta, USA; Dr. Imran Niazi, St. Luke's Medical Center, Milwaukee, USA; Dr. John Herre, Sentara Norfolk Hospital, Norfolk, USA; Dr. Sandeep Jain, University of Pittsburgh Medical Center, Pittsburgh, USA; Dr. Jay Franklin, Baylor University, Dallas, USA; Dr. David Law, Cardiovascular Consultants, Cape Girardeau, USA; Dr. Lawrence Rosenthal, University of Massachusetts, Worcester, USA; Dr. Walter Kerwin and Dr. P.S. Chen, Cedar Sinai Medical Center, Los Angeles, USA; Dr. Charles Athill, Sharp Memorial Hospital, San Diego, USA.

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Donahue, T., Niazi, I., Leon, A. et al. Acute and Chronic Response to CRT in Narrow QRS Patients. J. of Cardiovasc. Trans. Res. 5, 232–241 (2012). https://doi.org/10.1007/s12265-011-9338-3

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