Echocardiography Guided Cardiac Resynchronization Therapy (EchoCRT)

The EchoCRT trial evaluates the effects of Cardiac Resynchronization Therapy (CRT) on mortality and morbidity of subjects with heart failure due to left ventricular systolic dysfunction, already receiving optimized HF medication, with a narrow QRS width (\< 130 ms) and echocardiographic evidence of ventricular dyssynchrony.


Eligibility Criteria:
Inclusion Criteria:

* Men and women 18 years of age or older.
* Understand the nature of the procedure.
* Give written informed consent.
* Willing and able to complete all testing required by the clinical protocol.
* Indication for an implantable cardioverter defibrillator (ICD).
* NYHA class III-IV within the last three months prior to enrollment and at baseline (at baseline only: also Stage C according to ACC/AHA guidelines).
* Stable optimal pharmacologic therapy for HF.
* An ejection fraction ≤ 35% within one year prior to enrollment and confirmed on the baseline echocardiogram.
* Increased left ventricular dimension, defined as LVEDD ≥ 55 mm.
* Resting QRS duration \< 130 ms evidenced by a historical 12-lead ECG prior to enrollment and at baseline.
* Ventricular dyssynchrony assessed by echocardiography locally and confirmed by the echo core lab. One of the two following criteria has to be present to include the subject in the study:

  * Intra-left ventricular dyssynchrony measured by color Tissue Doppler Imaging (TDI) with an opposing wall delay of ≥ 80 ms in the 4-chamber or apical long-axis view.
  * Speckle-tracking radial strain septal-posterior wall delay ≥ 130 ms.

Exclusion Criteria:

* Implanted pacemaker or defibrillator with \>10% ventricular pacing, as demonstrated by device statistics averaged over at least the last three months prior to enrollment.
* Women who are pregnant, lactating, or planning to become pregnant during the course of the trial.
* Bradycardia pacing indication.
* Surgically correctable primary valvular heart disease, i.e. aortic stenosis, torn cordae, or flail segment.
* Coronary artery bypass graft surgery or percutaneous coronary intervention (balloon and/or stent angioplasty) within the past 3 months prior to enrollment.
* Enzyme-positive myocardial infarction within the past 3 months prior to enrollment.
* Angiographic evidence of coronary disease, candidates for coronary revascularization likely to undergo coronary artery bypass graft surgery or percutaneous coronary intervention in the next 3 months.
* Irreversible brain damage from preexisting cerebral disease.
* Reversible non-ischemic cardiomyopathy such as acute viral myocarditis.
* Permanent second or third degree heart block.
* Chagas disease.
* Persistent or paroxysmal atrial fibrillation within one month prior to enrollment.
* Expected to receive heart transplantation within six months.
* Current inotropic therapy.
* Acutely decompensated heart failure.
* Contrast dye allergy and unable or unwilling to undergo pretreatment with steroids and/or diphenhydramine.
* Life expectancy of less than six months.
* Presence of any disease, other than the subject's cardiac disease associated with a reduced likelihood of survival for the duration of the trial, (e.g. cancer).
* Significant renal insufficiency defined as a serum creatinine \> 2.5 mg/dL (\> 221 µmol/L) within the last four weeks prior to enrollment..
* Liver failure, defined as three times the upper limit of normal for aminotransferases.
* Participation in any other clinical trial.
* Unable to return for follow-up visits due to distance from the clinic.
* Do not anticipate being a resident of the area for the scheduled duration of the trial.