Clinical InvestigationCongestive Heart FailureClinical predictors and timing of New York Heart Association class improvement with cardiac resynchronization therapy in patients with advanced chronic heart failure: Results from the Multicenter InSync Randomized Clinical Evaluation (MIRACLE) and Multicenter InSync ICD Randomized Clinical Evaluation (MIRACLE-ICD) trials
Section snippets
Patients and study protocol
Included in this analysis were patients randomized to receive CRT as part of two multicenter, prospective trials (MIRACLE and MIRACLE-ICD) designed to assess the benefit of CRT compared with standard medical therapy in patients with moderate-to-severe (NYHA class III and IV) HF, LVEF ≤0.35, and QRS ≥130 milliseconds. The two studies shared similar inclusion criteria5, 16 except for indications for ICD therapy in the MIRACLE-ICD trial. After baseline assessment and randomization, patients were
Responders and nonresponders
Of the 224 patients in the MIRACLE trial, 143 (64%) responded and 81 (36%) did not respond to CRT. Nonresponders consisted of 65 (80%) patients who had no change in NYHA class from baseline to 6 months, 4 (5%) with a worse NYHA class (a change from NYHA class III to IV), and 12 (15%) who died before the 6-month follow-up visit. For MIRACLE-ICD patients, 190 (61%) responded and 123 (39%) did not respond to CRT. Nonresponders included 86 (70%) patients with no change in NYHA class, 8 (6.5%) with
Main findings
This analysis shows that (1) only about two thirds of patients enrolled in MIRACLE and MIRACLE-ICD trials have an improvement of ≥1 NYHA class, with just more than half showing early response (by 1 and 3 months) and that (2) several factors predict response and its timing, with high sensitivity (∼90%) but, owing to very low specificity (∼45%), a modest predictive accuracy (∼70%). The results are remarkably similar for patients enrolled in the two trials, although the predictive factors for
References (29)
- et al.
Tissue Doppler imaging predicts improved systolic performance and reversed left ventricular remodeling during long-term cardiac resynchronization therapy
J Am Coll Cardiol
(2002) - et al.
Predictors of left ventricular reverse remodeling after cardiac resynchronization therapy for heart failure secondary to idiopathic dilated or ischemic cardiomyopathy
Am J Cardiol
(2003) - et al.
Reliability of QRS duration on surface electrocardiogram to identify ventricular dyssynchrony in patients with idiopathic dilated cardiomyopathy
Am J Cardiol
(2003) - et al.
Comparison of characteristics in responders versus nonresponders with biventricular pacing for drug-resistant congestive heart failure
Am J Cardiol
(2002) - et al.
Long-term benefits of biventricular pacing in congestive heart failure: results from the Multisite Stimulation in Cardiomyopathy (MUSTIC) Study
J Am Coll Cardiol
(2002) - et al.
Left ventricular dyssynchrony predicts response and prognosis after cardiac resynchronization therapy
J Am Coll Cardiol
(2004) - et al.
Ventricular asynchrony predicts a better outcome in patients with chronic heart failure receiving cardiac resynchronization therapy
J Am Coll Cardiol
(2005) - et al.
Long-term effectiveness of cardiac resynchronization therapy in patients with refractory heart failure and “narrow” QRS
J Am Coll Cardiol
(2003) - et al.
Predictors of response to cardiac resynchronization therapy (PROSPECT)—study design
Am Heart J
(2005) - et al.
Clinical efficacy of cardiac resynchronization therapy using left ventricular pacing in heart failure patients stratified by severity of ventricular conduction delay
J Am Coll Cardiol
(2003)