Clinical course and outcome of patients enrolled in US and non-US centres in MADIT-CRT

Eur Heart J. 2011 Nov;32(21):2697-704. doi: 10.1093/eurheartj/ehr149. Epub 2011 Jun 2.


Aims: We aimed to evaluate within the MADIT-CRT database whether different enrollment characteristics between US and non-US centres affected the clinical course of study patients.

Methods and results: We evaluated differences in baseline characteristics, procedure-associated complications, clinical as well as echocardiographic response to cardiac resynchronization therapy with a defibrillator (CRT-D), between patients enrolled in 87 US centres (n = 1271) and 23 non-US centres (n = 549) in MADIT-CRT. Non-US patients displayed significant differences in baseline characteristics from US patients, including a higher frequency of left bundle branch block, a more advanced heart failure (HF) functional class >3 months prior to enrollment, and larger baseline cardiac volumes. Procedure-related complications occurred at a significantly higher frequency among patients enrolled in non-US centres (17%) than among those enrolled in US centres (10%; P < 0.001). During follow-up, CRT-D was associated with 42% (P = 0.003) and 38% (P < 0.001) reductions in the risk of HF or death in the two respective groups (P for the difference = 0.80), and with similar reductions in cardiac volumes (all P > 0.10). Subgroup analysis showed a more pronounced effect of CRT-D among women in the US group, including a significant 71% (P = 0.02) reduction in the risk of death, whereas CRT-D therapy was associated with a significant clinical benefit in men only in the non-US group.

Conclusion: Patients enrolled in US and non-US centres in MADIT-CRT displayed significant differences in baseline clinical and echocardiographic characteristics and in the frequency of procedure-related complications, but experienced an overall similar clinical and echocardiographic response to CRT-D.

Publication types

  • Comparative Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Cardiac Resynchronization Therapy / adverse effects
  • Cardiac Resynchronization Therapy / standards*
  • Cardiac Resynchronization Therapy / statistics & numerical data
  • Coronary Care Units / statistics & numerical data*
  • Defibrillators, Implantable / adverse effects
  • Defibrillators, Implantable / standards*
  • Defibrillators, Implantable / statistics & numerical data
  • Echocardiography / statistics & numerical data
  • Europe
  • Female
  • Heart Failure / therapy*
  • Humans
  • Israel
  • Male
  • Middle Aged
  • Patient Admission / statistics & numerical data*
  • Risk Factors
  • Survival Analysis
  • Treatment Outcome
  • United States
  • Young Adult