Archive for the ‘Implantable cardioverter-defibrillators’ Category

Journal Club 2 April 2014


Survival with Cardiac-Resynchronization Therapy in Mild Heart Failure





The Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchro-nization Therapy (MADIT-CRT) showed that early intervention with cardiac-resyn-chronization therapy with a defibrillator (CRT-D) in patients with an electrocardio-graphic pattern showing left bundle-branch block was associated with a significant reduction in heart-failure events over a median follow-up of 2.4 years, as compared with defibrillator therapy alone.


We evaluated the effect of CRT-D on long-term survival in the MADIT-CRT popula-tion. Post-trial follow-up over a median period of 5.6 years was assessed among all 1691 surviving patients (phase 1) and subsequently among 854 patients who were enrolled in post-trial registries (phase 2). All reported analyses were performed on an intention-to-treat basis.


At 7 years of follow-up after initial enrollment, the cumulative rate of death from any cause among patients with left bundle-branch block was 18% among patients ran-domly assigned to CRT-D, as compared with 29% among those randomly assigned to defibrillator therapy alone (adjusted hazard ratio in the CRT-D group, 0.59; 95% confidence interval [CI], 0.43 to 0.80; P<0.001). The long-term survival benefit of CRT-D in patients with left bundle-branch block did not differ significantly according to sex, cause of cardiomyopathy, or QRS duration. In contrast, CRT-D was not associ-ated with any clinical benefit and possibly with harm in patients without left bundle-branch block (adjusted hazard ratio for death from any cause, 1.57; 95% CI, 1.03 to 2.39; P = 0.04; P<0.001 for interaction of treatment with QRS morphologic findings).


Our findings indicate that in patients with mild heart-failure symptoms, left ventricular dysfunction, and left bundle-branch block, early intervention with CRT-D was associated with a significant long-term survival benefit.

Supplementary Material

Paper supplementary material


Journal Club 29 February 2012

February 29, 2012 3 comments


Development and validation of a risk score to predict early mortality in recipients of implantable cardioverter-defibrillators




An observational study in recipients of implantable cardioverter defibrillators to determine correlates of one-year mortality using stepwise logistic

regression. A derivation set was chosen and then a validation set used to assess the goodness of fit of the model.


Patients receiving implantable cardioverter defibrilllators (new implants)


Not applicable


Not applicable


One-year mortality

The total cohort included 2717 ICD patients (mean age = 64.6 ± 14.5, male = 77.2%, primary prevention = 74.7%). A simple risk score incorporating peripheral

arterial disease, age ≥ 70 years, creatinine ≥ 2.0 mg/dL, and ejection fraction ≤20% (PACE) accurately predicted 1-year mortality in the VG. Patients with a

risk score of ≥3 had a >4-fold excess 1-year mortality compared with patients with a risk score of ❤ (16.5% vs 3.5%; P <.0001).

Discussion Summary 

  • The paper is hypothesis generating. The issue of trying to develop criteria for futility are laudable from a patient interest and resourcing.
  • The limitations of risk scores were discussed in general, and consistent with other risk scores there was a poor positive predictive value.
  • The selection bias of cardiologists chosing patients who they perceived had reasonable survival had impacts such as narrowing the age range in the patient group. Age appears to have been a forced variable in the stepwise regression model. It was somewhat reassuring that even in the highest risk (from this model) 80% of patients survived one year.
  • Information regarding the appropriate discharge rate would have provided insight into the benefit in the high risk group. A control group without device with same risk score would have also provided insight. Dr. Atherton observed that patients with similar characteristics in the heart failure with LV systolic dysfunction had a 7% annual mortality.

Background Materials

Dr. Karin Chia kindly provided background material for this paper.