Comparison of Empiric to Physician-Tailored Programming of Implantable Cardioverter Defibrillators Trial - EMPIRIC

Jul 14, 2006
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Date Published:
01/01/2006
Date Updated:
07/14/2006
Original Posted Date:
07/14/2006
References

Description:

The goal of the trial was to evaluate whether standardized programmed settings are as effective as physician-chosen settings among patients with an implantable cardioverter defibrillator (ICD).

Hypothesis:

Initial programming of tachyarrhythmia detection and therapy parameters applied to a large group of unselected ICD patients will be as successful as individualized patient-specific physician-tailored programming.

Study Design

Study Design:

Patients Enrolled: 900
Mean Follow Up: 1 year
Mean Patient Age: Mean age 65 years
Female: 19
Mean Ejection Fraction: Mean 32% at baseline

Patient Populations:

Standard indications for ICD placement, undergoing their first placement of an ICD, and free of permanent atrial fibrillation

Primary Endpoints:

Percentage of recorded episodes in a therapeutic zone that produced a device shock for episodes determined to be VT/VF and those determined not to be VT/VF, evaluated for noninferiority

Secondary Endpoints:

Time to first shock for all rhythms (VT/VF and SVT), only VT/VF rhythms, and only SVT rhythms

Drug/Procedures Used:

Patients were randomized to standardized (n = 445) or physician-tailored (n = 455) ventricular tachycardia/ventricular fibrillation (VT/VF) programming of their ICD. In the standardized group, the programming was targeted to: 1) avoid detecting nonsustained tachycardias; 2) avoid detecting supraventicular tachycardias (SVTs) as VT; 3) empirical antitachycardia pacing (ATP) for slow and fast VTs; and 4) high-output first shocks.

Principal Findings:

ICD indication was primary prevention in 46% of patients and secondary prevention in 54% of patients, with spontaneous sustained monomorphic VT the most frequently reported type of secondary prevention (26%). As expected, the programming in the tailored arm varied greatly. Detection of VF was programmed at 12-16 beats in 50% of patients and 18-24 beats in 49% of patients. The number of patients received ≥1 shock in both arms (18.2% for standardized arm vs. 19.1% for tailored arm). The number of SVT episodes detected was higher in the standardized arm (1,083 vs. 585, p < 0.001), but inappropriate shocks did not differ (125 vs. 118).

The primary endpoint of VT/VF (22.3% vs. 28.7%) and SVT or other non-VT/VF event episodes (11.9% vs. 26.1%) resulting in a shock met both the criteria for noninferiority and superiority in the standardized arm compared to the tailored arm. Time to first all-cause shock was noninferior in the standardized arm (hazard ratio [HR], 0.95; 90% confidence interval [CI], 0.74-1.23; noninferiority p = 0.0016). Time to first VT/VF shock in the standardized arm was nonsignificantly longer than the tailored group (HR, 0.80; 90% CI, 0.56-1.14; superiority p=0.297). The percent of patients with ≥5 shocks for all-cause VT/VF was lower in the standardized arm (3.8% vs. 7.0%, p = 0.039), as was true VT/VF (0.9% vs. 3.3%, p = 0.018). In the standardized arm, there were fewer unscheduled hospitalizations (n = 163 vs. n = 216, p = 0.001), but there were no differences in other clinical measures, including total mortality (n = 24 vs. n = 30), syncope (n = 2 vs. n = 3), emergency room visits (n = 44 vs. n = 46), or unscheduled outpatient visits (n = 308 vs. n = 293).

Interpretation:

Among patients with standard indications for ICD placement, use of standardized VT/VF programming was associated with a reduction in the primary endpoints of VT/VF and SVT or other non-VT/VF event episodes resulting in shock compared with physician-tailored programming.

Programming of ICDs can be complicated, with multiple options for detecting and treating rhythms. The choice of programming is generally user specific, with some physicians favoring ATP for preventing shock, and can be tailored specifically to the patient. Delivery of inappropriate shocks as a result of misclassification of SVT as VT causes undue pain and can be anxiety-provoking, impairing patients' quality of life.

References:

Wilkoff BL, Ousdigian KT, Sterns LD, Wang ZJ, Wilson RD, Morgan JM. A comparison of empiric to physician-tailored programming of implantable cardioverter-defibrillators: results from the prospective randomized multicenter EMPIRIC trial. J Am Coll Cardiol 2006;48:330-9.

Keywords: Tachycardia, Ventricular, Ventricular Fibrillation, Syncope, Pain, Hospitalization, Defibrillators, Implantable


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