RESULTS Device diagnostics showed strong correlation with established HF biomarkers and hemodynamic measures .
The findings from this review indicate that device diagnostic parameters predict impending HF much earlier than traditional methods of monitoring do .
Device diagnostics are also more accurate in the early prediction of HF when compared with noninvasive objective measures , particularly when multiple parameters are combined and monitored for trends .
Device diagnostics possess a distinct advantage over traditional methods of monitoring for HF because they allow clinicians to remotely monitor the status of their HF patients without relying on patient compliance for data entry and reporting .
Studies regarding the efficacy of device diagnostic parameters suggest that their integration into clinical practice will provide a more accurate and reliable mechanism for assisting clinicians in risk stratifying and predicting potential episodes of decompensated HF
BACKGROUND Traditional methods of heart failure ( HF ) management are based on reactive strategies to treat late indicators of decompensated HF .
Advances in monitoring methods have become available with the evolution of implantable cardioverter-defibrillators and cardiac-resynchronization therapy devices .
These devices provide new diagnostic data and remote monitoring capabilities that allow clinicians to proactively monitor patients for earlier signs of worsening HF .
The integration of data obtained from implantable cardioverter-defibrillator and cardiac-resynchronization therapy technology could improve outpatient HF care , potentially leading to decreased readmission rates and improved patient outcomes .
OBJECTIVE This review will synthesize the literature regarding the efficacy of device diagnostic data and the usability of the data in the clinical setting .
Intrathoracic impedance vs daily weight monitoring for predicting worsening heart failure events: results of the Fluid Accumulation Status Trial (FAST).
The relative sensitivity and unexplained detection rate of changes in intrathoracic impedance has not been compared with st and ard heart failure ( HF ) monitoring using daily weight changes . The Fluid Accumulation Status Trial ( FAST ) prospect ively followed 156 HF patients with implanted cardioverter-defibrillator or cardiac resynchronization therapy defibrillator devices modified to record daily changes in intrathoracic impedance in a blinded fashion for 537±312 days .  Daily impedance changes were used to calculate a fluid index that could be compared with a prespecified threshold . True positives were defined as adjudicated episodes of worsening HF occurring within 30 days of a fluid index above threshold or an acute weight gain . Unexplained detections were defined as threshold crossings or acute weight gains not associated with worsening HF . Impedance measurements were performed on > 99 % of follow-up days , compared with only 76 % of days for weight measurements . Sixty-five HF events occurred during follow-up ( 0.32/patient-year ) . Forty HF events were detected by impedance but not weight , whereas 5 were detected by weight but not impedance . Sensitivity was greater ( 76 % vs 23 % ; P<.0001 ) and unexplained detection rate was lower ( 1.9 vs 4.3/patient-year ; P<.0001 ) for intrathoracic impedance monitoring at the threshold of 60Ω days compared with acute weight increases of 3 lbs in 1 day or 5 lbs in 3 days and also over a wide range of fluid index and weight thresholds . The sensitivity and unexplained detection rate  of intrathoracic  impedance monitoring was superior to that seen for acute weight changes . Intrathoracic impedance monitoring represents a useful adjunctive clinical tool for managing HF in patients with implanted devices
RESULTS Device diagnostics showed strong correlation with established HF biomarkers and hemodynamic measures .
The findings from this review indicate that device diagnostic parameters predict impending HF much earlier than traditional methods of monitoring do .
Device diagnostics are also more accurate in the early prediction of HF when compared with noninvasive objective measures , particularly when multiple parameters are combined and monitored for trends .
Device diagnostics possess a distinct advantage over traditional methods of monitoring for HF because they allow clinicians to remotely monitor the status of their HF patients without relying on patient compliance for data entry and reporting .
Studies regarding the efficacy of device diagnostic parameters suggest that their integration into clinical practice will provide a more accurate and reliable mechanism for assisting clinicians in risk stratifying and predicting potential episodes of decompensated HF
BACKGROUND Traditional methods of heart failure ( HF ) management are based on reactive strategies to treat late indicators of decompensated HF .
Advances in monitoring methods have become available with the evolution of implantable cardioverter-defibrillators and cardiac-resynchronization therapy devices .
These devices provide new diagnostic data and remote monitoring capabilities that allow clinicians to proactively monitor patients for earlier signs of worsening HF .
The integration of data obtained from implantable cardioverter-defibrillator and cardiac-resynchronization therapy technology could improve outpatient HF care , potentially leading to decreased readmission rates and improved patient outcomes .
OBJECTIVE This review will synthesize the literature regarding the efficacy of device diagnostic data and the usability of the data in the clinical setting .