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 .
Monitoring intrathoracic impedance with an implantable defibrillator reduces hospitalizations in patients with heart failure.
PURPOSE Some implantable cardioverter-defibrillators ( ICDs ) are now able to monitor intrathoracic impedance . The aim of the study was to describe the use of such monitoring in clinical practice and to evaluate the clinical impact of the fluid accumulation alert feature of these ICDs . METHODS AND RESULTS Five hundred thirty-two heart failure ( HF ) patients implanted with these ICDs  were followed up for 11 + /- 7 months . A clinical event ( CE ) was deemed to have occurred if it result ed in hospitalization or milder manifestations of HF deterioration . Three hundred sixty-two acute decreases in intrathoracic impedance ( Z events ) occurred in 230 patients . Of these episodes , 171 ( 47 % ) were associated with a CE within 2 weeks of the Z event . In another 71 ( 20 % ) Z events , drug therapy was adjusted despite the absence of overt signs of clinical deterioration . The rate of unexplained Z events was 0.25 per patient-year and 25 hospitalizations were not associated with Z events . The audible alert was disabled in a group of 102 patients ( OFF group ) .  HF hospitalizations occurred in 29 ( 7 % ) patients in the ON group and 20 ( 20 % , P < 0.001 ) patients in the OFF group . The rate of combined cardiac death and HF hospitalization was lower in patients with Alert ON ( log-rank test , P = 0.007 ) . CONCLUSIONS The ICD reliably detected CE and yielded low rates of unexplained and undetected events . The alert capability seemed to reduce the number of HF hospitalizations by allowing timely detection and therapeutic intervention
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 .