CONCLUSIONS Current evidence suggests that D-PA may be useful for assessing physical activity and predicting clinical outcomes in patients with cardiovascular implantable electronic devices when combined with other device parameters .
BACKGROUND  Physical activity  is predictive of cardiovascular outcomes in patients with cardiovascular implantable electronic devices , yet it is not regularly assessed in routine care .
Current-generation cardiovascular implantable electronic devices , however , continuously monitor patient activity through a built-in accelerometer , which provides new opportunities to remotely assess patient activity , detect changes in clinical status , and incorporate these data in risk stratification models .
This review critically examines the literature on device-measured physical activity ( D-PA ) , with a focus on identifying method ological issues that may affect interpretation of study results .
Predictive value of device-derived activity level for short-term outcomes in MADIT-CRT.
BACKGROUND There are limited data on the prognostic importance of declining activity level in patients with heart failure . OBJECTIVE We aim ed to assess the association of reduced activity level with adverse cardiovascular outcomes in the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy ( MADIT-CRT ) . METHODS Final device interrogations from patients enrolled in the MADIT-CRT with cardiac resynchronization devices capable of recording percent daily activity level were assessed . To determine temporal change , st and ardized activity levels ( SALs ) comparing each week to the monthly activity 3 months prior were obtained . Death , heart failure events (HFEs)/death , and ventricular tachyarrhythmias (VTAs)/death were the primary end points of this study . RESULTS The average absolute activity level and SAL of the final week prior to death or end of study were significantly lower in patients who died compared with those in patients who did not . The total cohort ( N = 1008 ) was further r and omized into 2 subgroups to identify ( group 1 ) and vali date an optimal threshold ( group 2 ) . Patients with > 40 % reduced SAL had a significantly increased 77-day short-term cumulative incidence of death ( P = .0006 ) , HFE/death ( P < .0001 ) , or VTA/death ( P = .0248 ) . After adjustment for clinical covariates , these patients remained at an increased risk for death ( hazard ratio [ HR ] , 2.7 ; 95 % confidence interval [ CI ] , 1.5 - 4.9 ; P = .001 ) , HFE/death ( HR , 2.7 ; 95 % CI , 1.8 - 3.9 ; P ≤ .001 ) and VTA/death ( HR , 1.9 ; 95 % CI , 1.31 - 2.6 ; P = .001 ) . A decline in SAL following a nonfatal VTA and HFE was also associated with an increased probability of death . CONCLUSIONS Decline in activity level is a short-term predictor for adverse cardiovascular events in patients with mild to moderate heart failure undergoing cardiac resynchronization
CONCLUSIONS Current evidence suggests that D-PA may be useful for assessing physical activity and predicting clinical outcomes in patients with cardiovascular implantable electronic devices when combined with other device parameters .
BACKGROUND  Physical activity  is predictive of cardiovascular outcomes in patients with cardiovascular implantable electronic devices , yet it is not regularly assessed in routine care .
Current-generation cardiovascular implantable electronic devices , however , continuously monitor patient activity through a built-in accelerometer , which provides new opportunities to remotely assess patient activity , detect changes in clinical status , and incorporate these data in risk stratification models .
This review critically examines the literature on device-measured physical activity ( D-PA ) , with a focus on identifying method ological issues that may affect interpretation of study results .