Implantable device diagnostics on day of discharge identify heart failure patients at increased risk for early readmission for heart failure

Abstract

Aims: We hypothesized that diagnostic data in implantable devices evaluated on the day of discharge from a heart failure hospitalization (HFH) can identify patients at risk for HF readmission (HFR) within 30 days.

Methods and results: In this retrospective analysis of four studies enrolling patients with CRT devices, we identified patients with a HFH, device data on the day of discharge, and 30-day post-discharge clinical follow-up. Four diagnostic criteria were evaluated on the discharge day: (i) intrathoracic impedance>8 Ω below reference impedance; (ii) AF burden>6 h; (iii) CRT pacing<90%; and (iv) night heart rate>80 b.p.m. Patients were considered to have higher risk for HFR if ≥2 criteria were met, average risk if 1 criterion was met, and lower risk if no criteria were met. A Cox proportional hazards model was used to compare the groups. The data cohort consisted of a total of 265 HFHs in 175 patients, of which 36 (14%) were followed by HFR. On the discharge day, ≥2 criteria were met in 43 (16% of 265 HFHs), only 1 criterion was met in 92 (35%), and none of the four criteria were met in 130 HFHs (49%); HFR rates were 28, 16, and 7%, respectively. HFH with ≥2 criteria met was five times more likely to have HFR compared with HFH with no criteria met (adjusted hazard ratio 5.0; 95% confidence interval 1.9–13.5, P=0.001).

Conclusion: Device-derived diagnostic criteria evaluated on the day of discharge identified patients at significantly higher risk of HFR.

Figure 1

Inclusion and exclusion process to select the final cohort of 175 patients with 265 heart failure hospitalizations (HFH). Thirty-eight patients out of 213 patients with HFH were excluded due to either unavailable device data on the day of discharge or unavailable clinical follow-up data for 30 days post-discharge.

Figure 2

Example cases where (A) no diagnostic criteria were met on the day of discharge and (B) ≥2 diagnostic criteria were met. Diagnostic data are plotted for 30 days prior to discharge and 30 days post-discharge. Occurrence of heart failure hospitalization (HFH) is shaded in grey, with the index event having the discharge day around day 30 on the plots. AT/AV, atrial tachycardia/atrial fibrillation; Avg V. rate, average ventricular rate.

Figure 3

Kaplan–Meier curves showing the readmissions for heart failure (HF) following discharge after an index HF hospitalization for the three groups categorized based on the combination of diagnostic parameters.