Background: 

Early infections after transcatheter aortic valve replacement (TAVR) represent one of the most common risk factors for non-cardiac 30-day mortality. Several wearable devices have been developed to measure vital signs and physical activity in real time while allowing full mobilization of the patient. However, their use has not been evaluated in a clinical setting with patients undergoing TAVR yet.

Purpose: 

We aimed to evaluate the feasibility of wearable patch sensors in assessing vital signs and daily activity before and after TAVR to predict an increased risk of early infections following TAVR.

Methods: 

Patients at high risk for infection undergoing transfemoral TAVR under local anesthesia were enrolled between September 2022 and April 2023. Postprocedural early infections were assessed, defined as C-reactive protein rise within 5 days after the procedure inducing antibiotic treatment. Vital signs (heart rate, respiratory rate, single-lead ECG) and activity (steps, posture) were monitored by a wearable patch sensor two days before (pre-TAVR) and two days after TAVR (post-TAVR).

Results: 

104 patients completed 5 days of in-hospital monitoring with wearable patch sensors. The mean age was 79.1+5.4 years, 60 patients (57.7%) were male. Early infections occurred in 12 of 104 (11.5%) high-risk patients, of whom two were a urinary tract, three a pulmonary, and three access site-related etiology. Four infections remained with unknown focus. 

Respiratory rate was generally higher in patients developing an early infection after TAVR in both time periods, before (early infection 22±3 vs. no infection 17±2 bpm; p<0.001) and after TAVR (early infection 24±4 vs. no infection 18±3 bpm; p<0.001).

Early infections were more prevalent in patients who showed less activity in the two days before TAVR regarding lower step count (early infection 212±322 vs. no infection 486±481; p=0.009) and high percentage of lying position during the whole day (early infection 82±18% vs. no infection 62±22%; p=0.011). Two days after TAVR, there were no significant differences in activity levels between both cohorts. Physical activity was reduced in both groups compared to the two days before TAVR, resulting in a reduced number of steps (pre-TAVR 481±421 vs. post-TAVR 279±321; p=0.015) and more daytime spent in lying position (pre-TAVR 58±22% vs. post-TAVR 74±21%; p<0.001).

Conclusion: 

Wearable patch sensors are feasible to track vital signs and physical activity during hospital stay with promising opportunity for improving clinical management in TAVR patients. Early infections after TAVR are associated with decreased preprocedural mobility in high-risk patients. Therefore, these patients may be prematurely detected using wireless respiratory rate monitoring and infections prevented by intensified physiotherapy.