Results of the Patient-Related Outcomes of Mechanical lead Extraction Techniques (PROMET) study: a multicentre retrospective study on advanced mechanical lead extraction techniques.

AIMS: Several large studies have documented the outcome of transvenous lead extraction (TLE), focusing on laser and mechanical methods. To date there has been no large series addressing the results obtained with rotational lead extraction tools. This retrospective multicentre study was designed to investigate the outcomes of mechanical and rotational techniques. METHODS AND RESULTS: Data were collected on a total of 2205 patients (age 66.0 ± 15.7 years) with 3849 leads targeted for extraction in six European lead extraction centres. The commonest indication was infection (46%). The targeted leads included 2879 pacemaker leads (74.8%), 949 implantable cardioverter-defibrillator leads (24.6%), and 21 leads for which details were unknown; 46.6% of leads were passive fixation leads. The median lead dwell time was 74 months [interquartile range (IQR) 41-112]. Clinical success was obtained in 97.0% of procedures, and complete extraction was achieved for 96.5% of leads. Major complications occurred in 22/2205 procedures (1%), with a peri-operative or procedure-related mortality rate of 4/2205 (0.18%). Minor complications occurred in 3.1% of procedures. A total of 1552 leads (in 992 patients) with a median dwell time of 106 months (IQR 66-145) were extracted using the Evolution rotational TLE tool. In this subgroup, complete success was obtained for 95.2% of leads with a procedural mortality rate of 0.4%. CONCLUSION: Patient outcomes in the PROMET study compare favourably with other large TLE trials, underlining the capability of rotational TLE tools and techniques to match laser methods in efficacy and surpass them in safety

A novel miniature in-line load-cell to measure in-situ tensile forces in the tibialis anterior tendon of rats.

Direct measurements of muscular forces usually require a substantial rearrangement of the biomechanical system. To circumvent this problem, various indirect techniques have been used in the past. We introduce a novel direct method, using a lightweight (~0.5 g) miniature (3 x 3 x 7 mm) in-line load-cell to measure tension in the tibialis anterior tendon of rats. A linear motor was used to produce force-profiles to assess linearity, step-response, hysteresis and frequency behavior under controlled conditions. Sensor responses to a series of rectangular force-pulses correlated linearly (R2 = 0.999) within the range of 0-20 N. The maximal relative error at full scale (20 N) was 0.07% of the average measured signal. The standard deviation of the mean response to repeated 20 N force pulses was ± 0.04% of the mean response. The step-response of the load-cell showed the behavior of a PD2T2-element in control-engineering terminology. The maximal hysteretic error was 5.4% of the full-scale signal. Sinusoidal signals were attenuated maximally (-4 dB) at 200 Hz, within a measured range of 0.01-200 Hz. When measuring muscular forces this should be of minor concern as the fusion-frequency of muscles is generally much lower. The newly developed load-cell measured tensile forces of up to 20 N, without inelastic deformation of the sensor. It qualifies for various applications in which it is of interest directly to measure forces within a particular tendon causing only minimal disturbance to the biomechanical system

Transvenous lead extraction: The influence of age on patient outcomes in the PROMET study cohort

Background Cardiac implantable electronic device (CIED) therapy contributes to an improvement in morbidity and mortality across all patient demographics. Patient age is a recognized risk factor for unfavorable outcomes in invasive procedures. This is the largest series of non-laser transvenous lead extraction (TLE) evaluating the association between patient age and procedure outcomes. Methods Data of 2205 (3849 leads) patients was collected retrospectively from six European TLE centers between January 2005–December 2018 in the PROMET study. Of these, 153 patients with 319 leads were excluded for incomplete data. A comparison of outcomes was performed between the age groups young [< 50 years], young intermediate [50–69 years], older intermediate [70–79 years], and octogenarian [≥80 years]. Results Infection was most common indication for TLE in the octogenarian cohort, less common in the younger population (60.1% vs. 33.2%, respectively, p < .01). High-voltage leads were extracted most frequently from young patients, less frequently from octogenarians (31.6% vs. 10%, p < .001), while the opposite was evident for pacemaker leads (p < .001). Rotational sheath use was equally prevalent across all patient groups (p = .79). Minor and major complications across all the age groups were statistically similar, as was procedural success; the 30-day mortality was most significant in the octogenarian and least in the young patients (4.9% vs. 0.4%, p = .005). Propensity matching multivariate analysis found systemic infection, lead dwell time, and patient age (p = .013, OR 1.064 [1.013–1.116]) increased risk of 30-day mortality. Conclusion TLE is safe and effective across all age groups. 30-day mortality risk is significantly higher in the older patients