Home telemonitoring for ALS early and late ventilated patients 

The exponential increase in use of NIV world-wide, limits the needed close surveillance, particularly in small ALS clinics(1) . Telemonitoring (TM) systems can improve healthcare utilization, with possible positive impact on functional and survival outcome (2). However, validation is required. We aim to compare two TM systems in order to find further evidence supportting early NIV. We compared two sets of patients, historical controls vs active arm, to study two different TM systems and ventilation modes (ST and ST-AVAPS). The historical group (Group 1) included 17 patients submitted to NIV in ST mode and early NIV with FVC > 80%. Group 2 included 25 consecutive ventilated patients with the new mode (ST-AVAPS) and late intervention (FVC ≤ 70%). All patients were prospectively evaluated (3 years), with ALSFRS-R, oximetry and respiratory function tests recorded every three months and remote access to ventilatory settings and compliancy but, only equivalent data of the two systems were compared. Results: At admission, ALSFRS-R scores, age, gender and region of onset, disease duration from disease onset and from diagnosis to NIV, and healthcare utilization throughout observation period (office visits, emergency room visits and episodes of admission) were similar (p>0.05) as well as ALSFRS-R at NIV start. Respiratory tests (FVC, MIP and MEP) at entry showed significant differences between groups (lower values in G2). During this study, the breath back-up rate was lower in G2 (p=0.001), IPAP was higher in G2 (p<0.001). Despite G2 patients started NIV one month later (ns), survival with NIV was comparable between groups (p=0.37), with a greater number of survivors in G2 (83%) than in G1 (52.9%). Kaplan-Meier curves showed that the probability of being alive was higher in G1 (LR: p=0-034). In a multiple Cox-regression model, the significant predictors of survival from diagnosis were: ALSFRS-R at diagnosis (B: -.848; p= 0,01); FVC (B:-.269; p=0,048); MIP at admission (B: 125; p= 0,026), IPAP (B: 9.659; p= 0,006); the mean breath rate (B: -9.406; p= 0,006 ) and the percentage of spontaneous cycling (B: 1.095; p = 0,007); the number of office visits (B: 1.147; p=0.009); and the number of hours of daily use  (B: -4.258; p=0.009).  Lower mean breath rate, number of hours of daily use and number of emergency room visits were associated  with increased survival from diagnosis in G2 patients. Discussion: Regardless of the TM system used, this study confirms previous results (table 1). Though the correct indicators for early NIV are not established (3), we accepted FVC ≥ 80 % and/or MIP ≤ 60 cmH2O. Our results showed longer survival for G1 (Fig. 1 and 2), despite patients in G2 had higher comfort with lower levels of mean BR mean, and lower levels in the % of spontaneous cycling with higher IPAP at NIV start (table 1). The higher IPAP aimed to improve comfortable time off during the day. We speculate that higher IPAP reduced the % of spontaneous cycling due to central drive interference, see Nilius and al., 2017 (4). On the other hand, the positive effect on survival of lower mean BR and hours of use/day (table 4) also suggest the need of a better balance between IPAP and mean BR, and the number of hours of use, possibly achieved with evaluation of Tc CO2 or Et CO2 during the night which is a limitation of this study(5). In addition, Cox-reg models showed that increase survival was related to FVC and ALSFRS-R at diagnosis, but not to MIP (Table 4). Furthermore, these results also confirm the need to reduce the number of office visits and admissions so that keeping patients away from Hospital is relevant to their survival. On the whole, successful NIV was equally achieved in both groups, but the benefit of early ventilation should be further explored.  References: 1.Rabec C, Gonzalez-Bermejo J, Arnold V, et al. [Initiation of domiciliary non-invasive ventilation: proposals of the Casavni working party]. Rev Mal Respir. 2010;27(8):874-889. 2.Pinto A, Almeida JP, Pinto S, Pereira J, Oliveira AG, de Carvalho M. Home telemonitoring of non-invasive ventilation decreases healthcare utilisation in a prospective controlled trial of patients with amyotrophic lateral sclerosis. J Neurol Neurosurg Psychiatry. 2010;81(11):1238-1242. 3.Prell T, Ringer TM, Wullenkord K, et al. Assessment of pulmonary function in amyotrophic lateral sclerosis: when can polygraphy help evaluate the need for non-invasive ventilation? J Neurol Neurosurg Psychiatry. 2016;87(9):1022-1026. 4.Nilius G, Katamadze N, Domanski U, Schroeder M, Franke KJ. Non-invasive ventilation with intelligent volume-assured pressure support versus pressure-controlled ventilation: effects on the respiratory event rate and sleep quality in COPD with chronic hypercapnia. Int J Chron Obstruct Pulmon Dis. 2017;12:1039-1045. 5.Vrijsen B, Testelmans D, Belge C, Vanpee G, Van Damme P, Buyse B. Patient-ventilator asynchrony, leaks and sleep in patients with amyotrophic lateral sclerosis. Amyotroph Lateral Scler Frontotemporal Degener. 2016;17(5-6):343-350