Remote patient monitoring after cardiac surgery: The utility of a novel telemedicine system

Abstract Objective We examined cardiac surgery patients who underwent monitoring of postoperative vital parameters using medical monitoring devices which transferred data to a mobile application and a web‐based software. Methods From November 2017 to November 2020, a total of 2340 patients were enrolled in the remote patient monitoring system after undergoing cardiac surgery. The medical devices recorded vital parameters, such as blood pressure, pulse rate, saturation, body temperature, blood glucose, and electrocardiography were measured via the Health Monitor DakikApp and Holter ECG DakikApp devices which reported data to web‐based software and a mobile application (DakikApp Mobile Systems, Remscheid, Germany). During the follow‐up period, patients were contacted daily through text and voice messages, and video conferences. Remote Medical Evaluations (RMEs) concerning patients' medical states were performed. Medication reminders, daily treatment were communicated to the patients with the DakikApp Mobile Systems Software. Results During a mean follow‐up period of 78.9 ± 107.1 (10–395) days, a total of 135,786 patient contacts were recorded (782 video conferences, 2805 voice messaging, and 132,199 text correspondence). The number of RMEs handled by the Telemedicine Team was 79,560. A total of 105,335 vital parameter measurements were performed and 5024 hospital application requests (6.3% per RME) were addressed successfully and hospitalization was avoided. A total of 144 (6.1%) potentially life‐threatening complications were found to have been diagnosed early using the Telemedicine System. Conclusion Remote Patient Monitoring Systems combined with professional medical devices are feasible, effective, and safe for the purpose of improving postoperative outcomes.


| INTRODUCTION
Technological innovations and advances have reflected strongly upon the medical field, especially in recent years. These developments have had a significant impact on life expectancy, which has resulted in an increase in life expectancy, and thus, a numerical increase is observed in the number of patients who require cardiac surgery. Older patients with high comorbidity are now undergoing cardiac surgery much more frequently, and the difficulty of caring for such patients is increasing with every passing day. [1][2][3][4] Cardiac surgeons can reduce pre-and postoperative mortality rates by using innovative techniques, as well as by keeping up with the pace of developments during and after treatment. [5][6][7] Similar to the effects of advanced surgical techniques which have reduced morbidity and mortality in cardiac surgery, 8,9 technology-assisted approaches to remote patient follow-up have the potential to revolutionize postoperative care-particularly during and after the coronavirus disease 2019 (COVID- 19) pandemic.
Follow-up after discharge is undoubtedly a primary part of care in Cardiac Surgery, and it has become a critical point due to the increasing age and comorbidities of patients. At the same time, the accessibility of knowledge via the internet has triggered an increase in the enthusiasm of patients who try and understand their illness by accessing available data. Smartphones, which have features similar to computers and are carried by almost everyone, have been demonstrated to have potential as medical monitoring systems for patients. [10][11][12] Although heart diseases are generally chronic, the management of patients progresses rapidly in the presence of surgery indication, and the surgery itself is usually performed as early as possible and hospitalization is quite short. As a result, patients are usually discharged to their homes while they still carry the psychological "shock" of the surgery. In the first month after discharge, delayed bleeding at the surgical site, wound infection, pleural or pericardial fluid formation, arrhythmias, and so forth may develop as serious complications. Additionally, irregular drug use, ineffective mobilization, disruptions in treatment and control processes, postoperative adaptation difficulties such as presenting high anxiety for normal postoperative progress, especially in postoperative pain management, and rehospitalization can also leave patients in difficult situations. To address these problems, some developed countries have structured routine rehabilitation processes in facilities that provide care to patients after cardiac surgery; however, others do not have such infrastructure. [13][14][15] The lack of adequate follow-up after major surgeries may be an important problem due to the aforementioned risks, and therefore, the possibility and benefits of conducting remote patient follow-up must be explored, especially considering the impact of COVID-19 on the method and application of patient management.
In this study, our aim was to assess the results of utilizing a sophisticated telemedicine solution for postoperative follow-up in patients discharged after cardiac surgery. and procedural properties (combined procedure and redo procedure) were recorded. During postoperative evaluations, causes for rehospitalization and the number of hospital admissions prevented with the utilization of remote patient management were recorded.

| Remote monitoring system
The patients had been hospitalized for 5.8 ± 2.8 days after heart surgery, and they underwent training for the use of the DakikApp Mobile Systems system before discharge. The system consisted of three major components: the mobile application (installed on each patient's smartphone), the DakikApp health monitor device (which measures six vital parameters: blood pressure, heart rate, oxygen saturation, body temperature, blood glucose, and electro-   Informative articles associated with the specific diagnosis and treatment of the patient were prepared and uploaded into the software system (Warning/Suggestion Module), and these articles were automatically sent to patients through an algorithm so that the patients could receive daily information about their condition. Thus, while the patients were informed about their own disease(s), they were also able to obtain relevant information, including the benefits or side effects of the drugs they used, what their considerations should be during the postoperative period, how to adhere to a healthy and effective diet, and the activities that they could partake in during the treatment period.

| Clinical outcomes of remote monitoring
Medical care events associated with remote follow-up data or RMEs were classified as follows: preventing erroneous medication use, preventing dosage errors, adjustment of medication(s) according to findings, wound care monitoring, constipation/diarrhea treatment, sleep problems treatment, pain management, warfarin dose adjustment, remote home care training, nutrition, and fluid consumption assessment and recommendations. Causes for rehospitalization and complaints/conditions associated with prevented repeat admissions were also recorded.
Patients were able to express their request to apply to the hospital through the application and these requests were recorded by the Telemedicine team. After meticulous evaluation of data and reported symptoms, patients deemed to have very low risk were remotely advised about their concerns and received remote medical care or treatment according to their condition. All individuals were informed in no uncertain terms that the final decision to apply to the hospital was theirs if their concerns continued or remote medical care was insufficient in ameliorating their complaints.

| In-person follow-up
Patients were scheduled for follow-up visits at the first, third and twelveth postoperative months. Their general condition was examined by physical examination, wound control was performed, and chest X-ray, echocardiography, ECG, and necessary blood tests were ordered. Apart from these controls, the patients were called to our clinic or the nearest health center when deemed necessary, and relevant clinical examinations causing in-person visits were performed and recorded. In this way, the findings detected during remote monitoring were re-examined under hospital conditions and the results were matched.

| Data collection and analysis
All data from IOS, Android, and web-based systems were collected in the SQL and NO-SQL 8.0 databases. Login was performed with a two-factor authentication security system, and all patient data was stored with 256bit encryption. Patients' demographic data were inserted into the live statistics panel, called Grafana Labs (Version 6.7), which provided continuous data-flow display, and thus, deviations or incorrect entries were evaluated instantly and corrected. The GraphPad Prism version 9.0 software was used to obtain descriptive statistics and graphical representations of the demographic characteristics of patients and the data recorded with the use of the remote patient monitoring system and inperson assessments, including all vital parameters and RME-related results. Data and frequencies were described relative to the number of RMEs, when applicable.

| RESULTS
A total of 2340 patients were included in the remote monitoring program after undergoing cardiac surgery. The mean age of the patients was 61.2 ± 13.1 (20-89) years and the mean preoperative Euro Risk II score was 5.3 ± 5.1% (0%-22%). The summary of patient per RME). The most common medical care event was adjustment of warfarin dose adjustment, performed a total of 8880 times (11.1% per RME) ( Table 2).
With the remote monitoring system, mild, and potential lifethreatening complications were diagnosed in a total of 612 (26.1%) cases in the early period, and, as a result, 144 patients (6.1%) were hospitalized and underwent relevant treatments (Table 3) (Table 3).
At the end of the follow-up period, patients were asked to fill out a questionnaire and, overall, 96% (n = 2246) of patients reported that they were satisfied with the remote monitoring system. Additionally, 87% (n = 2035) of patients stated that they did not have difficulty in using the system and felt more comfortable psychologically, 98% found that the information and warning module successfully addressed their specific condition, and 72% (n = 1684) stated that they wanted to extend the follow-up period with this system.

| DISCUSSION
Remote Patient Monitoring Systems began to spread all over the world even before the impact of the COVID-19 pandemic. [16][17][18][19]  easy-to-understand and definite manner, which prevents erroneous medication use.
The requests and measurements made by patients had a significant peak between 10 and 14 days, and then gradually declined.
We think that this finding may be associated with patients feeling concerned and uncontrolled at home during the early period after discharged ( Figure 3). Additionally, a second request peak was observed between 22 and 28 days, but the number of measurements was not increased in a similar manner, and the paramedical problems of the patients seemed to have a greater role. In parallel with the device measurements, we see that there is a considerable decrease in requests after the third and last peak. We attribute this third peak to mobilization and easing of movement restrictions after the first- In this study, a 6-in-1 device was used to measure all parameters of interest (Health Monitor DakikApp). This approach eliminates the need for several devices after discharge, thereby increasing compliance with the use of the remote monitoring system since all measurements were conducted from a single device. The second device (Holter ECG DakikApp) was used to record the heart rhythm of the patients, and they were treated remotely or by inviting for a check-up in the presence of arrhythmia. Devices to be integrated into Remote Patient Monitoring systems can be further developed, and different devices can be used for different fields of medicine with the possible inclusion/replacement of other parameters with respect to patient-specific needs. 25,26 The limitation of the study is that the outcomes of using remote monitoring could not be compared with a control group due to ethical considerations, and thus, all patients accepting to participate in the study received remote monitoring. We believe that a large number of patients and the experiences gained with this study can shed light on future studies and study goals in this field. Nonetheless, it may be valuable to re-examined clinical outcomes with randomized prospective studies. However, it may prove to be very difficult to randomize follow-up patient groups and draw reliable comparative data.
Randomized studies in similar branches should be increased 27,28 and end-points should be standardized to include all branches. By waiting for the results of randomized or matched-group studies, it may be necessary to bring a systematic to the field of Telemedicine and even a branching out can be made in this field. It is also evident that, due to the novel nature of different monitoring systems and the relative immaturity of remote medicine, there is considerable confusion concerning the nature of remote monitoring systems. Universally accepted terms should be described in this field to identify which types/models of remote monitoring or remote patient care can be described as "Remote Patient Monitoring" or "Telemedicine." In light of the experience we have gained with the remote follow-up of 2340 patients over a 3-year period, we would like to emphasize that such concepts have a considerable impact on increasing the comfort of patients, and that they can increase the level of success thanks to the professional control of the postoperative follow-up of primary cardiac surgery treatments. These effects are particularly important when the effects of COVID-19 on patient care are considered.