Comparison of the diagnostic accuracy of four smartphone-compatible blood pressure monitors in post-myocardial infarction patients.

Introduction Smartphone-compatible blood pressure devices may be a good alternative to enable self-measurement of blood pressure by patients. Furthermore, automatic transferral of data to the hospital allows for remote monitoring. To our knowledge, no study has compared four of these smartphone-compatible blood pressure devices. Methods Patients who were followed up for acute myocardial infarction were asked to participate during their outpatient clinic visit. After five minutes of rest, six blood pressure devices were applied. The order was randomised. Four devices were smartphone-compatible. One device was an automated oscillometric device. One device was a handheld aneroid sphygmomanometer (reference device). All measurements were compared using a linear mixed model. Results A total of 43 patients (62.7 ± 11.3 years, 79% male) were included. Compared to the reference device, four blood pressure monitors yielded a significant higher mean systolic blood pressure and four monitors yielded a significant higher diastolic BP. One device yielded a non-significant lower mean systolic blood pressure and one device yielded a non-significant higher mean diastolic blood pressure. Except for one blood pressure device, all mean differences were smaller than 5 mmHg. Conclusion In this study, average inter-device variability was shown to be statistically significant, however four devices remained within the predefined range of 5 mmHg for both systolic and diastolic blood pressures.