Self-Measured Doppler Blood Pressure Readings in Continuous-Flow LVAD Patients are Reliable

ABSTRACT

Background: Blood pressure (BP) management is imperative in reducing risk of adverse events in continuous flow (CF) left ventricular assist device (LVAD) patients. The gold standard for non-invasive blood pressure (BP) measurement in these patients is Doppler ultrasound, which requires training and dexterity and is not routinely used in the outpatient setting. In the current COVID-19 pandemic era, telehealth assessment has become mandatory to assess and monitor patients. At our institution, we have issued all CF-LVAD patients with a Doppler ultrasound device and an oscillometric BP monitor, and provided training to correctly use these devices. Accuracy of BP measurements in this setting has not been confirmed. Aim: We examined whether Doppler BP obtained by CF-LVAD patients (pts) correlates to Doppler BP obtained by health care workers (HCWs). Methods: CF-LVAD pts were recruited between November 2020 and January 2022. During these routine outpatient follow-up visits, Doppler BP measurements were obtained simultaneously and independently by pts and HCW. BP was taken in a comfortable seating position following 5 minutes rest. Results: A total 223 pairs of simultaneous patient Doppler BP readings and HCW Doppler BP readings were obtained from 38 CF-LVAD patients (87% male, mean age at implant 52 + 14 years, 15 HeartMate3 and 23 HeartWare HVAD, with support duration range 28 - 3492 days). Patient Doppler BP (average 85.9 + 9.8 mmHg) correlated closely with HCW Doppler BP (average 86.1 + 9.6 mmHg), r2=0.90, p<0.0001. There was no significant difference between BP taken by the patient and HCW (p=0.4). The mean difference between the two methods was -0.17 mmHg and the standard deviation was 0.22 mmHg (figure) using Bland-Altman analysis. Conclusions: These results demonstrate that in our patient-population, Doppler-derived blood pressure measurements in CF-LVAD patients were accurate and reliable. This supports the routine use of home Doppler BP measurement and monitoring by CF-LVAD patients, especially in the telehealth era. (Figure Presented).