Feasibility and Accuracy of Blood Pressure Measurement by Patients with Left Ventricular Assist Devices (LVAD)

Abstract

Blood pressure (BP) control reduces stroke in LVAD patients. Home monitoring is key for optimal control. Measurement by Doppler is the most reliable non-invasive method. No study assessed the feasibility of Doppler BP obtained by LVAD patients and caregivers. From 3-11/2018, 12 ambulatory patients with Heartware HVAD were recruited and taught to measure BP in 7 steps (1: quiet sitting, 2: cuff placement, 3: find radial artery flow, 4: inflate cuff, 5: deflate cuff, 6: find BP, 7: record BP). All received manual cuffs and Dopplers to check BP up to 3 times/day for 6 weeks, and had weekly reminder phone calls. They were observed to check BP at routine visits, and completed a survey at end of study. We made no medication changes based on home BP. Seven patients (median age 57yrs [IQ 44-67], median VAD support 39 days [IQ 32-48], 1 on support for > 1yr) completed the study. Median number of recorded BP was 42 (IQ 22-78). At enrollment, 4 patients easily learned 7 steps, 2 needed reteaching for step 3 or 5, and 1 needed reteaching for both. At follow-up, all completed 7 steps and obtained BP that modestly agreed with BP measured by staff (κ=0.25, 31% agreement, p=0.0002). Diurnal variation (higher afternoon BP) was seen in 2 patients; the rest had no change from morning to evening (Figure). Reasons for BP check failure were "forgetfulness", "too busy", "too sick", or "no help/did not seek help". Of the 5 patients who dropped out (median age 38yrs, support duration > 9 months), 3 needed reteaching for steps 3-6. Of the 2 patients who easily learned the steps, 1 lost caregiver and was hospitalized too frequently, the other was non-compliant. No one completely failed BP education after reteaching. This pilot study demonstrated feasibility of home BP monitoring by Doppler in select patients. Those who failed to obtain daily BP checks tended to have poor social support or were not proficient in the 7-step method. Further data are needed to define and prognosticate diurnal BP variation in LVAD patients.