The Management of hypertension in patients with LVAD is an important aspect of care due to the increased risk of fatal complications (CMP, LVAD thrombosis). However, noninvasive blood pressure measurement in patients with LVAD with continuous flow can offer many clinical pitfalls. The Doppler ultrasound method is still used in most centers, as the automated BP monitor is not successful in measuring up to 50% of cases due to the artificial reduction of pulse pressure. However, even the Doppler method is loaded with problems in interpretation of measured values (medium or systolic BP, i.e. MAP vs. SBP), which can lead to significant clinical consequences.
69-year old patient with terminal heart failure, indicated for LVAD (HeartWare) implantation as destination therapy in May 2016. After implantation was stable, without any serious difficulties. During follow-up visits, BP values measured by Doppler were repeatedly 90-100 mm Hg. The aortic valve opening was 1:1, LVAD was with normal parameters. Since the BP values were considered as MAP, antihypertensive therapy was up-titrated. We reached the reduction of MAP to 80-85 mm Hg, the patient was asymptomatic, LVAD with normal flow again, antihypertensive medication remained unchanged. After following 2 years the patient was stable, without any complications. We did not record any major clinical or echocardiographic changes, MAP was still around 80 mm Hg. We left the antihypertensive medication unchanged. In December 2018 the patient experienced syncope with craniotrauma and underwent decompression craniotomy. In stable condition and after gradual recovery, the values of BP measured by Doppler ultrasound were repeatedly 100–110 mm Hg after previous reduction of antihypertensive therapy. Because of craniotrauma and the necessity of exact BP measurement and exact management of antihypertensive therapy, we added an invasive BP measurement. The arterial line BP values were 100-110/60-65 mm Hg. This result means that BP values obtained by Doppler method were exactly SBP in our case.
This clinical problem (noninvasive BP measurement in patients with continuous flow LVAD and interpretation of obtained values - MAP vs. SBP) is documented in the story of our patient. It might be possible, that hypotension was one of the syncope contributing factors. We recommend that BP values in patients with LVAD should not be determined by a single isolated method, but that haemodynamics should be assessed in a comprehensive manner by a combination of several methods. The hopes are new monitors, developed specifically for non-invasive BP measurements in patients with LVAD. An individual comparison of the accuracy of each methods in a given patient at a time just before the end of the invasive monitoring of TK may be clinically beneficial.