(326) - Outcomes of Off-Pump Minimally Invasive Exchange of the HeartMate II (HMII) Left Ventricular Assist Device (LVAD)

Abstract

s S127 monitoring. Simple dipstick urinalysis (UA) for urine hemoglobin (U-Hb) overcomes this limitation. This study correlated U-Hb and plasma LDH levels and evaluated performance of UA for detection of significant hemolysis in CF-LVAD pts. Methods: U-Hb and plasma LDH were measured concurrently 910 times in 198 CF-LVAD pts. Statistics were computed to determine accuracy of UA in detecting LDH ≥ 600 with a positive result being any detected Hb. Readings with concurrent active cardiac, lung, brain, bone or liver injury or bacteremia were excluded from the analysis as these conditions may raise LDH. U-Hb was categorized into absent, trace-mild and moderate-severe. Mean plasma LDH levels are presented with and without exclusion of readings with concurrent hematuria, missing urine RBC data, or UA readings suggestive of urinary tract infection (UTI), as these conditions can be associated with false positive U-Hb readings. Results: A positive U-Hb had a sensitivity, specificity, positive and negative predictive value for detection of plasma LDH≥ 600 of 84%, 64%, 38% and 94%, respectively. Of note, among 159 false positive tests, 71 (45%) had UA readings suggestive of UTI that may call for additional work-up irrespective of U-Hb results. Mean LDH was 350/517/877 and 375/594/1260 for absent/ trace-mild/moderate-severe U-Hb before and after excluding measures associated with false positive U-Hb readings, respectively (all p’s < 0.0001) (Fig). Conclusion: Plasma LDH is significantly associated with U-Hb levels. Absence of U-Hb efficiently excludes significant hemolysis in CF-LVAD pts. U-Hb monitoring may enable more intense surveillance and earlier diagnosis of device thrombosis as it can be performed by pts at home.