Abstract WMP66: Cerebrovascular Hemodynamics of Mechanical Circulatory Support Device Patients

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Kara R Melmed ◽  
Konrad H Shlick ◽  
Brenda Rinsky ◽  
Shlee S Song ◽  
Patrick D Lyden

Background: Multiple types of mechanical circulatory support (MCS) devices are commonly used in heart failure patients. These devices carry risk for neurologic complications, specifically cardioembolic stroke. Alterations in blood flow play a role in the pathophysiology, however there is limited data regarding cerebrovascular hemodynamics in MCS patients. We used transcranial Doppler (TCD) to define hemodynamics of commonly used MCS devices. Methods: We retrospectively examined charts from 2/2013 through 6/2016 for patients with MCS who underwent TCD, and obtained the following: peak systolic,end-diastolic velocities, mean flow velocities, pulsatility indices (PI) and number of high-intensity transient signals (HITS). Waveform morphologies were compared between devices. Results: Of 1,796 TCDs studies screened, 62 TCD studies were from 32 MCS patients. Of these, 21 were on extracorporeal membrane oxygenation (ECMO), 15 had a left ventricular assist device (LVAD), 18 had total artificial heart (TAH), and 2 had intra-aortic balloon pumps (IABP). Waveforms in patients supported by ECMO demonstrated continuous flow without clear systolic peaks. The averaged mean MCA velocity was 57.57 (SD= 21.00) cm/sec and mean PI is 0.35 (0.17). LVAD averaged mean MCA velocity was 57.57 (14.38) cm/sec and mean PI of 0.45 (0.28). PIs were low in patients with continuous-flow LVADs. Impella patients had morphologically distinct pulsatile waveforms compared to other types of VADs. IABP had averaged mean velocity of 56.21 (14.78) cm/sec and mean PI of 0.77 (0.15). These waveforms demonstrated pronounced diastolic upstrokes not present in other devices. In TAH patients, mean MCA velocity was 73.69 (33.00) cm/sec and PI of 0.86 (0.40). Emboli detection was performed in 46 studies, and HITS were detected in 29 (63%). Of these 15 (51%) were administered 100% oxygen which suppressed >50% HITS in 10 (67%) patients. Conclusion: Patients supported by MCS devices produce unique and characteristic waveforms on TCD studies. Further studies will describe normative values in this special population. HITS were not universally present and intermittently suppressible by oxygen, suggesting some may be gaseous in nature. Risk of stroke in patients with MCS and HITS is under study.

Author(s):  
Yuriy Pya ◽  
Makhabbat Bekbossynova ◽  
Assel Medressova ◽  
Serik Bekbossynov ◽  
Saltanat Andossova ◽  
...  

Background. Mechanical circulatory support (MCS) has been applied as an effective therapy for patients with end stage heart failure (HF). The existing donor organ shortage issue in Kazakhstan, and hence long waiting times, have resulted in left ventricular assist device (LVAD) implantation being the predominant surgical treatment method for this condition. The purpose of this study is to analyze clinical outcomes of MCS program data in our Center. Methods. This study involves a retrospective analysis of 324 patients with different types of implantable MCS including LVAD (n=319), fully implantable LVAD (FIVAD, n=2), and total artificial heart (TAH, n=3). FIVAD and TAH cases were analyzed separately from other VAD types due to their small numbers. Results. Initially, LVADs were implanted as bridge-to-transplant (BTT) in 214 (67.1%) of patients and as a destination therapy (DT) in 105 (32.9%) cases, but only 30 (9.4%) patients proceeded to transplant. The overall survival rate of all LVAD patients at years 1, 2, 3, and 4 was 84.3%, 69.7%, 62.8%, and 52.5%, respectively. The distance from the clinic (Nur-Sultan) to patients’ cities of residence (average 1015 ± 668 kilometers) was not associated with patient survival. Conclusions. Developing MCS programs is crucial in providing care for patients with HF. Using LVAD as DT produced satisfactory outcomes with favorable survival rates, which are comparable to the outcomes reported in other studies. Further trials are needed to investigate the results of TAH and FIVAD implantation in order to establish them as an acceptable alternative treatment to heart transplantation.


2017 ◽  
Vol 44 (5) ◽  
pp. 357-360 ◽  
Author(s):  
Andrew C.W. Baldwin ◽  
Courtney J. Gemmato ◽  
Elena Sandoval ◽  
William E. Cohn ◽  
Jeffrey A. Morgan ◽  
...  

The widespread use of continuous-flow left ventricular assist devices for mechanical circulatory support has shown that long-term hemodynamic support is possible, even when a clinical “pulse” cannot be detected. We present the incidental discovery of ventricular fibrillation in 6 alert, hemodynamically stable patients supported only by a continuous-flow device (HeartMate II, n=5; Jarvik 2000, n=1). Ventricular fibrillation was found in 3 patients during routine outpatient follow-up visits and in 3 awaiting discharge from the hospital after device placement. Diagnosis was confirmed by electrocardiographic and echocardiographic studies. The average duration of mechanical circulatory support before ventricular fibrillation occurred was 221 ± 362 days (range, 5–864 d). All patients were conscious and ambulatory at the time of the arrhythmia. Three patients reported symptoms—primarily fatigue, nausea, and exertional dyspnea—that prompted evaluation. Serum chemistry analysis of blood drawn immediately after diagnosis showed no changes that suggested end-organ dysfunction. Three patients died of unrelated complications an average of 3.9 yr (range, 360–2,270 d) after the event. Two of the remaining 3 patients eventually underwent successful pump explantation, and one is on ongoing support. Our experience shows that it is possible for patients with continuous-flow left ventricular assist devices to remain hemodynamically stable while in ventricular fibrillation. Additional investigation is needed to determine whether defibrillator settings for these patients should be adjusted to limit delivery of shock therapy.


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