Mechanical Device Malfunction of the HeartMate II Versus the HeartMate 3 Left Ventricular Assist Device: The Rotterdam Experience.

Mechanical device malfunction remains a known issue in left ventricular assist devices (LVADs). We investigated the incidence of mechanical device malfunction in the HeartMate II and HeartMate 3 LVADs. We conducted a retrospective study of all HeartMate II and HeartMate 3 LVADs implanted in our center. We evaluated major malfunction, potential major malfunction, minor malfunction, and need of device exchange. In total, 163 patients received an LVAD; in 63 (39%) a HeartMate II, and in 100 (61%) a HeartMate 3, median support time of respectively 24.6 months (interquartile range [IQR]: 32.4) and 21.1 months [IQR: 27.2]. Mechanical device malfunction, consisting of both major and potential major malfunction, occurred significantly less in the HeartMate 3 patients with a hazard ratio (HR) of 0.37 (95% confidence interval [CI]: 0.15-0.87, p = 0.022). Major malfunction alone occurred significantly less in HeartMate 3 patients with a HR of 0.18 (95% CI: 0.05-0.66, p = 0.009). HeartMate 3 patients had a significantly decreased hazard of a pump or outflow graft exchange (HR 0.13, 95% CI: 0.08-0.81, p = 0.008). System controller defects occurred significantly less in HM 3 patients ( p = 0.007), but battery-clips defects occurred significantly more in HM 3 patients ( p = 0.039). Major device malfunction including pump or outflow graft exchange occurred significantly less in HeartMate 3 compared to HeartMate II, while minor malfunctions were similar. Periodical assessment of the technical integrity of the device remains necessary during long-term LVAD support.

Relapsing low-flow alarms due to suboptimal alignment of the left ventricular assist device inflow cannula.

OBJECTIVES: This retrospective study investigated the correlation between the angular position of the left ventricular assist device (LVAD) inflow cannula and relapsing low-flow alarms. METHODS: Medical charts were reviewed of all patients with HeartMate 3 LVAD support for relapsing low-flow alarms. A standardized protocol was created to measure the angular position with a contrast-enhanced computed tomography scan. Statistics were done using a gamma frailty model with a constant rate function. RESULTS: For this analysis, 48 LVAD-supported patients were included. The majority of the patients were male (79%) with a median age of 57 years and a median follow-up of 30 months (interquartile range: 19-41). Low-flow alarm(s) were experienced in 30 (63%) patients. Angulation towards the septal-lateral plane showed a significant increase in low-flow alarms over time with a constant rate function of 0.031 increase in low-flow alarms per month of follow-up per increasing degree of angulation (P = 0.048). When dividing this group using an optimal cut-off point, a significant increase in low-flow alarms was observed when the septal-lateral angulation was 28° or more (P = 0.001). Anterior-posterior and maximal inflow cannula angulation did not show a significant difference. CONCLUSIONS: This study showed an increasing number of low-flow alarms when the degrees of LVAD inflow cannula expand towards the septal-lateral plane. This emphasizes the importance of the LVAD inflow cannula angular position to prevent relapsing low-flow alarms with the risk of diminished quality of life and morbidity.

Relapsing low-flow alarms due to suboptimal alignment of the left ventricular assist device inflow cannula.

OBJECTIVES: This retrospective study investigated the correlation between the angular position of the left ventricular assist device (LVAD) inflow cannula and relapsing low-flow alarms. METHODS: Medical charts were reviewed of all patients with HeartMate 3 LVAD support for relapsing low-flow alarms. A standardized protocol was created to measure the angular position with a contrast-enhanced computed tomography scan. Statistics were done using a gamma frailty model with a constant rate function. RESULTS: For this analysis, 48 LVAD-supported patients were included. The majority of the patients were male (79%) with a median age of 57 years and a median follow-up of 30 months (interquartile range: 19-41). Low-flow alarm(s) were experienced in 30 (63%) patients. Angulation towards the septal-lateral plane showed a significant increase in low-flow alarms over time with a constant rate function of 0.031 increase in low-flow alarms per month of follow-up per increasing degree of angulation (P = 0.048). When dividing this group using an optimal cut-off point, a significant increase in low-flow alarms was observed when the septal-lateral angulation was 28° or more (P = 0.001). Anterior-posterior and maximal inflow cannula angulation did not show a significant difference. CONCLUSIONS: This study showed an increasing number of low-flow alarms when the degrees of LVAD inflow cannula expand towards the septal-lateral plane. This emphasizes the importance of the LVAD inflow cannula angular position to prevent relapsing low-flow alarms with the risk of diminished quality of life and morbidity.