We read with interest the communication by Dr. Amit Alam, “Effect of Near Monopoly in the Left Ventricular Assist Device Market.” Dr. Alam makes a convincing argument for the need for continued refinement and improvement of left ventricular assist devices (LVADs), and raises pressing concerns about the near monopoly held by the HeartMate 3 LVAD manufactured by Thoratec. These issues have also been raised by other cardiologists, including Dr. Mandeep Mehra of Harvard Medical School and Dr. Finn Gustafsson of the University of Copenhagen, Denmark. With this in mind, we sought to investigate adverse event reports for LVADs in the Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) database. Specifically, we examined trends in deaths attributed to LVADs as well as malfunctions attributed to LVADs from 2019 to present, and we analyzed how many deaths and malfunctions were attributable to LVADs from each major manufacturer. We additionally explored whether the number of deaths and malfunctions attributable to each manufacturer’s LVAD changed with the onset of the COVID-19 pandemic. We filtered the MAUDE data by device and adverse event type, examining “malfunction” and “death” reports with the filter “Ventricular (Assist) Bypass.”
We found that the total number of reported deaths and malfunctions attributed to LVADs did not significantly change from immediately before the pandemic to after the pandemic. The average number of monthly LVAD-attributed deaths in 2019 was 175, the average number of monthly LVAD-attributed deaths in 2020 was 146 (p value: 0.25 for 2019 vs 2020), and the average number of monthly LVAD-attributed deaths in 2021 through October 2021 was 189 (p value: 0.73 for 2019 vs 2021). The average number of monthly LVAD-attributed malfunctions in 2019 was 428, the average number of monthly LVAD-attributed malfunctions in 2020 was 390 (p value: 0.08 for 2019 vs 2020), and the average number of LVAD-attributed malfunctions in 2021 through October 2021 was 502 (p value: 0.47 for 2019 vs 2021). However, the number of reported malfunctions attributed to each LVAD manufacturer significantly shifted from 2019 to 2020 ( Figure 1 ). In 2019, 89% of reported LVAD malfunctions were attributed to Heartware, whereas only 11% of reported LVAD malfunctions were attributed to Thoratec devices. In 2020, the proportions dramatically changed, with 60% of reported LVAD malfunctions attributed to Heartware and 39% of reported LVAD malfunctions attributed to Thoratec devices (p value <0.00004 for 2019 vs 2020). Thus far in 2021, this shift has continued, with 52% of reported LVAD malfunctions attributed to Heartware and 48% of reported LVAD malfunctions attributed to Thoratec devices (p value <0.00004 for 2020 vs 2021).
We further analyzed the reported malfunctions for Thoratec HeartMate 2 devices and Thoratec HeartMate 3 devices. We found that the number of reported malfunctions for each of these devices increased dramatically from 2019 to 2020, and again from 2020 to 2021 ( Figures 2 and 3 ). These 2 devices were thus the drivers for the shift in reported malfunctions from Heartware devices to Thoratec devices during this period. From 2019 to 2020, the average number of reported malfunctions for Thoratec HeartMate 2 devices increased by almost fivefold, from 9.8 reported malfunctions per month in 2019 to 57 reported malfunctions per month in 2020 (p value <0.0002 for 2019 vs 2020). The increase is even more significant when comparing 2019 with 2021. From 2019 to 2021, the average number of reported malfunctions for Thoratec HeartMate 2 devices increased more than sixfold, from 9.8 reported malfunctions per month in 2019 to 71 reported malfunctions per month in 2021 (p value <0.00001 for 2019 vs 2021). From 2019 to 2020, the average number of malfunctions for Thoratec HeartMate 3 devices increased by almost sevenfold, from 6.3 reported malfunctions per month in 2019 to 50 reported malfunctions per month in 2020 (p value <0.0001 for 2019 vs 2020). Again, the increase is even more significant when comparing 2019 with 2021. From 2019 to 2021, the average number of reported malfunctions for Thoratec HeartMate 3 devices increased more than 13-fold, from 6.3 reported malfunctions per month in 2019 to 91 reported malfunctions per month in 2021 (p value <0.00001 for 2019 vs 2021). These findings validate the concerns of cardiologists for a near-monopoly of HeartMate 3 devices in the LVAD market.
