Q&A regarding the use of IMPELLA

Q—What is the duration of continued device use?

A—There is no description regarding usage duration in the Japanese Approval Documents. Regarding the design of the products, IMPELLA 2.5 is assumed to be used for 5 days, and IMPELLA 5.0 is assumed to be used for 10 days, based on approved EUCE Mark labeling.

Based upon the results of durability tests by the manufacturer, IMPELLA 2.5 showed 12 days use as the 80% reliability and 80% confidence interval (80/80 is the VAD reliability goal in the US FDA requirements). Also, regarding IMPELLA 5.0, the test results show 23 days use with the same 80% reliability and 80% confidence interval.

Q—In the case of continuous use of the devices, what should be given special attention in terms of maintenance or administration?

A—There are no specific time-dependent needs for maintenance or management of the devices. The management of the devices is addressed in their package inserts. The end of life of the devices is sometime signaled by an increase in motor current trends, reflecting bearing wear out, but not always. As stated in the package insert, there is a stated need to maintain heparin in the purge system to maintain the patency of the gap between the impeller and the space it rotates in. If this gap is contaminated with blood due to the lack of heparin or proper purge pressure maintenance, the purge pressure will increase as the gap gets smaller and the motor current will also increase due to additional friction.

This would be an end of life signal for the pump, but it is induced by a failure to follow heparin instructions or purge pressure maintenance instructions, both of which are in the package inserts and training.

Q—What is the practice in the US or Europe?

A—In the US or Europe, institutions are advised to consider the duration of the device use, when they observe changes in levels of motor current, or purge pressures. Regarding this, when changing the pump, they are asked to make decisions swiftly while considering carefully the risks with pump changing such as possible impacts on hemodynamics, embolism, vascular injuries, and also, the risk of immediate pump stop which can happen.

Each institution is asked to use the IMPELLA system under a physician’s judgements, incorporating the information above and the designed usage duration as a guide.

Please also note the package insert label describes that the use length of circulation support should be decided with consideration of these aspects including as such the patient’s underlying diseases, condition, treatment records, body size, hemodynamic status, co-morbidities.