Introduction:

In end-stage heart failure, implantation of left ventricular assist device (LVAD) is an expanding therapy today. Unfortunately, often initially severely impaired physical condition in most LVAD Patients is not yet normalized along with a normalization of cardiac output shortly after implantation. In these patients, especially in the commonly encountered presence of muscle wasting, the assessment of submaximal exercise capacity appears to be a promising alternative to peak VO2 assessment. On the other hand, the protocol of submaximal constant workload testing is laborious itself and can be challenging in this purge patient population. Therefore, we investigated the feasibility of submaximal exercise testing in patients after recent LVAD implantation.

Methods:

We enrolled 31 end-stage heart failure patients who had received LVAD implantation 20.8 ± 8.1 days prior to study examination, mean age 55.4 ± 7.3 years, 27 males (87 %). Exercise tolerance was assessed using cardiopulmonary exercise testing (CPX) with a standard incremental test and submaximal constant workload testing at 75% peak oxygen uptake level.

Results:

Patients showed peak oxygen uptake values of 7.2 ± 2.2 ml/min/kg at a mean workload of 45.6 ± 11.4 watts and a mean anaerobic threshold of 6.8 ± 1.8 ml/min/kg at a workload of 32.4 ± 7.2 watts at baseline. Tolerance time at submaximal constant workload testing was 320 ± 177 seconds. There were no adverse events during exercise testing on LVAD.

Conclusions:

Shortly after LVAD implantation, cardiopulmonary exercise testing (CPX) objectivizes severely impaired cardiopulmonary exercise capacity. The constant workload test offers a feasible tool to assess submaximal exercise capacity in these patients in more detail to develop an individual patient training.