Feasibility and Safety of Using External Counterpulsation to Augment Cerebral Blood Flow in Acute Ischemic Stroke-The Counterpulsation to Upgrade Forward Flow in Stroke (CUFFS) Trial

Abstract

Background: External counterpulsation (ECP) increases perfusion to a variety of organs and may be helpful for acute stroke.

Methods: We conducted a single-blinded, prospective, randomized controlled feasibility and safety trial of ECP for acute middle cerebral artery (MCA) ischemic stroke. Twenty-three patients presenting within 48 hours of symptom onset were randomized into one of two groups. One group was treated with ECP for 1 hour at a pressure of up to 300 mmHg ("full pressure"). During the procedure, we also determined the highest possible pressure that would augment MCA mean flow velocity (MFV) by 15%. The other group was treated with ECP at 75 mmHg ("sham pressure"). Transcranial Doppler MCA flow velocities and National Institutes of Health Stroke Scale (NIHSS) scores of both groups were checked before, during, and after ECP. Outcomes were assessed at 30 days after randomization.

Results: Although the procedures were feasible to implement, there was a frequent inability to augment MFV by 15% despite maximal pressures in full-pressure patients. In sham-pressure patients, however, MFV frequently increased as shown by increases in peak systolic velocity and end diastolic velocity. In both groups, starting ECP was often associated with contemporaneous improvements in NIHSS stroke scores. There were no between-group differences in NIHSS, modified Rankin Scale Scores, and Barthel Indices, and no device or treatment-related serious adverse events, deaths, intracerebral hemorrhages, or episodes of acute neuro-worsening.

Conclusions: ECP was safe and feasible to use in patients with acute ischemic stroke. It was associated with unexpected effects on flow velocity, and contemporaneous improvements in NIHSS score regardless of pressure used, with a possibility that even very low ECP pressures had an effect. Further study is warranted.

Keywords: Cerebral blood flow velocity; External counterpulsation; Ischemic stroke; Transcranial Doppler.

Figure 1

Representative TCD spectra from one of the full-pressure patients over time, revealing a tendency for peak systolic velocity (PSV) and end-diastolic velocity (EDV) to drift downward as a concomitant ECP-induced augmentation of flow velocity during diastole developed, and then reverse upon ECP being stopped.

Figure 2

NIHSS (NIH Stroke Scale) score profiles of study subjects receiving ECP. ECP was frequently associated with an acute improvement in an NIHSS score that had remained relatively stable from screening to just before starting ECP (PRE-ECP). There was no statistically significant difference between groups with regards to this phenomenon. Each line represents an individual subject. SHAM pressure, sham-pressure patients; FULL pressure, full-pressure patients.