Abstract T P87: Does an Increased Pulsatility of the Intracranial Blood Flow Spectral Waveform on Transcranial Doppler (TCD) Point to Peripheral Arterial Disease in Stroke Patients?

Abstract

Background: Peripheral arterial disease (PAD) is common in patients with acute cerebral ischemia, yet little testing, if any, is done during in-hospital stay. The pulsatility index (PI) from the systolic and diastolic velocity measurements on TCD is routinely used in stroke patients to assess resistance to flow and thereby intracranial atheromatous disease. We sought to explore whether the PI can indirectly predict the presence of PAD in these patients. Methods: We prospectively evaluated consecutive patients with acute cerebral ischemia by TCD and ankle-brachial-index (ABI) measurements. Clinical variables were collected at baseline. On TCD, peak systolic, end-diastolic and mean flow velocities in both middle cerebral and basilar arteries were manually measured. According to a complete four-cardiac cycle sweep without arrhythmias, PI was automatically calculated for each of the 3 arteries and the average was used for analysis. Bilateral brachial, tibial and pedal systolic blood pressures were measured using a 4-MHz continuous-wave Doppler (average over two measurements). ABI 0.91 to 0.99 was considered as borderline, ABI <=0.9 as abnormal and predictive of PAD. All examinations were done in supine position. Results: We enrolled a total of 53 patients: 68% ischemic stroke, 32% TIA, 60% Caucasians, 42% male, mean age 64±10 yrs, median NIHSS 4 (range 0-20). ABI was borderline or abnormal in 26/53 (49%) including 12/53 (23%) patients with ABIs consistent with PAD. Baseline characteristics were similar between patients with and without PAD. The mean PI did not differ among patients with and without PAD (0.92±0.08 vs. 1.01±0.04, p=0.24). The PI was not found to be an independent predictor of PAD (OR=0.21, 95% CI 0.01-3.64, p=0.285). Similarly, the PI did not predict ABI (p=0.96). PI strongly predicted history of arterial hypertension (OR=530.04, 95%CI 5.18-54215.57, p=0.008). Conclusions: Our findings do not suggest that the presence of PAD can be inferred from intracranial flow parameters predictive of atheromatous disease and risk factors such as hypertension among patients with acute cerebral ischemia. However, the high frequency of PAD in these patients warrants further investigation to facilitate routine and early detection of this disease.