Increased Pulsatility of the Intracranial Blood Flow Spectral Waveform on Transcranial Doppler Does Not Point to Peripheral Arterial Disease in Stroke Patients

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Peripheral arterial disease (PAD) is common in patients with acute cerebral ischemia. Indexes of resistance derived from the systolic and diastolic velocities are routinely used in diagnostic transcranial Doppler (TCD) to detect intracranial arterial disease. We sought to explore whether these indexes can predict the presence of PAD in acute cerebral ischemia. We prospectively evaluated consecutive patients with acute cerebral ischemia. On TCD, peak-systolic and end-diastolic velocities in both middle cerebral and basilar arteries were manually measured to calculate pulsatility index (PI) and resistance index (RI). Increased resistance was defined as PI equal to 1.2 or more and RI equal to .75 or more. Ankle-brachial index (ABI) measurements were performed and an ABI equal to .9 or more was considered predictive of definite PAD. We included 95 patients (45 male, 50 female) aged 66 ± 9 years with a median National Institutes Health Stroke Scale score of 3 (interquartile range, 8) points. The ABI was abnormal and consistent with definite PAD in 24 of 95 (25.3%; 95% confidence interval [CI], 16.4-34.2) patients. Increased PI did not differ among patients with and without PAD (20.8% vs. 28.2%, P = .60). Only 1 patient with PAD had increased RI as opposed to 4 patients without PAD (4.2% vs. 5.6%, P = 1.0). Increased PI was not found to be an independent predictor of PAD (odds ratio [OR], .68; 95% CI, .22-2.12; P = .51). Increases in both PI and RI independently predicted arterial hypertension (OR, 1.62; 95% CI, 1.19-2.21; P = .002 and OR, 3.20; 95% CI, 1.51-6.77; P = .002, respectively). Our findings indicate that PAD cannot be inferred from intracranial flow parameters predictive of arterial disease and risk factors such as hypertension among patients with acute cerebral ischemia.