Calcium antagonist drugs were proposed for use in patients with recent
aneurysmal subarachnoid hemorrhage (SAH) because of their ability to block the effects of a wide variety of
vasoconstrictor substances on cerebral arteries in vitro. It was suggested that these agents might, therefore, be useful in ameliorating
cerebral vasospasm and its ischemic consequences which frequently complicate SAH. This hypothesis was tested in an arm of a randomized double-blind placebo-controlled trial of high-dose intravenous
nicardipine in patients with recently
ruptured aneurysms. Participating investigators were required to send selected copies of all admission and follow-up angiograms obtained between Days 7 and 11 following
hemorrhage (the peak period of risk for vasospasm) to the Central Registry of the Cooperative
Aneurysm Study for blinded interpretation and review for the presence and severity of angiographic vasospasm. In centers with transcranial Doppler ultrasound (TCD) capabilities, middle cerebral artery (MCA) mean flow velocities were measured and recorded. Angiograms obtained between Days 7 and 11 were available for 103 (23%) of 449 patients receiving
nicardipine and 121 (26%) of 457 receiving placebo. There was a balance of prognostic factors for vasospasm between the groups. Fifty-one percent of placebo-treated patients had moderate or severe vasospasm on "Day 7-11 angiograms" compared to 33% of
nicardipine-treated patients. This difference is statistically significant (p < 0.01). Sixty-seven (49%) of 137 placebo-treated patients examined with TCD between Days 7 and 11 had mean MCA flow velocities exceeding 120 cm/sec compared to 26 (23%) of 112
nicardipine-treated patients (significant difference, p < 0.001). These data suggest that high-dose intravenous
nicardipine reduces the incidence and severity of delayed cerebral arterial narrowing in patients following aneurysmal SAH.